预应力混凝土简支箱梁足尺模型试验及非线性全过程分析

对一片30 m跨的预应力混凝土小箱梁和一片20 m跨的预应力混凝土空心板进行了足尺模型试验，破坏模式分别为预应力筋拉断和顶板混凝土压碎，按能量的观点计算的延性指标小箱梁和空心板分别为1.99和1.23。基于平截面假定，采用有限条带法编制了非线性计算程序，可对包括卸载过程在内的全过程受力性能进行分析。重点介绍了卸载曲线如何在应力-应变、弯矩-曲率及荷载-位移3个层面进行计算。通过程序，对预应力筋配筋量、预应力筋张拉系数对结构的承载力、变形性能及延性的影响进行了分析。

Full scale model tests and nonlinear analysis of prestressed concretesimply supported box girders

Full scale model tests were carried out on a 30 m span prestressed concrete box girder and a 20 m span prestressed concrete hollow slab. Failure models were prestressed reinforcement tensile failure and crushing of roof concrete, respectively. The ductility indexes of the box girder and hollow slab were 1.99, 1.23, respectively according to the energy viewpoint. Based on the horizontal section hypothesis, the nonlinear computation procedure was established using the limited banding law, and it could carry out the entire performance analysis including the unloading, mainly focusing on how to achieve the unloading curves computation through stress-strain, moment-curvature and load-displacement curves. Through the procedure, parameters that influence on the bearing capacity, deformation performance and ductility of the structures were analyzed. Those parameters were quantity of prestressed reinforcement and tension coefficients of prestressed reinforcement.