Research On Properties Of CFG Pile-Cap-Net Composite Foundation

Better social and economic benefits was obtained because of the features of CFG pile composite foundation such as small settlement, high bearing capacity, fast stability, short time for construction, variable pile strength, and significant reinforcement effect etc. CFG pile has been widely adopted in each field like construction, mining, water conservancy, transportation and etc since 1988 successfully applied in engineering practice , and now becomes the focus of extensive attention of civil engineering scholars at home and abroad. During recent years, pile cap has been introduced to CFG pile composite foundation, which changes the properties of the CFG pile composite foundation, Therefore, the research on properties of CFG pile-cap-net composite foundation has important engineering significance.This paper firstly refers to the on-site measurement data of CFG pile composite foundation on high-speed railway, built the three-dimensional numerical model by FLAC3D of CFG pile composite foundation under embankment load, compared and analyzed between the calculation results and on-site measurement data to verify the reliability of the model. Then, it makes numerical analysis of factors respectively including pile space, pile cap size, cushion module, cushion thickness, pile length into the bearing stratum, module of soil between piles, module of bearing stratum, which will impact on the properties of CFG pile-cap-net composite foundation, according to the influence rules and extent by analysing the factors from two aspects of settlement and the stress of pile and soil, thus gives a comprehensive analysis of the CFG pile-cap-net composite foundation properties.This paper also makes numerical calculation comparative analysis of the common soft soil treatment methods including pile net, pile-cap-net and pile-plank structure composite foundation to conclude the characters of the three foundation treatment methods in settlement, stress ratio of pile to soil and load shearing ratio of pile to soil, thus gives a reference for the design of composite foundation actual engineering.At last, it summarizes the character of CFG pile-cap-net composite foundation different from the others, based on the comprehensive analysis of the CFG pile-cap-net composite foundation properties and comparison between the three different treatment methods.