薄壁空心墩的墩顶约束效应研究

摘要

薄壁空心墩的墩顶截面受非线性温度和桥墩支承条件的作用，产生了温度约束应力，温度应力是导致混凝土结构产生裂缝的主要原因之一。文章通过分析薄壁空心墩墩顶约束对墩身温度应力影响，研究了在墩顶自由和部分约束条件下温度荷载对墩身温度应力的影响规律，提出了利用墩身刚度修正系数K来简化计算空心墩温度应力的计算方法。通过工程实例，将空间有限元程序和平面杆系程序计算结果进行对比，实现了利用一般杆系有限元程序解决非线性温度荷载作用下的温度应力计算，减轻了高墩设计中对空心墩温度应力进行实体分析的复杂工作量，为空心墩的设计和研究提供参考。%The top section of thin-walled hollow pier generates temperature restraint stresses by the function of nonlinear temperature and the supporting of the pier condition,which is one of the main causes of cracks in concrete structures. Through analysis of the influence of the temperature stress of the thin-walled hollow pier top constraint,this paper studies the regular pattern of the pier stress under the temperature load by the pier top free and partial constraint conditions. And it presents a simplified calculation method for the calculation of temperature stress of hollow pier with the pier stiff-ness correction coefficient K.Compared the results of the space finite element program and plane bar system procedures, the paper realizes the temperature stress calculation using the general bar system finite element program to solve nonlin-ear temperature load.This method reduces the workload of complex entities analysis on thermal stress of hollow pier in the high pier design.Besides,it provides the reference to design and research of hollow pier.