基于Pasternak模型的基坑开挖对邻近桩基影响分析  

Analysis of the Influence of Foundation Pit Excavation on Adjacent Pile Foundation Based on Pasternak Model

作　　者：陈晓飞 Chen Xiaofei(China Railway ERJU Group Co.,Ltd.,Chengdu 610031,China)

机构地区：[1]中铁二局集团有限公司,四川成都610031

出　　处：《华东交通大学学报》2025年第1期38-44,共7页Journal of East China Jiaotong University

基　　金：国家自然科学基金项目(52108321)。

摘　　要：为准确预测基坑开挖过程中对邻近桩基础的影响,文章基于Pasternak模型采用两阶段法分析桩基础水平变形及沉降等问题。第一阶段通过计算基坑开挖引起的桩基础轴线处地基土水平位移与竖向沉降,第二阶段采用考虑土体剪切应变的Pasternak模型模拟桩基础变形,并结合叠加法对基坑开挖引起邻近桩基础水平变形及沉降进行求解,提出了简化计算方法。依托横琴杧洲隧道工程基坑施工监测数据对比文章计算结果,验证了文章方法的准确性。结果表明:基坑开挖对邻近桩基的侧向位移、弯矩的影响主要在距离基坑0.4倍开挖深度范围内;而对桩身沉降的影响主要在0.6倍开挖深度范围内。采取支护结构对邻近土体进行加固的方法,能有效减小接近支护结构处地表沉降值。In order to accurately predict the influence of foundation pit excavation on adjacent pile foundation,this paper uses two-stage method to analyze the horizontal deformation and settlement of pile foundation based on Pasternak model.In the first stage,the horizontal displacement and vertical settlement of foundation soil at the axis of pile foundation caused by foundation pit excavation are calculated by the formula.In the second stage,the Pasternak model considering soil shear strain is used to simulate the deformation of pile foundation,and the horizontal deformation and settlement of adjacent pile foundation caused by foundation pit excavation are solved by superposition method,and a simplified calculation method is proposed.Based on the monitoring data of foundation pit construction of Hengqin-Mangzhou tunnel project,the accuracy of this method is verified by comparing the calculation results of this paper.The results show that the influence of foundation pit excava-tion on the lateral displacement and bending moment of adjacent pile foundation is mainly within the range of 0.4 times the excavation depth of foundation pit.The influence on the settlement of the pile is mainly in the range of 0.6 times the excavation depth.The method of reinforcing the adjacent soil by supporting structure can effectively reduce the surface settlement value near the supporting structure.

关 键 词：基坑开挖 桩基础 二阶段法 Pasternak模型 

分 类 号：TU437[建筑科学—岩土工程] U25[建筑科学—土工工程]