水化学作用对滑坡滑带土的物理力学特性影响试验研究  

Effect of pore water chemistry on physical and mechanical properties of sliding-zone soil:An experimental study

作　　者：汤文[1] 姚志宾 李邵军[3] 孙钱程[3] 

机构地区：[1]中国地质大学(武汉)工程学院,湖北武汉430074 [2]东北大学深部金属矿山安全开采教育部重点实验室,辽宁沈阳110819 [3]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071

出　　处：《岩土力学》2016年第10期2885-2892,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.51178187);国家重点基础研究发展计划项目(973计划)(No.2013CB036405)~~

摘　　要：滑带是影响滑坡稳定的最关键内在因素之一。对原状土进行X射线衍射、压汞试验,获得了滑带土体的成分及其含量和孔隙结构参数,结果表明,滑带土成分以石英、拉长石、伊利石等为主,孔隙孔径以小孔和过渡孔居多;依据工程实例滑坡滑带土所处的水化学环境,模拟不同水化条件,通过剪切试验、渗透试验和扫描电镜试验,获得不同化学条件的强度和渗透性参数及微细观结构特征,分析了滑带土在不同水化学条件下力学特性和渗透性变化规律。试验结果表明:相同p H条件下,较之蒸馏水,土样经化学溶液浸泡后峰值强度和残余强度变大,且残余强度的变化更明显;不同p H条件下,酸碱性溶液使得土的强度参数显著降低。该研究结果为水化学条件下滑坡滑带土力学特性变化、多场耦合理论模型分析提供了重要的基础数据。Sliding-zone soil is one of the most critical inherent factors that can affect the stability of landslide. A series of X-ray diffraction and mercury intrusion tests is conducted on the undisturbed sliding soil samples to obtain the composition and content as well as structure in the sliding-zone soil. The results show that the sliding-zone soil is mainly composed of quartz, labradorite, illite, etc, and the pores include mainly micropores and transition pores. Based on a practical landslide in which the pore water chemistry of the sliding-zone soil is variable, different chemical solutions are introduced as the saturating fluid. Through a series of tests including shear, permeability and scanning electron microscopy, variations of strength parameters, permeability and microstructure of sliding-zone soil are obtained. Variations of mechanical properties and permeability of the sliding-zone soil are analyzed. The results indicate that at the same p H value, the peak and residual strengths of soil soaked in the salt solution are larger compared to distilled water. However, under different p H conditions, introducing acid and alkali solutions as the saturating fluid can significantly reduce the strength parameters of sliding-zone soils. The results provide important data for both the analysis of the variation law of mechanical properties and the multifield coupling theoretical models of the sliding-zone soil under water chemical conditions.

关 键 词：滑坡 滑带土 水化学环境 物理力学特性 

分 类 号：TU462[建筑科学—结构工程]