长钢顶管稳定特性的有限元分析

随着钢顶管直径和顶进距离的不断增大，复杂受力条件下的钢顶管屈曲破坏成为了施工过程中的工程隐患.通过简化长径比超过100的钢顶管受力模型，探讨了长钢顶管稳定特性有限元分析方法.首先进行钢顶管管道的特征值屈曲计算，得到管道的一阶屈曲模态.再将一阶模态作为初始缺陷引入到钢管，进行弹塑性屈曲极限分析.通过算例分析了钢顶管在各种基本荷载及不同组合荷载下的屈曲模态，并探讨了其弹塑性稳定极限荷载的变化规律.分析结果反映了钢顶管屈曲工程案例现象，并建议通过控制注浆效果和顶进措施来提高管道的稳定安全性，对于高围压下的钢顶管尤其需要注重顶力控制.

FEM Analysis on the Buckling of a Long Steel Jacking Pipe

The buckling of steel jacking pipe under complex loads has been an important factor in construction because of the increasing of diameter and jacking distance. Numerical analysis on the buckling of long steel jacking pipe, whose distance diameter ratio is larger than 100, is studied in this paper with finite element method (FEM). The first buckling mode of pipe jacking under different loads are obtained by the buckle analysis. By introducing the first mode as the initial imperfection, the elastic plastic buckling behavior of steel pipes is analyzed with the RIKS method. Both the buckling mode and ultimate load of buckling of the steel jacking pipe are discussed, and the buckling phenomenon in practice is verified. Parametric analysis shows that the stability of steel pipe can be improved by reducing friction and face resistance of pipe jacking, and the jacking load of the pipes with high confining pressure should be carefully controlled.
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