一种新型预制桥墩连接构造的抗剪承载力分析

Shear Capacity Analysis of a New Type of Precast Pier Connection Structure

连接构造是预制拼装桥墩结构的薄弱环节.为改善预制桥墩的力学性能,提出了榫卯+波纹管的预制桥墩节段新型连接形式.设计并进行了该接头的剪切试验,根据试验结果对该连接构造的受剪力学行为进行假设,基于莫尔应力圆理论推导了其抗剪承载力公式,并与试验结果进行对比.结果表明:所设计的新型连接构造受剪发生凹槽一侧的斜剪破坏形态,纵向钢筋在斜裂缝充分发展后提供抗剪作用;文中的抗剪承载力公式对于破坏模式的分析符合实际破坏形态,剪应力分布系数取0.7时,预测的抗剪承载力较为理想,当其作为设计依据时,应取适当的安全系数.

Connection is the weak link of precast pier structure.In order to improve the mechanical properties of precast pier,a new connection form of precast pier segments with mortise and tenon and corrugated pipe was put forward.The shear test of the joint was designed and carried out,and the shear mechanical behavior of the joint structure was assumed according to the test results.Based on Mohr’s stress circle theory,the formula of its shear capacity was deduced and compared with the experimental results.The results show that the designed new connection structure has oblique shear failure at one side of the groove,and the longitudinal reinforcement provides shear resistance after the oblique crack is fully developed.The analysis of the failure mode by the proposed shear capacity formula accords with the actual failure mode.When the shear stress distribution coefficient is 0.7,the predicted shear bearing capacity is ideal.When it is used as the design basis,an appropriate safety factor should be taken.