吉尔木隧道出口边坡赤平投影稳定性分析  

Stability Analysis of Jiermu Tunnel Exit Slope Based on Stereographic Projection

作　　者：刘伟鹏 毛邦燕[1] 侯伟龙[1] LIE Wei-peng;MAO Bang-yan;HOU Wei-long(China Railway Eryuan Engineering Group Co.Ltd,Chengdu,Sichuan 610031,China)

机构地区：[1]中铁二院工程集团有限责任公司,成都610031

出　　处：《铁道工程学报》2018年第10期59-64,共6页Journal of Railway Engineering Society

基　　金：中铁二院工程集团有限责任公司科研项目[院控KYY2016001(16-17)]

摘　　要：研究目的:赤平投影可通过空间投影关系直观反映不同结构面的空间组合关系,适用岩质边坡稳定性定性评价。块体理论可对不同破坏类型的结构体稳定性进行定量计算。本文将基于吉尔木隧道出口边坡的现场调查,分析该边坡岩体结构类型和基本破坏模式,并利用Barton模型估计岩体结构面强度参数。在此基础上,结合赤平投影理论和块体理论分析该边坡潜在失稳岩体的结构面组合关系,并确定各模式块体的稳定性系数,以期为边坡防护设计提供一定的指导。研究结论:(1)通过Barton模型计算结构面的力学指标表明:在法向应力为2 MPa时,结构面的内聚力C=0. 12 MPa,内摩擦角φ=34°～36°;(2)隧道出口边坡岩体主要破坏模式有倾倒式破坏、楔形体滑动破坏和平面滑动破坏,其中倾倒式破坏主要受直立卸荷裂隙控制;平面滑动破坏主要为沿与坡面近平行的长大卸荷裂隙滑动和沿岩层层面滑动;楔形体破坏主要受到了岩层层面、近直立卸荷裂隙和密集节理面的共同控制;(3)赤平投影分析表明:边坡岩体沿单滑面破坏的块体1和块体2以及沿双滑面交线破坏的块体12是不稳定的,其中块体2的稳定性最差;(4) Barton模型、赤平投影及块体理论相结合的岩质边坡稳定性分析方法具有准确和快捷的优点,该方法在高陡岩质边坡分析中具有良好的应用前景。Research purposes： Stereographic projection can directly reflect the spatial combination relation of different structural planes through the spatial projection relation,which can be used to evaluate the stability of rock slope. The block theory can be used to calculate the stability of structures with different failure types. In this paper,the analysis of structure type of the slope rock mass and the basic failure mode would be done based on investigation of the slope on the exit of Jiermu tunnel and the Barton model is used to estimate the strength parameters of rock mass structural plane. On this basis,combined with stereographic projection method and the block theory,the analysis of structural plane combination relation and the stability coefficient of the slope instability of rock mass are done to provide guidance for the design of slope protection.Research conclusions：（ 1） The mechanical index of the structural plane calculated by the Barton model shows that the cohesive force C = 0. 12 MPa and the internal friction angle φ = 34° ～ 36°when the corresponding force is 2 MPa.（ 2） The failure modes of the slope are toppling failure,wedge sliding failure and plane sliding failure. The toppling failure is mainly controlled by a set of near vertical unloading fractures. The plane failure mainly is sliding along the unloadingfracture parallel to the slope or sliding along the rock layer. The wedge failure is mainly controlled by the rock layer,the near vertical unloading fracture and a joint.（ 3） The stereographic projection analysis shows that block 1 and block2 which are destroyed by the single sliding surface along the single slip surface and the block 12 that are broken along the intersection of the double sliding surfaces are unstable. The block 2 is of poor stability.（ 4） The analysis method of rock slope stability combined with Barton model,stereographic projection and block theory has the advantages of accuracy,rapidity,and convenience. This method has a good application prospect in

关 键 词：岩质边坡 稳定性评价 赤平投影 Barton模型 结构面强度 

分 类 号：P642.3[天文地球—工程地质学]