黄土-泥岩接触面滑坡的启动及运动特征  

Characteristics of Initiation and Movement of Loess-Mudstone Contact Surface Landslides

作　　者：董建明 张志萍 黄纲领 刘静伟 DONG Jianming;ZHANG Zhiping;HUANG Gangling;LIU Jingwei(China Highway Engineering Consultants Co.,Ltd.,Beijing 100089,China)

机构地区：[1]中国公路工程咨询集团有限公司,北京100089

出　　处：《铁道勘察》2025年第2期65-71,共7页Railway Investigation and Surveying

基　　金：西藏自治区科技计划项目(XZ202402ZD0008)。

摘　　要：黄土-泥岩接触面滑坡是黄土滑坡的一种,滑动面发育在下伏泥岩层,具有滑动速度低、滑动距离小和复活性强等特点,不容易发现。因此,研究此类滑坡的启动机理至关重要。通过分析滑体、滑带和滑床的颗粒分布曲线,滑带中粒径为0.02~0.037 mm细颗粒富集;基于易溶盐测试,分析离子在滑体、滑带和滑床中的变化规律,发现钙离子在滑带位置出现富集现象。研究表明,大量细颗粒在滑带位置富集后引起滑带中黏土矿物含量增加,钙离子会和细颗粒表面的弱结合水发生离子交换作用,加之环境pH值的变化,导致离子交换容量处于变化状态,该过程破坏了土体颗粒间的结构,颗粒极易发生溃散,溃散之后产生滑坡。研究结果表明,邻近310国道的滑坡滑带处于饱水状态,经过颗粒筛分、易溶盐等实验分析,滑带中的钙离子较为活跃,且会发生离子交换,为该地区滑坡形成的重要因素;此外,处于饱和状态的黄土-泥岩接触带为上覆结构以“乘船”形式滑动创造有利条件。The loess-shale interface landslide is a form of loess landslide,where the sliding surface develops in the underlying shale layer.This type of landslide features low sliding speed,short distance,and strong reactivation,making it hard to detect.Therefore,understanding the initiation mechanism of this type of landslide is of utmost importance.By analyzing the particle distribution curves of the landslide mass,slip zone,and slip bed,it was found that fine particles with a diameter range of 0.02~0.037 mm accumulate in the slip zone.Through soluble salt testing,the changes in ions within the landslide body,shear zone,and shear bed were analyzed,revealing that calcium ions are concentrated in the shear zone.Research shows that the accumulation of fine particles in the shear zone increases the content of clay minerals.Calcium ions interact with the weakly bound water on the surface of the fine particles through ion exchange.Moreover,changes in pH contribute to fluctuations in the ion exchange capacity,disrupting the particle structure and making them prone to disaggregation,which ultimately leads to landslides.The research findings suggest that the landslide shear zone near National Highway 310 is saturated.Through particle sieving and soluble salt analysis,it was found that calcium ions in the shear zone are quite active and undergo ion exchange,which is a crucial factor contributing to the landslide formation in the region.In addition,the saturated loess-shale contact zone provides favorable conditions for the overlying structure to slide in a“boat-like”fashion.

关 键 词：公路 黄土-泥岩接触面 滑坡 易溶盐测试 颗粒分布曲线 离子交换 

分 类 号：U412[交通运输工程—道路与铁道工程] P642.2[天文地球—工程地质学] P641[天文地球—地质矿产勘探]