软土深基坑滑坡机制分析与优化方案设计  

Slope Failure Mechanism Analysis on a Deep Foundation Pit of Soft Soil and Its Optimization Design

作　　者：王佳俊 王斌 周欣[3] 周傲 程瑶[1] WANG Jiajun;WANG Bin;ZHOU Xin;ZHOU Ao;CHENG Yao(Faculty of Engineering,China University of Geosciences(Wuhan),Wuhan 430074,China;Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China;Jiangsu Transportation Engineering Construction Bureau,Nanjing 210004;School of Civil Engineering,Architecture and Environment,Hubei University of Technology,Wuhan 430064,China)

机构地区：[1]中国地质大学(武汉)工程学院,湖北武汉430074 [2]中国科学院武汉岩土力学研究所,湖北武汉430071 [3]江苏省交通工程建设局,江苏南京210004 [4]湖北工业大学土木建筑与环境学院,湖北武汉430064

出　　处：《安全与环境工程》2022年第1期119-127,共9页Safety and Environmental Engineering

基　　金：国家自然科学基金青年科学基金项目(51709258);江苏省交通工程建设局科技项目(212019YH111205)。

摘　　要：以无锡太湖隧道项目某处软土深基坑开挖施工过程中出现的滑坡实例为研究背景,通过对滑坡破坏模式的现场调查,基于FLAC;软件建立了基坑地质剖面数值模型,结合数值分析结果与现场监测结果的对比,探讨了滑坡发生的机制,并提出了3种边坡加固设计优化方案并进行了对比分析。结果表明:引起本次滑坡发生的原因可能是由于土体空间分布不均匀,使得部分桩体按设计施工时,桩体加固强度和加固深度未达到预期要求,进而导致边坡失稳;在排桩加固强度不足的情况下,在坡脚增加排桩和进一步加固坡脚土体对边坡的加固效果不明显,而在坡脚加入反压土能明显抑制边坡水平位移;在排桩加固深度不足时,3种优化方案对边坡均有不错的加固效果,但综合考虑,建议采用在坡脚加入反压土方案,后续监测数据显示该方案对边坡的加固效果良好。Taking a slope failure that occurred during the construction process in a deep foundation pit of soft soil of Taihu Tunnel Project as its object, through the in-situ investigation of the slope failure, this paper reconstructs the geological profiles of the pit before its failure by using FLAC 3 D software.By comparing the numerical analysis results with the monitoring data, the paper analyzes the mechanism of the slope failure and propose three optimized design schemes and compare them with each other.The results show that the slope failure is most possibly caused by the uneven spatial distribution of the soil properties.Thereby the strength and strengthening depth of some piles may fail to meet the expected requirements when they are constructed, leading to slope instability.When the strength of row piles is insufficient, adding row piles and strengthening the soil at the slope toe have no obvious effect on slope stability, while adding earth berm to the slope toe can significantly prohibit the horizontal slope displacement;when the strengthening depth of row piles is insufficient, all the three optimization schemes show good stabilization effect.Therefore, adding earth berm to the slope toe is recommended and adopted on site, with the subsequent monitoring data showing excellent stabilization effect.

关 键 词：软土深基坑 滑坡机制 桩体失效 优化方案 数值模拟 

分 类 号：X4[环境科学与工程—灾害防治] P642.22[天文地球—工程地质学]