车辆荷载下穿越道路直埋供热管段应力分析

Stress Analysis of Directly Buried Heating Pipeline across Road under Vehicle Load

针对某市D1020×12、D920×10、D820×10、D720×10规格热水供热管道穿越道路直埋管段(未设置钢质保护套管),在考虑车辆荷载的前提下,采用应力分类法对穿越道路直埋管段进行强度校核、疲劳校核,采用ANSYS有限元分析软件模拟计算穿越道路直埋管段的应力、沉降位移等。结合两种应力分析方法的验算与模拟计算结果,对穿越道路直埋管段的安全性进行评估。应力分类法的验算结果表明,4种规格穿越道路直埋管段均满足强度、疲劳校核条件,D920×10规格穿越道路直埋管段的当量环向应力与钢材许用应力相当,需采取措施降低该管段的环向应力。有限元分析结果与应力分类法验算结果基本一致,D1020×12、D920×10两种规格穿越道路直埋管段的环向应力、轴向应力处于较高水平,主要原因为管顶埋深较浅。较高的环向应力、轴向应力水平是引起沉降位移突出的关键原因。D1020×12、D920×10规格穿越道路直埋管段位于市区相对繁华地带,为确保安全运行,建议增大管顶埋深或加装钢质保护套管。

For directly buried pipe sections across road （without steel protection casing） with D1 020×12,D920×10,D820×10 and D720×10 specifications of hot water heating pipeline in a city,on the premise of considering the vehicle load,the strength and fatigue of the directly buried pipe sections across road are checked by the stress classification method. The stress and settlement displacement and so on of the directly buried pipe sections across road are simulated by the ANSYS finite element analysis software. Combined with the checking calculation and simulation calculation results of two kinds of stress analysis methods,the safety of the directly buried pipe sections across road is evaluated. The checking calculation results of the stress classification method show that the directly buried pipe sections across road with 4 kinds of specifications all meet the strength and fatigue checking conditions,the equivalent circumferential stress of the directly buried pipe section across road with D920×10 specification is equal to the allowable stress of steel,and measures should be taken to reduce the circumferential stress of this pipe section. The results of finite element analysis are basically in good agreement with the checking calculation results of stress classification method. The circumferential stress and axial stress of directly buried pipe sections crossing road with D1 020×12 and D920×10 specifications are at a high level,which is mainly due to the shallow pipe top buried depth. The high circumferential stress and axial stress levels are the key reasons for the settlement displacement outburst. The directly buried pipe sections across road with D1 020×12 and D920×10 specifications are located in urban relatively prosperous zone,in order to ensure safe operation,it is suggested to increase the pipe top buried depth or install the steel protection casing.