顶管施工引起邻近地下管线附加荷载的分析

ANALYSIS OF ADDITIONAL LOAD ON ADJACENT UNDERGROUND PIPELINE INDUCED BY PIPE JACKING CONSTRUCTION

利用弹性力学的Mindlin解,推导得到顶管掘进机与土体之间的摩擦力和后续管道与土体之间的摩擦力引起的土体附加应力计算公式。假定土体为Winkler模型,推导得到土体损失引起的垂直向土体附加应力计算公式。研究了顶管施工在邻近垂直交叉地下管线上引起的附加荷载分布规律。研究结果表明:附加荷载的变化规律与地下管线和掘进机的相对位置密切相关,是一个三维问题;随着地下管线与顶管之间距离的减小,附加荷载急剧增大;在正常施工时,竖直方向引起的附加荷载值最大,顶进方向其次,垂直于管壁方向最小。

The computing formulas of soil additional stress induced by force of friction between shield and soil,and the force of friction between follow-up pipes and soil are derived from Mindlin solution in elastic mechanics.By assuming the soil as the Winkler model,the vertical soil additional stress formula caused by ground loss is derived.The distribution regularity of total additional load on perpendicularly crossing buried pipeline induced by pipe jacking construction is studied.The analytical results show that the distribution regularity of additional load is closely related with the relative position of underground pipeline and shield,and it is a three-dimensional problem.The value of additional load increases rapidly with the decreased distance of underground pipeline and pipe.The value of additional load toward vertical direction is the maximum,that toward the pipe jacking direction is the second,and that toward perpendicular to the pipe wall is the minimum during the normal construction condition.