滑坡水土作用体系中Ca^(2+)的地球化学行为的反向模拟  

Inverse modeling of geochemical behavior of Ca^(2+) in landslide water-soil interaction system near the Three Gorges Reservoir

作　　者：刘媛[1] 梁和成[1] 唐朝晖[2] 蔡鹤生[1] 刘佳伟[1] 

机构地区：[1]中国地质大学(武汉)环境学院,武汉430074 [2]中国地质大学(武汉)工程学院,武汉430074

出　　处：《水文地质工程地质》2012年第2期106-110,共5页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金资助项目(40702059)

摘　　要：定量准确地描述滑坡水土作用体系中复杂的地球化学反应对于水化反应微观尺度的研究尤为重要。本文针对三峡库区石榴树包滑坡水土作用体系,选取Ca2+为特征作用离子,设计去离子水及pH=4,7,10的钙离子水溶液在土水质体比为1∶5,水流速度20mL/min,室内温度17±2℃的条件下对滑坡土体进行30d室内循环饱水土柱试验。通过对实验测试数据的分析,利用PHREEQCE对试验中的水土化学作用进行反向地球化学模拟,探讨在Ca2+影响下发生的主要地球化学反应特征。结果表明溶液中Ca2+的存在抑制了对水土作用体系反应进程起着控制性作用的钙质胶结物的溶解及粘土矿物的生成,增强了土体表面的离子交换作用,胶结物的生成和胶结作用及离子交换作用使得土体孔隙变小,颗粒间变紧密,使得滑坡体更加趋于稳定。研究成果对研究三峡库区滑坡这一典型而特殊的水土作用体系的水土化学作用机理及过程具有重要的理论意义和实际应用价值。Quantitative and accurate description of the complex geochemical interaction of landslide water - soil interaction system is particularly important for the research of geochemical interaction of micro scale. In this study, purple soil samples were collected from the Shilinshubao landslide near the Three Gorges. Ca2＋ was selected as the characteristic ions in simulation solutions. Indoor circulatory soil column simulated experiments were conducted with deionized water and calcium solution with pH = 4, 7, and 10 under the conditions of the flow speed of 20mL/min, indoor temperature of 17± 2 ℃, the proportion of soil quality and solution volume of 1 ： 5. PHREEQCE was used to study the water-soil interaction in the experiment and analyze the hydrogeochemical behavior of Ca2＋ . The results show that the existence of Ca2＋ in the solution restrained the solution of calcareous cement and the production of clay minerals, enhanced ion-exchange action. The production of clay minerals and ion-exchange action make soil porosity become small, particles become close and the landslide gets stable. It is of an important theoretical significance and applicable value for studying mechanism and process of water-soil geochemical interaction of Shiliushubao landslide.

关 键 词：石榴树包滑坡 水土化学作用 CA2+ PHREEQCE 反向地球化学模拟 

分 类 号：P642.22[天文地球—工程地质学] P641.3[天文地球—地质矿产勘探]