真空堆载联合预压作用下地基沉降预测

Prediction of ground settlement under vacuum preloading combined with surcharge

真空堆载联合预压现场施工加载条件复杂,对地基沉降发展影响较大。利用满载后期沉降曲线与等效线性加载沉降曲线基本相同的特点,基于等效线性加载竖向排水井地基固结理论,提出了根据满载期后的实测沉降数据反演最终沉降的方法,并将其编制为应用程序。对某工程的算例分析表明,该计算方法与三点法结果较为接近,但可避免三点法仅利用个别数据点的缺陷;经验双曲线法推算的最终沉降量最大,实际工程中利用其结果来计算地基固结度时,其值往往偏低。

Loading conditions are complicated in practical vacuum preloading combined with surcharge engineering, and it has a great influence on the development of foundation settlement. The field settlement curve after full load has the same characteristics as that under equivalent linear load. According to this phenomenon, the final settlement inversion method through measured settlement of late stage is proposed based on the consolidation theory of ground with vertical drains under equivalent linear load. The method is coded into a program for application and it is used to analyze an engineering case. It shows that the result obtained by the present method is closer to that obtained by three-point method, and it can avoid the shortcomings of the three-point method using only individual data points. The final settlement predicted by the experienced hyperbolic law is the largest. It can lead to smaller consolidation degree in practical engineering.