含向斜软硬互层岩质边坡失稳离心模型试验  

Centrifugal Model Test on Instability of Synclinic Soft-Hard Interbedded Rock Slope

作　　者：柳万里 周春宏 程万强 王滨 王磊[2] LIU Wanli;ZHOU Chunhong;CHENG Wangqiang;WANG Bin;WANG Lei(PowerChina Huadong Engineering Corporation Limited,Hangzhou,311122,China;State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]中国电建集团华东勘测设计研究院有限公司,杭州311122 [2]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：《山地学报》2025年第1期132-143,共12页Mountain Research

基　　金：中国电建集团华东勘测设计研究院有限公司科技立项项目(KY2022-KC-02-03)。

摘　　要：中国西南地区超过76%的深层倾倒体发育于软硬互层边坡中。工程界对这类特殊结构体的认知深度不足,现有工程模型多忽略地质构造影响,对构造-岩性耦合效应考虑不足。本研究以卡拉水电站一江滑坡为研究对象(杂谷脑组典型软硬互层边坡),创新性构建含向斜构造的地质概化模型。通过大型离心模型试验(以石英砂、水泥、重晶石粉、石膏、水为原料制作相似材料),实现构造控制型倾倒变形的全过程动态模拟,揭示软硬岩层差异破坏的时空演化规律。研究发现:(1)位移场呈现显著空间分异。坡面各监测点的竖向位移曲线按演化趋势可划分为6个阶段。坡顶处累计竖向位移最大,约81.1 mm;坡体中部位移次之,约10 mm;坡脚位移最小,约8.3 mm。(2)破坏演化具阶段性。边坡模型由坡顶开始发生倾倒变形破坏,位于坡体中部的向斜产生压缩变形与小角度旋转(≤3.1°);大量压致拉裂缝集中发育于向斜上部坡体内,并贯通形成倾倒折断面。(3)构造缓冲效应显著。软硬互层岩体结构导致的非协调变形与坡体中部向斜构造压缩变形的缓冲作用,削弱了边坡上部岩体对向斜下部坡体的推挤压缩作用,宏观表现为向斜以下坡体无明显变形。(4)含向斜软硬互层反倾岩质边坡的变形失稳模式为自上而下的非协调式深层倾倒破坏。本研究能够丰富软硬互层这一特殊结构岩质边坡的孕灾变形与成灾失稳理论,并为西南地区同类型边坡的防治设计提供科学依据。Over 76%of deep-seated toppling geo-bodies in southwestern China develop within soft-hard interbedded slopes.Available engineering models inadequately address the structural complexity of such slopes,particularly neglecting the tectonic-lithological coupling effect.In this study,it took the Yijiang landslide at the Kala Hydropower Station(a typical hard-soft interbedded slope in the Zagunao Formation)as research object.An innovative generalized geological model incorporating synclinal structures was developed.Large-scale centrifugal model tests were conducted using simulated materials(quartz sand,cement,barite powder,gypsum,and water)to dynamically replicate the entire syncline-controlled toppling process,revealing spatiotemporal evolution mechanisms of differential failure in soft-hard interlayers.(1)Significant spatial differentiation in displacement fields:Vertical displacement curves at monitoring points exhibited six evolutionary stages.Maximum cumulative vertical displacement occurred at the slope crest(81.1 mm),followed by mid-slope(10 mm)and slope toe(8.3 mm).(2)Stage-dependent failure evolution:Deformation initiated from the crest,with synclinal compression and minor rotation(≤3.1°)observed at mid-slope.Compression-induced tensile cracks concentrated in the upper syncline zone,coalescing into through-going toppling surfaces.(3)Remarkable structural buffering effect:Non-coordinated deformation from lithological contrasts and synclinal compression at mid-slope reduced thrust transmission efficiency,resulting in negligible deformation below the syncline.(4)A“top-down non-coordinated deep toppling”failure mode was identified for syncline-containing soft-hard interbedded counter-tilted slopes.This study advances the theoretical framework for hazard evolution in structurally complex slopes and provides scientific guidelines for slope reinforcement in southwestern China.

关 键 词：离心试验 软硬互层 复杂结构边坡 倾倒变形 失稳机制 

分 类 号：P642.2[天文地球—工程地质学]