Study On The Influence Of Post Grouting On The Mechanical Performance Of Rotary Bored Pile

Due to the influence of the construction process, Rotary Drilled and Bored Piles often have residual sediment and mud cake at the end of the pile and the side of the pile, this will seriously affect the bearing capacity of the pile. Through the study of the high pressure grouting to the end and the side of the pile to improve the negative impact of the bottom sediment and the mud cake, it can greatly improve the carrying capacity and reduce settlement of the pile. Currently, theoretical studies on post grouting to improve the bearing capacity of rotary drilled and bored piles is not perfect, the technology also do not have a unified standard.This article is a series of studies conducted by grouting pile model test, mainly include none grouting pile, side grouting pile and end grouting pile, testing the ultimate bearing capacity, the axial force and the friction resistance, then comparing each other. Analysis of the pile stress distribution and the mechanism of the three situations, and compared with the test results by FLAC3 D numerical simulation software, verify the feasibility that FLAC3 D software numerically simulate related issues of grouting pile. In addition, this paper uses FLAC3 D software to analyze the bearing capacity of Qinhuangdao Tang River International Residential Project No. 2 building pile foundation. Based on the engineering example, simulation and analysis are made on the different position, the different distance and the different grouting radius of the pile. At the same time, comparing the properties of the pile stress of the end grouting, the side grouting and the joint grouting. A series of rules are obtained, hoping that through these laws to guide practice, which can be helpful to the actual project.Research shows, post grouting can effectively improve the physical properties of the pile soil contact surface and the soil around the pile, squeezed soil around pile, improve the bearing capacity of the pile. The lower the grouting position and the greater the grouting radius, the more effectively improve the pile bearing capacity. For the influence of the different grouting distance, the mechanical properties of the grouting pile is not obvious. The effect of joint grouting on the pile side is better than the end grouting pile and the side grouting pile, the effect of grouting at the end of the pile is better than that of the pile side.