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2011 Vol. 41, No. 5
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2011, 41(5): 1-5.
doi: 10.13204/j.gyjz201105001
Abstract:
Firstly, the compressive and flexural strength of mortar with chloride ion permeating in sands during mixing investigated in 3, 5, 7, 14, 28, and 90 d.It is found that chloride ion permeating in sands will not improve the mortar strength of early stage, but reduce the corresponding strength, which is obviously different from the effect of chloride ion permeating in water.Then the bond performance of above mortar in 270, 360, 450, 630, 810, 1 050, 1 170, 1 320, and 1 440 d was studied based on 4 years long-term exposure experiments.The -s slipping curve with different content of chloride ion, the time-variant maximal bonding strength, also its tensility change rule are presented.Finally, the fitting formula of -s was gained by origin software.
Firstly, the compressive and flexural strength of mortar with chloride ion permeating in sands during mixing investigated in 3, 5, 7, 14, 28, and 90 d.It is found that chloride ion permeating in sands will not improve the mortar strength of early stage, but reduce the corresponding strength, which is obviously different from the effect of chloride ion permeating in water.Then the bond performance of above mortar in 270, 360, 450, 630, 810, 1 050, 1 170, 1 320, and 1 440 d was studied based on 4 years long-term exposure experiments.The -s slipping curve with different content of chloride ion, the time-variant maximal bonding strength, also its tensility change rule are presented.Finally, the fitting formula of -s was gained by origin software.
2011, 41(5): 6-9.
doi: 10.13204/j.gyjz201105002
Abstract:
Cracking and self-healing are inevitable phenomenon for concrete structures.Three types of concrete specimens with multi-pre-cracks are designed for the test.Then the specimens were exposed to 6% NaCl solution for 40 d and 160 d.At last the self-healing area fraction in cracks' surface and chloride concentration in concrete near cracks were detected by RCT methods.Results show that self-healing area is increased with exposure time and the value of W/C, it decreases the crack surface and chloride ion in the crack, which makes the chloride ion ingress into concrete through crack surface be less than that through exposed surface.
Cracking and self-healing are inevitable phenomenon for concrete structures.Three types of concrete specimens with multi-pre-cracks are designed for the test.Then the specimens were exposed to 6% NaCl solution for 40 d and 160 d.At last the self-healing area fraction in cracks' surface and chloride concentration in concrete near cracks were detected by RCT methods.Results show that self-healing area is increased with exposure time and the value of W/C, it decreases the crack surface and chloride ion in the crack, which makes the chloride ion ingress into concrete through crack surface be less than that through exposed surface.
2011, 41(5): 10-13,22.
doi: 10.13204/j.gyjz201105003
Abstract:
The steel rebar inside reinforced concrete structures is susceptible to corrosion when Cl-content at the surface of the steel exceeding a chloride threshold level(CTL).The CTL is an important influence on the service life of concrete structures exposed to chloride environments.Especially in high temperature regions, reinforced concrete structures are more severely damaged.The paper focused on studying the influence of high temperature on CTL.The experiment was carried out in 50 ℃ synthetic pore solution, considering the influences of electric potentials and pHs, and CTL of 95% acceptance value achieved.Results show that CTL under 50 ℃ is much smaller than that under normal temperature(25 ℃), and the controlling effect of temperature is more obvious as the corrosion potential decreases and pH value increases.Fitting curve of CTL to temperature was also presented.
The steel rebar inside reinforced concrete structures is susceptible to corrosion when Cl-content at the surface of the steel exceeding a chloride threshold level(CTL).The CTL is an important influence on the service life of concrete structures exposed to chloride environments.Especially in high temperature regions, reinforced concrete structures are more severely damaged.The paper focused on studying the influence of high temperature on CTL.The experiment was carried out in 50 ℃ synthetic pore solution, considering the influences of electric potentials and pHs, and CTL of 95% acceptance value achieved.Results show that CTL under 50 ℃ is much smaller than that under normal temperature(25 ℃), and the controlling effect of temperature is more obvious as the corrosion potential decreases and pH value increases.Fitting curve of CTL to temperature was also presented.
2011, 41(5): 14-18,38.
doi: 10.13204/j.gyjz201105004
Abstract:
The specimens of concrete core with diameter of 100 mm were drilled from wave-preventing dam and concrete blocks.The content of calcium carbonate and chloride distribution from the specimens were measured;pore structure in inner part and in the surface of concrete was measured by mercury intrusion test.Influence of materials and environments on carbonation and chloride distribution was analyzed.The test shows that the carbonation rate is slow in extremely humid environment, and the incomplete carbonation zone is dominated in carbonation.The invading depth of chloride ions is low in exposure condition;difference of the pore structure exists between outer zone and inner zone of exposed concrete, the hydration in proceeding of concrete and the substance of sea water filling in the outer zone of concrete block the chloride ion invading of concrete.
The specimens of concrete core with diameter of 100 mm were drilled from wave-preventing dam and concrete blocks.The content of calcium carbonate and chloride distribution from the specimens were measured;pore structure in inner part and in the surface of concrete was measured by mercury intrusion test.Influence of materials and environments on carbonation and chloride distribution was analyzed.The test shows that the carbonation rate is slow in extremely humid environment, and the incomplete carbonation zone is dominated in carbonation.The invading depth of chloride ions is low in exposure condition;difference of the pore structure exists between outer zone and inner zone of exposed concrete, the hydration in proceeding of concrete and the substance of sea water filling in the outer zone of concrete block the chloride ion invading of concrete.
2011, 41(5): 19-22.
doi: 10.13204/j.gyjz201105005
Abstract:
Under the specified artificial climate environment of chloride corrosion, it was studied in the experiment that chloride contaminated RC beams with two different water-cement ratios at different corrosion time and was analyzed the bearing capacity and corrosion ratio of rebars after being corroded by chloride ion.The results show that bearing capacity of RC beams with the same water-cement ratio at different corrosion time is closely related to the corrosion depth of chloride in concrete and the degree of corrosion in rebars.In addition, rebars in RC beams with higher water-cement ratio is corroded more seriously.
Under the specified artificial climate environment of chloride corrosion, it was studied in the experiment that chloride contaminated RC beams with two different water-cement ratios at different corrosion time and was analyzed the bearing capacity and corrosion ratio of rebars after being corroded by chloride ion.The results show that bearing capacity of RC beams with the same water-cement ratio at different corrosion time is closely related to the corrosion depth of chloride in concrete and the degree of corrosion in rebars.In addition, rebars in RC beams with higher water-cement ratio is corroded more seriously.
2011, 41(5): 23-26.
doi: 10.13204/j.gyjz201105006
Abstract:
The concrete resistance to sulfate attack was improved by applying repair mortar overlay(RMO)-cement paste coating in different ways.The degradation mechanisms and processes of sulfate attack in concrete with different ways of applying coatings were discussed.Results showed that the penetration of sulfate ions into concrete was effectively reduced by applying the coatings on both the positive and the negative side.It's more efficient on preventing sulfate attack by applying the coatings on the positive side.
The concrete resistance to sulfate attack was improved by applying repair mortar overlay(RMO)-cement paste coating in different ways.The degradation mechanisms and processes of sulfate attack in concrete with different ways of applying coatings were discussed.Results showed that the penetration of sulfate ions into concrete was effectively reduced by applying the coatings on both the positive and the negative side.It's more efficient on preventing sulfate attack by applying the coatings on the positive side.
2011, 41(5): 27-33.
doi: 10.13204/j.gyjz201105007
Abstract:
Based on uniaxial compression experiments of BFRP-confined concrete circular column under freeze-thaw cycles and freeze-thaw cycles in sodium chloride solution respectively, the effects of environments on tangent Poisson ratio-longitudinal stress curves and tangent Poisson ratio were studied.The experiment results show that tangent Poisson ratio-longitudinal stress curves change regularly because of the environment effects.Based on the discussions on the environment influence factors of ultimate tangent Poisson ratio of BFRP-confined concrete circular column, environment variable was introduced in analyzing the influence by aggressive environments and calculation formulas for ultimate tangent Poisson ratio under aggressive environments were presented.The analytical results were in good agreement with the test results.
Based on uniaxial compression experiments of BFRP-confined concrete circular column under freeze-thaw cycles and freeze-thaw cycles in sodium chloride solution respectively, the effects of environments on tangent Poisson ratio-longitudinal stress curves and tangent Poisson ratio were studied.The experiment results show that tangent Poisson ratio-longitudinal stress curves change regularly because of the environment effects.Based on the discussions on the environment influence factors of ultimate tangent Poisson ratio of BFRP-confined concrete circular column, environment variable was introduced in analyzing the influence by aggressive environments and calculation formulas for ultimate tangent Poisson ratio under aggressive environments were presented.The analytical results were in good agreement with the test results.
2011, 41(5): 34-38.
doi: 10.13204/j.gyjz201105008
Abstract:
The hoop bond performance between corroded rebar and concrete was explored in this paper.The research is significant to the prediction of time when the internal cracking due to corrosion happened.Concrete strength and type of rebar was taken into account at the design of torsion specimen.In the test, constant current was used to accelerate corrosion course.Torque wrench was the loading tool.The relative angle between concrete and rebar was recorded by use of clinometer.The results indicate that the ultimate torsional bearing capacity and torsional rigidity of plain round bar are less than deformed rebar.The ring bonding shear strength is steady when the corrosion level is small for the deformed rebar.When the corrosion level reaches a certain extent, the ring bonding shear strength begins to decrease.Because of additional mechanical bite force, the hoop bonding shear strength is increased with corrosion level.When the corrosion level reaches a certain extent, the hoop bonding shear strength decreases in a smaller rate.
The hoop bond performance between corroded rebar and concrete was explored in this paper.The research is significant to the prediction of time when the internal cracking due to corrosion happened.Concrete strength and type of rebar was taken into account at the design of torsion specimen.In the test, constant current was used to accelerate corrosion course.Torque wrench was the loading tool.The relative angle between concrete and rebar was recorded by use of clinometer.The results indicate that the ultimate torsional bearing capacity and torsional rigidity of plain round bar are less than deformed rebar.The ring bonding shear strength is steady when the corrosion level is small for the deformed rebar.When the corrosion level reaches a certain extent, the ring bonding shear strength begins to decrease.Because of additional mechanical bite force, the hoop bonding shear strength is increased with corrosion level.When the corrosion level reaches a certain extent, the hoop bonding shear strength decreases in a smaller rate.
2011, 41(5): 39-42,133.
doi: 10.13204/j.gyjz201105009
Abstract:
It is the necessary premise of reliability evaluation on the corroded RC member to study the distribution rule of pit corrosion for the rebar.The wet-dry cycle tests outdoors on salt-doped reinforced concrete members were conducted for two years.The 89 corroded rebars were peeled, acid cleaned, weighed, measured and analyzed.Then, the ratio of the maximum pit depth and the average corrosion penetration depth was calculated.As the analysis index of the rebar corrosion character, whose probability distribution was analyzed deeply by the method of mathematical statistics.The result shows that the ratio follows lognormal distribution for the rebar under chloride environment.
It is the necessary premise of reliability evaluation on the corroded RC member to study the distribution rule of pit corrosion for the rebar.The wet-dry cycle tests outdoors on salt-doped reinforced concrete members were conducted for two years.The 89 corroded rebars were peeled, acid cleaned, weighed, measured and analyzed.Then, the ratio of the maximum pit depth and the average corrosion penetration depth was calculated.As the analysis index of the rebar corrosion character, whose probability distribution was analyzed deeply by the method of mathematical statistics.The result shows that the ratio follows lognormal distribution for the rebar under chloride environment.
2011, 41(5): 43-46,49.
doi: 10.13204/j.gyjz201105010
Abstract:
Industrial building space is an important part of the urban landscape, also the second living space of industrial workers.Concerning the design quality of industrial building space can improve the life quality of workers and work efficiency.It is the spatial design cases of German enterprises, which provides experiences in industrial building design for architects.
Industrial building space is an important part of the urban landscape, also the second living space of industrial workers.Concerning the design quality of industrial building space can improve the life quality of workers and work efficiency.It is the spatial design cases of German enterprises, which provides experiences in industrial building design for architects.
2011, 41(5): 47-49.
doi: 10.13204/j.gyjz201105011
Abstract:
It was analyzed the campus public environment according to the integration of old and new public space.It was also proposed that the basic framework and the specific contents of integrating old and new campus public space, which provided a valuable method for realizing an old and the new integration design.
It was analyzed the campus public environment according to the integration of old and new public space.It was also proposed that the basic framework and the specific contents of integrating old and new campus public space, which provided a valuable method for realizing an old and the new integration design.
2011, 41(5): 50-52,65.
doi: 10.13204/j.gyjz201105012
Abstract:
The integration installation of solar energy collector of residential buildings is an inevitable trend of residential energy-saving development.Its main operation is to install the collector to the building in order to achieve the perfect combination with the construction.It was explored the installation of heat collectors for various building by means of analyzing the features and service requirements of solar energy collectors.
The integration installation of solar energy collector of residential buildings is an inevitable trend of residential energy-saving development.Its main operation is to install the collector to the building in order to achieve the perfect combination with the construction.It was explored the installation of heat collectors for various building by means of analyzing the features and service requirements of solar energy collectors.
2011, 41(5): 53-56,70.
doi: 10.13204/j.gyjz201105013
Abstract:
Based on the conception of passive solar energy residence and design thinking for patterns of getting heat deriving from the idea of sustainalde development, it also gived some examples to design solar energy residence the ways how to use effectively solar energy by elaborately planning programming.
Based on the conception of passive solar energy residence and design thinking for patterns of getting heat deriving from the idea of sustainalde development, it also gived some examples to design solar energy residence the ways how to use effectively solar energy by elaborately planning programming.
2011, 41(5): 57-59,92.
doi: 10.13204/j.gyjz201105014
Abstract:
The development of sustainable building has a practical significance for alleviating resource constraints and maintaining the environment.It is required that the wall materials should have characteristics of energy and land conservation, using scrap.Straw is an excellent green wall material because of easily obtained, simple processing and low cost.It is carried out a comprehensive analysis of single-straw brick structure and physical properties and elaborated the composition and behavior of several straw composite panels, it is revealed that the straw wall has the unique advantages in the energy conservation, economy, thermal insulation and environmental protection, and the development of straw wall may be a new idea for future energy-saving wall.
The development of sustainable building has a practical significance for alleviating resource constraints and maintaining the environment.It is required that the wall materials should have characteristics of energy and land conservation, using scrap.Straw is an excellent green wall material because of easily obtained, simple processing and low cost.It is carried out a comprehensive analysis of single-straw brick structure and physical properties and elaborated the composition and behavior of several straw composite panels, it is revealed that the straw wall has the unique advantages in the energy conservation, economy, thermal insulation and environmental protection, and the development of straw wall may be a new idea for future energy-saving wall.
2011, 41(5): 60-65.
doi: 10.13204/j.gyjz201105015
Abstract:
Making full use of site investigation and references, probabilistic models of loads and resistances during building construction were presented.In view of the significant failure modes of formwork-supporting system and reinforced concrete member, the reliability of time-dependent system during the construction of typical multistory reinforced concrete buildings was developed.The influences of the number of levels of shoring/reshoring and live load during construction of the building on system reliability were included in the analysis.
Making full use of site investigation and references, probabilistic models of loads and resistances during building construction were presented.In view of the significant failure modes of formwork-supporting system and reinforced concrete member, the reliability of time-dependent system during the construction of typical multistory reinforced concrete buildings was developed.The influences of the number of levels of shoring/reshoring and live load during construction of the building on system reliability were included in the analysis.
2011, 41(5): 66-70.
doi: 10.13204/j.gyjz201105016
Abstract:
Based on the introduction of seismic design of frame-shear wall structure with viscous dampers, this paper put forward the method of distributing damping coefficients according to the direct proportion of damping force and floor shear.The nibbling method was adopted to realize more accurate calculation of additional damping ratio needed by the structure.Combining examples of building design, the frame-shear wall structures with or without viscous dampers were modeled and analyzed to compare their structural performance and economic effects;which were further studied the effect of viscous dampers.
Based on the introduction of seismic design of frame-shear wall structure with viscous dampers, this paper put forward the method of distributing damping coefficients according to the direct proportion of damping force and floor shear.The nibbling method was adopted to realize more accurate calculation of additional damping ratio needed by the structure.Combining examples of building design, the frame-shear wall structures with or without viscous dampers were modeled and analyzed to compare their structural performance and economic effects;which were further studied the effect of viscous dampers.
2011, 41(5): 71-79.
doi: 10.13204/j.gyjz201105017
Abstract:
Railing system as the important accessory of buildings and bridges is very important for ensuring the safety of lives and properties of the public user though it may not influence the performance of main structure.The existing research on the structural performance of railing systems and the safety design of railing systems is lacked, and the design criteria and the design loads in various codes in the world are different.In Chinese codes, the bearing capacity of railing under uniform load is evaluated but there is no rule on concentrated load and deformation limit.In this paper, the load requirements for railing structure in foreign and domestic codes were compared and investigated firstly.Based on the theoretical analysis and the practical requirements, a deformation limit of 1/100 height for railing systems was proposed.Then, a number of railing structures with the various design parameters were analyzed with finite element method, their deformation and safety were investigated under the concentrated load and uniform load separately.Based on the above, a complete design approach for the railing structure, in which the strength and the deformation under the various load patterns were considered, was also proposed.
Railing system as the important accessory of buildings and bridges is very important for ensuring the safety of lives and properties of the public user though it may not influence the performance of main structure.The existing research on the structural performance of railing systems and the safety design of railing systems is lacked, and the design criteria and the design loads in various codes in the world are different.In Chinese codes, the bearing capacity of railing under uniform load is evaluated but there is no rule on concentrated load and deformation limit.In this paper, the load requirements for railing structure in foreign and domestic codes were compared and investigated firstly.Based on the theoretical analysis and the practical requirements, a deformation limit of 1/100 height for railing systems was proposed.Then, a number of railing structures with the various design parameters were analyzed with finite element method, their deformation and safety were investigated under the concentrated load and uniform load separately.Based on the above, a complete design approach for the railing structure, in which the strength and the deformation under the various load patterns were considered, was also proposed.
2011, 41(5): 80-83.
doi: 10.13204/j.gyjz201105018
Abstract:
It has been shown that channel-masonry composite beams feature high bearing capacity, good stability and ductility etc, which may be used for strengtherming projects, according to the flexural behavior tests of two channel-masonry composite beams and one channel beam, and also a comparison between the results of theoretical calculations and those of FE numerical calculations.
It has been shown that channel-masonry composite beams feature high bearing capacity, good stability and ductility etc, which may be used for strengtherming projects, according to the flexural behavior tests of two channel-masonry composite beams and one channel beam, and also a comparison between the results of theoretical calculations and those of FE numerical calculations.
2011, 41(5): 84-87.
doi: 10.13204/j.gyjz201105019
Abstract:
In order to obtain the optimal parameters of TMD devices for a building structure subjected to TMD random wind loads and based on comfort and power reliability, the analytical solution for the acceleration of windinduced response associated with the comfort of the structure of the first-order mode was got. Then, according to extreme value theory of random process, the average maximum wind-induced displacement of the structure was got. And the ratio of the standard deviation of the first-order modal displacement of the structure with TMD dampers to that without TMD dampers was defined as the index of damping effect and it was used as the optimal objective, which had degrees of comfort and dynamic reliability for the restrictive conditions. Finally, the optimal parameters of TMD dampers are got by the improved genetic algorithm . Therefore, a series of methods for the optimum design of TMD dampers structure based on the constraint of comfort and dynamic reliability were established. Studies show that the method can effectively obtain the optimum parameters of TMD devices.
In order to obtain the optimal parameters of TMD devices for a building structure subjected to TMD random wind loads and based on comfort and power reliability, the analytical solution for the acceleration of windinduced response associated with the comfort of the structure of the first-order mode was got. Then, according to extreme value theory of random process, the average maximum wind-induced displacement of the structure was got. And the ratio of the standard deviation of the first-order modal displacement of the structure with TMD dampers to that without TMD dampers was defined as the index of damping effect and it was used as the optimal objective, which had degrees of comfort and dynamic reliability for the restrictive conditions. Finally, the optimal parameters of TMD dampers are got by the improved genetic algorithm . Therefore, a series of methods for the optimum design of TMD dampers structure based on the constraint of comfort and dynamic reliability were established. Studies show that the method can effectively obtain the optimum parameters of TMD devices.
2011, 41(5): 88-92.
doi: 10.13204/j.gyjz201105020
Abstract:
A calculation method of earth pressure on the retaining wall of different movement models was proposed by taking the soil arching and wall's displacement into account.The relationship between the internal and external friction angle and coefficient of lateral earth pressure were incorporated into the horizontal layer analysis to derive the theoretic formulae of the active and passive earth pressures, the calculated results were compared with those of the test models.It is found that the calculation results are basically consistent with the ones of six models, with the active condition being better than the passive condition and the passive earth pressure of the movement model of rotation about bottom(RB) having the largest error.In general, the present method was taken into overall account the influences of wall movement and soil arching on the distribution of earth pressure.
A calculation method of earth pressure on the retaining wall of different movement models was proposed by taking the soil arching and wall's displacement into account.The relationship between the internal and external friction angle and coefficient of lateral earth pressure were incorporated into the horizontal layer analysis to derive the theoretic formulae of the active and passive earth pressures, the calculated results were compared with those of the test models.It is found that the calculation results are basically consistent with the ones of six models, with the active condition being better than the passive condition and the passive earth pressure of the movement model of rotation about bottom(RB) having the largest error.In general, the present method was taken into overall account the influences of wall movement and soil arching on the distribution of earth pressure.
2011, 41(5): 93-98.
doi: 10.13204/j.gyjz201105021
Abstract:
Based on the large scale tri-axial tests of coarse-grained red sandstone soil reinforced with double twisted hexagonal wire mesh, the reinforced mechanism, the playing process of reinforced effect, the influence of water content and reinforcement layers on the fact that the reinforced effect were studied.The results show that, due to the reinforcement can increase both the cohesion and internal fraction angle of soil, the quasi-cohesion theory is not suitable to this kind of reinforcement, its contribution to soil's internal friction angle should be considered in engineering;the effect of reinforcement on soil needs a playing process, only after the soil strain transcended a critical strain, should the really reinforced effect be brought to play.The reinforcement effect under low confining stress is better than that under high confining stress, and under the low confining stress the reinforced effect of sample reinforced with three layers steel mesh played earlier than the one reinforced with two layers steel mesh, but under the high confining pressure, it is exactly the opposite;the water content and reinforced spacing have big influence on the effect, the shear strength parameters c and of reinforced samples decreased while the water content increased, and they increased with the decrease of reinforced spacing, the empirical formula of c and with reinforced spacing and water content were gotten by multiple regression analysis.
Based on the large scale tri-axial tests of coarse-grained red sandstone soil reinforced with double twisted hexagonal wire mesh, the reinforced mechanism, the playing process of reinforced effect, the influence of water content and reinforcement layers on the fact that the reinforced effect were studied.The results show that, due to the reinforcement can increase both the cohesion and internal fraction angle of soil, the quasi-cohesion theory is not suitable to this kind of reinforcement, its contribution to soil's internal friction angle should be considered in engineering;the effect of reinforcement on soil needs a playing process, only after the soil strain transcended a critical strain, should the really reinforced effect be brought to play.The reinforcement effect under low confining stress is better than that under high confining stress, and under the low confining stress the reinforced effect of sample reinforced with three layers steel mesh played earlier than the one reinforced with two layers steel mesh, but under the high confining pressure, it is exactly the opposite;the water content and reinforced spacing have big influence on the effect, the shear strength parameters c and of reinforced samples decreased while the water content increased, and they increased with the decrease of reinforced spacing, the empirical formula of c and with reinforced spacing and water content were gotten by multiple regression analysis.
2011, 41(5): 99-103.
doi: 10.13204/j.gyjz201105022
Abstract:
In order to design a slope reinforced by anti-slide piles rationally, a calculated method of interaction process of the pile-soil was presented.It was analyzed the reliability of slope reinforced by anti-slide piles by means of displacement iterative finite element method based on the method of strength reduction theory.The calculated parameters were regarded as random variables when considering the different values of random variable impact on the reliability of anchoring depth for anti-slide piles and reinforced slope.The classification of a slope project was considered in selecting the reliability index, the target reliability as control index to guide the design of the anchoring depth of anti-slide piles.Examples show that using reliability analysis to design the slope reinforced by anti-slide piles is rational and is useful for engineering applications.
In order to design a slope reinforced by anti-slide piles rationally, a calculated method of interaction process of the pile-soil was presented.It was analyzed the reliability of slope reinforced by anti-slide piles by means of displacement iterative finite element method based on the method of strength reduction theory.The calculated parameters were regarded as random variables when considering the different values of random variable impact on the reliability of anchoring depth for anti-slide piles and reinforced slope.The classification of a slope project was considered in selecting the reliability index, the target reliability as control index to guide the design of the anchoring depth of anti-slide piles.Examples show that using reliability analysis to design the slope reinforced by anti-slide piles is rational and is useful for engineering applications.
2011, 41(5): 104-107,98.
doi: 10.13204/j.gyjz201105023
Abstract:
Through the resonant column test on the 4 sorts of typical soils as mud, silty caly, silty clay and silty sand interbedded strata, residual soil, the influence of confining pressure and soil property on dynamic shear modulus G and damping ratio of the 4 typical soils was explored in detail.By means of tests and theoretical analyses, the average curves of G/Gmax and /max with the change of under different confining pressures as well as their recommended values of parameters for the 4 sorts of typical soils in Quanzhou were presented.Besides, the influence patterns of the average curve parameters for G/Gma and /max of such 4 soils with the change of were also quantified.
Through the resonant column test on the 4 sorts of typical soils as mud, silty caly, silty clay and silty sand interbedded strata, residual soil, the influence of confining pressure and soil property on dynamic shear modulus G and damping ratio of the 4 typical soils was explored in detail.By means of tests and theoretical analyses, the average curves of G/Gmax and /max with the change of under different confining pressures as well as their recommended values of parameters for the 4 sorts of typical soils in Quanzhou were presented.Besides, the influence patterns of the average curve parameters for G/Gma and /max of such 4 soils with the change of were also quantified.
2011, 41(5): 108-111,125.
doi: 10.13204/j.gyjz201105024
Abstract:
It was mainly introduced the assembling, hoisting and integral installation of steel roof of a sports center.The software ANSYS was used to simulate the construction process of the steel roof.Two cable tension plans were compared and one of them was chosen as the final plan.The main feature of this plan was that it was operated step by step.Considering quicken the speeding up of construction and ensuring structure stability, the jack was moved from center to both sides of the structure and symmetric tension was done, so that it could conform the state of the design.Reasonable hoisting and tension plan made the structure be completed according to the plan.
It was mainly introduced the assembling, hoisting and integral installation of steel roof of a sports center.The software ANSYS was used to simulate the construction process of the steel roof.Two cable tension plans were compared and one of them was chosen as the final plan.The main feature of this plan was that it was operated step by step.Considering quicken the speeding up of construction and ensuring structure stability, the jack was moved from center to both sides of the structure and symmetric tension was done, so that it could conform the state of the design.Reasonable hoisting and tension plan made the structure be completed according to the plan.
2011, 41(5): 112-115.
doi: 10.13204/j.gyjz201105025
Abstract:
Based on the experiment of a model of one-bay, two-story four-angle composite steel frame with cross-stiffened steel plate shear walls under cyclic load, it was analyzed the mechanical property and failure mechanism of the structure, and also researched the hysteretic behavior, the failure mode, ductility and energy dissipation.The experimental results demonstrate that the structural system has large initial stiffness and good ductility and energy dissipation.The structural system loses its bearing capacity because of forming plastic hinges at the column feet.
Based on the experiment of a model of one-bay, two-story four-angle composite steel frame with cross-stiffened steel plate shear walls under cyclic load, it was analyzed the mechanical property and failure mechanism of the structure, and also researched the hysteretic behavior, the failure mode, ductility and energy dissipation.The experimental results demonstrate that the structural system has large initial stiffness and good ductility and energy dissipation.The structural system loses its bearing capacity because of forming plastic hinges at the column feet.
2011, 41(5): 116-119,9.
doi: 10.13204/j.gyjz201105026
Abstract:
An experimental study on ultimate capacity of stressed-skin for aluminum alloy structure with semi-rigid connections under snow and wind load was presented in the paper.The deformation and destruction characteristics of the structure were analyzed.The relationship of M- was derived through the joints experimental study.It was used in finite element nonlinear analysis, and the effects of semi-rigid connections on ultimate capacity were also investigated, and it was pointed out that the panels changed the internal force distribution in frames.
An experimental study on ultimate capacity of stressed-skin for aluminum alloy structure with semi-rigid connections under snow and wind load was presented in the paper.The deformation and destruction characteristics of the structure were analyzed.The relationship of M- was derived through the joints experimental study.It was used in finite element nonlinear analysis, and the effects of semi-rigid connections on ultimate capacity were also investigated, and it was pointed out that the panels changed the internal force distribution in frames.
2011, 41(5): 120-125.
doi: 10.13204/j.gyjz201105027
Abstract:
In order to study the anti-seismic performance of out-shell connection(OSC) between cold-formed square tubular column and H-shaped steel beam, a quasi-static experiment under low-frequency cyclic load of cross-shaped specimens was designed and carried out, and main data acquired from the experiment was analyzed.With the software ANSYS, the finite element model of outer-shell connection(OSC) was built and its results were compared with test data.The comparsion shows that they fit well with test data.Based on the finite element model and yield-line theory, simplified design method of the rib stiffener and out shell was put forward.
In order to study the anti-seismic performance of out-shell connection(OSC) between cold-formed square tubular column and H-shaped steel beam, a quasi-static experiment under low-frequency cyclic load of cross-shaped specimens was designed and carried out, and main data acquired from the experiment was analyzed.With the software ANSYS, the finite element model of outer-shell connection(OSC) was built and its results were compared with test data.The comparsion shows that they fit well with test data.Based on the finite element model and yield-line theory, simplified design method of the rib stiffener and out shell was put forward.
2011, 41(5): 126-133.
doi: 10.13204/j.gyjz201105028
Abstract:
The rung-shape long-span tensile cable-membrane structure in Foshan Century Lotus Stadium was conducted to investigate its dynamic responses under earthquake waves when its cable's prestressing was changed.Results show that the structure's stiffness increases with increasing the prestressing of the cable system.At the same time, the vertical displacement of the cable system decreases under seismic loading, but other members' vertical displacement and their internal force increase.And the damage by seismic action to the structure also increases.The slacking of some cables' prestressing has little effects on the axis stress of the cable system and the compression ring, but more effects on their displacement.It has also more effects on the bending moment of the compression ring and the truss web.The damage of the structure can be identified by monitoring the changes of its displacement and internal force.
The rung-shape long-span tensile cable-membrane structure in Foshan Century Lotus Stadium was conducted to investigate its dynamic responses under earthquake waves when its cable's prestressing was changed.Results show that the structure's stiffness increases with increasing the prestressing of the cable system.At the same time, the vertical displacement of the cable system decreases under seismic loading, but other members' vertical displacement and their internal force increase.And the damage by seismic action to the structure also increases.The slacking of some cables' prestressing has little effects on the axis stress of the cable system and the compression ring, but more effects on their displacement.It has also more effects on the bending moment of the compression ring and the truss web.The damage of the structure can be identified by monitoring the changes of its displacement and internal force.
2011, 41(5): 134-138,83.
doi: 10.13204/j.gyjz201105029
Abstract:
The top-down construction method of pressured grout prestressed anti-floating anchor used in Taiyuan Wanda Plaza was introduced.This kind of anchor posesses of good durability when beared compression so that the anchor fixed length was not easy to crack.In the meanwhile, the flexible arrangements and high anchoring efficiency were good for the even stress of foundation plate.In this project, the influnce of confined water was successfully removed by driving steel pipes into the layer, with which the abundant confined water was cut off and running sand was separated.Several kinds of measures were taken to prevent ground water from leaking into the basement and it was proved to be in good effect.At the same time, top-dowm construction method of anti-floating anchor was discussed.
The top-down construction method of pressured grout prestressed anti-floating anchor used in Taiyuan Wanda Plaza was introduced.This kind of anchor posesses of good durability when beared compression so that the anchor fixed length was not easy to crack.In the meanwhile, the flexible arrangements and high anchoring efficiency were good for the even stress of foundation plate.In this project, the influnce of confined water was successfully removed by driving steel pipes into the layer, with which the abundant confined water was cut off and running sand was separated.Several kinds of measures were taken to prevent ground water from leaking into the basement and it was proved to be in good effect.At the same time, top-dowm construction method of anti-floating anchor was discussed.
2011, 41(5): 139-142.
doi: 10.13204/j.gyjz201105030
Abstract:
The pipe truss, profiled steel sheet, PVC waterproof material and corresponding construction technology were used in the project of a large international convention and exhibition center.The project featured a large area of single roof, large working face, many joints, complicated site management and short construction period etc.As compared with the traditional roof, this roof had the following merits, such as close construction process, no request of technical interval, no wet operation and light roof load etc, which was very suitable for large span.After using and testing for more than a year the construction technology of the roof could fully meet the requirements of the actual use.
The pipe truss, profiled steel sheet, PVC waterproof material and corresponding construction technology were used in the project of a large international convention and exhibition center.The project featured a large area of single roof, large working face, many joints, complicated site management and short construction period etc.As compared with the traditional roof, this roof had the following merits, such as close construction process, no request of technical interval, no wet operation and light roof load etc, which was very suitable for large span.After using and testing for more than a year the construction technology of the roof could fully meet the requirements of the actual use.
