摘要
地裂缝是西安典型的城市地质灾害,强降雨是黄土地裂缝场地沉降变形的诱发因素之一。为揭示黄土地裂缝场地雨水入渗导致的沉降变形规律,基于室内物理模型试验,模拟强降雨下黄土地裂缝场地的雨水入渗过程,结合分布式光纤监测技术,分析强降雨下地裂缝场地土层应力应变状态,讨论次级裂缝产生过程及影响范围。研究表明:降雨入渗过程中雨水向地裂缝处汇集,地裂缝上盘0.5~0.7 m(原型5~7 m)范围内土压力显著增加;降雨导致地裂缝附近产生较大的孔隙水压力,且距地裂缝越近,孔隙水压力越大;降雨引起地裂缝两侧土体应变呈“马鞍型”变化态势,应变增量随深度增加而逐渐减小;地裂缝的存在导致上、下盘之间出现明显差异沉降,在距离主地裂缝约0.7 m(原型7 m)范围内的地表产生与主裂缝产状基本一致的次级张裂缝。研究结果可为黄土地区地裂缝场地建(构)筑物地基稳定性与地裂缝设防提供科学依据。
Ground fissure is a typical urban geohazard in Xi’an,and heavy rainfall is one of the inducing factors for the settlement-deformation in loess ground fissure sites.Based on the indoor physical model test,the infiltration process of rainwater into the loess ground fissure site under heavy rainfall was simulated to reveal the settlement-deformation characteristics induced by rainfall infiltration in loess ground fissure site.The stress-strain state of soil layers was analyzed in ground fissure sites under heavy rainfall.Using distributed optical fiber monitoring technology,the generation process and influence range of secondary cracks were discussed.The results show that during the infiltration process of rainfall,rainwater converges towards the ground fissure,and the earth pressure increases significantly within the range of 0.5−0.7 m(5−7 m for the prototype)in the hanging wall of ground fissure.Pore water pressure near the fissure is elevated,with values increasing as the distance to the fissure decreases.The soil strain on both sides of ground fissures caused by rainfall shows a"saddle shape"change trend,with the strain increment gradually decreasing with depth.The presence of ground fissures induces differential settlement between the hanging and footwalls,causing the formation of secondary tensile fissures on the surface,oriented similarly to the main fissure,within approximately 0.7 m(7 m in prototype scale).This study provides a scientific basis for the foundation stability and fortification of buildings(structures)in loess ground fissure sites.
作者
马祥
黄强兵
苟玉轩
郝健儒
郭治宇
张岩
MA Xiang;HUANG Qiangbing;GOU Yuxuan;HAO Jianru;GUO Zhiyu;ZHANG Yan(Department of Geological Engineering,Chang’an University,Xi’an,Shaanxi 710054,China;Key Laboratory of Earth Fissures Geological Disaster,Ministry of Natural Resources,Nanjing,Jiangsu 210049,China)
出处
《水文地质工程地质》
北大核心
2026年第1期204-216,共13页
Hydrogeology & Engineering Geology
基金
国家重点研发计划项目(2023YFC3008404)
自然资源部地裂缝地质灾害重点实验室开放基金项目(EFGD20240609)。
关键词
黄土场地
地裂缝
强降雨
渗透变形
模型试验
loess site
ground fissure
heavy rainfall
seepage deformation
model test
