摘要
深层原生裂隙在膨胀土地层中普遍存在,沿裂隙面的深层滑动是膨胀土边坡失稳的重要模式。为掌握深层裂隙性失稳模式下膨胀土高边坡的变形演化特征,开展了高边坡开挖卸荷的现场原型试验。由试验测得了从稳定发展至破坏过程中边坡的水平位移,获得了滑裂面几何形态,进而推导了深层裂隙性失稳模式的力学机制;采用位移速率幂指数作为边坡变形演化趋势的量化参数,分析了开挖速率及降雨对边坡变形状态的影响;按变形发展快慢趋势,将边坡变形划分为缓慢稳定、缓慢失稳、短时失稳和快速失稳4种状态类别,并提出定量判别阈值;根据不同变形状态下边坡的位移速率及其幂指数的分布规律,提出了适用于膨胀土深层裂隙性滑坡的预警方法。所得成果为膨胀土边坡变形控制和滑坡预警提供了理论和试验依据。
Deep native fissures are ubiquitous in expansive soil.Deep sliding along the fissure surface is an important mode of slope instability in expansive soil.In order to understand the deformation evolution characteristics of expansive soil high slope under deep fractured instability mode,a prototype test of high slope excavation unloading was carried out.The horizontal displacement of the slope developing from stable to failure was tested,and the geometry of slip surface was obtained,so that the mechanical mechanism of deep fractured instability mode was derived.The displacement rate exponent was used as the quantitative parameter to describe the slope deformation evolution trend,and the influence of excavation rate and rainfall on slope deformation state was analyzed.According to the trend of deformation development,slope deformation is divided into three state categories:slow instability,long-term instability and rapid failure,and their quantitative thresholds are proposed;according to the distribution law of slope displacement rate and its power exponent under different deformation states,a method for predicting deep fissured landslide in expansive soil is proposed.The results provide theoretical and experimental basis for deformation control and landslide early warning of expansive soil slopes.
作者
吴庚
宋书学
陈雪兵
熊勇
WU Geng;SONG Shuxue;CHEN Xuebing;XIONG Yong(Head Section,Middle Branch of China South-to-North Water Diversion,Co.,Ltd.,Nanyang 473000,China;Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of WaterResources,Changjiang River Scientific Research Institute,Wuhan 430010,China)
出处
《人民长江》
北大核心
2023年第11期175-181,共7页
Yangtze River
基金
国家自然科学基金青年基金项目(51709016)
中央级公益性科研院所基本科研业务费项目(CKSF2019199/YT)
水利部科技推广项目(SF-202201)。
关键词
膨胀土高边坡
深层裂隙
力学机制
变形演化特征
原型试验
expansive soil high slope
deep fissure
mechanical mechanism
deformation evolution characteristics
prototype test
