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2022 Vol. 52, No. 12
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2022, 52(12): 1-8,26.
doi: 10.13204/j.gyjzG22062908
Abstract:
In view of the current situation of the derelict land of Wangping Coal Mine, the green renewal and transformation of Wangping Coal Mine were studied based on the concept of productive, urban renewal and ecological restoration resilience, the theory of catalyst, space syntax strategy and water ecological restoration. The traditional green means were transformed to comprehensive management methods, such as comprehensive environmental management, energy green production, resource recycling and utilization, functional transformation and expansion, from the perspective of multi-objective, multi-angle and multi-scale to explore the green regeneration of mining wasteland. It was expected to realize the vision of ecological landscape restoration, cultural value reappearance and architectural landscape reconstruction of abandoned coal mines, promote the economic development of surrounding areas, and promote urban transformation and sustainable development.
In view of the current situation of the derelict land of Wangping Coal Mine, the green renewal and transformation of Wangping Coal Mine were studied based on the concept of productive, urban renewal and ecological restoration resilience, the theory of catalyst, space syntax strategy and water ecological restoration. The traditional green means were transformed to comprehensive management methods, such as comprehensive environmental management, energy green production, resource recycling and utilization, functional transformation and expansion, from the perspective of multi-objective, multi-angle and multi-scale to explore the green regeneration of mining wasteland. It was expected to realize the vision of ecological landscape restoration, cultural value reappearance and architectural landscape reconstruction of abandoned coal mines, promote the economic development of surrounding areas, and promote urban transformation and sustainable development.
2022, 52(12): 9-18.
doi: 10.13204/j.gyjzG22081109
Abstract:
The goals of carbon peaking and carbon neutrality affects urban renewal and the transformation and upgrding of old industrial areas. The productive regeneration strategy was integrated into the transformation of the Wangping Coal Mine abandoned land through ecological restoration of soil, planting of agricultural landscape, implantation of new energy landscape, green transformation of waste buildings, treatment of coal gangue mountain, and comprehensive utilization of waste resources such as waste bricks and tiles. At the same time, carbon neutrality technology was introduced, a clean energylty base, a wise carbon operation center, and a water treatment ecosystem were established to integrate and innovate with productive strategies in a multi-functional and diversified way. The purpose of this paper was to transform the abandoned mining area into a green and low-carbon ecological smart park with productive functions.
The goals of carbon peaking and carbon neutrality affects urban renewal and the transformation and upgrding of old industrial areas. The productive regeneration strategy was integrated into the transformation of the Wangping Coal Mine abandoned land through ecological restoration of soil, planting of agricultural landscape, implantation of new energy landscape, green transformation of waste buildings, treatment of coal gangue mountain, and comprehensive utilization of waste resources such as waste bricks and tiles. At the same time, carbon neutrality technology was introduced, a clean energylty base, a wise carbon operation center, and a water treatment ecosystem were established to integrate and innovate with productive strategies in a multi-functional and diversified way. The purpose of this paper was to transform the abandoned mining area into a green and low-carbon ecological smart park with productive functions.
2022, 52(12): 19-26.
doi: 10.13204/j.gyjzG21110210
Abstract:
The abandoned mining land formed after the depletion of mineral resources seriously threatens the ecological environment and sustainable development of the surrounding areas, and its regeneration is an urgent task for the construction of ecological civilization and the transformation of urban development. Taking Wangping Coal Mine as the research object, the paper analyzed its history, current situation, external development opportunities and existing resources. Based on the concept of urban renewal and ecological restoration, the design of regeneration and renewal was conducted from four aspects:ecological restoration, site planning, architectural renewal and landscape reconstruction, with a view to providing a reference for the regeneration and utilization of abandoned mining land in China.
The abandoned mining land formed after the depletion of mineral resources seriously threatens the ecological environment and sustainable development of the surrounding areas, and its regeneration is an urgent task for the construction of ecological civilization and the transformation of urban development. Taking Wangping Coal Mine as the research object, the paper analyzed its history, current situation, external development opportunities and existing resources. Based on the concept of urban renewal and ecological restoration, the design of regeneration and renewal was conducted from four aspects:ecological restoration, site planning, architectural renewal and landscape reconstruction, with a view to providing a reference for the regeneration and utilization of abandoned mining land in China.
2022, 52(12): 27-34.
doi: 10.13204/j.gyjzG22042514
Abstract:
A large number of mining wasteland left behind after mining has become a problem of ecological construction and urban sustainable development in China. In addition to the ecological restoration and safe life of mining areas, the recycling of mining wasteland also needs to consider a variety of practical needs such as flexible expansion, disaster prevention and emission reduction, and sustainable development. Using the concept of resilience to guide the transformation and renewal of mining wasteland not only meets the current development needs of green and low carbon, but also improves the adaptability and resistance of mining areas in response to external shocks. Taking the abandoned land of Wangping Coal Mine in Mentougou District of Beijing as an example, the land use elastic planning, ecological elastic strategy, engineering elastic design and cultural elastic policy of mining wasteland were put forward by using the concept of resilience. After analyzing the advantages and disadvantages of Wangping Mine, some suggestions were put forward such as elastic control and zoning of Wangping Mine land, rainwater management and phytoremediation of the site, the use of green energy and green building materials, and the inheritance and innovation of mining area culture, in order to realize the functional regeneration and sustainable development of Wangping Coal Mine from multiple perspectives.
A large number of mining wasteland left behind after mining has become a problem of ecological construction and urban sustainable development in China. In addition to the ecological restoration and safe life of mining areas, the recycling of mining wasteland also needs to consider a variety of practical needs such as flexible expansion, disaster prevention and emission reduction, and sustainable development. Using the concept of resilience to guide the transformation and renewal of mining wasteland not only meets the current development needs of green and low carbon, but also improves the adaptability and resistance of mining areas in response to external shocks. Taking the abandoned land of Wangping Coal Mine in Mentougou District of Beijing as an example, the land use elastic planning, ecological elastic strategy, engineering elastic design and cultural elastic policy of mining wasteland were put forward by using the concept of resilience. After analyzing the advantages and disadvantages of Wangping Mine, some suggestions were put forward such as elastic control and zoning of Wangping Mine land, rainwater management and phytoremediation of the site, the use of green energy and green building materials, and the inheritance and innovation of mining area culture, in order to realize the functional regeneration and sustainable development of Wangping Coal Mine from multiple perspectives.
2022, 52(12): 35-41,93.
doi: 10.13204/j.gyjzG22050613
Abstract:
A large number of derelict mine land left behind after mining have restricted urban renewal and sustainable development. " Urban Catalysts " advocates the transformation and upgrading of old cities to stimulate regional development vitality and promote urban economic revival and vitality regeneration. Wangping derelict mine land was taken as an example, and the catalyst theory was introduced into the study of the renewal of the wasteland. With functional catalyst, landscape catalyst, cultural catalyst and traffic catalyst as its catalyst characteristics, the existing elements in Wangping derelict mine land were subjected to multiple functional replacement, landscape placement, and spatial and functional integration. The material elements such as buildings and components with mining characteristics and non-material elements such as mining culture were retained, inherited, developed, and the transportation system inside the site was integrated and optimized. The construction sequence of the early, medium and long-term development was formulated to inject new vitality into the city and realize the transformation and upgrading of Wangping Coal Mine.
A large number of derelict mine land left behind after mining have restricted urban renewal and sustainable development. " Urban Catalysts " advocates the transformation and upgrading of old cities to stimulate regional development vitality and promote urban economic revival and vitality regeneration. Wangping derelict mine land was taken as an example, and the catalyst theory was introduced into the study of the renewal of the wasteland. With functional catalyst, landscape catalyst, cultural catalyst and traffic catalyst as its catalyst characteristics, the existing elements in Wangping derelict mine land were subjected to multiple functional replacement, landscape placement, and spatial and functional integration. The material elements such as buildings and components with mining characteristics and non-material elements such as mining culture were retained, inherited, developed, and the transportation system inside the site was integrated and optimized. The construction sequence of the early, medium and long-term development was formulated to inject new vitality into the city and realize the transformation and upgrading of Wangping Coal Mine.
2022, 52(12): 42-48,54.
doi: 10.13204/j.gyjzG22051023
Abstract:
With the adjustment of industrial structure and the exhaustion of mineral resources, a large number of abandoned mine land have been generated and seriously affected the efficient use of urban land. The traditional research on the renewal of abandoned mine land focuses more on theoretical application, and lacks the quantitative and visual research on the existing problems of abandoned mine land, while the practice of space syntax focuses on the quantitative analysis of spatial problems. Taking Wangping abandoned coal mine land in Mentougou District of Beijing as an example, based on the theory and technology of space syntax, the paper quantitatively analyzed the accessibility, spatial visibility and functional connectivity of building groups of Wangping abandoned coal mine land from three dimensions of street, site and building group, explored its connection with the surrounding road system, put forward the potential problems of the interior space of the site and excavated the architectural core that could represent the coal mine production culture. The renewal strategy was proposed from the four aspects of upper planning, road system, site space and cultural memory.
With the adjustment of industrial structure and the exhaustion of mineral resources, a large number of abandoned mine land have been generated and seriously affected the efficient use of urban land. The traditional research on the renewal of abandoned mine land focuses more on theoretical application, and lacks the quantitative and visual research on the existing problems of abandoned mine land, while the practice of space syntax focuses on the quantitative analysis of spatial problems. Taking Wangping abandoned coal mine land in Mentougou District of Beijing as an example, based on the theory and technology of space syntax, the paper quantitatively analyzed the accessibility, spatial visibility and functional connectivity of building groups of Wangping abandoned coal mine land from three dimensions of street, site and building group, explored its connection with the surrounding road system, put forward the potential problems of the interior space of the site and excavated the architectural core that could represent the coal mine production culture. The renewal strategy was proposed from the four aspects of upper planning, road system, site space and cultural memory.
2022, 52(12): 49-54.
doi: 10.13204/j.gyjzG22042411
Abstract:
In recent years, with the successive closure of mining enterprises, a large number of abandoned coal mine land have emerged, most of which are facing problems such as frequent rainstorm and flood disasters, perennial water shortages, and water pollution, water ecological restoration is imminent.Taking Wangping Coal Mine in Mentougou District of Beijing as an example, the water ecological characteristics of abandoned coal mines land was deeply analyzed. From the three aspects of site layout combing, building element transformation and mine landscape restoration, effective water ecological restoration strategies according to local conditions were proposed, so as to improve the efficiency of water resources recycling, improve the ecological environment of abandoned coal mine land and reduce flood disasters.
In recent years, with the successive closure of mining enterprises, a large number of abandoned coal mine land have emerged, most of which are facing problems such as frequent rainstorm and flood disasters, perennial water shortages, and water pollution, water ecological restoration is imminent.Taking Wangping Coal Mine in Mentougou District of Beijing as an example, the water ecological characteristics of abandoned coal mines land was deeply analyzed. From the three aspects of site layout combing, building element transformation and mine landscape restoration, effective water ecological restoration strategies according to local conditions were proposed, so as to improve the efficiency of water resources recycling, improve the ecological environment of abandoned coal mine land and reduce flood disasters.
2022, 52(12): 55-61.
doi: 10.13204/j.gyjzG22031503
Abstract:
With the rapid increase of resident car ownership, the parking contradiction in old community is acute. Based on the static traffic space investigation of old communities in Xi'an, the existing unit-type old communities were classified from the perspective of static traffic space. Guided by the integration of blocks, the static traffic space constituent elements of old communities and the evaluation index system of the current situation characteristics were constructed by discussing the constituent elements of the static traffic space of old communities. For the three types of old communities in Xi'an, the weight of the evaluation index was analyzed by analytic hierarchy process. The current situation characteristics and main problems of their respective types of old community static traffic space were obtained, and then the optimization direction and implementation path of community static traffic space were proposed.
With the rapid increase of resident car ownership, the parking contradiction in old community is acute. Based on the static traffic space investigation of old communities in Xi'an, the existing unit-type old communities were classified from the perspective of static traffic space. Guided by the integration of blocks, the static traffic space constituent elements of old communities and the evaluation index system of the current situation characteristics were constructed by discussing the constituent elements of the static traffic space of old communities. For the three types of old communities in Xi'an, the weight of the evaluation index was analyzed by analytic hierarchy process. The current situation characteristics and main problems of their respective types of old community static traffic space were obtained, and then the optimization direction and implementation path of community static traffic space were proposed.
2022, 52(12): 62-65,100.
doi: 10.13204/j.gyjzG22071702
Abstract:
Zhanghuatai is an important case of the Eastern Zhou Dynasty gardens,but the perception of these gardens is still vague. Firstly, the plane layout characteristics of Zhanghuatai confirmed by the archaeological excavation report were sorted out. Secondly, other features of the spatial layout of the Zhanghuatai were obtained by analyzing the archaeological excavation data of the site. Then, the basic characteristics of Zhanghuatai building image were analyzed. Finally, the basic characteristics of Zhanghuatai gardens were revealed and expounded, such as the spatial mode of the combination of building, courtyard, patio, curved corridor and straight corridor, which showed that some important spatial patterns of ancient Chinese gardens had already appeared at least in Chu State during the Eastern Zhou Dynasty. The conclusion could considerably extend and deepen the understanding of the gardens of the Eastern Zhou Dynasty.
Zhanghuatai is an important case of the Eastern Zhou Dynasty gardens,but the perception of these gardens is still vague. Firstly, the plane layout characteristics of Zhanghuatai confirmed by the archaeological excavation report were sorted out. Secondly, other features of the spatial layout of the Zhanghuatai were obtained by analyzing the archaeological excavation data of the site. Then, the basic characteristics of Zhanghuatai building image were analyzed. Finally, the basic characteristics of Zhanghuatai gardens were revealed and expounded, such as the spatial mode of the combination of building, courtyard, patio, curved corridor and straight corridor, which showed that some important spatial patterns of ancient Chinese gardens had already appeared at least in Chu State during the Eastern Zhou Dynasty. The conclusion could considerably extend and deepen the understanding of the gardens of the Eastern Zhou Dynasty.
2022, 52(12): 66-71,165.
doi: 10.13204/j.gyjzG21030909
Abstract:
Thermal break connection can effectively deal with the problem of thermal bridge effect within the overhanging steel components. The selection of thermal insulation materials is a key to thermal break connection technology while there are few research focused on it. Materials of PA6, PVC, FR4 and PEEK were selected for the potential insulating materials through extensive investigations. A total of 40 compressive tests and 12 thermal conductivity tests of PA6, PVC, FR4 and PEEK were conducted, and their compressive strength, compressive modulus of elasticity, and thermal conductivity coefficients were recorded. The yielding points were studied by using the Farthest Point Method, and the compressive constitute models were obtained by curve-fitting according to Sherwood-Frost model. Combined with the performances of these four materials including mechanical properties, thermal properties and economy, the adaptability of these four materials used in thermal break connections was analyzed. The results indicated that PA6, PVC and PEEK specimens showed a ductile failure mode, while FR4 showed a laminated brittle failure mode. The tested yield strength were 60.1, 50.4 and 125.8 MPa respectively for PA6, PVC and PEEK, while their thermal conductivity coefficients were 0.1755, 0.1424 and 0.2318 W/(m·K), respectively. It was found that FR4 showed the best comprehensive performance while PA6 took the second place, and PVC took the last place. Due to its high cost, PEEK is not appropriate for thermal break material in practical engineering.
Thermal break connection can effectively deal with the problem of thermal bridge effect within the overhanging steel components. The selection of thermal insulation materials is a key to thermal break connection technology while there are few research focused on it. Materials of PA6, PVC, FR4 and PEEK were selected for the potential insulating materials through extensive investigations. A total of 40 compressive tests and 12 thermal conductivity tests of PA6, PVC, FR4 and PEEK were conducted, and their compressive strength, compressive modulus of elasticity, and thermal conductivity coefficients were recorded. The yielding points were studied by using the Farthest Point Method, and the compressive constitute models were obtained by curve-fitting according to Sherwood-Frost model. Combined with the performances of these four materials including mechanical properties, thermal properties and economy, the adaptability of these four materials used in thermal break connections was analyzed. The results indicated that PA6, PVC and PEEK specimens showed a ductile failure mode, while FR4 showed a laminated brittle failure mode. The tested yield strength were 60.1, 50.4 and 125.8 MPa respectively for PA6, PVC and PEEK, while their thermal conductivity coefficients were 0.1755, 0.1424 and 0.2318 W/(m·K), respectively. It was found that FR4 showed the best comprehensive performance while PA6 took the second place, and PVC took the last place. Due to its high cost, PEEK is not appropriate for thermal break material in practical engineering.
2022, 52(12): 72-79,148.
doi: 10.13204/j.gyjzG22081007
Abstract:
Since the one-time forming stirrups and multi-spiral stirrups (refers to as "new stirrups") have an excellent confined effect, a prefabricated concrete beam-column joints with new stirrups was proposed. Based on the difference of joint strength, joint types, construction methods and stirrup types, six full-scale concrete beam-column joint specimens were designed. According to the quasi-static load tests, the failure modes, hysteresis curves, skeleton curves, ductility, energy dissipation capacity, strength degradation, stiffness degradation, and joint rotation were discussed. It was found that:strong joint specimens collapsed by the bending failure of beam ends, and weak joint specimens failed by the shear failure of joint zones; the prefabricated concrete beam-column joints with new stirrups had plump hysteresis curves, and their seismic performance indexes were similar to that of the cast-in-place joints; the joint rotation of the prefabricated concrete beam-column joints with new stirrups was larger than that of the cast-in-place joints. In addition, the Code of Concrete Structures Design(GB 50010-2010) can be used to design the prefabricated concrete beam-column joints with new stirrups, accompanied with a certain degree of safety reserve.
Since the one-time forming stirrups and multi-spiral stirrups (refers to as "new stirrups") have an excellent confined effect, a prefabricated concrete beam-column joints with new stirrups was proposed. Based on the difference of joint strength, joint types, construction methods and stirrup types, six full-scale concrete beam-column joint specimens were designed. According to the quasi-static load tests, the failure modes, hysteresis curves, skeleton curves, ductility, energy dissipation capacity, strength degradation, stiffness degradation, and joint rotation were discussed. It was found that:strong joint specimens collapsed by the bending failure of beam ends, and weak joint specimens failed by the shear failure of joint zones; the prefabricated concrete beam-column joints with new stirrups had plump hysteresis curves, and their seismic performance indexes were similar to that of the cast-in-place joints; the joint rotation of the prefabricated concrete beam-column joints with new stirrups was larger than that of the cast-in-place joints. In addition, the Code of Concrete Structures Design(GB 50010-2010) can be used to design the prefabricated concrete beam-column joints with new stirrups, accompanied with a certain degree of safety reserve.
2022, 52(12): 80-87,215.
doi: 10.13204/j.gyjzG21121802
Abstract:
In order to improve the seismic performance of precast concrete floor structures in different seismic intensity, based on the concept of performance-based seismic design, a new type of dry connectors which could be used for the connections of precast concrete diaphragms in site was proposed. It showed the characteristics of dual energy dissipation properties of friction and metals, and could meet the multi-level seismic performance requirements based on two-stage energy dissipation, referred to as friction-metal damper (FMD) connectors. In order to study the mechanical properties of FMD connectors in different stress states, six quasi-static tests of precast floor slabs equipped with FMD connectors under pure shear and tension-shear coupling force were conducted. The test results showed that the new type of dry connectors had stable hysteretic characteristics and energy dissipation capacity, showing a cooperative working mechanism of friction and metals, which could realize the objectives of multi-level seismic fortification, and could meet the requirements for fast recovery of structural functions after earthquakes.
In order to improve the seismic performance of precast concrete floor structures in different seismic intensity, based on the concept of performance-based seismic design, a new type of dry connectors which could be used for the connections of precast concrete diaphragms in site was proposed. It showed the characteristics of dual energy dissipation properties of friction and metals, and could meet the multi-level seismic performance requirements based on two-stage energy dissipation, referred to as friction-metal damper (FMD) connectors. In order to study the mechanical properties of FMD connectors in different stress states, six quasi-static tests of precast floor slabs equipped with FMD connectors under pure shear and tension-shear coupling force were conducted. The test results showed that the new type of dry connectors had stable hysteretic characteristics and energy dissipation capacity, showing a cooperative working mechanism of friction and metals, which could realize the objectives of multi-level seismic fortification, and could meet the requirements for fast recovery of structural functions after earthquakes.
2022, 52(12): 88-93.
doi: 10.13204/j.gyjzG22072916
Abstract:
Due to the decrease of the joint stiffness after gap opening for the self-centering prestressed concrete (SCPC) frames, the inter-story drift of structures under rare earthquakes has increased obviously. The SCPC beam-to-column joints with variable friction dampers (VFD), characterized by a third stiffness, is useful to improve the stiffness of structures under major earthquakes, so as to decrease the inter-story drift of structures. A VFD-SCPC frame located in the area with a seismic fortification intensity of eight degree was taken as the analytical case. The numerical model was established via nonlinear finite software OpenSees, and 12 earthquake waves were used as the excitation to study the influence of the connection stiffness after gap opening, including the second and third stiffness, on the seismic performance of VFD-SCPC frames. The results showed that increasing the second stiffness could reduce the inter-story drift for entire structures, while the distribution of lateral deformation could not be changed. While increasing the third stiffness was not only useful to decrease the inter-story drift and column moment, but also beneficial to decrease the higher mode effect so as to decrease the deformation of higher stories, guaranteeing the expected re-centering effect.
2022, 52(12): 94-100.
doi: 10.13204/j.gyjzG21062514
Abstract:
To study the deformation mechanism of prefabricated steel frame beam-column joints and clarify the cause of joint rotation deformation, the calculation method of rotation deformation of beam-column joints with extended end-plate connections was theoretically deduced based on component method, and the joint specimens were tested under quasi-static loading. The deformation of joints during loading test was analyzed by image processing method, and the equivalent simplified numerical model of the joint specimens with extended end-plate connection was established. The results showed that the rotational deformation of the extended end-plate joint consists of shear deformation in the panel zone, relative deformation between end-plate and column flange, and yield deformation of end-plate stiffener, among which the relative deformation between end-plate and column flange and yield deformation of end-plate stiffener were the main factors affecting the joint rotation angle. Compared with the traditional processing method, considering the influence of multiple components on the deformation of the joint in the rotating spring could make the numerical simulation results closer to the test results, which was beneficial to evaluate the seismic performance of the joint. The calculation method of joint rotation angle showed good accuracy and applicability for predicting the seismic performance of joints.
To study the deformation mechanism of prefabricated steel frame beam-column joints and clarify the cause of joint rotation deformation, the calculation method of rotation deformation of beam-column joints with extended end-plate connections was theoretically deduced based on component method, and the joint specimens were tested under quasi-static loading. The deformation of joints during loading test was analyzed by image processing method, and the equivalent simplified numerical model of the joint specimens with extended end-plate connection was established. The results showed that the rotational deformation of the extended end-plate joint consists of shear deformation in the panel zone, relative deformation between end-plate and column flange, and yield deformation of end-plate stiffener, among which the relative deformation between end-plate and column flange and yield deformation of end-plate stiffener were the main factors affecting the joint rotation angle. Compared with the traditional processing method, considering the influence of multiple components on the deformation of the joint in the rotating spring could make the numerical simulation results closer to the test results, which was beneficial to evaluate the seismic performance of the joint. The calculation method of joint rotation angle showed good accuracy and applicability for predicting the seismic performance of joints.
2022, 52(12): 101-106.
doi: 10.13204/j.gyjzG20010903
Abstract:
The tensile member of angle steel is a kind of common component for steel structures. It often occurs local deformation in practical project because of mechanical collision or accidents. There are a lot of domestic research on the bearing capacity of tensile member of single angle. However, when it comes to the double equal-angle steel component with local concave-convex deformation, there is still a lack of research of its bearing capacity in related specifications. With the verified method of finite element simulation using ABAQUS software, a simulation study on three types of tensile members of double equal-angle was conducted. As a result, the reduction coefficient of tensile capacity with different local deformations was deduced, which could be used to check the tensile capacity of tensile members of double angle with different surface defects.
The tensile member of angle steel is a kind of common component for steel structures. It often occurs local deformation in practical project because of mechanical collision or accidents. There are a lot of domestic research on the bearing capacity of tensile member of single angle. However, when it comes to the double equal-angle steel component with local concave-convex deformation, there is still a lack of research of its bearing capacity in related specifications. With the verified method of finite element simulation using ABAQUS software, a simulation study on three types of tensile members of double equal-angle was conducted. As a result, the reduction coefficient of tensile capacity with different local deformations was deduced, which could be used to check the tensile capacity of tensile members of double angle with different surface defects.
2022, 52(12): 107-112.
doi: 10.13204/j.gyjzG22092306
Abstract:
The quasi-static loading test and finite element analysis on three groups of joints between H-steel beams and columns after fire were conducted, M-θ hysteretic curves and M-θ skeleton curves were obtained, and the changes of the bearing capacity, stiffness degeneration, ductility and energy dissipation capacity for specimens were analyzed. The results showed that performance damage of bolts after fire caused degeneration of initial stiffness for joints; replacement of joint bolts after fire could improve the ductility, energy dissipation capacity and the stiffness of joints, but had little effect on the ultimate bearing capacity. The larger the axial compression ratio of column subjected to fire, the lower the bearing capacity, ductility, energy dissipation capacity and initial stiffness of the joint after fire; the protection measures of joints could improve the bearing capacity and ductility of joints after fire.
The quasi-static loading test and finite element analysis on three groups of joints between H-steel beams and columns after fire were conducted, M-θ hysteretic curves and M-θ skeleton curves were obtained, and the changes of the bearing capacity, stiffness degeneration, ductility and energy dissipation capacity for specimens were analyzed. The results showed that performance damage of bolts after fire caused degeneration of initial stiffness for joints; replacement of joint bolts after fire could improve the ductility, energy dissipation capacity and the stiffness of joints, but had little effect on the ultimate bearing capacity. The larger the axial compression ratio of column subjected to fire, the lower the bearing capacity, ductility, energy dissipation capacity and initial stiffness of the joint after fire; the protection measures of joints could improve the bearing capacity and ductility of joints after fire.
Experimental Research on Seismic Performance of New-Type Steel Reinforced Concrete Composite Columns
2022, 52(12): 113-120,127.
doi: 10.13204/j.gyjzG21072801
Abstract:
Combined with the advantages of steel tube-reinforced concrete column and cross-shaped steel reinforced concrete column, a new type of steel reinforced concrete column was proposed. Steel flanges connected to the inner steel tube were arranged in the reinforced concrete outer layer of the steel tube of the steel tube-reinforced concrete column. The steel flanges could play the role of acting on the longitudinal bars to reduce the number of longitudinal bars in the column. And the steel flanges could improve the mechanical properties of concrete outside the steel tube and reduce the difference of mechanical properties of concrete inside and outside the steel tube in the traditional steel tube-reinforced concrete column. The quasi-static tests were carried out on 6 new type steel reinforced concrete columns and 1 cross-shaped steel reinforced concrete column, the design parameters mainly included section form, flange width and web height. The hysteretic performance, skeleton curve, stiffness degradation, displacement ductility coefficient, energy dissipation capacity, moment-curvature character, strain level of steel pipe and steel bars of composite column under quasi-static loading were studied.
Combined with the advantages of steel tube-reinforced concrete column and cross-shaped steel reinforced concrete column, a new type of steel reinforced concrete column was proposed. Steel flanges connected to the inner steel tube were arranged in the reinforced concrete outer layer of the steel tube of the steel tube-reinforced concrete column. The steel flanges could play the role of acting on the longitudinal bars to reduce the number of longitudinal bars in the column. And the steel flanges could improve the mechanical properties of concrete outside the steel tube and reduce the difference of mechanical properties of concrete inside and outside the steel tube in the traditional steel tube-reinforced concrete column. The quasi-static tests were carried out on 6 new type steel reinforced concrete columns and 1 cross-shaped steel reinforced concrete column, the design parameters mainly included section form, flange width and web height. The hysteretic performance, skeleton curve, stiffness degradation, displacement ductility coefficient, energy dissipation capacity, moment-curvature character, strain level of steel pipe and steel bars of composite column under quasi-static loading were studied.
2022, 52(12): 121-127.
doi: 10.13204/j.gyjzG21083002
Abstract:
In order to study the effects of opening shape, opening ratio and concrete floor on the seismic performance of the end-plate joint of castellated beam-to-column, four full-scale side joints were designed and tested under quasi-static loading. The failure mode, bearing capacity, ductility and energy dissipation of the specimens were studied. The results showed that for the specimens with floor plates, the opening shape had a great influence on the failure mode and seismic performance of joints, the hexagonal opening was more prone to beam hinge failure and showed a better energy dissipation. The opening ratio had a great influence on the failure mode, bearing capacity and ductility of the joints, appropriately increasing the opening ratio was conducive to the stress migrated from the end plate connection to the first opening, and the strain limit value between the end plate and the column flange was reduced. The combined effect of the floor increased the flexural capacity of the joints by more than 25%, the energy consumption and ductility by 16.5% and 30.7%, and the ultimate angle by 40.9%, respectively, but weakened the stress migration effect from the end plate joint to the first opening.
In order to study the effects of opening shape, opening ratio and concrete floor on the seismic performance of the end-plate joint of castellated beam-to-column, four full-scale side joints were designed and tested under quasi-static loading. The failure mode, bearing capacity, ductility and energy dissipation of the specimens were studied. The results showed that for the specimens with floor plates, the opening shape had a great influence on the failure mode and seismic performance of joints, the hexagonal opening was more prone to beam hinge failure and showed a better energy dissipation. The opening ratio had a great influence on the failure mode, bearing capacity and ductility of the joints, appropriately increasing the opening ratio was conducive to the stress migrated from the end plate connection to the first opening, and the strain limit value between the end plate and the column flange was reduced. The combined effect of the floor increased the flexural capacity of the joints by more than 25%, the energy consumption and ductility by 16.5% and 30.7%, and the ultimate angle by 40.9%, respectively, but weakened the stress migration effect from the end plate joint to the first opening.
2022, 52(12): 128-135,155.
doi: 10.13204/j.gyjzG21020601
Abstract:
The composite concrete-filled steel tubes (CFST) pier column with the cross-section form of outer rectangular-inner double circular was proposed. The composite column was divided into three parts:the outer rectangular steel tube considering deformation yield differences between the long side and the short side, the interlayer concrete confined by the outer steel tube, and two inner circular CFSTs. According to the limit equilibrium theory, calculation formulas of the axial bearing capacity of the column were derived. Afterwards, the FE ABAQUS was used to simulate the axial compressive tests on the composite columns and the rectangular concrete-filled steel tubular stubs, and the failure modes all were in good agreements with test results. Meanwhile, the force mechanism of each component of the composite column was analyzed, and the validity of the FE models were verified. By changing the compressive strength of concrete, the yield strength of steel tubes, the diameter of inner steel tubes with the same steel ratio, the diameter-thickness ratio of inner steel tubes, and the width-thickness ratio of outer steel tubes, the parametric analysis on the ultimate axial compressive capacity of the composite CFST pier column was carried out. The results showed that the ultimate bearing capacity increased with the increase of compressive strength of concrete and yield strength of steel tubes, and decreased with the increase of width-thickness ratio of outer steel tubes. The increasing diameter of the inner steel tubes resulted in the increase of ultimate bearing capacity. However, when the diameter of the inner steel tubes increased to a certain extent (2/3 of the width of the outer steel tube), it had little influence on the ultimate axial compressive capacity. The average ratio of the ultimate axial compressive capacity obtained from FE simulations to the calculated values was 0.923, and the mean square deviation was 0.046.
The composite concrete-filled steel tubes (CFST) pier column with the cross-section form of outer rectangular-inner double circular was proposed. The composite column was divided into three parts:the outer rectangular steel tube considering deformation yield differences between the long side and the short side, the interlayer concrete confined by the outer steel tube, and two inner circular CFSTs. According to the limit equilibrium theory, calculation formulas of the axial bearing capacity of the column were derived. Afterwards, the FE ABAQUS was used to simulate the axial compressive tests on the composite columns and the rectangular concrete-filled steel tubular stubs, and the failure modes all were in good agreements with test results. Meanwhile, the force mechanism of each component of the composite column was analyzed, and the validity of the FE models were verified. By changing the compressive strength of concrete, the yield strength of steel tubes, the diameter of inner steel tubes with the same steel ratio, the diameter-thickness ratio of inner steel tubes, and the width-thickness ratio of outer steel tubes, the parametric analysis on the ultimate axial compressive capacity of the composite CFST pier column was carried out. The results showed that the ultimate bearing capacity increased with the increase of compressive strength of concrete and yield strength of steel tubes, and decreased with the increase of width-thickness ratio of outer steel tubes. The increasing diameter of the inner steel tubes resulted in the increase of ultimate bearing capacity. However, when the diameter of the inner steel tubes increased to a certain extent (2/3 of the width of the outer steel tube), it had little influence on the ultimate axial compressive capacity. The average ratio of the ultimate axial compressive capacity obtained from FE simulations to the calculated values was 0.923, and the mean square deviation was 0.046.
2022, 52(12): 136-141,178.
doi: 10.13204/j.gyjzG22031713
Abstract:
FRP-concrete-steel double-skin tubular columns (DSTCs), which consist of an outer FRP tube, an inner steel tube and the concrete infilled between the two tubes, have excellent seismic performance and anti-corrosion performance. Existing studies on DSTCs focused on specimens with a circular cross-section or a square cross-section, while specimens with a rectangular cross-section are rarely investigated. According to engineering needs, the rectangular aspect ratio could be designed optimally for rectangular DSTCs to provide different bending stiffness around two axes of symmetry. 3 rectangular DSTCs were tested under constant axial compression and lateral cyclic loading to assess their seismic performance, and the parameters included the FRP thickness and the lateral loading direction (i.e., bending around the strong axis or the weak axis of the rectangular cross-section). Rectangular DSTCs in the present study had a length of 300 mm and a width of 200 mm for the cross-section, and a total height of 2 150 mm. The results indicated that the specimen with a thicker FRP tube had a larger bearing capacity;the specimen loaded around its strong axis had better bearing capacity and ductile than the corresponding specimen loaded around its weak axis; the predictions for the experimental hysteretic curves by numerical model based on OpenSees were slightly conservative.
FRP-concrete-steel double-skin tubular columns (DSTCs), which consist of an outer FRP tube, an inner steel tube and the concrete infilled between the two tubes, have excellent seismic performance and anti-corrosion performance. Existing studies on DSTCs focused on specimens with a circular cross-section or a square cross-section, while specimens with a rectangular cross-section are rarely investigated. According to engineering needs, the rectangular aspect ratio could be designed optimally for rectangular DSTCs to provide different bending stiffness around two axes of symmetry. 3 rectangular DSTCs were tested under constant axial compression and lateral cyclic loading to assess their seismic performance, and the parameters included the FRP thickness and the lateral loading direction (i.e., bending around the strong axis or the weak axis of the rectangular cross-section). Rectangular DSTCs in the present study had a length of 300 mm and a width of 200 mm for the cross-section, and a total height of 2 150 mm. The results indicated that the specimen with a thicker FRP tube had a larger bearing capacity;the specimen loaded around its strong axis had better bearing capacity and ductile than the corresponding specimen loaded around its weak axis; the predictions for the experimental hysteretic curves by numerical model based on OpenSees were slightly conservative.
2022, 52(12): 142-148.
doi: 10.13204/j.gyjzG21082401
Abstract:
The laws for load transfer and displacement of top-uplift piles, top-down piles without soil at bottoms, top-down piles with soil at bottoms and self-anchored test piles were studied by model tests in the laboratory. The results showed that Q-s curves for top-uplift piles presented a sudden drop and the curves of top-down piles without soil at bottoms prensted a slow drop. The Q-s curves of top-down piles with soil at bottoms consists of two stages, which were linear stages and nonlinear stages. The Q-s curves for the upper segment of self-anchoring test piles were of properties of top-uplift piles, while the curves for the lower segment were of properties of top-down piles with soil at bottoms. Comparing the load transfer law of top-down piles without soil at bottoms and top-down piles with soil at bottoms, it was found that the friction resistance reached to the ultimate value before the pile tip resistance. For top-down piles with soil at bottoms, the bearing capacity of single piles went through two stages. The first stage was the development stage of lateral friction resistance, which approximately corresponded to the linear stage of Q-s curves. The second stage was the development stage of pile tip resistance, which approximately corresponded to the nonlinear stage of Q-s curves. Based on the above analysis, a two-stage conversion method from Q-s curves of self-anchoring test piles to Q-s curves of top-down piles with soil at bottoms was proposed. Compared with the results of static load tests for model piles and in situ piles, the converted Q-s curves of self-anchoring test piles were highly consistent with Q-s curves of top-down piles with soil at bottoms after being conversed by the two-stage conversion method, which provided a reliable conversion method of Q-s curves for the engineering application of self-anchored test piles.
The laws for load transfer and displacement of top-uplift piles, top-down piles without soil at bottoms, top-down piles with soil at bottoms and self-anchored test piles were studied by model tests in the laboratory. The results showed that Q-s curves for top-uplift piles presented a sudden drop and the curves of top-down piles without soil at bottoms prensted a slow drop. The Q-s curves of top-down piles with soil at bottoms consists of two stages, which were linear stages and nonlinear stages. The Q-s curves for the upper segment of self-anchoring test piles were of properties of top-uplift piles, while the curves for the lower segment were of properties of top-down piles with soil at bottoms. Comparing the load transfer law of top-down piles without soil at bottoms and top-down piles with soil at bottoms, it was found that the friction resistance reached to the ultimate value before the pile tip resistance. For top-down piles with soil at bottoms, the bearing capacity of single piles went through two stages. The first stage was the development stage of lateral friction resistance, which approximately corresponded to the linear stage of Q-s curves. The second stage was the development stage of pile tip resistance, which approximately corresponded to the nonlinear stage of Q-s curves. Based on the above analysis, a two-stage conversion method from Q-s curves of self-anchoring test piles to Q-s curves of top-down piles with soil at bottoms was proposed. Compared with the results of static load tests for model piles and in situ piles, the converted Q-s curves of self-anchoring test piles were highly consistent with Q-s curves of top-down piles with soil at bottoms after being conversed by the two-stage conversion method, which provided a reliable conversion method of Q-s curves for the engineering application of self-anchored test piles.
2022, 52(12): 149-155.
doi: 10.13204/j.gyjzG22031206
Abstract:
Most landfills in China are in a long-term service state. Dynamic evaluation on stability of garbage dumps based on real-time monitoring data is of important guiding significance for daily safe operation of landfills. The limit equilibrium method was used to calculate and analyze influences of the existing form of leachate, the liquid level of leachate and the height and position of new rubbish dumps on the stability of landfills. The results showed that the safety factor had a linear relation with the luquid level and the height of the new rubbish dump. The position of the new rubbish dump should be reasonably arranged, which could not be arranged too close to bottoms of landfills and the new rubbish dump should be bulldozed in time to lower the landfill height. In order to ensure the long-term stability of landfills, the drainage system in landfills should be checked in time.
Most landfills in China are in a long-term service state. Dynamic evaluation on stability of garbage dumps based on real-time monitoring data is of important guiding significance for daily safe operation of landfills. The limit equilibrium method was used to calculate and analyze influences of the existing form of leachate, the liquid level of leachate and the height and position of new rubbish dumps on the stability of landfills. The results showed that the safety factor had a linear relation with the luquid level and the height of the new rubbish dump. The position of the new rubbish dump should be reasonably arranged, which could not be arranged too close to bottoms of landfills and the new rubbish dump should be bulldozed in time to lower the landfill height. In order to ensure the long-term stability of landfills, the drainage system in landfills should be checked in time.
2022, 52(12): 156-165.
doi: 10.13204/j.gyjzG21090402
Abstract:
A water-soil coupling finite element analysis for the dynamic response of underground structure in the liquefiable site during and after earthquakes was performed. In the calculation, the water-soil fully coupled finite element-finite difference method based on the effective stress theory and the CM model (the Cyclic Mobility model) accurately reflected the dynamic characterisitcs of soil under cyclic loads were adopted. Considering the structural volume effect, the hybrid elements composed of elastic beams and columns were used to construct the model of the station structure, and the joint elements at soil-structure interfaces were set. The acceleration response of soil during a rare earthquake, the development of excess pore water pressure, the internal force of the underground structure and the consolidation settlement after the earthquake were simulated and analyzed. The results showed that the underground structure continued to float up after the earthquake, and the displacement development after the earthquake was significantly greater than that during the earthquake. When the excess pore pressure almost completely dissipated, the structure settlement tended to be stable.
A water-soil coupling finite element analysis for the dynamic response of underground structure in the liquefiable site during and after earthquakes was performed. In the calculation, the water-soil fully coupled finite element-finite difference method based on the effective stress theory and the CM model (the Cyclic Mobility model) accurately reflected the dynamic characterisitcs of soil under cyclic loads were adopted. Considering the structural volume effect, the hybrid elements composed of elastic beams and columns were used to construct the model of the station structure, and the joint elements at soil-structure interfaces were set. The acceleration response of soil during a rare earthquake, the development of excess pore water pressure, the internal force of the underground structure and the consolidation settlement after the earthquake were simulated and analyzed. The results showed that the underground structure continued to float up after the earthquake, and the displacement development after the earthquake was significantly greater than that during the earthquake. When the excess pore pressure almost completely dissipated, the structure settlement tended to be stable.
2022, 52(12): 166-170.
doi: 10.13204/j.gyjzG21112405
Abstract:
Taking fully weachered phyllite soil as a reserch object, the pressure plate method and saturated salt solution method were used to test the soil water characteristic curve(SWCC) in a wide suction range of phyllite weathered compaction soils with different dry densities. A uniaxial tensile tester was developed to study the tensile strength of specimens with different dry densities in a wide range of saturation, and combined with the mercury injection test to study tensile strength change trend. The experimental results showed that the tensile strength presented two peaks with increase of the water content, which were considered to be the results of the increased quantity of "liquid Bridges", capillary pressure and the stronger cementation force respectively. Besides, it was corresponding to the "double peak" structure of the compacted specimens in the mercury injection test. Analyzing the SWCC of soil specimens, it was shown that the higher the dry density of compacted soil specimens was, the lower the saturated water content was; the air entry value was larger, the tensile strength was higher. The results showed that the dry density and water content had different effects on tensile strength. Moreover, it was verified that the model could reasonably predict the tensile strength of fully weathered phyllite soils in the full saturation range with different dry densities.
Taking fully weachered phyllite soil as a reserch object, the pressure plate method and saturated salt solution method were used to test the soil water characteristic curve(SWCC) in a wide suction range of phyllite weathered compaction soils with different dry densities. A uniaxial tensile tester was developed to study the tensile strength of specimens with different dry densities in a wide range of saturation, and combined with the mercury injection test to study tensile strength change trend. The experimental results showed that the tensile strength presented two peaks with increase of the water content, which were considered to be the results of the increased quantity of "liquid Bridges", capillary pressure and the stronger cementation force respectively. Besides, it was corresponding to the "double peak" structure of the compacted specimens in the mercury injection test. Analyzing the SWCC of soil specimens, it was shown that the higher the dry density of compacted soil specimens was, the lower the saturated water content was; the air entry value was larger, the tensile strength was higher. The results showed that the dry density and water content had different effects on tensile strength. Moreover, it was verified that the model could reasonably predict the tensile strength of fully weathered phyllite soils in the full saturation range with different dry densities.
2022, 52(12): 171-178.
doi: 10.13204/j.gyjzG21110211
Abstract:
Diaphragm wall is a kind of typical temporary retaining structure for construction of metro stations and open-cut tunnels. When the trench of a diaphragm wall was drilled in rock, vibration was generated by rock fracturing, which might threaten the safty of adjacent structures, especially ancient buildings. Field monitoring records under construction of Wushan Square Metro Station in Hangzhou were selected. The characteristics of vibration and attenuation during wave propagation were analyzed for three common trench cutting machines:the impact drill, the slot milling machine and the rotary drill. Results showed that the initial vibration speed produced by the rotary drill in the vertical direction at the vibration source was maximum, the second was produced by the slot milling machine, and the smallest was produced by the impact drill. But in the horizontal direction, the rotary drill was the largest, the next was produced by the impact drill, and the smallest was produced by the slot milling machine. The results were applied in analysis of safe space between construction machinery and a typical ancient stone tower under tunnelling construction. The impact severity in descending order due to construction on adjacent towers was the rotary drill, the impact drill and the slot milling machine. Therefore, it was recommended the slot milling machine to be used, when there was a need to protect ancient stone towers.
Diaphragm wall is a kind of typical temporary retaining structure for construction of metro stations and open-cut tunnels. When the trench of a diaphragm wall was drilled in rock, vibration was generated by rock fracturing, which might threaten the safty of adjacent structures, especially ancient buildings. Field monitoring records under construction of Wushan Square Metro Station in Hangzhou were selected. The characteristics of vibration and attenuation during wave propagation were analyzed for three common trench cutting machines:the impact drill, the slot milling machine and the rotary drill. Results showed that the initial vibration speed produced by the rotary drill in the vertical direction at the vibration source was maximum, the second was produced by the slot milling machine, and the smallest was produced by the impact drill. But in the horizontal direction, the rotary drill was the largest, the next was produced by the impact drill, and the smallest was produced by the slot milling machine. The results were applied in analysis of safe space between construction machinery and a typical ancient stone tower under tunnelling construction. The impact severity in descending order due to construction on adjacent towers was the rotary drill, the impact drill and the slot milling machine. Therefore, it was recommended the slot milling machine to be used, when there was a need to protect ancient stone towers.
2022, 52(12): 179-185.
doi: 10.13204/j.gyjzG220032707
Abstract:
To explore the influence of polyformaldehyde (POM) fibers on the fracture properties of ultra-high strength concrete (UHSC), the three-point bending beam method was used for fracture test, the influence of fiber length and fiber volume content on the UHSC crack toughness, instability of toughness, fracture energy and ductility indexes was studied. The experimental results showed that the addition of POM fibers could improve the fracture properties of UHSC. With the increase of fiber volume content and fiber length, the descending segment of P-δCMOD curve became fuller. When the fiber length was 12 mm and fiber content was 1.5%, the crack initiation toughness was improved most significantly. When the fiber length was 20 mm and the fiber content was 1.5%, the specimens' instability toughness, fracture energy and ductility indexes reached the maximum.
To explore the influence of polyformaldehyde (POM) fibers on the fracture properties of ultra-high strength concrete (UHSC), the three-point bending beam method was used for fracture test, the influence of fiber length and fiber volume content on the UHSC crack toughness, instability of toughness, fracture energy and ductility indexes was studied. The experimental results showed that the addition of POM fibers could improve the fracture properties of UHSC. With the increase of fiber volume content and fiber length, the descending segment of P-δCMOD curve became fuller. When the fiber length was 12 mm and fiber content was 1.5%, the crack initiation toughness was improved most significantly. When the fiber length was 20 mm and the fiber content was 1.5%, the specimens' instability toughness, fracture energy and ductility indexes reached the maximum.
2022, 52(12): 186-194.
doi: 10.13204/j.gyjzG21070606
Abstract:
“Pavilion” has not been clearly defined in the field of contemporary architectural design. It has been applied to buildings, works of art or devices. Therefore, since its emergence in modern international expositions and architectural exhibitions, it has been caused and kept evolving in either forms or functions. So far, it has become a new paradigm in architectural activities. It is avant-garde, experimental and original. As a medium to express their ideas, it demonstrated the strong vanguard and display tendency. Based on the definition of "Pavilion" in dictionaries, the display tendency of "Pavilions" in the historical evoluation were revealed. Aiming at the Serpentine Gallery Pavilion, the characteristics of structure materials and high technology were analyzed, the display tendency and main characteristics for "Pavilions" at all times and in all countries were revealed.
“Pavilion” has not been clearly defined in the field of contemporary architectural design. It has been applied to buildings, works of art or devices. Therefore, since its emergence in modern international expositions and architectural exhibitions, it has been caused and kept evolving in either forms or functions. So far, it has become a new paradigm in architectural activities. It is avant-garde, experimental and original. As a medium to express their ideas, it demonstrated the strong vanguard and display tendency. Based on the definition of "Pavilion" in dictionaries, the display tendency of "Pavilions" in the historical evoluation were revealed. Aiming at the Serpentine Gallery Pavilion, the characteristics of structure materials and high technology were analyzed, the display tendency and main characteristics for "Pavilions" at all times and in all countries were revealed.
2022, 52(12): 195-199,194.
doi: 10.13204/j.gyjzG21101901
Abstract:
Steel structure detection is an important method of steel structure quality and safety control. Steel strength or designation is an important index of steel structure detection, which provides an important basis for engineering quality evaluation, safety evaluation and reinforcement. The practice showed that the existing detection methods have some shortcomings and can not meet the requirements of engineering. In this paper, through a large number of Leeb hardness and steel tensile strength tests, the test results were statistically analyzed, a method for judging steel grade by Leeb hardness method was determined, and the limit values of Leeb hardness for Q235 and Q345 were obtained. The engineering verification showed that this method could meet the requirements of field detection and caused less damage to the original structure.
Steel structure detection is an important method of steel structure quality and safety control. Steel strength or designation is an important index of steel structure detection, which provides an important basis for engineering quality evaluation, safety evaluation and reinforcement. The practice showed that the existing detection methods have some shortcomings and can not meet the requirements of engineering. In this paper, through a large number of Leeb hardness and steel tensile strength tests, the test results were statistically analyzed, a method for judging steel grade by Leeb hardness method was determined, and the limit values of Leeb hardness for Q235 and Q345 were obtained. The engineering verification showed that this method could meet the requirements of field detection and caused less damage to the original structure.
2022, 52(12): 200-208.
doi: 10.13204/j.gyjzG21091610
Abstract:
The combination of BIM and information technology can effectively improve the efficiency of construction projects. At present, China is vigorously promoting the development of building informatization, especially the application of BIM and the new generation of information technology. Combined with practical engineering cases, the problems in the application of BIM-based project management information interaction platform were found. Therefore, a BIM information integration service platform for the whole life cycle of construction engineering based on the integration of BIM and the new generation of information technology was proposed, and the theoretical research on the applicability of its key technologies was conducted. Exploratory factor analysis was carried out by factor analysis method, and then confirmatory factor analysis was carried out by measurement model and structural model in structural equation model. Finally, the research hypothesis was verified, providing reference for the application and development of BIM and the new generation of information technology.
The combination of BIM and information technology can effectively improve the efficiency of construction projects. At present, China is vigorously promoting the development of building informatization, especially the application of BIM and the new generation of information technology. Combined with practical engineering cases, the problems in the application of BIM-based project management information interaction platform were found. Therefore, a BIM information integration service platform for the whole life cycle of construction engineering based on the integration of BIM and the new generation of information technology was proposed, and the theoretical research on the applicability of its key technologies was conducted. Exploratory factor analysis was carried out by factor analysis method, and then confirmatory factor analysis was carried out by measurement model and structural model in structural equation model. Finally, the research hypothesis was verified, providing reference for the application and development of BIM and the new generation of information technology.
2022, 52(12): 209-215.
doi: 10.13204/j.gyjzG21061811
Abstract:
Deformation monitoring is one of the most essential means of ensuring construction safety for lifting space frames. Current traditional methods only enable deformation monitoring at local points, but not for the whole structure. Three-dimensional (3D) laser scanning technology can capture accurate point clouds of as-built structures through full-coverage scanning, thus providing a innovative solution to the above issue. To this end, the research on intelligent deformation monitoring for lifting space frames based on point cloud data, including point cloud data preprocessing, non-rigid matching of point clouds and lifting deformation visualization, was carried out based on a practical engineering project, namely Luzhou Railway Station. Based on clustering algorithms, random sample consensus, graph structural methods and orthogonal procrustes analysis, a non-rigid matching algorithm integrating intelligent sphere positioning, coarse sphere matching, non-rigid sphere matching was proposed for the non-rigid matching of point clouds of space frames before and after lifting. The results showed that the proposed intelligent deformation monitoring approach based on point cloud data was efficient, comprehensive and practical.
Deformation monitoring is one of the most essential means of ensuring construction safety for lifting space frames. Current traditional methods only enable deformation monitoring at local points, but not for the whole structure. Three-dimensional (3D) laser scanning technology can capture accurate point clouds of as-built structures through full-coverage scanning, thus providing a innovative solution to the above issue. To this end, the research on intelligent deformation monitoring for lifting space frames based on point cloud data, including point cloud data preprocessing, non-rigid matching of point clouds and lifting deformation visualization, was carried out based on a practical engineering project, namely Luzhou Railway Station. Based on clustering algorithms, random sample consensus, graph structural methods and orthogonal procrustes analysis, a non-rigid matching algorithm integrating intelligent sphere positioning, coarse sphere matching, non-rigid sphere matching was proposed for the non-rigid matching of point clouds of space frames before and after lifting. The results showed that the proposed intelligent deformation monitoring approach based on point cloud data was efficient, comprehensive and practical.
2022, 52(12): 216-223.
doi: 10.13204/j.gyjzG22011204
Abstract:
In recent years, many special-shaped complex buildings have been widely used in mountain natural landscape areas, but these special-shaped complex buildings are difficult to be realized by conventional floor dropped or hanger frame structure. Therefore, a new structural scheme is proposed based on a special-shaped complex building in the complex mountain area of Chongqing, which not only meets the requirements of architectural modeling, but also solves the problem of foundation setting on the slope. The building consists of a curved facade and a inclined roof to form a complex spatial surface, and the building plan resembles a crescent shape. In order to solve the problem of vertical force transmission under such terrain conditions, and at the same time meet the requirements of building shape and large openings, the structure innovatively adopts space multi-curved arch and inclined column structural force system, in which multi-curved arch adopts inclined pile foundation, and inclined column adopts straight pile foundation. The effects of column inclination angle on the structural system were analyzed, and the results showed that increasing column inclination angle would increase the stiffness of the structure, which was beneficial to the structural force. Based on the final structural scheme, the structural deformation, structural stress and structural stability were analyzed, and stability calculations were performed for the multi-curved arch according to two methods. Multiple elements were connected with multi-curved arch to form a complex space joint, which was a key joint for load transfer. Cast steel joint was used for design, and the finite element software ABAQUS was used to analyze the stress and ultimate bearing capacity of the joint, and the results showed that the bearing capacity of the cast steel joint could meet the design requirements. Finally, the comfort of this kind of long-span special-shaped structure was analyzed in detail, and the connections between multi-curved arch or inclined column and pile foundation were introduced.
In recent years, many special-shaped complex buildings have been widely used in mountain natural landscape areas, but these special-shaped complex buildings are difficult to be realized by conventional floor dropped or hanger frame structure. Therefore, a new structural scheme is proposed based on a special-shaped complex building in the complex mountain area of Chongqing, which not only meets the requirements of architectural modeling, but also solves the problem of foundation setting on the slope. The building consists of a curved facade and a inclined roof to form a complex spatial surface, and the building plan resembles a crescent shape. In order to solve the problem of vertical force transmission under such terrain conditions, and at the same time meet the requirements of building shape and large openings, the structure innovatively adopts space multi-curved arch and inclined column structural force system, in which multi-curved arch adopts inclined pile foundation, and inclined column adopts straight pile foundation. The effects of column inclination angle on the structural system were analyzed, and the results showed that increasing column inclination angle would increase the stiffness of the structure, which was beneficial to the structural force. Based on the final structural scheme, the structural deformation, structural stress and structural stability were analyzed, and stability calculations were performed for the multi-curved arch according to two methods. Multiple elements were connected with multi-curved arch to form a complex space joint, which was a key joint for load transfer. Cast steel joint was used for design, and the finite element software ABAQUS was used to analyze the stress and ultimate bearing capacity of the joint, and the results showed that the bearing capacity of the cast steel joint could meet the design requirements. Finally, the comfort of this kind of long-span special-shaped structure was analyzed in detail, and the connections between multi-curved arch or inclined column and pile foundation were introduced.
