With the rapid development of subway, the ground movement induced by water and sand gushing occurs frequently in the process of tunnel construction. Existing research has not paid significant attention in the influence of sand inflow on the ground settlement and the development process of deep soil after water and sand gushing. Thus, the aims of the present study were: (i) to numerically explore the laws of ground movement, ground loss and the developing process due to water and sand gushing; and (ii) to theoretically explore a prediction formula for the maximum ground settlement after water and sand gushing. The numerical results showed that the surface settlement above the tunnel increased with the increase of mass loss ratio MLR. The development of ground movement can be divided into soil settlement stage induced by seepage, expansion stage of sand loosening region, and trenching stage of ground. The sand inflow first increased slowly, and then sharply, which finally kept stable growth. The growth rate of water inflow increased firstly and then kept it stable state. A simplified theoretical formula is proposed to predict the maximum ground settlement after water and sand gushing by establishing a simplified theoretical model. Moreover, the simulation results were compared with experimental results, and reasonable agreement could be obtained, which could provide a reference significance for the treatment and control of water and sand gushing in subway.

【摘要】：随着地铁的快速发展,隧道施工过程中频繁发生由涌水、涌沙引起的地面运动。现有研究对沙土流入对地面沉降的影响以及水沙涌出后深层土壤的发育过程没有引起重视。因此，本研究的目的是：(i) 数值探讨地表运动、地表损失和水沙涌出的发展过程；(ii) 从理论上探索水沙涌出后最大地面沉降的预测公式。数值结果表明，随着质量损失比MLR的增加，隧道上方的地表沉降增加。. 地表运动的发展可分为渗流引起的土壤沉降阶段、松散区扩张阶段和地基开沟阶段。入沙量先缓慢增加，然后急剧增加，最终保持稳定增长。入水量增长率先增加后保持稳定。通过建立简化理论模型，提出了预测水沙涌出后最大地面沉降的简化理论公式。并将模拟结果与试验结果进行对比，得出了合理的一致性，可为地铁涌水、涌沙的治理与控制提供参考意义。