桂三高速公路高架桥右侧边坡稳定性时空演变规律分析

以桂三高速公路高架桥右侧边坡工程为依托，研究开挖过程中碎石土高边坡的稳定性时空演变规律，对该边坡岩土体表面位移、深部位移、桩基承台变形及地下水位的变化进行长期监测，并利用FLAC3D软件对该边坡进行稳定性数值对比分析。结果表明：降雨引起地下水位抬升，导致边坡坡脚处体积含水率逐渐升高，孔隙水压逐渐上升，基质吸力逐渐减小，稳定性逐渐降低；在监测期内，边坡地表累计沉降位移前期变化较大，中期呈现起伏状态，最终趋于稳定数值；抗滑桩累积沉降位移变形为先增大后减小，最终逐渐稳定；水位孔高程随时间变化呈先递减后增加的状态，最终趋于平缓；同时，测斜孔监测结果反映边坡深部12m处曾产生一定变形，但变形量较小，这与数值分析结果基本相符，说明采用抗滑桩加固碎石土高边坡效果良好。

Temporal and spatial evolution of slope stability on right side of a viaduct on the Guisan Expressway

The purpose of this work was to study the temporal and spatial evolution of slope stability during excavation on the right side of a viaduct on the Guisan Expressway. It was based on long-term monitoring to surface displacement, deep displacement, deformation of pile foundation and change of groundwater level.And FLAC3D software was used to analyze the stability of the slope. Results show that the groundwater level rose by rainfall, leading to the increase of volumetric water content at the foot of the slope, while the pore water pressure gradually increased and the matrix suction decreases, thus stability gradually declined. During the monitoring period, the cumulative settlement displacement of the slope surface changed greatly in the early stage, undulating in the middle period, and eventually tended to be stable.The cumulative settlement displacement of anti-slide piles increased first, then decreased, and finally stabilized.The elevation of the water level hole decreased first and then increased with time, and eventually tended to be gentle.At the same time, the monitoring results of the inclined hole reflects that some deformation has occurred at depth 12m in the slope, but its magnitude is small, basically consistent with the numerical analysis results, indicating that the high slope of the gravel soil can be strengthened effectively by anti-slide piles.