大厚度黄土质素填土湿陷性深度变化规律及地基处理研究

Collapsible law on depth of large thickness loess fill and foundation treatment plan

将大厚度黄土质素填土的湿陷性试验成果数据与原状黄土进行了对比分析,分析结果表明,大厚度黄土质素填土与原状黄土在26m以浅没有明显差异,26~42m深度上大厚度黄土质素填土比原状黄土的湿陷性稍大,42m以深湿陷性趋于一致。根据黄土湿陷性机理分析,认为开挖、回填对黄土结构的扰动未对其产生湿陷性的架空结构产生本质的影响,大厚度黄土质素填土湿陷性的关键影响因素为先期固结压力,其湿陷性随深度变化的规律与原状黄土基本一致,可以按照原状黄土方法评价、处理其湿陷性。通过剩余湿陷量计算,提出了对拟建不同建筑物的相应地基处理方案。

The results of collapsible test data of large thickness loess fill are compared with original loess show that there is no obvious difference between the large thickness loess fill and the original loess in the shallow 26 m, and the large thickness of the loess in the depth of 26-42 m is slightly larger than the original loess,and the collapsibility deep than 42 m tends to be to converge. According to the collapsibility mechanism of the loess, the disturbance of the excavation and backfilling has not an essential influence on the collapsible structure of the loess. The key factor affecting the collapsibility of the large thickness loess is the pre consolidation pressure,and the law of its collapsibility with the depth of the loess is basically consistent with the original loess. The collapsibility of undisturbed loess is evaluated and treated. Based on the calculation of residual collapsibility,the corresponding foundation treatment plan for different buildings is proposed.