Experimental Study On The Performance And The Uplift Mechanism Of Cement-soil Core-insert Uplift Pile

Cored uplift pile with rotary-jet mixing soil-cement designed in recently is a new type of uplift pile.The pile has higher bearing capacity and availably solves a crack problem in the traditional uplift pilebody.for the reason that cored uplift pile subjected to vertical load is in pressed status.The new type of uplift pile is consisted of concrete core and cement in outer parter.This kind of structure can lower construction cost.for takeing full advantage of the loading characteristic of material.Besides.there are specialized protection steel pipe to protect prestress wire set in the pile.so Cored uplife pile will have higher service life.The dissertation first introduces the development of uplift pile at home and abroad, and look into the foreground of it. The evolution of the uplift pile divides into three stages, uplift pile with equal section,uplift pile with non-equal section and press uplift pile in recent years.Base on the continuous development of uplift pile,it is necessary to research a new type of pilecand verifies the design scheme of the pile is possibility and necessity.On the foundation for uplift pile experimenting such as Nantong Ten Street test,Kunming yuantang Road test and Jiashan hengli Square test.this paper analyses load-bearing capacity of cored uplift pile on the scene and improve its structure and construction technology in order to solve the problem in the pile testing.Besides.on the base of the Static loading test,the paper studies the Loading characteristic and the load transfer mechanism of Cored uplift pile.The research expresses that it could be most economical.if pile body material and ground soil can reach their ultimately bearing capacity simultaneously. Moreover.the model of load transfer is many layers spread mode:vertical load transfer from the pile bottom to the pile crest,from the inner-cored pile to the external cement-soil pile, from external pile to the compression soil rimmde the cement-soil pile and from the compression soil to the surrounding soil.By studying the relationship between the U～δcurve.the paper summarezes the judgment standard of the pile limit load.In the static load test,it will happen sometime that cored uplift pile can't pull damage. For the sake of predicting limit bearing capacity of the cored uplift pile.this paper creates a type of modified exponential model and obtains a better fitting result.At last,the paper explores the design factors of the pile and indicates the failure modes.Meanwhile.the paper advices some suggestions and measures in order to improve the structure of the pile and construction technology,and expects the research results could supply some help to the future development of the cored uplift pile. Figure [40] table [11] reference [42]...