A Study On Deformation Characteristics Of The Rigid Gird-micropile Groups Composite Foundation

The rigid gird–micropile groups composite foundation is a new soft soil foundation reinforcement technique. It consists of rigid grid, micropile structure, transition subcrust and soft soil foundation. Load is applied to the transition subcrust transferred to the rigid gird, than transferred to deep soil through the micropile groups. This composite foundation can't only restrict the side deformation of soft soil, but also give full play to the strength an the deformation properties of the soil, in order to effectively improve the strength of the soft soil foundation, reduce settlement of the soft soil foundation after reinforcement, short construction period and lower construction costs.This article as a part of the study on properties of the rigid grid-micropile groups composite foundation, mainly research function mechanism and theory calculation of the rigid grid-micropile groups by combining the reinforcement method of composite foundation and research result of pile-web composite foundation. Meanwhile, this article researches the deformation properties of the rigid gird-micropile groups composite foundation by the large-scale finite element analysis software MIDAS/GTS, and lays a good theoretical foundation for future experiment research and engineering application. The main contents of this article include:(1)On account of the research actualities of composite foundation and the shortcomings of soft soil foundation reinforcement currently, this article put forward a good reinforcement effect, low-cost soft soil foundation reinforcement technique(the rigid gird-micropile groups composite foundation reinforcement method), and describes its main components. (2)On account of the design thought of the composite foundation, this article researchfunction mechanism and the settlement design philosophy of the rigid gird–micropile groups composite foundation and discuss the Computational Method of settlement.(3)On account of the analysis theory of finite element, this article analyses the impact of the pile-soil modulus ratio, pile length, rigid mesh stiffness, pile spacing, tension network flexibility, pile diameter, subcrust thickness and other parameters on the deformation properties of the rigid gird–micropile groups composite foundation by the large-scale finite element analysis software MIDAS/GTS.