隧道开挖及疏水引起的地表沉降与变形

Ground Surface Settlement and Deformation Caused by Tunnel Excavation and Dewatering

应用随机介质理论、渗流理论和岩土固结理论,推导了隧道开挖疏水渗降漏斗曲线方程和考虑水渗流作用的隧道周边岩土体中有效应力的计算公式,并由此推导了隧道疏水地表沉降和水平位移计算公式;最后利用叠加原理,导出最终的地表沉降及水平位移计算公式。通过对某工程实例的计算分析,验证了该方法的正确性。结果表明:隧道开挖疏水产生的渗流对地表沉降的大小和范围影响明显。

By using stochastic medium theory, seepage theory and rock consolidation theory, the settlement curve equation caused hy tunnel excavation and dewatering and the calculated formulas of effective stress in soil around tunnel which the seepage action of water was considered were deduced. Then, the calculated formulas of ground surface settlement and horizontal displacement caused by tunnel dewatering were obtained. By using the adding principle, the ultimate calculated formulas for calculating the ground surface settlement and horizontal displacement were obtained. An engineering example was calculated and analyzed in the end. The calculated results which show that the range and value of ground surface settlement is influenced by seepage due to tunnel excavation and dewatering obviously tally well with the measurement results.