黎细军,邓黎旭,张国栋,易庆林,邓茂林,尚敏,李俊,张亚鑫,杨剑飞

• 1:防灾减灾湖北省重点实验室
• 2:湖北长江三峡滑坡国家野外观测研究站
• 3:三峡库区地质灾害教育部重点实验室

摘要(Abstract)：

【目的】库区水位周期性波动使库岸涉水滑坡滑带土长期处于有荷载的干湿循环环境中，导致滑坡的稳定性受到显著影响。然而，有荷干湿循环作用对滑带土微细观结构与宏观力学性质之间的多尺度演变机制依旧模糊不清。【方法】基于此，以三峡库区树坪滑坡滑带土为研究对象，在有荷条件下，对经历不同干湿循环次数的重塑滑带土进行直剪试验、扫描电镜(SEM)和核磁共振(NMR)试验，分析了有荷干湿循环作用下重塑滑带土强度和细观结构演化规律。【结果】结果表明：随着有荷干湿循环次数的增加，重塑滑带土黏聚力呈现逐渐增加的趋势(劣化度达到约-30%),而内摩擦角呈现减小的趋势(劣化度达到约22%);孔隙微观上小孔隙逐渐贯通形成大孔隙，但宏观上孔隙度呈指数减小(降幅约7%);其内部集合体由初始的凝块状逐渐分散为细粒状，随后发生了由面-角接触逐渐向面-面接触的演化特征，导致了其内摩擦角的劣化。同时，干燥重塑滑带土的含水率与其黏聚力呈显著的正相关关系，指示其黏聚力随循环次数逐渐增大可能与矿物间水的“水桥效应”密切相关。【结论】研究成果阐明了有荷干湿循环下滑带土结构的多尺度演变机制，对由其结构劣化诱发的地质灾害研究具有重要意义。

关键词(KeyWords)： 滑带土;有荷干湿循环;细观结构;多尺度演变;黏土矿物;滑坡;模型试验

Abstract:

Keywords:

基金项目(Foundation): 国家自然科学基金青年科学基金项目(4190323);; 国家野外科学观测研究站开放基金(2018KTL07)

作者(Author): 黎细军,邓黎旭,张国栋,易庆林,邓茂林,尚敏,李俊,张亚鑫,杨剑飞

DOI: 10.13928/j.cnki.wrahe.2024.12.015

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