跨逆断层岩质边坡上下盘动力响应和破坏模式振动台试验  

Shaking table test of dynamic responses and failure mechanism of hanging wall and footwall on rock slope across reverse faults

作　　者：漆芍见 范宣梅[1] 夏明垚 魏涛 张欣欣 王文松 QI Shaojian;FAN Xuanmei;XIA Mingyao;WEI Tao;ZHANG Xinxin;WANG Wensong(State Key Laboratory of Geohazard Prevention and Geoenvironment Potection,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,成都610059

出　　处：《地质科技通报》2025年第1期138-149,共12页Bulletin of Geological Science and Technology

基　　金：国家杰出青年科学基金项目(42125702);国家自然科学基金项目(42207224);四川省自然科学基金项目(2022NSFSC0003,2022NSFSC1071);腾讯基金会项目(EXPLORER-2022-1012)。

摘　　要：强震作用下近断层滑坡常造成灾难性的后果。其中,逆断层活动影响下的地震诱发滑坡动力响应特性复杂,破坏性强。然而,目前国内外对逆冲型地震作用下,断层的存在和错动作用对此类滑坡动力响应规律和失稳破坏模式的影响缺乏系统的认识。开展了含软弱逆断层错动机制下岩质边坡大型振动台试验,对跨逆断层边坡的错动过程进行了模拟,结合粒子图像测速技术(PIV),深入分析了不同振幅值、下同频率的地震波作用下,模型边坡上下盘的动力响应规律和失稳破坏模式的差异性。试验结果表明,随着地震波加载振幅值和频率的增大,模型边坡加速度放大系数呈非线性增大趋势;在逆断层错动过程中,坡体发生显著破坏,且上下盘放大系数被显著增强,其中上盘加速度峰值被放大1.24倍,下盘被放大1.13倍;基于PIV观测模型边坡的失稳破坏过程分析表明,上盘以张拉破坏为主,坡体中上部发育大量张拉裂隙;而下盘则以先张拉后剪切破坏为主,在上盘的摩擦与挤压作用下产生由断层面向坡外贯穿的拉剪裂纹。模型试验有效地揭示了考虑断层错动作用下跨逆断层边坡的动力响应规律和失稳破坏模式,表现出明显的上下盘效应,且断层错动过程增强了模型边坡的上下盘效应,对滑坡破坏模式具有显著影响。本研究从试验的角度探究了考虑逆断层错动机制下斜坡的上下盘效应与破坏模式。[Objective]Near-fault landslides frequently result in catastrophic consequences under strong earthquakes,Among them,the dynamic response characteristics of earthquake-induced landslides under the influence of reverse fault activity are complex and destructive.However,there is a lack of systematic understanding,both domestically and internationally,concerning the influence of the presence and dislocation of faults on the dynamic response and failure mechanism of earthquake-induced landslides,specifically under thrust earthquakes.[Methods]In this study,the large-scale shaking table tests were conducted on rock slopes considering weak reverse fault dislocation to simulate the fault dislocation process of cross–reverse fault slopes.Combined with particle image velocity(PIV)technology,the differences in the dynamic response law and failure mechanism between the hanging wall and footwall of cross-reverse fault slopes under the influence of seismic waves with varying amplitudes and frequencies were analyzed deeply.[Results]The results show that with increasing loading amplitude and frequency,the slope amplification factors of the model increase nonlinearly.During the reverse fault dislocation process,the model slope experiences significant damage,with notable increases in amplification factors for both the hanging wall and footwall.Specifically,the peak acceleration of the hanging wall is amplified by a factor of 1.24,whereas that of the footwall increases by a factor of 1.13.Based on PIV observations,the failure mechanism of the model slope was discovered:the hanging wall was dominated by tension failure,and the tensile cracking failure was concentrated in the middle-higher edge of the slope.On the conteary,the failure of the footwall is caused mainly by tension and then shear.The footwall produces penetrating tensile-shear cracks under the friction and extrusion of the hanging wall.[Conclusion]The model tests have effectively revealed the dynamic response laws and failure mechanisms of cross-reverse fault slopes und

关 键 词：逆冲型地震 振动台试验 粒子图像测速技术 动力响应规律 失稳破坏模式 上下盘效应 岩质边坡 

分 类 号：P642.22[天文地球—工程地质学]