全风化花岗岩滑坡稳定性与降雨关系分析OA北大核心CSTPCD
Analysis of the Relationship Between Stability of Fully Weathered Granite Landslides and Rainfall
降雨是滑坡诱发的主要因素,当前我国防灾工作理念从注重灾后救助向注重灾前预防转变、从减少灾害损失向减轻灾害风险转变,因此明晰降雨诱发机理并建立合理的预警机制,对做好地质灾害防灾减灾工作至关重要.针对降雨型全风化花岗岩滑坡稳定性问题,以青岛崂山风景区全风化花岗岩返岭滑坡为实例,进行了不同含水率原状土剪切试验与大型物理相似模型试验.揭示了边坡的降雨响应规律,探究了全风化花岗岩滑坡稳定性与降雨关系,并拟合相关量化公式.同时采用ABAQUS建立边坡流固耦合三维数值模型,基于强度折减法验证了公式的合理性.研究结果表明:(1)降雨型全风化花岗岩滑坡的破坏模式分为浸润侵蚀→表层变形→破坏加深→整体失稳4个阶段,变形期间坡体存在"鼓状凸起"与"片状溜滑"现象,最终发生推移式破坏;(2)边坡对降雨入渗的响应规律在水平及竖向空间上存在差异,降雨强度越大,含水率与孔压增速越大;(3)基于试验结果推导了滑坡含水率、安全系数与降雨强度、降雨持时之间的影响关系公式,数值模拟验证误差率较小,能够较好的描述全风化花岗岩滑坡稳定性与降雨之间的定量关系.研究结果为类似强～全风化花岗岩地区滑坡的预警与防治提供参考.
Rainfall is the primary trigger for landslides.With China's disaster prevention efforts chang-ing from post-disaster relief to pre-disaster prevention,and from disaster loss reduction to disaster risk mitigation,it is crucial to understand the triggering mechanisms for rainfall-induced disasters and es-tablish effective early warning systems for geological disaster prevention and mitigation.To address the stability issues of rainfall-induced landslides in fully weathered granites,shear tests on in-situ soils with different moisture contents and large-scale physical similarity model tests were carried out in Qin-gdao's Lao Mountain area as an example.The slope's response to rainfall was revealed,the relation-ship between the stability of fully weathered granite landslides and rainfall was explored,and relevant quantitative formulas were fitted.Additionally,ABAQUS was used to establish a three-dimensional flow-solid coupled numerical model for the slope,validating the equations through the strength reduc-tion method.The research results showed that:(1)Rainfall-induced fully weathered granite landslides failure progressed through four stages:infiltration and erosion → surface deformation → damage deep-ening → overall instability.The slope exhibited the phenomena of"drum-like bulge"and"sheet-like slipping"during the deformation period,and ended up with a translational slipping.(2)The slope's re-sponse to rainfall infiltration showed spatial variability,with greater rainfall intensity leading to faster increases in moisture content and pore pressure.(3)Based on the experimental results,formulas de-scribing the relationship between landslide moisture content,safety factors,and rainfall intensity and duration were derived.Numerical simulation confirmed the accuracy of these formulas with minor devi-ation,accurately describing the quantitative relationship between landslide stability and rainfall.The results of the study provide insights on early warning and prevention strategies for landslides in areas with similar strongly to fully weathered granite.
刘红军;武闻禹;耿林;刘良;张国良;孙文雨;于鹏
中国海洋大学环境科学与工程学院,山东 青岛 266100自然资源部滨海城市地下空间地质安全重点实验室,山东 青岛 266100||青岛地质工程勘察院(青岛地质勘查开发局),山东 青岛 266100
地质学
全风化花岗岩降雨诱发滑坡物理模型试验数值模拟定量研究
fully weathered graniterainfall-induced landslidesphysical model testsnumerical simula-tionquantitative studies
《防灾减灾工程学报》 2024 (002)
322-332 / 11
自然资源部滨海城市地下空间地质安全重点实验室开放基金(BHKF2021Z11)项目、青岛地质工程勘察院科研基金项目(2022-QDDZYKY06)资助
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