依托上海某项目地基处理工程, 针对其中28#和30#区块进行大面积的真空预压地基处理现场试验, 分别对真空预压过程中的地基沉降、水平位移、地下水位、真空度和孔隙水压力等指标进行跟踪监测, 研究在真空度上升及维持过程中各指标的变化特性, 特别是土体内的真空度、孔隙水压力以及二者之间的相互关系. 此外, 采用5%水泥掺入量的双排水泥土搅拌桩作为密封墙, 不仅起到了很好的防渗作用, 同时也避免了采用普通泥浆搅拌桩作为密封墙导致该位置地基强度较低的问题. 试验结果表明, 真空预压法在上海地区取得了良好的效果, 值得在工程建设中进一步推广.
The vacuum preloading drainage consolidation method is used in Shanghai a project. In the project, field tests are conducted in areas No.28 and No.30. The variation rule of surface settlement, horizontal displacement, groundwater level, pore-water pressure, and especially the relationship between vacuum and pore-water pressure are studied by means of field monitoring in the process of vacuum preloading. Two rows of mixing piles including 5% of cement are used as a sealing wall in the project, which play an important role in seepage control. Compared with traditional mixing piles, the two rows of mixing piles can avoid the disadvantage of low foundation strength at the location. It is shown that the vacuum preloading method has achieved good results in Shanghai, and the method is worth popularization.
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