复杂岩体边坡关键块体搜索及开挖支护

Search of Key Block in Complex Rock Mass Slope and Support of Excavated Slope

采用非接触摄影测量技术采集某高速公路工程边坡岩体的结构面信息,导入自行开发的GeoSMA-3D系统,建立该边坡三维数值模型,从几何学角度搜索出其关键块体.用三维离散元数值计算软件3DEC模拟该边坡工程的开挖过程以及锚索支护后的开挖过程.结果表明,本岩质边坡工程开挖后,引起岩体内部应力重分布,坡体有大范围的剪切塑性区,位移矢量、速度矢量大量集中在开挖面附近的节理上,矢量的方向偏向于临空面,并呈现逐渐增加趋势,整体稳定性较差,若不对边坡采取适当支护措施,必将发生边坡整体失稳破坏;在锚索支护后,边坡的潜在滑移面被控制,边坡整体处于稳定状态.

The information of the structural planes was collected using a contactless photography measurement technique,and then it was imported into GeoSMA-3D system which was developed by author to establish the spatial numerical model of rock mass slope.In this way,the key blocks can be defined in terms of dimensions and positions.Then 3DEC was used to simulate the slope excavation and excavation after anchor support.The results showed that the excavation of the rock slope causes the rock internal stress redistribution and a wide range of the shear plastic zone,and the displacement and velocity are heavily concentrated on the joints in the vicinity of the excavation face.The directions of displacement and velocity lean to the free face and their magnitude tends to increase gradually.So if no appropriate supporting measures are applied,the overall instable failure of rockmass slope will happen.After anchor support,the potential slip surface of the slope is controlled and the slope is in a steady state as a whole.