The development of each work is inseparable from the management, the quality of the work and the management level is closely related, especially in some production operations, the safety management work occupies an im...The development of each work is inseparable from the management, the quality of the work and the management level is closely related, especially in some production operations, the safety management work occupies an important position, is an important measure to ensure safe production. In recent years, the TBM tunnel has been more and more widely used, and the related production of precast concrete pipe segments has also gradually developed towards standardization and standardization.Combined on the author's work experience of the author, this paper analyzes the production safety management of precast concrete segments and explores the details of safety management from all angles.展开更多
The quality of segment is very important to the service life of shield tunnel.Concerning the complex engineering environment of the Wuhan Yangtze River Shield Tunnel,the principle of functionally graded materials was ...The quality of segment is very important to the service life of shield tunnel.Concerning the complex engineering environment of the Wuhan Yangtze River Shield Tunnel,the principle of functionally graded materials was introduced to design and produce the functionally graded concrete segment(FGCS).Its key manufacturing technique was proposed and its performance was tested.展开更多
The comparative research on the seismic performance of grouted sleeve connected pier(GS)and prestressed precast segmental concrete pier(PC)is mostly carried out by numerical simulation.In this study,the GS pier and th...The comparative research on the seismic performance of grouted sleeve connected pier(GS)and prestressed precast segmental concrete pier(PC)is mostly carried out by numerical simulation.In this study,the GS pier and the PC pier of the new railway project from Hetian to Ruoqiang are taken into consideration.Two kinds of 1/5-scale assembled double-column specimens are made,and the quasi-static tests are carried out.The overall seismic performance of the two spliced piers is studied,and compared in terms of failure mechanism,bearing capacity,ductility,stiffness and energy dissipation capacity.The results show that the failure modes of both GS pier and PC pier are characterized by bending.However,the specific failure location and form are different.The GS pier presents a complete hysteretic curve,large equivalent stiffness and strong energy dissipation capacity.The hysteretic area of the PC pier is small.However,it has good self-reset ability and quasi-static residual displacement.Finite element models are set up using DispBeamColumn fiber elements and ZeroLength elements.The models that are calibrated with the test data can effectively simulate the damage development under monotonic loading.The load−displacement curves are in good agreement with the backbone curves of the test results.展开更多
The influence of polypropylene fiber on the flexural fatigue performance of high-strength concrete (HSC), which could be used as cover of reinforcement of segment, was investigate by three-point load bending tests. Al...The influence of polypropylene fiber on the flexural fatigue performance of high-strength concrete (HSC), which could be used as cover of reinforcement of segment, was investigate by three-point load bending tests. Also, the flexural fatigue equations of high-strength concrete with and without polypropylene fiber were established through test analysis. The experimental results indicate that the addition of polypropylene fiber can improve the static bending strength of segment concrete, and the important is that it can markedly increase the flexural fatigue performance of the HSC subjected to cyclic bending load. Especially when with 1.37 kg/m3 addition of the fiber was corporate with silica fume and slag powder, the fatigue life of the HSC can be increased by 43.4% compared to that of the segment concrete without fiber, silica fume and slag.展开更多
文摘The development of each work is inseparable from the management, the quality of the work and the management level is closely related, especially in some production operations, the safety management work occupies an important position, is an important measure to ensure safe production. In recent years, the TBM tunnel has been more and more widely used, and the related production of precast concrete pipe segments has also gradually developed towards standardization and standardization.Combined on the author's work experience of the author, this paper analyzes the production safety management of precast concrete segments and explores the details of safety management from all angles.
文摘The quality of segment is very important to the service life of shield tunnel.Concerning the complex engineering environment of the Wuhan Yangtze River Shield Tunnel,the principle of functionally graded materials was introduced to design and produce the functionally graded concrete segment(FGCS).Its key manufacturing technique was proposed and its performance was tested.
基金Project(N2018G034)supported by China Railway Corporation。
文摘The comparative research on the seismic performance of grouted sleeve connected pier(GS)and prestressed precast segmental concrete pier(PC)is mostly carried out by numerical simulation.In this study,the GS pier and the PC pier of the new railway project from Hetian to Ruoqiang are taken into consideration.Two kinds of 1/5-scale assembled double-column specimens are made,and the quasi-static tests are carried out.The overall seismic performance of the two spliced piers is studied,and compared in terms of failure mechanism,bearing capacity,ductility,stiffness and energy dissipation capacity.The results show that the failure modes of both GS pier and PC pier are characterized by bending.However,the specific failure location and form are different.The GS pier presents a complete hysteretic curve,large equivalent stiffness and strong energy dissipation capacity.The hysteretic area of the PC pier is small.However,it has good self-reset ability and quasi-static residual displacement.Finite element models are set up using DispBeamColumn fiber elements and ZeroLength elements.The models that are calibrated with the test data can effectively simulate the damage development under monotonic loading.The load−displacement curves are in good agreement with the backbone curves of the test results.
基金Funded by the National "863" Program (No.2005AA332010)
文摘The influence of polypropylene fiber on the flexural fatigue performance of high-strength concrete (HSC), which could be used as cover of reinforcement of segment, was investigate by three-point load bending tests. Also, the flexural fatigue equations of high-strength concrete with and without polypropylene fiber were established through test analysis. The experimental results indicate that the addition of polypropylene fiber can improve the static bending strength of segment concrete, and the important is that it can markedly increase the flexural fatigue performance of the HSC subjected to cyclic bending load. Especially when with 1.37 kg/m3 addition of the fiber was corporate with silica fume and slag powder, the fatigue life of the HSC can be increased by 43.4% compared to that of the segment concrete without fiber, silica fume and slag.
