Application Research On Soft Soil Foundation Treatment Of Pipeline Engineering

When long-distance water transmission pipeline pass through soft foundation, the low bearing capacity of soft foundation will lead to collapse of construction machinery, construction difficulties, even other safety accidents. Therefore, making economic and reasonable construction scheme to deal with the problems caused by water transmission pipeline that pass through soft foundation has engineering reference value and profound significance.After a extensively reviewed of relevant researches of home and abroad, based on the second phase water supply project in Changxing Island Port Industrial Zone, with the experimental study on physical and mechanical properties of mucky silty clay, statistical analysis of datas, numerical simulation of the test section and inspection test of the test section, the following research work about soft foundation of pipeline has been carried out: with more than80physical and mechanical property experiments study and statistical analyses of mucky silt clay, the empirical formulations of natural moisture content and void ratio, of unit weight and void ratio, and of liquid-limit and plasticity-limit index have been proposed. The qualitative and quantitative analyses of complicated mechanical property parameters have been performed, which can be utilized to provide theoretical basis for foundation treatment scheme.Through scheme comparison and selection, dumping rockfill and extruding silt methodology was suggested. According to the theoretical analysis, formulations to calculate the height of the rockfill, the deposition inside the mud and the height above mud surface have been developed. The software package FLAC3D is used to analyze the foundation bearing capacity and corresponding settlement for five rockfill height conditions (1.00,1.25,1.50,1.75and2.00m). The final decision of rockfill height is based on the numerical simulations and design requirements of the foundation bearing capacity. The field measurement towards12points of heavy dynamic sounding test collects the foundation bearing capacity datas after the proposals have been carried out to verify the effectiveness of the developed formulations.Research and test results show that1.5m height of rockfill of test section can satisfy design and construction requirements of the foundation bearing capacity. Therefore, dumping rockfill and extruding silt methodology is efficient to solve the problem of low foundation bearing capacity of mucky silt clay.