房凯,王硕,刘念武.临近基坑开挖条件下有限土体主动土压力分析[J].河南理工大学学报(自然科学版)，doi:10.16186/j.cnki.1673-9787.2024010009

FANG K,WANG S,LIU N W．Active earth pressure analysis of adjacent foundation pits excavated[J].Journal of Henan Polytechnic University(Natural Science)，doi:10.16186/j.cnki.1673-9787.2024010009

临近基坑开挖条件下有限土体主动土压力分析(网络首发)

房凯¹，王硕¹，刘念武²

（1.山东科技大学 能源与矿业工程学院,山东 青岛 266590；2.浙江理工大学 建筑工程学院,浙江 杭州 310018）

摘要: 目的 在临近基坑同时开挖时，坑间有限土体双侧的基坑变形都会对土压力的分布产生影响，合理的分析和确定其有限土压力特性已经成为工程面临的重要问题。 方法 为了表征临近基坑开挖条件下有限土体土压力，利用离散元分析了临近基坑同时开挖条件下有限土体的变形规律和临近基坑开挖对土压力发展的影响机理，通过不同区域土体单元的受力分析构建了临近基坑开挖过程中有限土体主动土压力的分析模型，并对不同挡墙位移条件下的有限土体土压力的发挥特性进行了分析。结果 结果表明，当临近基坑开挖时，有限土体的位移场和滑移模式表现出与单侧基坑开挖不同的特征，相对于单侧基坑开挖条件下的有限土体，临近基坑同时开挖条件下挡墙所受有限土体土压力更小，两种情况下的土压力差值受有限土体宽高比以及挡墙位移影响，有限土体宽高比越小，压力差值越大；随着挡墙位移的增加，两者土压力差值呈先增大后减小的趋势，当挡墙位移达到土体整体主动状极限态所需位移量的一半时，土压力差达到最大值。结论 本文所提方法可以较好地表征临近基坑同时开挖条件下的土压力分布特征，为受两侧挡墙位移影响条件下的有限土体主动土压力计算提供理论支撑。

关键词: 主动土压力；有限土体；临近基坑；离散元方法

doi:10.16186/j.cnki.1673-9787.2024010009

基金项目: 国家自然科学基金资助项目(52078466)

收稿日期：2024-01-02

修回日期：2024-02-25

网络首发日期：2024-03-05

Active earth pressure analysis of adjacent foundation pits excavated

FANG Kai¹,WANG Shuo¹,LIU Nianwu²

( 1.College of Energy and Mining Engineering,Shandong University of Science and Technology,Qingdao 266590,Shandong,China; 2.School of Civil and Architecture,Zhejiang Sci-Tech University,Hangzhou 310018,Zhejiang,China)

Abstract: Objective When adjacent foundation pits are excavated simultaneously, the deformations of both sides of the finite soil between the pits will influence the distribution of earth pressure. The rational analysis and determination of the characteristics of finite soil pressure have become crucial issues in engineering. Methods In order to characterize the soil pressure of finite soil under the condition of adjacent foundation pit excavation, the deformation law of finite soil under the condition of simultaneous excavation of adjacent foundation pits and the influence mechanism of adjacent foundation pit excavation on the development of soil pressure are analyzed by discrete element method. Through the stress analysis of soil elements in different regions, the analysis model of active soil pressure of finite soil in the process of adjacent foundation pit excavation is constructed, and the characteristics of soil pressure of finite soil under different retaining wall displacement conditions are analyzed. Results The results show that the displacement field and slip mode of finite soil are different from those of unilateral foundation pit excavation. Compared with the finite soil under the condition of unilateral foundation pit excavation, the earth pressure on the retaining wall under the condition of simultaneous excavation of adjacent foundation pits is smaller. The difference of earth pressure between the two cases is affected by the aspect ratio of the finite soil and the displacement of the retaining wall. The smaller the aspect ratio of the finite soil, the greater the pressure difference. With the increase of the displacement of the retaining wall, the difference of the earth pressure between the two increases first and then decreases. When the displacement of the retaining wall reaches half of the displacement required for the overall active limit state of the soil, the earth pressure difference reaches the maximum value. Conclusion The method proposed in this paper can better characterize the distribution characteristics of earth pressure under the condition of simultaneous excavation of adjacent foundation pits, and provide theoretical support for the calculation of active earth pressure of limited soil under the influence of displacement of retaining walls on both sides.

Key words: active earth pressure; limited soil mass; adjacent foundation pits; distinct element method