岩脉多次侵入条件下斜坡变形破坏模式及稳定性分析  

DEFORMATION AND FAILURE MODE AND STABILITY ANALYSIS OF THE SLOPE UNDER MULTI-STAGE DIKE INTRUSIONS

作　　者：张玉明[1] 张明[1] 胡新丽[1] 谭福林[1] 祝廷尉 徐聪[1] 

机构地区：[1]中国地质大学(武汉)工程学院,武汉430074

出　　处：《工程地质学报》2015年第2期227-232,共6页Journal of Engineering Geology

基　　金：国家自然基金项目(No.41202200;41472264);国家重点基础研究发展计划(973计划)项目(2011CB710604);中国地质大学(武汉)中央高校基本科研业务费专项资金项目(No.CUGL140409)资助

摘　　要：岩质斜坡受到花岗岩脉的多次侵入,坡体结构和岩体结构均有较大的改变,因此斜坡的变形破坏模式和稳定性均有可能发生变化。本文以雅砻江中游楞古水电站坝址区嘎夏帕斜坡为例,对多次花岗岩脉侵入条件下斜坡的变形破坏模式和稳定性进行分析。嘎夏帕斜坡原本为陡倾中薄层砂岩组成的逆向坡,岩体完整性较好,稳定性较高;由于受到花岗岩脉的多次侵入,坡体变成砂岩和岩脉互层的结构,在岩脉挤压作用下,大部分岩体呈碎裂状,完整性差,坡体的变形模式由弯曲-倾倒式变为"挡墙"溃决式。中部完整性较好的砂岩成为"挡墙",和前部岩脉一起阻止后部大方量碎裂状岩体下滑,但是随着前部脉体的失稳破坏,斜坡有可能发生"挡墙"溃决式整体滑坡。并通过数值模拟软件3DEC进行了验证,计算结果与定性分析一致。本文的结论可以为此类斜坡的稳定性分析和防治提供理论支持,具有一定的参考价值和实际意义。Multi-stage intrusions of dikes can change the rock and slope structures greatly,and further change the deformation and failure mode and the stability of the slope.This paper examines the Gaxiapa slope in the dam area of the Lenggu waterpower station at the midstream of the Yalongjiang River as a case study.Before dike intrusions, Gaxiapa slope was a stable slope with thin-middle layer sandstone.The bedding dip direction is opposite to the slope dip direction.After intrusions,the slope constitutes interbedded sandstone and granite dike.The rock was cracked by crushing of the dikes.The original deformation mode“bending-dumping”changes into“outburst of retaining wall”.The comparatively intact sandstone in the middle became the retaining wall,which blocks the sliding of the cracked rock at the back,together with the front dike.However,the front dike is deforming severely and in a critical steady state now.If the front dike fails,the Gaxiapa slope is likely to slide down entirely.The result of the failure mode analysis is validated using 3DEC numerical simulation software.The conclusions of the study can be of some value for the similar study,and provide the theoretical support for the stability analysis and prevention of the landslide with the similar structures.

关 键 词：雅砻江 岩质斜坡 岩脉侵入 变形破坏模式 3DEC 稳定性分析 

分 类 号：P642.22[天文地球—工程地质学]