某隧道发生涌砂的机理及工程应对措施

Mechanism of Sand Gushing in Tunnel and Engineering Measures

介绍了隧道区地质条件以及涌砂事故发生的过程,从地质角度分析了隧道发生涌砂的机理,主要原因为隧道顶部的粉质黏土受到上覆砂层孔隙水的软化以及施工扰动,强度降低,难以支撑上覆土层压力,导致顶部粉质黏土坍塌,砂层涌出;并介绍了对涌砂事故采取的工程应对措施,提出施工中改进方法。

The paper introduces the geological conditions of the tunnel area and the process of sand inrush accident, analyzes the mechanism of sand gushing from the geological point of view. The main reason is that the silty clay at the top of the tunnel is affected by the softening of the pore water and the construction disturbance. So the strength of silty clay is reduced to hardly support the overburden pressure, leading to the collapse of silty clay and sand. The paper also introduces the engineering measures for sand inrush accident and proposes the improved solution in the construction.