基于离心模型试验的深厚层软基加固方案比较研究

在深厚层软基上修筑路堤的沉降控制技术是一项世界性难题,其中选择合理的地基处理措施是关键。针对福厦铁路深厚层软基的工程特性,以土工离心模型试验为研究手段,分析了袋装砂井处理、粉喷悬浮桩加固及粉喷悬浮桩与袋装砂井联合作用等3种加固方案的沉降变形特点。测试数据表明:①采用袋装砂井方案,能基本解决地基的稳定问题,但工后沉降较难控制;②采用粉喷悬浮桩方案,能较好解决软基加固区的稳定问题,但变形受下卧软土层强度的影响较大;③采用粉喷悬浮桩与袋装砂井联合加固方案,可克服粉喷悬浮桩后期沉降大和袋装砂井堆载预压时间长的固有缺陷,是一种比较理想的地基处理措施。

Comparative research on reinforcement of thick soft clay ground based on centrifugal model tests

The settlement control technology of constructing embankments on thick soft clay foundations is a worldwide difficult problem,and the selection of reasonable treating measures of the ground is very critical.In view of the characteristics of the thick soft clay ground of Fu-Xia railway project,taking the geo-centrifugal model tests as the research method,the characteristics of three kinds of reinforcement were used and analyzed to reduce the settlement deformation: sand wick DJM piles,and combination of the DJM piles and the sand wick.It was indicated that: ① using the sand wick the stability problem of ground could be basically solved,but it was difficult to control the settlement after construction;② using the DJM piles the stability problem of ground could be better solved,but the deformation was influenced evidently by the underlying soft clay layer;③ using the combination of the DJM piles and the sand wick the inherent individual flaw of the DJM piles and the sand wick could be overcome,so it was a kind of relatively ideal measure in ground treatment.