某岩质边坡卸荷作用下分步开挖动态响应分析

Dynamic Response Analysis of Rock Slope Excavation by Steps under Action of Unloading

鉴于岩质边坡在分步开挖过程中,边坡内应力会相应发生动态变化,每一步开挖都会对边坡产生不同程度的影响,基于卸荷岩体力学理论,通过模拟某水电站放空洞进水口岩质边坡的开挖,分析了分步开挖引起的水平向应力场动态变化规律。结果表明,随着边坡分步开挖的进行,边坡内部应力因开挖距离的变化而变化,在应力剧变阶段,受开挖影响强烈,不利于边坡稳定。因此,边坡开挖和加固设计应合理适时地进行,以避免地质灾害发生。

Because the stress of slope appears dynamical change in the process of rock slope excavation by steps,every step of excavation has impact on the slope to some degree.Based on the unloading rock mass mechanics theory,the dynamic change rule of the horizontal stress field,which is caused by step excavation,has been analyzed by simulating excavation of rock slope of the emptying tunnel＇s water inlet in a hydropower station.It shows that the internal stress of slope varies with excavation distance along with the process of step excavation.At the stage of stress dramatic change,the internal stress will be strongly influenced by excavation,which is bad to slope stability.Therefore,the slope excavation and strengthening design should be done duly and reasonably to avoid the geological disasters.