Study On Influence Of Compaction Effect On Rigid Pile Composite Foundation

With the rapid development of city construction the technology of ground treatment promoted gradually. Different construction technology of pile composite foundation is widely used in engineering practice. The rigid pile composite foundation has many advantages in practice because the rigid pile takes the advantages of high bearing capacity and high stiffness.Static pile has some superiority such as small impact on surrounding environment when constructing, the construction speed is quick, the economy benefit well and so on. Static pile takes the favor of civil engineers.Accompany the construction of prefabricated rigid pile there exists compaction effect. Soil located at the position of pile is greatly extrusion and spread to a pile. Soil around the pile has certain vertical uplift and horizontal displacement, when the soil is saturated cohesive soil excess pore water pressure exists. All these will affect the surrounding environment. Compaction pile composite foundation differs from non-compaction pile composite foundation on bearing characteristics when bearing load for the soil is compacting and there is large pressure between pile and soil.This paper summarizes the compaction effect theory analysis method. Analyze the influence of compaction effect on composite foundation. Using finite element software ABAQUS simulate the process of pile driving. Analyze compaction effect rules. Based on round hole expansion theory establish single pile composite foundation model compared with non-compaction pile composite foundation, analysis the influence of compaction effect on composite foundation. The achievements mainly include:(1) With the driving process soil proximal the pile goes into plastic. The vertical displacement of soil along the pile performed sinking for friction role on pile-soil interface, in a distant the soil uplift. With the increase of depth of pile into soil the uplift of soil increase. The horizontal displacement decreases exponentially with distance of soil and pile increases.(2) There is great pressure between pile and soil. Soil compaction causes certain additional stress on soil around pile. Horizontal stress diminishes quickly with the increase of distance from surface of pile. The vertical stress of pile soil in the proximal shallow place have larger effects when the piling, while it influences little for the soil distant.(3) The p-s curve of compaction pile composite foundation differs from that of non-compaction pile composite foundation. When bearing the same load the settlement of compaction pile composite foundation is smaller than non-compaction pile composite foundation. The bearing capacity of soil around the pile plays first in compaction pile composite foundation. Pile-soil stress ratio of compaction pile composite foundation is smaller than non-compaction pile composite foundation when the load is small.(4) The maximum lateral friction of compaction pile composite foundation is bigger than that of non-compaction pile composite foundation. The tip resistance of pile plays relatively lags. When the load is large enough, the friction of compaction pile composite foundation plays completely, and then the tip resistance of pile increase rapidly.