Login
Register
E-alert
2013 Vol. 43, No. 9
Display Method:
2013, 43(9): 7-11.
doi: 10.13204/j.gyjz201309001
Abstract:
Based on the test results of shear capacity of steel recycled aggregate concrete beam and according toUnified Standard for Ｒeliability Design of Building Structure(GB 500682001)，the Monte-Carlo method wasused to calculate the reliability of shear capacity of steel recycled aggregate concrete beam． The influences of shearspanratio，replacement rate of recycled aggregate，stirrup ratio，steel ratio of webs，strength grades of recycled concrete and steel strength on the reliability of steel recycled aggregate concrete beam were studied． The results show that the reliability indexes of shear capacity of steel recycled aggregate concrete beam can meet the demand of existing code in the range of studied parameters． And it can be used in practical project． The results also show that the reliability indexes decreased with the increase of replacement rate of recycled aggregate and shear-span ratio． The reliability indexes increased with the increase of stirrup ratio and steel ratio of steel webs and also increased with the increase of recycled aggregate concrete strength grade and steel strength． The conclusions can provide reference for the design and application of steel recycled aggregate concrete beam．
Based on the test results of shear capacity of steel recycled aggregate concrete beam and according toUnified Standard for Ｒeliability Design of Building Structure(GB 500682001)，the Monte-Carlo method wasused to calculate the reliability of shear capacity of steel recycled aggregate concrete beam． The influences of shearspanratio，replacement rate of recycled aggregate，stirrup ratio，steel ratio of webs，strength grades of recycled concrete and steel strength on the reliability of steel recycled aggregate concrete beam were studied． The results show that the reliability indexes of shear capacity of steel recycled aggregate concrete beam can meet the demand of existing code in the range of studied parameters． And it can be used in practical project． The results also show that the reliability indexes decreased with the increase of replacement rate of recycled aggregate and shear-span ratio． The reliability indexes increased with the increase of stirrup ratio and steel ratio of steel webs and also increased with the increase of recycled aggregate concrete strength grade and steel strength． The conclusions can provide reference for the design and application of steel recycled aggregate concrete beam．
2013, 43(9): 11-16,29.
doi: 10.13204/j.gyjz201309002
Abstract:
In order to reveal the flexural behavior of steel reinforced recycled coarse aggregate concrete beams，6specimens were designed for flexural test． The study considered two impact parameters，which are coarse aggregatereplacement rate and concrete strength grade． Through this test，the whole mechanical process，crack distribution andfailure behavior of this kind of specimens were observed，and obtained the stress-strain distribution curves，theultimate bearing capacity and load-displacement curves parameters． Based on the test data，the impact of coarseaggregate replacement rate and concrete strength grade on the mechanical behavior of steel reinforced recycled coarseaggregate concrete beams was deeply analyzed． The result shows that the replacement rate influences the bearingcapacity of steel reinforced recycled concrete beams，and with replacement rate increases，the bearing capacityincreases from 5. 95% to 17. 63%; during loading process the section strain agreed with the plane sectionassumption，and the beams have good bearing capacity and deformation performance． Finally，put forward normalsection strength calculation method of steel reinforced recycled coarse aggregate concrete beams． The researchconclusions can be a help to relevant study and engineering application．
In order to reveal the flexural behavior of steel reinforced recycled coarse aggregate concrete beams，6specimens were designed for flexural test． The study considered two impact parameters，which are coarse aggregatereplacement rate and concrete strength grade． Through this test，the whole mechanical process，crack distribution andfailure behavior of this kind of specimens were observed，and obtained the stress-strain distribution curves，theultimate bearing capacity and load-displacement curves parameters． Based on the test data，the impact of coarseaggregate replacement rate and concrete strength grade on the mechanical behavior of steel reinforced recycled coarseaggregate concrete beams was deeply analyzed． The result shows that the replacement rate influences the bearingcapacity of steel reinforced recycled concrete beams，and with replacement rate increases，the bearing capacityincreases from 5. 95% to 17. 63%; during loading process the section strain agreed with the plane sectionassumption，and the beams have good bearing capacity and deformation performance． Finally，put forward normalsection strength calculation method of steel reinforced recycled coarse aggregate concrete beams． The researchconclusions can be a help to relevant study and engineering application．
2013, 43(9): 17-22.
doi: 10.13204/j.gyjz201309003
Abstract:
In order to investigate the seismic behavior of steel recycled concrete short columns，eight specimens ofsteel recycled aggregate concrete short columns were tested under the low-cyclic reversed loading with the cantilevercolumn type equipment． The loading progress and the failure patterns of steel recycled aggregate concrete shortcolumns were observed during the test． The results indicate that the main failure pattern of steel recycled aggregateconcrete short columns with the shear span ratio of 1. 4 is mainly the shear compression failure． The influence of theaxial compression ratio，stirrup ratio and the recycled aggregate replacement rate on the shear capacity of specimenswas studied． The mechanism and failure feature of steel recycled aggregate concrete short columns were analyzed． Theformula for calculating the shear bearing capacity of steel recycled aggregate concrete short columns was deduced． Atlast，a simplified calculating formula for the shear bearing capacity of steel recycled aggregate concrete short columnswas put forward for engineering application． It is shown that the calculation results are in good agreement with the testresults．
In order to investigate the seismic behavior of steel recycled concrete short columns，eight specimens ofsteel recycled aggregate concrete short columns were tested under the low-cyclic reversed loading with the cantilevercolumn type equipment． The loading progress and the failure patterns of steel recycled aggregate concrete shortcolumns were observed during the test． The results indicate that the main failure pattern of steel recycled aggregateconcrete short columns with the shear span ratio of 1. 4 is mainly the shear compression failure． The influence of theaxial compression ratio，stirrup ratio and the recycled aggregate replacement rate on the shear capacity of specimenswas studied． The mechanism and failure feature of steel recycled aggregate concrete short columns were analyzed． Theformula for calculating the shear bearing capacity of steel recycled aggregate concrete short columns was deduced． Atlast，a simplified calculating formula for the shear bearing capacity of steel recycled aggregate concrete short columnswas put forward for engineering application． It is shown that the calculation results are in good agreement with the testresults．
2013, 43(9): 23-29.
doi: 10.13204/j.gyjz201309004
Abstract:
In this paper，it was carried out nonlinear numerical simulation of six axial specimens and nine eccentriccompression specimens of steel reinforced recycled aggregate concrete columns using open-source earthquakeengineering simulation system OpenSees． It was also analysed the effects of the recycled aggregate replacement rate，slenderness ratio and concrete strength on the bearing capacity of the exially loaded specimens，and also analyzed theeffects of the recycled aggregate replacing rate，relative eccentricity and concrete strength on the bearing capacity ofthe eccentrically loaded specimens． In the analyzing process，the column section was fine-divided and different fiberswere defined to simulate the appropriate material properties． And then，a model of SＲＲAC column was establishedbased on the nonlinear beam-column element． The comparative analysis of the simulation results and the experimentalresults indicates that OpenSees Program can be used in simulating the loading process of steel reinforced recycledaggregate concrete columns effectively．
In this paper，it was carried out nonlinear numerical simulation of six axial specimens and nine eccentriccompression specimens of steel reinforced recycled aggregate concrete columns using open-source earthquakeengineering simulation system OpenSees． It was also analysed the effects of the recycled aggregate replacement rate，slenderness ratio and concrete strength on the bearing capacity of the exially loaded specimens，and also analyzed theeffects of the recycled aggregate replacing rate，relative eccentricity and concrete strength on the bearing capacity ofthe eccentrically loaded specimens． In the analyzing process，the column section was fine-divided and different fiberswere defined to simulate the appropriate material properties． And then，a model of SＲＲAC column was establishedbased on the nonlinear beam-column element． The comparative analysis of the simulation results and the experimentalresults indicates that OpenSees Program can be used in simulating the loading process of steel reinforced recycledaggregate concrete columns effectively．
2013, 43(9): 30-34,45.
doi: 10.13204/j.gyjz201309005
Abstract:
Based on the test of seven steel reinforced recycled aggregate concrete (SＲＲC) columns under low-cyclicreversed loading，the lateral bearing capacity and axial compression ratio limit of the steel reinforced recycledaggregate concrete columns were studied． The influences of the axial compression ratio，stirrup ratio and recycledcoarse aggregate replacement rate on the bearing capacity of steel reinforced recycled aggregate concrete column wereanalyzed in this paper． It is shown that the lateral bearing capacity increases and the ductility coefficient reduces asthe increase of the axial compression ratio of the column． The column exhibits good bearing capacity as the increase ofthe stirrup ratio． There is no obvious influence of coarse aggregate replacement rate on the load carrying capacity ofthe column，which shows the same good bearing capacity and ductility as those of ordinary steel reinforced concretecolumn． The axial compression ratio limit of steel reinforced recycled aggregate concrete column was deduced basedon the force balanced condition at balanced failure． Finally，the axial compression ratio limit values of the SＲＲCcolumn under different seismic levels were put forward for engineering design reference in terms of the test data andductility analysis of the specimen．
Based on the test of seven steel reinforced recycled aggregate concrete (SＲＲC) columns under low-cyclicreversed loading，the lateral bearing capacity and axial compression ratio limit of the steel reinforced recycledaggregate concrete columns were studied． The influences of the axial compression ratio，stirrup ratio and recycledcoarse aggregate replacement rate on the bearing capacity of steel reinforced recycled aggregate concrete column wereanalyzed in this paper． It is shown that the lateral bearing capacity increases and the ductility coefficient reduces asthe increase of the axial compression ratio of the column． The column exhibits good bearing capacity as the increase ofthe stirrup ratio． There is no obvious influence of coarse aggregate replacement rate on the load carrying capacity ofthe column，which shows the same good bearing capacity and ductility as those of ordinary steel reinforced concretecolumn． The axial compression ratio limit of steel reinforced recycled aggregate concrete column was deduced basedon the force balanced condition at balanced failure． Finally，the axial compression ratio limit values of the SＲＲCcolumn under different seismic levels were put forward for engineering design reference in terms of the test data andductility analysis of the specimen．
2013, 43(9): 35-39,161.
doi: 10.13204/j.gyjz201309006
Abstract:
Based on the quasi-static test results of 7 steel reinforced recycled aggregate concrete (SＲＲC) columns，the method of calculation of the characteristic parameters was given and thedesignated pointbroken tri-linearrestoring force model for steel reinforced recycled aggregate concrete columns was also proposed by the theoreticalanalysis and experimental data fitting． The results show that the axial compression ratio，stirrup ratio and coarseaggregate replacement rate have little influence on the ratio of ultimate load to yield load，which approximates 0. 8．The ultimate load increases with the increase of axial compression ratio． However，the ductility decreases with theincrease of the coarse aggregate replacement rate and axial compression ratio，yet it increases as the stirrup ratioincreasing． Through the comparison between the test results and the calculated results，the restoring force model canreflect the mechanical performance of SＲＲC components and the results agree well with the test results，indicatingthat the restoring force model can be used for SＲＲC columns．
Based on the quasi-static test results of 7 steel reinforced recycled aggregate concrete (SＲＲC) columns，the method of calculation of the characteristic parameters was given and thedesignated pointbroken tri-linearrestoring force model for steel reinforced recycled aggregate concrete columns was also proposed by the theoreticalanalysis and experimental data fitting． The results show that the axial compression ratio，stirrup ratio and coarseaggregate replacement rate have little influence on the ratio of ultimate load to yield load，which approximates 0. 8．The ultimate load increases with the increase of axial compression ratio． However，the ductility decreases with theincrease of the coarse aggregate replacement rate and axial compression ratio，yet it increases as the stirrup ratioincreasing． Through the comparison between the test results and the calculated results，the restoring force model canreflect the mechanical performance of SＲＲC components and the results agree well with the test results，indicatingthat the restoring force model can be used for SＲＲC columns．
2013, 43(9): 40-45.
doi: 10.13204/j.gyjz201309007
Abstract:
Construction waste can be re-used for a steel reinforced recycled aggregate concrete structure，whosestrength and energy dissipation capacity can be improved． In this paper，nonlinear numerical simulation on sevensteel reinforced recycled aggregate concrete( SＲＲC) columns using open-source earthquake engineering simulationsystem OpenSees was carried out． The load-bearing capacity，ductility and energy dissipation capacity under differentrecycled aggregate replacement rate，axial compression ratio and volumetric stirrup ratio of the columns wereanalyzed． In the modeling process，the column section was fine-divided and different fibers were defined to simulatethe appropriate material properties． And then，an model of SＲＲC column was established based on the nonlinearbeam-column element． The comparative analysis of the simulation results and the experimental results indicated thatthe OpenSees can be used to simulate the loading process of steel reinforced recycled aggregate concrete columns．
Construction waste can be re-used for a steel reinforced recycled aggregate concrete structure，whosestrength and energy dissipation capacity can be improved． In this paper，nonlinear numerical simulation on sevensteel reinforced recycled aggregate concrete( SＲＲC) columns using open-source earthquake engineering simulationsystem OpenSees was carried out． The load-bearing capacity，ductility and energy dissipation capacity under differentrecycled aggregate replacement rate，axial compression ratio and volumetric stirrup ratio of the columns wereanalyzed． In the modeling process，the column section was fine-divided and different fibers were defined to simulatethe appropriate material properties． And then，an model of SＲＲC column was established based on the nonlinearbeam-column element． The comparative analysis of the simulation results and the experimental results indicated thatthe OpenSees can be used to simulate the loading process of steel reinforced recycled aggregate concrete columns．
2013, 43(9): 46-49,115.
doi: 10.13204/j.gyjz201309008
Abstract:
The London Olmpics main stadium design concept is different from that of thenestin Beijing． Its foundation is the research on the sustainable development． The low carbon environment of the site and the circulation of the resources，the seperate structure of the stadium，the natural ventilation are all the reflections of the origion intention of ODA． The stadium improves the neighborhood and reuses the waste and old building resources． Which achieves also the objective that the structure and function could be multi functional．
The London Olmpics main stadium design concept is different from that of thenestin Beijing． Its foundation is the research on the sustainable development． The low carbon environment of the site and the circulation of the resources，the seperate structure of the stadium，the natural ventilation are all the reflections of the origion intention of ODA． The stadium improves the neighborhood and reuses the waste and old building resources． Which achieves also the objective that the structure and function could be multi functional．
2013, 43(9): 50-52,128.
doi: 10.13204/j.gyjz201309009
Abstract:
The emergence of a large number of roadside buildings with the acceleration of urbanization process should attract the attention of the people concerned． As the displayed special products，the influence of the buildings on environments can not be underestimated． Starting with the view point of green buildings，it was compared the existing roadside buildings in various countries and also pointed out the necessity and feasibility of planning，designing and supervising roadside buildings．
The emergence of a large number of roadside buildings with the acceleration of urbanization process should attract the attention of the people concerned． As the displayed special products，the influence of the buildings on environments can not be underestimated． Starting with the view point of green buildings，it was compared the existing roadside buildings in various countries and also pointed out the necessity and feasibility of planning，designing and supervising roadside buildings．
2013, 43(9): 53-58.
doi: 10.13204/j.gyjz201309010
Abstract:
A two-story reinforced recycled aggregates concrete (ＲAC) frame was tested under low-cycle repeatedload． The failure characteristics，hysteretic behavior，skeleton curve，strength degradation，stiffness degradation andenergy dissipation capacity etc． were evaluated． Meanwhile，the change law of the strains on the reinforcement barslocated in columns and beams was also analyzed using the embedded strain gages． The experimental results show thathysteretic curves obtained from the tested ＲAC frame have plump shapes，indicating the ＲAC frame has good energydissipation capacity． No significant decrease was found in bearing capacity when the deformation reached 3. 5 timesthe yield deformation． The seismic performances of ＲAC frame are quite good and the application of ＲAC frame isfeasible for civil engineering structures．
A two-story reinforced recycled aggregates concrete (ＲAC) frame was tested under low-cycle repeatedload． The failure characteristics，hysteretic behavior，skeleton curve，strength degradation，stiffness degradation andenergy dissipation capacity etc． were evaluated． Meanwhile，the change law of the strains on the reinforcement barslocated in columns and beams was also analyzed using the embedded strain gages． The experimental results show thathysteretic curves obtained from the tested ＲAC frame have plump shapes，indicating the ＲAC frame has good energydissipation capacity． No significant decrease was found in bearing capacity when the deformation reached 3. 5 timesthe yield deformation． The seismic performances of ＲAC frame are quite good and the application of ＲAC frame isfeasible for civil engineering structures．
2013, 43(9): 59-64,87.
doi: 10.13204/j.gyjz201309011
Abstract:
In the paper，the connection with steel plate hoop and bolt tendon between the prefabricated concretemembers was put forward． The 1 ∶ 2 scale test models were made for the low cycle-way repeated loading test toresearch the mechanism and failure modes，and work performance of prefabricated components． The contrast of thetest results with the cast-in-situ components validated that the prefabricated component with the new connection hasthe same bending performance and seismic capacity of the cast-in-place components，and the new connection can beused in assembly connection of the beam and column．
In the paper，the connection with steel plate hoop and bolt tendon between the prefabricated concretemembers was put forward． The 1 ∶ 2 scale test models were made for the low cycle-way repeated loading test toresearch the mechanism and failure modes，and work performance of prefabricated components． The contrast of thetest results with the cast-in-situ components validated that the prefabricated component with the new connection hasthe same bending performance and seismic capacity of the cast-in-place components，and the new connection can beused in assembly connection of the beam and column．
2013, 43(9): 65-70,110.
doi: 10.13204/j.gyjz201309012
Abstract:
Because of its own characteristics of a prestressed concrete frame，when prestressed concrete frame isdesigned by the limit of column axial compression ratio in current common reinforced concrete codes，the columnsection size is usually small，an interlayer yielding mechanism will form in the structure so as to suffer the severedamage under earthquake． In the other hand，excess emphasis on the limit of axial compression ratio will lead to thecost up． This paper carried out research on the yielding mechanism of prestressed concrete (PC) frames in differentaxial compression ratios and the effects of axial compression ratio on the seismic capacity of the PC frames designed bythe current codes based on PBSD． The rationality and economy of the limited values of axial compression ratio of thePC frames were discussed． The analysis results show that an improvement of the limited values of axial compressionratio of the PC frames can ensure the seismic capacity of prestressed concrete frame under rare earthquake．
Because of its own characteristics of a prestressed concrete frame，when prestressed concrete frame isdesigned by the limit of column axial compression ratio in current common reinforced concrete codes，the columnsection size is usually small，an interlayer yielding mechanism will form in the structure so as to suffer the severedamage under earthquake． In the other hand，excess emphasis on the limit of axial compression ratio will lead to thecost up． This paper carried out research on the yielding mechanism of prestressed concrete (PC) frames in differentaxial compression ratios and the effects of axial compression ratio on the seismic capacity of the PC frames designed bythe current codes based on PBSD． The rationality and economy of the limited values of axial compression ratio of thePC frames were discussed． The analysis results show that an improvement of the limited values of axial compressionratio of the PC frames can ensure the seismic capacity of prestressed concrete frame under rare earthquake．
2013, 43(9): 71-76,143.
doi: 10.13204/j.gyjz201309013
Abstract:
According to the damage parameters of reinforcement and concrete and considering effective prestressingloss of prestressing tendon，the damage model was established，then based on ANSYSsecond developmenttechnology the full-range fatigue analysis of partially prestressed concrete beams was carried out． The calculatingresults compared with the experimental results shown that it fit favorably with the experimental results within theaccepted limits，and that this model can reflect the mechanical properties of partially prestressed concrete beams withfatigue loading． It provided reliable and efficient method for simulating fatigue behavior of such sorts of beams forpractical projects．
According to the damage parameters of reinforcement and concrete and considering effective prestressingloss of prestressing tendon，the damage model was established，then based on ANSYSsecond developmenttechnology the full-range fatigue analysis of partially prestressed concrete beams was carried out． The calculatingresults compared with the experimental results shown that it fit favorably with the experimental results within theaccepted limits，and that this model can reflect the mechanical properties of partially prestressed concrete beams withfatigue loading． It provided reliable and efficient method for simulating fatigue behavior of such sorts of beams forpractical projects．
2013, 43(9): 77-82,100.
doi: 10.13204/j.gyjz201309014
Abstract:
A comparison of the provisions for punching shear capacity calculations of reinforced concrete slab wasstudied based on China code(GB 50010 － 2010)，ACI 318 － 08 and EN 1992 － 1 － 1:2004． The effects of concretestrength，shape and dimensions of loading，longitudinal reinforcement ratio，reinforcement lagout on the punchingshear capacity were studied． According to experimental results of 423 specimens，calculated values and experimentalvalues of the punching shear capacity were compared and analyzed for different codes． The results indicate thatbecause of the consideration of longitudinal reinforcement ratios effect on punching failure capacity in Europe code，the calculated values of Europe code are more reasonable，and are the highest ones，and those by China code are thelowest ones．
A comparison of the provisions for punching shear capacity calculations of reinforced concrete slab wasstudied based on China code(GB 50010 － 2010)，ACI 318 － 08 and EN 1992 － 1 － 1:2004． The effects of concretestrength，shape and dimensions of loading，longitudinal reinforcement ratio，reinforcement lagout on the punchingshear capacity were studied． According to experimental results of 423 specimens，calculated values and experimentalvalues of the punching shear capacity were compared and analyzed for different codes． The results indicate thatbecause of the consideration of longitudinal reinforcement ratios effect on punching failure capacity in Europe code，the calculated values of Europe code are more reasonable，and are the highest ones，and those by China code are thelowest ones．
2013, 43(9): 83-87.
doi: 10.13204/j.gyjz201309015
Abstract:
The objective of this study is to investigate the effect of domestic pollution on hydrophysical andmechanical properties of cohesive soils． Initially，cohesive soils polluted by various concentrations of sodium chloride(NaCl)，sodium carbonate (Na2CO3) and ammonium chloride (NH4Cl) were precisely prepared through immersiontests． Then，the variation of plasticity，permeability，compressibility and shear strength of polluted cohesive soils withincreasing pollution degrees was determined through geotechnical tests． Finally，the evolution mechanisms of thehydrophysical and mechanical properties of polluted cohesive soils were discussed． The study showed that an increasein plasticity and compressibility as well as a decrease in permeability and shear strength of cohesive soils was causedby the pollution of NaCl and Na2CO3 ． Conversely，a decrease in plasticity and compressibility as well as an increase in permeability and shear strength of cohesive soils was contributed to the pollution of NH4Cl． Meanwhile，thevariation rate of the physical and mechanical properties of clay was much higher than that of silty clay． Domesticpollutants might provide an important effect on the hydrophysical and mechanical properties through the transformationof the double electrode layer structure on clay particles．
The objective of this study is to investigate the effect of domestic pollution on hydrophysical andmechanical properties of cohesive soils． Initially，cohesive soils polluted by various concentrations of sodium chloride(NaCl)，sodium carbonate (Na2CO3) and ammonium chloride (NH4Cl) were precisely prepared through immersiontests． Then，the variation of plasticity，permeability，compressibility and shear strength of polluted cohesive soils withincreasing pollution degrees was determined through geotechnical tests． Finally，the evolution mechanisms of thehydrophysical and mechanical properties of polluted cohesive soils were discussed． The study showed that an increasein plasticity and compressibility as well as a decrease in permeability and shear strength of cohesive soils was causedby the pollution of NaCl and Na2CO3 ． Conversely，a decrease in plasticity and compressibility as well as an increase in permeability and shear strength of cohesive soils was contributed to the pollution of NH4Cl． Meanwhile，thevariation rate of the physical and mechanical properties of clay was much higher than that of silty clay． Domesticpollutants might provide an important effect on the hydrophysical and mechanical properties through the transformationof the double electrode layer structure on clay particles．
2013, 43(9): 88-91.
doi: 10.13204/j.gyjz201309016
Abstract:
To analyze and forecast sea wall working state，a sea wall monitoring model was established by thefollowing steps: selecting former tidewater factor，integral rain factor and time effect factor based on causality study，using radial basis function ( ＲBF ) artificial neural network as modeling tool， considering monitoring datacharacteristics，and using fuzzy C-mean algorithm(FCM) to confirm ＲBF centers． And then，the forecast of sea wallworking state was realized by the methods below: errors of the model were studied，including error values，trend anddistribution，based on these，a hypothesis testing method was presented to evaluate forecast results consideringconfidence level，and stabilities of different forecast length was compared on a same confidence level，finally theinstance model were set up，the training and forecast effects were analyzed．
To analyze and forecast sea wall working state，a sea wall monitoring model was established by thefollowing steps: selecting former tidewater factor，integral rain factor and time effect factor based on causality study，using radial basis function ( ＲBF ) artificial neural network as modeling tool， considering monitoring datacharacteristics，and using fuzzy C-mean algorithm(FCM) to confirm ＲBF centers． And then，the forecast of sea wallworking state was realized by the methods below: errors of the model were studied，including error values，trend anddistribution，based on these，a hypothesis testing method was presented to evaluate forecast results consideringconfidence level，and stabilities of different forecast length was compared on a same confidence level，finally theinstance model were set up，the training and forecast effects were analyzed．
2013, 43(9): 92-95.
doi: 10.13204/j.gyjz201309017
Abstract:
The precise integration method is an accurate numerical method for solving first-order differentialequations． The fundamental governing equations of layered elastic foundation were introduced into the duality system，and governing equations were represented as Hamilton canonical equations in the frequency-wave number domain．Based on which，a new method was proposed to solve dynamic flexibility of layered elastic foundation． The segmentmatrix of micro layer was obtained by using the precise integration method，and then，through merging segment matrixof micro layer，it was evaluated the segment matrix of the whole foundation． Finally，the dynamic flexibility of layeredelastic foundation was calculated by incorporating the radiation condition of boundary into the segment matrix of thewhole foundation． In the end，accuracy of the method was verified by numerical examples．
The precise integration method is an accurate numerical method for solving first-order differentialequations． The fundamental governing equations of layered elastic foundation were introduced into the duality system，and governing equations were represented as Hamilton canonical equations in the frequency-wave number domain．Based on which，a new method was proposed to solve dynamic flexibility of layered elastic foundation． The segmentmatrix of micro layer was obtained by using the precise integration method，and then，through merging segment matrixof micro layer，it was evaluated the segment matrix of the whole foundation． Finally，the dynamic flexibility of layeredelastic foundation was calculated by incorporating the radiation condition of boundary into the segment matrix of thewhole foundation． In the end，accuracy of the method was verified by numerical examples．
2013, 43(9): 96-100.
doi: 10.13204/j.gyjz201309018
Abstract:
The design guiding ideology of precast self-draining pile was proposed，and the pile-sinking drainage effectof precast self-draining pile was examined through the indoor test and field test，and then the pile body bearingcapacity and vertical bearing capacity of a single pile of precast self-draining pile were experimentally studied． Theresults showed that as compared with an ordinary square pile，precast self-draining pile had good drainage properties，and its pile-side sand channel could play the role in vertical offset well，especially the precast self-draining pile withthe ＜ -shaped side channel． At the same time，from the perspective of pile body bearing capacity and its liftingsecurity，precast self-draining pile could meet the operating requirements better using side channel and angular pointto control protective layer． The vertical bearing capacity of a single pile of precast self-draining pile was slightlyhigher than that of the ordinary square pile，due to the faster consolidation speed of the soil around the pile．
The design guiding ideology of precast self-draining pile was proposed，and the pile-sinking drainage effectof precast self-draining pile was examined through the indoor test and field test，and then the pile body bearingcapacity and vertical bearing capacity of a single pile of precast self-draining pile were experimentally studied． Theresults showed that as compared with an ordinary square pile，precast self-draining pile had good drainage properties，and its pile-side sand channel could play the role in vertical offset well，especially the precast self-draining pile withthe ＜ -shaped side channel． At the same time，from the perspective of pile body bearing capacity and its liftingsecurity，precast self-draining pile could meet the operating requirements better using side channel and angular pointto control protective layer． The vertical bearing capacity of a single pile of precast self-draining pile was slightlyhigher than that of the ordinary square pile，due to the faster consolidation speed of the soil around the pile．
2013, 43(9): 101-105,119.
doi: 10.13204/j.gyjz201309019
Abstract:
The K7 + 914 － K7 + 984 segment of deep foundation pit in the Purui Tunnel is adjacent to the 12-layerbuilding，in order to determine the design and construction safety of deep foundation pit，the structure of pile-anchorsupport was used． The 5. 3 calculation software was adopted for the calculation of foundation pit structure，at the sametime the Midas numerical calculation software was also used to simulate excavation of the foundation pit ，the datashows that the foundation pit is safe． It was checked the anti floating computation of the main structure of foundationpit ，the floating resistance value can meet the standard requirements without the need for anti floating design offoundation pit．
The K7 + 914 － K7 + 984 segment of deep foundation pit in the Purui Tunnel is adjacent to the 12-layerbuilding，in order to determine the design and construction safety of deep foundation pit，the structure of pile-anchorsupport was used． The 5. 3 calculation software was adopted for the calculation of foundation pit structure，at the sametime the Midas numerical calculation software was also used to simulate excavation of the foundation pit ，the datashows that the foundation pit is safe． It was checked the anti floating computation of the main structure of foundationpit ，the floating resistance value can meet the standard requirements without the need for anti floating design offoundation pit．
EXPERIMENTAL DETERMINATION OF FRACTURE TOUGHNESS OF THREE-POINT BENDING UHPCC BEAM AND INFLUENCE LAW
2013, 43(9): 106-110.
doi: 10.13204/j.gyjz201309020
Abstract:
Through the tests of 14 sets of three-point bending UHPCC beam specimens with the different compressivestrength，sizes and initial crack-depth ratios，their double-K fracture parameters are studied． The initial fracturetoughness KiniIC and unstable fracture toughness KunIC are calculated from the initial load Pini，the maximum load Pmax andcritical crack mouth open displacement CMODC ． The results indicate that the KiniIC and KiniIC of UHPCC and cementbasedspecimens increase with the increasing of compressive strength． The KiniIC and KunIC of UHPCC significantlyincrease with the decrease of initial crack-depth ratio，but the KiniIC (KunIC ) of cement-based specimens increase a little．The KiniIC and KunIC of UHPCC significantly increase with the increase of specimen size，but that of cement-basedspecimens present some discreteness．
Through the tests of 14 sets of three-point bending UHPCC beam specimens with the different compressivestrength，sizes and initial crack-depth ratios，their double-K fracture parameters are studied． The initial fracturetoughness KiniIC and unstable fracture toughness KunIC are calculated from the initial load Pini，the maximum load Pmax andcritical crack mouth open displacement CMODC ． The results indicate that the KiniIC and KiniIC of UHPCC and cementbasedspecimens increase with the increasing of compressive strength． The KiniIC and KunIC of UHPCC significantlyincrease with the decrease of initial crack-depth ratio，but the KiniIC (KunIC ) of cement-based specimens increase a little．The KiniIC and KunIC of UHPCC significantly increase with the increase of specimen size，but that of cement-basedspecimens present some discreteness．
2013, 43(9): 111-115.
doi: 10.13204/j.gyjz201309021
Abstract:
After most of the mountain tunnels in China entered into service stage，all of them had different degrees ofdiseases． Especially when the tunnel was in an area with rich groundwater，serious cracks，leakage，dissolution andchemical etching occurred in the tunnel structures． The primary reason leading to the tunnel structure durabilitydeficiency is the poor property of the cementitious material which is basically composed of Portland cement，and theingredient of the cementitious material is very single，has poor grade and quality． Improving the performances of theraw materials is a radical method to solve the tunnel structure durability problems． So it was suggested that multiplecomposite cementitious materials should be used to prepare high-performance concrete，and separate grinding andcollective distribution should be used for the main powder materials of the composite cementitious materials． Theexperimental study show that the high-performance concrete，which is prepared by the composite cementitiousmaterials，has excellent work performance，mechanical property and durability，and at the same time it has thevirtues of energy conservation，environmental protection and cost reduction．
After most of the mountain tunnels in China entered into service stage，all of them had different degrees ofdiseases． Especially when the tunnel was in an area with rich groundwater，serious cracks，leakage，dissolution andchemical etching occurred in the tunnel structures． The primary reason leading to the tunnel structure durabilitydeficiency is the poor property of the cementitious material which is basically composed of Portland cement，and theingredient of the cementitious material is very single，has poor grade and quality． Improving the performances of theraw materials is a radical method to solve the tunnel structure durability problems． So it was suggested that multiplecomposite cementitious materials should be used to prepare high-performance concrete，and separate grinding andcollective distribution should be used for the main powder materials of the composite cementitious materials． Theexperimental study show that the high-performance concrete，which is prepared by the composite cementitiousmaterials，has excellent work performance，mechanical property and durability，and at the same time it has thevirtues of energy conservation，environmental protection and cost reduction．
2013, 43(9): 116-119.
doi: 10.13204/j.gyjz201309022
Abstract:
From the standpoint of applicability design of large crawler crane for the third generation nuclear powerunit，considering the better economics and construction safety，it was analysed type selection，disposal of workingfield，and overhang method of large crawler cranes based on full utilization of the capacity and effective reduction ofthe groud bearing pressure，which can not only improve the construction efficiency but also reduce the cost ofconstruction． This paper can provide experience for improving the applicability design of large crawler crane forconstruction of the successive AP1000 series nuclear power unit．
From the standpoint of applicability design of large crawler crane for the third generation nuclear powerunit，considering the better economics and construction safety，it was analysed type selection，disposal of workingfield，and overhang method of large crawler cranes based on full utilization of the capacity and effective reduction ofthe groud bearing pressure，which can not only improve the construction efficiency but also reduce the cost ofconstruction． This paper can provide experience for improving the applicability design of large crawler crane forconstruction of the successive AP1000 series nuclear power unit．
2013, 43(9): 120-123,148.
doi: 10.13204/j.gyjz201309023
Abstract:
Using the compactness of sandy pebble as main parameter，static experimental study on the axialcompressive mechanical property of ten sandy-pebble-filled thin-walled square steel tubular columns，was carried outto analyze comparatively the load-carrying capacity，the load-strain curves，failure characteristics and mechanism ofdifferent test specimens． The experimental results indicate that the load-carrying capacities of empty and lowcompactnesssandy-pebble-filled thin-walled square steel tubular column were low，local buckling of tube walloccurred prior to steel yielding，resulting in steel performance failing to get into full play． Compared with square steeltubular stub columns that mentioned above，the co-action of the higher-compactness sandy pebble and tube wall caneffectively delay the local bucking of steel tube wall and enhance greatly the ultimate load-carrying capacity andimprove the global stability of the columns． And whats more，this new type of composite column has good repeatableutilization，as well as economic and environmental characteristics．
Using the compactness of sandy pebble as main parameter，static experimental study on the axialcompressive mechanical property of ten sandy-pebble-filled thin-walled square steel tubular columns，was carried outto analyze comparatively the load-carrying capacity，the load-strain curves，failure characteristics and mechanism ofdifferent test specimens． The experimental results indicate that the load-carrying capacities of empty and lowcompactnesssandy-pebble-filled thin-walled square steel tubular column were low，local buckling of tube walloccurred prior to steel yielding，resulting in steel performance failing to get into full play． Compared with square steeltubular stub columns that mentioned above，the co-action of the higher-compactness sandy pebble and tube wall caneffectively delay the local bucking of steel tube wall and enhance greatly the ultimate load-carrying capacity andimprove the global stability of the columns． And whats more，this new type of composite column has good repeatableutilization，as well as economic and environmental characteristics．
2013, 43(9): 124-128.
doi: 10.13204/j.gyjz201309024
Abstract:
A 41.5m span steel transport corridor for feeding system between B1 － B2 transfer stations in PTKE GroupCo． was studied in this paper，especially temperature and bearer forms effects on the corridor were given，the modalshapes and dynamic response of the corridor were calculated． The results show that for a large span steel transportcorridor with one end fixed and one end sliding rubber bearer can reduce the adverse effects of temperature stress onmember internal forces，the short bracing arranged in cross-sections can greatly improve the overall stiffness andreduce lateral deformation of the corridor．
A 41.5m span steel transport corridor for feeding system between B1 － B2 transfer stations in PTKE GroupCo． was studied in this paper，especially temperature and bearer forms effects on the corridor were given，the modalshapes and dynamic response of the corridor were calculated． The results show that for a large span steel transportcorridor with one end fixed and one end sliding rubber bearer can reduce the adverse effects of temperature stress onmember internal forces，the short bracing arranged in cross-sections can greatly improve the overall stiffness andreduce lateral deformation of the corridor．
2013, 43(9): 129-133,139.
doi: 10.13204/j.gyjz201309025
Abstract:
For large-span steel structure with transparent materials，or the one is outdoor，its temperature is usuallynot only higher than the corresponding ambient temperature，but also very non-uniform under solar radiation．Therefore，the high non-uniform temperature is the control load for the large-span steel structures． However，there areno definite and scientific bases for determining the thermal load in current codes and published papers． Combinedwith an actual project of a bi-directional beam string structure，the numerical simulation method for the temperaturefield analysis of steel structures under solar radiation was established． The temperature distribution and the thermalload response were also analyzed．
For large-span steel structure with transparent materials，or the one is outdoor，its temperature is usuallynot only higher than the corresponding ambient temperature，but also very non-uniform under solar radiation．Therefore，the high non-uniform temperature is the control load for the large-span steel structures． However，there areno definite and scientific bases for determining the thermal load in current codes and published papers． Combinedwith an actual project of a bi-directional beam string structure，the numerical simulation method for the temperaturefield analysis of steel structures under solar radiation was established． The temperature distribution and the thermalload response were also analyzed．
2013, 43(9): 134-139.
doi: 10.13204/j.gyjz201309026
Abstract:
The uses of special shaped steel coal scuttles are gradually increased in the modern industrial field，butthey bear more complicated forces than the regular ones． Which can be analyzed by FEA，and the results are differentbecause of varying the mesh from coarse to fine． It was proposed a reasonable mesh division method by comparing theresults among different grid-making between Powergraphics and Fullgraphics． Further studies and comparisons indicatethat the mesh division method is reasonable under considering the influence of nonlinear materials． Additionally，theinfluence on force property of special shaped steel coal scuttle caused by horizontal stiffening ribs was also studied． Itwas found that the effect was more pronounced on improving the force property of special shaped steel coal scuttle byincreasing the depth of rib section than increasing its width．
The uses of special shaped steel coal scuttles are gradually increased in the modern industrial field，butthey bear more complicated forces than the regular ones． Which can be analyzed by FEA，and the results are differentbecause of varying the mesh from coarse to fine． It was proposed a reasonable mesh division method by comparing theresults among different grid-making between Powergraphics and Fullgraphics． Further studies and comparisons indicatethat the mesh division method is reasonable under considering the influence of nonlinear materials． Additionally，theinfluence on force property of special shaped steel coal scuttle caused by horizontal stiffening ribs was also studied． Itwas found that the effect was more pronounced on improving the force property of special shaped steel coal scuttle byincreasing the depth of rib section than increasing its width．
2013, 43(9): 140-143.
doi: 10.13204/j.gyjz201309027
Abstract:
The roof structure of huge main pipe truss + second plane truss was used in final phase /flight line hangarin Tianjin Airbus A320 project． A high-strength bolt-plate connection in the main pipe truss was firstly used at home．In this paper，the mechanical features of the structure were analyzed; the design of high-strength bolt-plateconnections in pipe truss was introduced in detail． The design and construction of this hangar demonstrates that themechanical features were simple and definite for the main-second truss system，the construction of the high-strengthbolt plate connections in pipe truss is simple，which can shorten the construction time．
The roof structure of huge main pipe truss + second plane truss was used in final phase /flight line hangarin Tianjin Airbus A320 project． A high-strength bolt-plate connection in the main pipe truss was firstly used at home．In this paper，the mechanical features of the structure were analyzed; the design of high-strength bolt-plateconnections in pipe truss was introduced in detail． The design and construction of this hangar demonstrates that themechanical features were simple and definite for the main-second truss system，the construction of the high-strengthbolt plate connections in pipe truss is simple，which can shorten the construction time．
2013, 43(9): 144-148.
doi: 10.13204/j.gyjz201309028
Abstract:
A general damage detecting and safety appraisal of Xidan No. 4 aluminum overpass were done for realizingits technological safety conditions and supporting reference for related safety appraisal of aluminum bridge structures，including the visual detecting，calculation using finite element method，experiment under static load and dynamicproperty measurement． The detecting results showed that the bearing capacity of the overpass could meet therequirements of the design． However，the safety margin and the stiffness were not enough． Some appropriatereinforcement measures should be taken to ensure the safety of the overpass under some special situations such asintensive crowds and emergency evacuation．
A general damage detecting and safety appraisal of Xidan No. 4 aluminum overpass were done for realizingits technological safety conditions and supporting reference for related safety appraisal of aluminum bridge structures，including the visual detecting，calculation using finite element method，experiment under static load and dynamicproperty measurement． The detecting results showed that the bearing capacity of the overpass could meet therequirements of the design． However，the safety margin and the stiffness were not enough． Some appropriatereinforcement measures should be taken to ensure the safety of the overpass under some special situations such asintensive crowds and emergency evacuation．
2013, 43(9): 149-153,168.
doi: 10.13204/j.gyjz201309029
Abstract:
The results of 6 sets of tests showed that the main body structure of primary member in the generalindustrial and civil building after reinforced by steel fiber ferrocement mortar，reinforcement layer and originalstructure could work together effectively，bearing capacity was greatly improved，mode of component failure changedto ductile failure and crack also came to be fine and den． According to the actual conditions of a project and optionaltransformation reinforcement scheme，all together 14 technical and economic indexes，including strengthening layerthickness，direct construction cost and environmental protection effect，etc were selected to determine the weight ofeach index by entropy decision and finally fuzzy comprehensive evaluation was used to judge three design programs，itwas found that steel fiber ferrocement mortar was a strengthening method with good technical performance，reasonableeconomic costs and dominant comprehensive value．
The results of 6 sets of tests showed that the main body structure of primary member in the generalindustrial and civil building after reinforced by steel fiber ferrocement mortar，reinforcement layer and originalstructure could work together effectively，bearing capacity was greatly improved，mode of component failure changedto ductile failure and crack also came to be fine and den． According to the actual conditions of a project and optionaltransformation reinforcement scheme，all together 14 technical and economic indexes，including strengthening layerthickness，direct construction cost and environmental protection effect，etc were selected to determine the weight ofeach index by entropy decision and finally fuzzy comprehensive evaluation was used to judge three design programs，itwas found that steel fiber ferrocement mortar was a strengthening method with good technical performance，reasonableeconomic costs and dominant comprehensive value．
2013, 43(9): 154-157.
doi: 10.13204/j.gyjz201309030
Abstract:
It is more difficult to rectity and reinforce a building tilting along long-axis direction than to rectify and reinforce the one tilting along short-axis direction． For a building tilting along long-axis direction in soft soil area，the method of drawing out soil was used for two wings and the top of the raising side，and the static press pile of anchorage was used for the overturning side，by which the tilted building was successfully rectified，and satisfactory results were obtained． Which may provide reference and experience for design and construction of rectifying and reinforcing tilted houses in similar regions．
It is more difficult to rectity and reinforce a building tilting along long-axis direction than to rectify and reinforce the one tilting along short-axis direction． For a building tilting along long-axis direction in soft soil area，the method of drawing out soil was used for two wings and the top of the raising side，and the static press pile of anchorage was used for the overturning side，by which the tilted building was successfully rectified，and satisfactory results were obtained． Which may provide reference and experience for design and construction of rectifying and reinforcing tilted houses in similar regions．
2013, 43(9): 158-161.
doi: 10.13204/j.gyjz201309031
Abstract:
The development of contemporary test buildings is toward multifunction，complex technology and flexible use of spaces． By introducing the design concept of Zhengzhou University Center for Safety Evaluation of Drugs，it was analysed the way of reasonable layout and elaborate design in complex architectural design process，and how to create a quality building with rational and cultural connotation．
The development of contemporary test buildings is toward multifunction，complex technology and flexible use of spaces． By introducing the design concept of Zhengzhou University Center for Safety Evaluation of Drugs，it was analysed the way of reasonable layout and elaborate design in complex architectural design process，and how to create a quality building with rational and cultural connotation．
2013, 43(9): 162-164.
doi: 10.13204/j.gyjz201309032
Abstract:
Qingdao Wanlihaijing project is a large-scale integrated project including luxury houses，apartments andcommercial rooms． Located in the interchange of the new and old urban areas in Qingdao City，it is an importantbuilding in the city landscape node． Architectural design concept comes from unique conception ofsailing city．Three sail-shaped towers with different heights form graceful shape，whose plane is formed by the shape ofYinterlocking side by side，which can not only try to get the south sea view but also can avoid the other unit windows．Overhead lobby of one layer ensures the transparent of view of the sea． The whole building is harmonious with thesurrounding mountains，sea and city． In addition，the controlling of building height，reasonable layout of the planefunction，coupled with intelligent technology and design detail make the building become a new landmark in Qingdao．
Qingdao Wanlihaijing project is a large-scale integrated project including luxury houses，apartments andcommercial rooms． Located in the interchange of the new and old urban areas in Qingdao City，it is an importantbuilding in the city landscape node． Architectural design concept comes from unique conception ofsailing city．Three sail-shaped towers with different heights form graceful shape，whose plane is formed by the shape ofYinterlocking side by side，which can not only try to get the south sea view but also can avoid the other unit windows．Overhead lobby of one layer ensures the transparent of view of the sea． The whole building is harmonious with thesurrounding mountains，sea and city． In addition，the controlling of building height，reasonable layout of the planefunction，coupled with intelligent technology and design detail make the building become a new landmark in Qingdao．
2013, 43(9): 165-168.
doi: 10.13204/j.gyjz201309033
Abstract:
Due to the fact that the production of Cast-in-place reinforced concrete has some disadvantages，such aslong construction period and quality instability，etc． A prefabricated composite shear wall structure system was usedin No． 27 building of WankeJin Yu Lan Wan; also the experiments and exploration were carried out in theconstruction of precast wall panels、segmentation，waterproof． It was expected to provide reference for the design ofprefabricated shear wall high-rise residential in the future．
Due to the fact that the production of Cast-in-place reinforced concrete has some disadvantages，such aslong construction period and quality instability，etc． A prefabricated composite shear wall structure system was usedin No． 27 building of WankeJin Yu Lan Wan; also the experiments and exploration were carried out in theconstruction of precast wall panels、segmentation，waterproof． It was expected to provide reference for the design ofprefabricated shear wall high-rise residential in the future．
2013, 43(9): 169-171.
doi: 10.13204/j.gyjz201309034
Abstract:
Based on the analysis of old town decline，it was pointed out the significance that maintains the old townattraction． According to the function and value of urban square in the old town，it was also clarified the significancethat urban square construction to the old town regeneration． It was further analyzed the square design strategies on theurban squares layout in the old town，and the relationship to the old buildings etc．
Based on the analysis of old town decline，it was pointed out the significance that maintains the old townattraction． According to the function and value of urban square in the old town，it was also clarified the significancethat urban square construction to the old town regeneration． It was further analyzed the square design strategies on theurban squares layout in the old town，and the relationship to the old buildings etc．
