计算方法对钢筋混凝土圆管涵受力分析的影响研究

Influence of Calculation Methods on Stress Analysis of Circular Reinforced Con-crete Culvert Pipe

以某钢筋混凝土圆管涵为工程背景,针对是否考虑土体与钢筋混凝土圆管涵的接触非线性采用两种不同的计算方法对其进行受力分析,且计算中均考虑了钢筋与混凝土的材料非线性。计算分析表明:考虑土体与钢筋混凝土圆管涵的接触非线性后,钢筋混凝土圆管涵的变形增大约30%,混凝土的第一主应力最大值不变,普通钢筋的拉应力最大值增大45.88%、压应力最大值增大16.49%,裂缝宽度最大值是不考虑接触非线性时的2.19倍;钢筋混凝土圆管涵考虑材料和接触双重非线性时,其计算收敛难度显著增大,在对计算结果要求不是很高或硬件条件达不到时,也可不考虑钢筋混凝土圆管涵与土体的接触非线性,采用共节点简化其接触关系,但计算结果偏于危险,建议考虑2作为放大系数。

Based on the engineering project of a circular reinforced concrete culvert pipe,two different cal-culation methods considering the nonlinear contact between the pipe and underlying soil were used to analyze the stresses.In this paper,the material nonlinearity of steel and concrete is considered in the calculation.The results show that when considering the nonlinear contact between the pipe and underlying soil,the deformation of the pipe is increased by about 30%,the maximum value of the first principal stress of the concrete remains unchanged,the maximum tensile stress of the ordinary reinforcement is increased by 45.88%,the maximum compressive stress is increased by 16.49%,and the maximum crack width is 2.19 times that without considering contact nonlinearity.When the double nonlinearity of material and contact is considered,the difficulty of calculation convergence is significantly increased.Therefore,when the calculation results are not very demanding and the hardware conditions cannot be met,the common node can be used to simplify the contact relationship and the contact nonlinearity can be ignored.However,the calculation results using this method are not conservative.Thus,it is recommended to use 2 as the magnification factor.