Numerical Analysis And Application Research On Dynamic Compaction Used In Coarse-grained&Backfilled Foundation Treatment

With the constant reduction of the constructive land, a lot of buildings had to beconstructed on the poor-geological-condition sites. And the foundations with finegeological condition might still need some treatments in the particular situations.Dynamic compaction is one of the important methods for foundation treatment, whichhas been widely used at home and abroad. Although the rationality of dynamiccompaction has been proved in engineering practices, the design and implementationare still in a semi-empirical state. Therefore, this paper is going to study the variationlaw of the properties of soil in the compaction process. And it’s significant to applytheoretical achievements to engineering practices.This paper is based on a25-metre backfilled foundation treatment project inShenzhen City, which the technique of “dynamic compaction with a drainage system”has been successfully used in. And it is about to make an exhaustive research on thedynamic response and consolidated effect of coarse-grained&backfilled foundation.The research mainly includes the following aspects:(1) On the basis of consulting and summarizing the related literature, this paperwill discuss the dynamic compaction mechanism of coarse-grained&backfilledfoundation and analysis the influential factors of the effective improvement depth.(2) The research is about to analysis the variation of specific weight, deformationmodulus, cohesive strength and internal friction angle, put forward the calculationmethod and model of the aforementioned soil parameters in each compaction anddifferent depths, then justify the correctness and rationality of this hypothesis.(3) A numerical simulation of the entire compaction process will be conducted byestablishing three-dimensional finite element models with Midas/GTS. And this paperis going to study the dynamic response of soil under the impact load and summarizethe variation law of the physical quantities in each compaction.(4) This paper is about to study the technique’s application in a specificfoundation treatment project, then prove its outstanding contribution to ensuring theconstruction quality, saving the construction cost and shortening construction period,and justify its remarkable social and economic benefits.