考虑时空效应的隧道开挖及降水引起的地层变形计算

隧道降水及开挖引起的地层变形在时间上和空间上是不断发展变化的,目前国内外针对这一问题的研究大多只考虑最终的地表沉降。本文采用随机介质理论和岩土固结压密理论,考虑隧道开挖前降水以及隧道开挖施工引起的地层变形随时间的变化过程,对隧道开挖及降水引起的地层沉降和变形进行分析,推导相应的计算公式。工程算例分析表明,推导的计算方法具有较好的可靠性。进一步的计算分析表明,隧道降水引起的地层沉降较大,对隧道周边建筑设施不利,当降水井距隧道较近时,降水及开挖引起的地层变形在最大值处相互叠加,使得最终的地层变形值很大。因此,为保护隧道周边的建筑设施,降水井应距离隧道有一定的距离。

Calculation of stratum deformation caused by tunnel excavation and dewatering

The stratum deformation caused by tunnel excavation and dewatering will change with time and space,but the available studies on this problem often only consider the ultimate ground surface subsidence.Using the stochastic medium theory and soil consolidation theory,the stratum subsidence and deformation caused by tunnel excavation and dewatering are analyzed,and the calculation equations are deduced.A calculation case shows that the calculation method is reliable.Further calculation and analysis show that the stratum subsidence caused by dewatering is comparatively large and may be of detrimental effects on the nearby buildings.When dewatering well is close to the tunnel,the stratum deformation caused by excavation and dewatering will superimpose,causing more stratum deformation.To protect the buildings and pipelines in the vicinity of the tunnel,dewatering well should be placed a certain distance away from tunnel.