关键词: 浅层软黏土, 模袋, 袖阀管, 可泵性

Abstract: The grouting has been an effective method in treating unfavorable geological conditions, which has received remarkable results. However, in the shallow deposited cohesive soils, due to the difficulties in fixing the grouting sleeve, the soil layer is hard to be split and the grouting fluid cannot penetrate into the cohesive soils as a result of the low grouting pressure. A new grouting procedure, which uses the sleevevalve pipe inserted into the geotextile tube, is introduced to resolve this difficulty. The new procedure utilizes character of the longer initial hardening time of the cement based grouting slurry, adjusts the ratio of the fast hardening additives to the cement slurry and controls the grouting pressure to achieve the optimized pumping results. This procedure has been applied to the groundwater cutoff in the deep excavation of Shangyuanmen Station in Nanjing. The shallow deposited cohesive soil groundwater cutoff is achieved by the new grouting method and it has a significant contribution to the stability of the deep excavation.

Key words: Shallow Deposited Soft Cohesive Soils, Geotextile Tube, Sleeve-Vale Pipe, Pumping Workability