单排围护桩选型对深基坑工程的影响研究

Study on the Influence of Single-Row Enclosure Pile Selection on Deep Foundation Pit Engineering

依托成都市市区某基坑工程,使用有限元软件分析了单排桩不同桩径及桩间距对场地及围护结构体系的影响。分析表明:随围护桩桩间距的加密,基顶水平位移值、基底隆起值、桩身最大弯矩、桩身最大剪力减小,基顶沉降值增大;随着围护桩桩径的增大,基顶水平位移值、基底隆起值减小,基顶沉降值、桩身最大剪力增大,桩身最大弯矩明显增大。围护桩每延米抗弯刚度增大3倍,基顶沉降增大20.2%,基顶水平位移减小8.6%,基底隆起减小12.5%,桩身最大水平位移减小10.2%;桩间距相同时,桩径由1.2 m增大至1.5 m,最大弯矩增大约130%。围护桩远离基坑的水平变形使得基顶沉降变小,地下水对本工程影响较小。

Based on a certain foundation pit project in the urban area of Chengdu, the influence of different pile diameters and spacing on the site and retaining structure system was analyzed using finite element software. The analysis indicates that: with the densification of the spacing between retaining piles, the horizontal displacement at the foundation top, foundation uplift, maximum bending moment of the pile, and maximum shear force of the pile decrease, while the foundation settlement increases. With the increase of the diameter of the retaining piles, the horizontal displacement at the foundation top, and foundation uplift decrease, while the foundation settlement, maximum pile shear force, and maximum pile bending moment significantly increase. The flexural stiffness of a retaining pile per meter increases by 3 times, leading to a 20.2% increase in foundation settlement, an 8.6% decrease in horizontal displacement at the foundation top, a 12.5% decrease in foundation uplift, and a 10.2% decrease in maximum pile horizontal displacement. With the same spacing, as the pile diameter increases from 1.2m to 1.5m, the maximum bending moment increases by approximately 130%. The horizontal deformation of the retaining piles away from the foundation pit results in reduced foundation settlement, and the impact of groundwater on this project is relatively small.