海河隧道干坞边坡的稳定性

Dry dock slope stability for constructing a tunnel crossing Haihe river

采用简单条分法和简化毕肖普法,对中央大道海河沉管隧道工程的干坞边坡稳定性在开挖、充水和再排水3种工况下进行了分析.对开挖阶段,考虑了渗流力和开挖扰动的影响;对充水阶段,考虑了浸润面以上毛细作用区内毛细吸力丧失的影响;对排水阶段,考虑了水位骤降引起的应力变化和超孔隙水压力的影响.这项研究成果已作为该项目的设计依据.

The Fellenius method of slices and the simplified Bishop Method are adopted for the dry dock slope stability analysis at three typical stages, i. e. , excavating stage, water filling stage and water vacating stage. In the excavation condition, the seepage force and the disturbance effect on the soil due to excavation are considered. In the water filling condition, the capillarity suction lose because of soil saturation below the phreatic line is discounted from the soil strength. In the water vacating condition, the stress change and pore water re-distribution are discussed. The achievement has been used as the base of construction design for this project.