Research On Application Of Ground Treatment With Earth Pile & CFG Pile Composite Foundation In Collapsible Loess Regions

Loess widely distributes in China and more and more tall, large, heavy buildings are built in loess regions with the development of the society. The tall, large, heavy buildings with big loads require a higher bearing capacity and a little foundation settlement. When constructions are built in loess regions, adversely affecting caused by the collapsibility of loess must be taken into account.According to high-rise building which is under construction in collapsible loess regions of Sanmenxia, this paper presents a ground treatment method with Earth Pile 　& CFG Pile composite foundation. Through laboratory test and field test,the author carried out experimental study about the composite foundation with Eeath Pile and CFG Pile. The conclusions of these tests have certain theoretical guiding significance to the construction which is build in collapsible loess regions.The main research wo-rk of this paper can be summarized as follows:(1) In the paper,the author analyzed the mechanism of loess collapsibility, elabo-rated the distribution and aracteristic of loess in our ountry, introduced several me-thods of collapsible loess foundation treatment in our country.(2) The author analyzed the mechanism of action on compacting and strength-ening the foundation with Earth Pile and CFG Pile, elaborated the characteristics and construction methods of Earth Pile and CFG Pile,the author also analyzed the mechanism of action and characteristics on strengthening the composite foundation with CFG Pile　& Earth Pile.(3) When high-rise building is built in collapsible loess regions,in order to solve the problem of foundation,the author suggest the solution with Earth Pile&CFG Pile composite foundation.(4) Researched the effect of collapsible loess foundation treatment with Earth Pile.The research shows that it is very obvious to compact and reinforce collapsible loess, reach the expected purpose of foundation treatment, basically eliminate the collapsibility of loess,moreover control measured collapse under overburden pressure.(5) Researched the vertical compressive bearing capacity of CFG Pile.The research shows that the characteristic value of vertical compressive bearing capacity of CFG pile is 710kN,reach the design value of bearing capacity.(6) Through the field test about the composite foundation with Earth Pile& CFG Pile,The test shows that the characteristic value of bearing capacity of composite foundation is 540kPa.Compared with the original natural foundation,the bearing capacity of composite foundation improve obviously.