PVC-FRP管钢筋混凝土梁受力机理及设计方法研究

This project takes the PVC-FRP confined reinforced concrete beam as the research object, and adopts the method of combining the model test, the theoretical analysis and the numerical simulation, the flexural behavior of PVC-FRP confined reinforced concrete beam is studied, the boundary condition of members under different bending failure modes is determined, the conditions for ductile failure of members are given; and the calculation method of flexural bearing capacity, stiffness, ductility and load-deflection relationship of members is put forward. The shear behavior of PVC-FRP confined reinforced concrete beam is studied, the failure mode and shear mechanism of members are revealed, and the boundary conditions of members under different shear failure modes are determined; a calculation model for shear bearing capacity of members is put forward, and the related calculation theory for shear-deformation relationship of members are established. The failure mode and energy dissipation mechanism of PVC-FRP confined reinforced concrete beam under low cyclic loading is studied, and the boundary state of members under different seismic failure modes is determined; the calculation method of the bearing capacity, stiffness degradation, ductility coefficient and skeleton curve of members is put forward, and the restoring force model of members is established. The design method of PVC-FRP confined reinforced concrete beam is studied, and the control objectives, control conditions, design calculation methods and construction measures are proposed. The research results provide a scientific basis for the design of PVC-FRP confined concrete structure and its application in engineering, and also promote the development of composite structure system.

本项目以PVC-FRP管钢筋混凝土梁为研究对象，采用模型试验、理论分析与数值模拟相结合的方法，研究PVC-FRP管钢筋混凝土梁抗弯性能，确定构件在不同受弯破坏模式下的界限状态，给出构件发生延性破坏条件；提出构件抗弯承载力、刚度、延性及荷载-挠度关系计算方法。研究PVC-FRP管钢筋混凝土梁抗剪性能，揭示构件破坏模式与抗剪机理，确定构件在不同剪切破坏形态下的界限条件；提出构件抗剪承载力计算模型，建立构件剪力-变形计算理论。研究低周反复荷载作用下PVC-FRP管钢筋混凝土梁破坏模式与耗能机制，确定不同抗震破坏模式下的界限状态；提出构件承载力、刚度退化、延性系数及骨架曲线计算方法，建立构件恢复力模型。研究PVC-FRP管钢筋混凝土梁设计方法，提出构件设计控制目标、控制条件、设计计算方法和构造措施。研究成果为PVC-FRP管混凝土结构的工程应用提供科学依据，同时也促进组合结构体系发展。

本项目立足工程实际，紧紧围绕新型PVC-FRP管钢筋混凝土梁的基本特点，以PVC-CFRP管钢筋混凝土梁受力机理研究为基础，以PVC-CFRP管钢筋混凝土梁计算方法研究为主线，重点解决单调荷载和低周反复荷载作用下PVC-CFRP管钢筋混凝土梁的破坏模式、受力机理、计算理论和设计方法等关键问题。（1）开展了PVC-CFRP管钢筋混凝土梁抗弯性能研究，分析配筋率、纵向CFRP布宽度和层数、混凝土强度以及试件尺寸等参数对PVC-CFRP管钢筋混凝土梁的破坏形式、抗弯承载力、刚度、延性、变形以及荷载-挠度关系等的影响规律，揭示构件的破坏模式与抗弯机理，确定PVC-CFRP管钢筋混凝土梁在不同受弯破坏模式下的界限状态，给出PVC-CFRP管钢筋混凝土梁发生延性破坏的条件，提出构件抗弯承载力、刚度、延性及荷载-挠度关系的计算方法。（2）开展了PVC-CFRP管钢筋混凝土梁的抗剪性能试验，分析试件尺寸、箍筋配箍率、环向CFRP条带配纤率（环箍宽度与层数）、条带粘贴方式、纵向CFRP布层数以及剪跨比等参数对PVC-CFRP管钢筋混凝土梁的破坏形式、抗剪承载力、延性、应变和剪力-变形相关曲线的影响规律，揭示构件的破坏模式与抗剪机理，确定PVC-CFRP管钢筋混凝土梁在不同剪切破坏模式下的界限条件，提出PVC-CFRP管钢筋混凝土梁抗剪承载力的计算方法，建立构件剪力-变形的相关计算理论。本项目的研究将为工业与民用建筑、桥梁结构和海洋结构等工程提供新的结构体系，为PVC-CFRP管混凝土结构的设计及工程应用提供科学依据。