真空负压源深度对吹填土地基固结沉降的影响

为研究真空负压源深度对吹填土预压处理效果的影响,开展真空负压源分别位于深部的下位抽真空和位于表层的上位抽真空预压加固室内试验。根据固结过程中土体分层沉降量、排水量、不同深度处真空度监测结果,对不同真空负压源深度的固结土层真空度传递效率、固结沉降特点等进行分析。结果表明:当负压源位于加固土体深部时,可有效提高真空度传递效率,缩短下层土体排水路径并改变中层土体渗流方向,同时上层固结土体可保持较高真空负压;深部土体可得到有效加固且土层固结沉降将更为均匀,真空预压加固方法的有效加固深度得到较大幅度的增加并可一定程度上控制加固土体的工后沉降。

Effects of vacuum source location on consolidation settlement of dredger fill foundation

The location of vacuum sources with negative pressures was considered in analysis of the effects of dredger fill foundation reinforcement under vacuum preloading. Model tests were performed to simulate dredger fill foundation reinforcement using the vacuum preloading method, with vacuum sources located at the top and bottom. Over the course of foundation consolidation, the amounts of water drainage and settlement for different soil layers and the vacuum degree at different depths were monitored, and the transmission efficiency of the vacuum degree and consolidation settlement properties for soil layers with vacuum sources located at different depths were studied. Results show that the vacuum preloading method, with vacuum sources located at the bottom of the dredger fill foundation, can enhance the transmission efficiency of the vacuum degree, shorten the drainage path in deep soil layers, change the seepage direction in middle soil layers, and maintain a high vacuum degree in upper soil layers. Meanwhile, deep soil layers can be reinforced effectively, and the consolidation settlement tends to be more uniform. Moreover, this method can increase the effective reinforcement depth to a great extent and reduce the post-construction settlement to a certain degree.