浅埋隧道开挖纵向地表变形预测及其基本规律

Prediction of ground surface deformation in longitude due to tunnel excavation and its basic regularization

将隧道围岩看作一种随机介质,将隧道开挖所引起的上覆岩土体的移动看作一随机过程,应用随机介质理论,对浅埋隧道施工所引起的纵向地表移动与变形进行了分析计算,推导了相应的地表下沉、水平移动、倾斜、水平变形以及地表弯曲曲率的计算公式。工程实例分析表明:计算结果同实测结果吻合较好。在此基础上,分析总结了浅埋隧道开挖引起的纵向地表移动与变形的一些基本规律,得出沿隧道纵向开挖只对工作面前后一定范围(2R)地表建筑物产生明显影响的结论。

The rock and soil around tunnel is considered as a stochastic medium and the movement in it due to tunnel excavation is considered as a stochastic process in this paper.By using the stochastic medium theory,the ground surface movement and deformation in longitude along the tunnel due to its excavation are calculated and analyzed. The formulas of ground surface's subsidence, horizontal displacement, inclination, horizontal strain and curvature in longitude along tunnel are deduced. An engineering example shows that the calculating results tally well with the measuring results. Based on these,some basic regularization of ground surface movement and deformation in longitude along tunnel due to its excavation are summarized,and a conclusion that only ground surface buildings in the range of 2R on working face are influenced obviously by tunnel excavation is drawn.