冻融循环作用下黄土的孔隙特征试验  

Experimental Study on Porosity Characteristics of Loess Under Freezing-Thawing Cycle

作　　者：张泽[1] 周泓[2,3] 秦琦[3,4] 邴慧[1] 武俊杰[1] 周攀峰 

机构地区：[1]中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室,兰州730000 [2]上海建科工程咨询有限公司,上海200032 [3]兰州大学土木工程与力学学院,兰州730000 [4]上海浦桥工程建设管理有限公司,上海200032 [5]核工业广州工程勘察院,广州510800

出　　处：《吉林大学学报（地球科学版）》2017年第3期839-847,共9页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学基金项目(41301070;41401087;4101072);甘肃省交通运输厅科技项目(2014-03);青海省交通科学研究院开放基金项目(2016-01-04)~~

摘　　要：为得到冻融循环后黄土孔隙分布的变化规律,以重塑黄土为研究对象,采用压汞法对历经不同冻融循环次数后黄土的孔隙特征进行研究。试验结果表明:冻融作用使土样内部颗粒发生重新排列连结,孔隙结构发生改变,孔隙分布逐步向小孔隙数量减少、大孔隙数量增多方向推进;冻融前10次过程中,孔隙分布变化不稳定,但随着冻融循环次数增加,趋势逐渐明朗,表现为0.010.10μm范围内的超微孔隙数量减少,而5.0010.00μm范围内的细微孔隙数量增多;孔隙率也随冻融次数增加先增大,在冻融第8次时达到最大,其后减小,50次后逐渐趋于稳定。根据试验结果,结合孔隙分形进行分析,认为孔隙结构在冻融循环作用下,不均匀性及复杂程度降低。Shaanxi Fuping remolded loess was taken as the studied object. Mercury instrusion porosimetry was used to research the porosity characteristics of loess after different freezing-thawing cycles to get the changing rule of the distribution of loess porosity. Test results showed that rearrangement of the soil particles occurred under freezing-thawing cycle, and pore structure changed. At the same time, the number of pores with small size （especially pores of 0.01 - 0.10 μm） gradually decreased, and the number of pores with large size （especially pores of 5.00 10.00 μm） increased. During the first 10 cycles, the change in pore size distribution was unstable, and with the increase in freezing-thawing cycles, it became clearly. Porosity increased with the increasing freezing-thawing cycles, and reached its peak value after only 8 freezing-thawing cycles, and then it decreased and became stable after 50 cycles. Finally, according to test results and pore fractal dimension, the inhomogeneity and complexity of pore were decreased by the freezing-thawing cycle.

关 键 词：黄土 冻融循环 压汞法 孔隙分布 孔隙分形 

分 类 号：P642.131[天文地球—工程地质学]