地震作用下预应力锚杆岩质边坡动力特性数值模拟研究

针对以往研究对动力作用下的岩质边坡与锚固结构的联合受力特征研究较少这一不足,利用岩土工程专业软件Geostudio,建立了含预应力锚杆岩质边坡的动力有限元计算模型,模拟了在峰值加速度为0.3 g的EI-central波作用下的岩质边坡不同位置的位移、速度、应力及锚杆轴力变化规律。结果表明:地震动力作用对边坡的水平位移有累计增大效应,同时岩质边坡的水平位移具有典型的“鞭梢效应”,岩质边坡的水平位移上部大于下部,表层大于内部,同时竖向位移与水平位移相比可以忽略不计;岩质边坡的水平速度明显大于竖向速度,边坡表层的速度大于内部速度,表明地震动力作用下表层部分更容易失稳破坏。岩质边坡的最大主应力随高程的降低而增大,坡脚处的最大主应力最大,表明地震动力作用下的坡脚部分最容易破坏;地震动力作用下预应力锚杆轴力随地震波沿预应力值进行波动,随着岩质边坡高程的增大,峰值锚固力越大。研究成果可为认识地震动力作用下的岩质边坡与预应力锚杆联合受力规律提供参考。

Numerical Simulation of Dynamic Characteristics of Prestressed Anchor Rock Slope under Seismic Action

The Dynamic finite element model of rock slope with prestressed anchor is established by using software of geotechnical engineering Geostudio, in order to simulate the displacement, velocity, stress and axial force change law of rock slope under the action of EI-central wave with peak acceleration of 0.3 g. The results show that the seismic dynamic action has cumulative increase effect on the horizontal displacement of slope, and the horizontal displacement of rock slope has typical "whip tip effect ", The horizontal displacement of the upper part is larger than that of the lower part, the horizontal displacement of the surface layer is larger than that of the inner part, and the vertical displacement is negligible compared with the horizontal displacement; the horizontal velocity of the rock slope is obviously larger than the vertical velocity, which indicates that the surface part is more vulnerable to instability under seismic action; The axial force of prestressed anchor rod fluctuates with the prestress value of seismic wave under the action of seismic force and with the rock quality With the increase of slope elevation, the greater the peak anchoring force. The research results provide a reference for the understanding of the joint force law of rock slope and prestressed anchor rod under seismic dynamic action.