基于排水固结效应的古滑坡稳定性增长分析  

Analysis on Stability Growth of Ancient Landslide Based on Drainage Consolidation Effect

作　　者：胡惠华 陈鑫 胡新红 彭元生 HU Huihua;CHEN Xin;HU Xinhong;PENG Yuansheng(Hunan Provincial Communications Planning,Survey&Design Institute Co.,Ltd.,Changsha 410200,China;Key laboratory of Central South Highway Construction and Maintenance Technology in Hunan Province,Changsha 410200,China;China Nonferrous Metals Changsha Survey and Design Institute Co.,Ltd.,Changsha 410011,China)

机构地区：[1]湖南省交通规划勘察设计院有限公司,长沙410200 [2]中南公路建设及养护技术湖南省重点实验室,长沙410200 [3]中国有色金属长沙勘察设计研究院有限公司,长沙410011

出　　处：《路基工程》2024年第4期27-33,共7页Subgrade Engineering

基　　金：湖南交通科技进步与创新计划(201003,202120)。

摘　　要：京珠高速公路湘境K244滑坡是在雨季开挖路堑诱发巨型古滑坡复活形成的大型土质公路滑坡,滑坡形成的外因是公路路堑开挖和降雨入渗,内因是古滑坡存在连续贯通的滑动带及承压性的地下水。公路滑坡经过排水及抗滑支挡治理后趋于稳定,支挡结构中锚索预应力缓慢衰减。基于公路滑坡和古滑坡滑带土共同的排水固结强度再生机理,提出滑带土再生强度参数的多断面及分层反算法,计算得水上强度参数大于水下强度参数,强度分层特征明显;公路滑坡经排水廊道降水多年后,露出水面的滑带土强度参数增长明显,由此可计算公路滑坡治理后的长期稳定系数;考虑滑带土排水固结强度再生的滑坡推力减小,大致符合锚索长期监测的预应力损失规律;滑坡在治稳后,廊道排水促进滑坡稳定性增长是持续缓慢的过程,符合滑带土强度再生特征。The K244 landslide of Jingzhu Expressway Hunan Section is a large-scale soil highway landslide formed by the revival of a giant ancient landslide induced by road cutting excavation in the rainy season.The external cause of the landslide is the excavation of road cutting and rainfall infiltration,and the internal cause is the existence of continuous cut-through slip zone and bearing groundwater in the ancient landslide.Highway landslide tends to be stable after drainage and anti-sliding support treatment,and the prestress of anchor cable in the support structure slowly decays.Based on the regeneration mechanism of drainage consolidation strength of soil in the slip zone of highway landslide and ancient landslide,the multi-section and inverse algorithm for the regeneration strength parameters of the slip zone soil is proposed.The calculated strength parameters above water are larger than those below water,and the characteristics of the strength delamination are obvious.After many years of dewatering in the drainage corridor,the strength parameter of the soil in the slip zone above the water surface increases obviously,and the long-term stability coefficient of highway landslide treatment can be calculated.Considering the reduction of landslide thrust due to the regeneration of drainage consolidation strength of soil in the slip zone,it generally accords with the law of prestress loss monitored by anchor cable for a long time.After landslide stabilization,corridor drainage promotes the stability growth of landslide in a slow and continuous process,which accords with the characteristics of soil strength regeneration in the slip zone.

关 键 词：古滑坡 推力 位移监测 反算法 排水固结 强度系数 长期稳定性 

分 类 号：TU47[建筑科学—结构工程]