成层土地基堆载预压工后沉降预测

Prediction of settlement after pre-compaction on stratified land base

软弱夹心层地基是软粘土夹在上下两层硬土中间的一类典型土层,其为珠江地区特殊的层土地基,该特殊地基在堆载荷载作用下的工后沉降预测一直是困扰工程师的难题。文中以广州灵山岛尖区域内侧水系建设堆载预压实体工程为例,对其施工期和施工完成之后进行的现场试验和数值仿真模拟研究,获得了珠江河口地区层土地基堆载预压沉降特性。通过大量反分析研究其工后沉降预测方法的适用性,最终确定双曲线法为其最优模型,并提出了工后沉降预测公式,其能为未来同类型工程的工后沉降预测提供指导。

Soft clay sandwiched in two stiff layered soils is a typical soil profile in the area of Pear river.It is a big challenge for engineers for the settlement prediction for typical layered foundation under preloading.Field tests and numerical simulation have been carried out for one preloading project located in the Lingshan island of Guangzhou,which are aimed to provide insight into the behavior of settlement of the typical layered soils improved by preloading in the Pearl river basin.A series of back-analysis have been conducted to compare the probability of different prediction methods.Based on the results,it is found that the hyperbolic method is the optimized model for predicting the post-settlement of layered soil foundation under improvement of preloading in Peral river basin.Finally,a model of hyperbolic method with several fixed parameters that can reflect the typical characteristics of layered soil foundation under preloading in Pearl river basin was proposed,which can provide guidance for the design of layered soil foundation improved by preloading in the future for similar projects.