FINITE ELEMENT ANALYSIS OF JUMP-LAYER TOP-DOWN CONSTRCTION METHOD WITH THE SOIL-ROCK DUALISTIC STRUCTURE

In recent years,top-down constrction method has become popular in construction of deep foundation pits.But in the region of soil-rock dualistic structure,successful cases of design and construction experiments of this kind of construction are rarely seen.In this paper,the deep foundation pit near Donghai Road was taken as an example to introduce the construction process and main construction methods of top-down construction method with bored pile supporting pattern in a typical region of soil-rock dualistic structure like Qingdao,when there are soil and rock field in the excavate effected extent.The Plaxis finite element software was applied to simulate soil excavation in order to analyze the effect of deformation of the supporting construction influenced by the depth of soil excavate and tney were stressed analysed to disscuss the feasibility of jump-layer excavation and the influence to the construction process.