震区岩质边坡稳定性现场监测试验

Experiment of In-situ Monitoring of Rock Slope Stability in Seismic Area

本文结合理县至小金公路(理县段)豹子嘴边坡灾后重建项目实际情况开展了边坡现场稳定性监测试验,监测期间区域范围曾发生3次4.8级以上的地震,根据监测结果得到以下结论:施工后坡面在经历2个月的变形衰减后,基本趋于稳定;该处边坡为反向结构面,地震还将对坡表岩体结构产生一个挤密的变形作用,利于坡表岩层的稳定;地震作用对边坡浅层岩体结构面水平变形有较大的影响,这与边坡处于逆冲断裂上盘的推覆体构造存在压剪作用的区域应力环境有关;水平位移变化在前期较为频繁,这与该处位于道路弯道部位,除了受到行车荷载、地震激发的影响外,可能还有其它未知因素的作用,后期的观测数据表明该处已基本恢复稳定。

Based on the road reconstruction project at Lixian-Xiaojin section in Sichuan Province after earthquake,the in-situ monitoring test for stability of Baozizui rock slope was carried out,three earthquakes which exceed 4.8-magnitude had occurred during the monitoring period.According to monitoring results,it is concluded that（1） the slope deformation attenuated and tended to be stable two months after construction;（2）due to the anti-inclined structural face in the slope,the compacting deformation action,which is beneficial to slope stability,will appear in rock mass under seismic load;（3） the seismic load had great influence on horizontal deformation of structural face in surface rock layer of the slope,which was caused by the regional stress bearing compression and shear in the nappe structures located on the thrust fault upper plate of this slope;（4） the variation of horizontal deformation was frequent in earlier stage located at the road curve,in which there existed traffic load,seismic excitation effects,and maybe other unknown factors.And the later observed data indicates that the deformation has been basically stabilized.