梅大高速公路路基边坡失稳条件与滑坡机理初探  

Study on the instability condition and landslide mechanism of subgrade slope in Mei-Da Expressway

作　　者：岳中琦 YUE Zhongqi(School of Science,Harbin Institute of Technology(Shenzhen),Shenzhen,Guangdong 518055,China;Department of Civil Engineering,The University of Hong Kong,Hong Kong 999077,China)

机构地区：[1]哈尔滨工业大学(深圳)理学院,广东深圳518055 [2]香港大学土木工程系,中国香港999077

出　　处：《中国地质灾害与防治学报》2024年第4期1-12,共12页The Chinese Journal of Geological Hazard and Control

基　　金：国家自然科学基金项目(41372336)。

摘　　要：文章对广东梅大(梅州—大埔)高速公路路基边坡失稳和滑坡的成因机制进行了初步研究和分析,基于香港地区路基边坡失稳滑坡调查研究资料、成果和现场勘察获得了失稳路基边坡附近完全风化花岗岩土的颗粒分布和液限塑限含水率,定量计算、分析了该段路基边坡稳定性。通过Google地形图分析了失稳路基边坡附近的几个可能汇水区域和汇水量,对该路基边坡失稳与滑流的成因机制进行了分析。研究认为山坡公路建设需要开挖削坡和填土,可完全改变自然山坡汇水流域;公路可成为瞬态河流,将大量雨水跨流域调流到其他公路边坡或山坡,导致边坡失稳和滑坡,形成公路坍塌丢失。这种路基边坡失稳模式亟待深入研究并加强防范。This paper presents a preliminary investigation of the instability and landslide of a road subgrade slope that occurred on May 1,2024 along Mei–Da Expressway.The investigation method is on the basis of past investigation results and findings about instability and landslide of road subgrade slopes in Hong Kong.The Mei–Da Expressway subgrade was constructed by cutting and filling on mountainous slopes.The landslide occurred at a fill slope along a gully.The fill soil was excavated from local soil of completely decomposed granite(CDG).The paper tests the particle size distribution and liquid and plastic limits of the three CDG soil samples that were excavated from adjacent natural slopes.It then examines the stability of the fill slope with a simplified geological slope model.It further investigates the catchments before and after the road construction.It then presents a possible mechanism for the slope instability and landslide.The field observations by others can confirm this mechanism.The cutting and filling of the hillside slopes significantly changed the runoff paths of the three natural catchments above the road.The road can intercept the runoff along the three gullies and direct all the runoff into the fill slope.The large volume of rainfall water can erode and liquefy the fills,which can cause the instability and landslide of the road subgrade slope.There is an urgent need to further investigate this mode of road subgrade instability and landslide since it is not uncommon.

关 键 词：边坡稳定性 滑坡机理 山区公路 降雨 汇水盆地 跨流域调水 

分 类 号：P642.22[天文地球—工程地质学]