红砂岩顺层边坡监测及变形破坏分析

 由于红砂岩易风化崩解、长期强度低以及层间发育泥化夹层等特点，坡脚开挖后往往形成稳定性差的顺层边坡。根据现场调查分析认为，不利的地质结构、坡脚开挖及降水诱发是红砂岩顺层边坡发生变形破坏失稳的主要原因。长期的边坡监测数据表明，边坡在抗滑桩支护后仍处于蠕滑变形，边坡及抗滑桩均出现不同程度的变形。结合以往研究工作，综合分析边坡监测数据认为，持续高强度降水和滑面向深部发展是处治后的边坡及支护结构变形的主要原因。抗滑桩支护后滑面向深部发展，新滑面位于稳定地下水位以上。持续的高强度降水对泥化夹层的淋滤作用明显，并使泥化夹层含水量增大、强度降低，边坡的剩余下滑力增大，抗滑桩通过变形协调发挥抗滑作用。

MONITORING AND DEFORMATION FAILURE ANALYSIS OF RED SANDSTONE BEDDING SLOPE

Because of the characteristics of weathering disintegrating easily，low long-term strength and argillization intercalation development for red sandstone，toe excavation produces enormous susceptible bedding slopes. Combining a construction project，the main reasons of red sandstone bedding slope failure are unfavorable geological structure，toe excavation and precipitation. According to long-term slope monitoring data，the slope is still in the stage of creep deformation after treatment of anti-slide piles and the slope and anti-slide piles deform to different extents. Based on previous research and data processing of long-term slope monitoring，analysis results indicate that the main reasons of deformation of slope and piles are continuous and intensive precipitation and sliding surface going deeper. New sliding surface is above stable underground water table，so that eluviations and water content increase of argillization intercalation could happen only under continuous and intensive precipitation which lead to shear strength reducing and residual sliding force increasing. Piles deform to adjust increasing residual sliding force.