高吸力下持水曲线的温度效应及其吸附热力学模型  

Temperature effect on water retention curve under high suction and its modeling based on thermodynamics of sorption

作　　者：秦冰[1] 陈正汉 孙发鑫 方祥位 刘月妙[3] 王驹[3] 

机构地区：[1]后勤工程学院营房管理与环境工程系,重庆401311 [2]岩土力学与地质环境保护重庆市重点实验室,重庆401311 [3]核工业北京地质研究院,北京100029

出　　处：《岩土工程学报》2012年第10期1877-1886,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(11072265);重庆市自然科学基金项目(CSTC;2009BB7343);军队后勤科研项目(BY211C014)

摘　　要：以高庙子膨润土为例,对高吸力下持水曲线的温度效应进行了试验研究和理论分析。试验结果表明,在试验范围内,随着温度升高,吸力平衡时间会显著缩短,持水能力会下降,高吸力段内持水曲线的滞后性亦会减弱;不同温度下的持水曲线大致彼此平行。依据吸附热力学与Le Chatelier原理,分析认为土吸附水总会放热,高吸力段内持水能力随温度升高而减弱是一个必然现象;在吸附热不随温度变化及不同温度持水曲线彼此平行的条件下,建立了高吸力段内持水曲线的温度效应模型,利用本文及文献中报道的相关试验结果对模型在全吸力范围内进行了验证。The temperature effect on water retention curve under high suction is investigated experimentally and theoretically. Water retention tests are conducted on GMZ bentonite at five temperatures ranging from 20℃ to 100℃. The test results show that the suction equilibrium time, the water retention capacity and the hysteresis of the water retention curve decrease with the increasing temperatures, and the water retention curves at different temperatures are almost parallel to each other. According to the thermodynamics of sorption and the Le Chatelier＇s principle, the water adsorption by soil is always an exotherrnic process, and it is an inevitable phenomenon that the water retention capacity under high suction decreases with the increasing temperatures. Assuming that the adsorption heat is independent on the temperature and the water retention curves at different temperatures are parallel, a model is established to describe the temperature effect on the water retention curve. Comparisons are made between the model predictions and the test results in this work and some literatures. Good agreement of those comparisons shows that the proposed model has the capability to cover the full suction range.

关 键 词：膨润土 温度 持水曲线 高吸力 吸附热 高放废物 

分 类 号：TU443[建筑科学—岩土工程]