污水盾构管道管片结构性能退化数值分析

Numerical Analysis of Structural Performance Degradation of Sewage Shield Tunnel Segment

为解决污水管道寿命期内力学性能和变形难以动态定量评估的问题,对混凝土污水管道腐蚀机制进行研究,建立多因素耦合作用下的污水盾构管道结构性能退化计算模型,应用Matlab软件对东濠涌试验段管道的力学性能和变形进行数值分析,通过分析可知:污水管道内力在寿命期内一直处于增加状态,管道两侧(0°和180°位置,管道水平轴线右侧为0°,逆时针为正)轴力的数值和增长率均最大;最大负弯矩出现在管道两侧,最大正弯矩出现在管道底部,且寿命后期的增长率较大;寿命期内最大正剪力出现在135°和315°附近,最大负剪力出现在45°和225°附近,且后期增长率较大;通过内力变化对比分析得知,干湿循环区是内力变化最不利的区域;管道最大竖向位移发生在管道顶部,由于管片接头的存在,最大水平位移发生在18°和162°位置。

It is difficult to assess the mechanical properties and deformation of urban sewage tunnel in whole service life quantitatively and dynamically. The corrosion mechanism of concrete pipe for sewage discharge is studied. Calculation model of segment structural performance degradation under multifactor coupling action is established. The mechanical properties and deformation of Donghaoyong test section is analyzed by Matlab software. The numerical analysis results show that： 1） The internal force of sewage tunnel in whole service life continuously increases. The axial forces on both sides of the sewage tunnel are the largest and increase continuously. 2） The negative bending moment on the both sides of the sewage tunnel are the largest; the positive bending moment on the bottom of the sewage tunnel is the smallest; and they increase obviously in post-stage service life. 3） The maximum positive shear forces occur at 135° and 315°positions; the maximum negative shear forces occur at 45° and 225° positions; and they increase obviously in post-stage service life. 4） The drying and watering cycle zone is the worst zone for internal force variation of the sewage tunnel; the maximum vertical displacement occurs at crown top; and the maximum horizontal displacements occur at 18° and 162°positions.