考虑水—岩劣化效应的深基坑开挖变形与支护结构稳定性研究  

The Deformation of Deep Foundation Pit Excavation and Stability of Support Structure Considering Water-rock Deterioration Effect

作　　者：武越 WU Yue(Southwest electric power design Institute Co.,Ltd.,Chengdu 610021,China)

机构地区：[1]中国电力工程顾问集团西南电力设计院有限公司,成都610021

出　　处：《广东水利水电》2023年第10期77-82,共6页Guangdong Water Resources and Hydropower

摘　　要：为研究水岩劣化效应对基坑开挖形变及支护稳定性的影响规律,该文以西南某基坑工程为背景,采用室内试验对不同干湿循环下岩土体物理性能演化规律进行研究,通过构建三维数值仿真模型,对不同工况下考虑了水岩劣化效应的基坑应力场、位移场及支护结构的受力形变规律进行模拟分析。结果表明:随着干湿循环次数的增加,岩土体抗剪强度受到不同程度的削弱,内摩擦角和粘聚力分别衰减了27%和59%。相较于常规基坑开挖,由于水岩劣化效应导致基坑开挖后的地表最大沉降增加到18.5 cm,基坑底部隆起幅度增加了116%。同时支护结构位移量最大增加了约1.5倍。在该类工程中应考虑水岩劣化效应的影响,并及时强化支护设计和加强监测。In order to study the influence of water-rock deterioration effect on the excavation deformation and support stability of foundation pit,this paper takes a foundation pit project in southwest China as the background,uses indoor tests to study the evolution law of geotechnical properties under different wet and dry cycles,and simulates the stress field,displacement field and force deformation law of foundation pit support structure under different working conditions by constructing a three-dimensional numerical simulation model with water-rock deterioration effect.The results show that:with the number of wet and dry cycles,the stress field and displacement field of the pit are reduced.The results show that with the increase of wet and dry cycles,the shear strength of the geotechnical body is weakened to different degrees,and the internal friction angle and cohesion are attenuated by 27%and 59%,respectively.Compared with the conventional pit excavation,the maximum settlement of the surface after the pit excavation increased to 18.5cm due to the water-rock deterioration effect,and the uplift of the bottom of the pit increased by 116%.At the same time the maximum displacement of the support structure increased by about 1.5 times.The influence of water-rock deterioration effect should be considered in this type of project,and the support design should be strengthened and the monitoring should be enhanced in time.

关 键 词：基坑工程 水岩劣化 强度衰减 基坑变形 支护稳定性 

分 类 号：TU753[建筑科学—建筑技术科学]