以大连海事大学附近黄浦路路基土为研究对象,通过SLB-1型三轴试验仪进行不同冻融次数的三轴压缩试验,研究冻融对土的特性的影响.在不同围压(0~800kPa)和不同冻融循环(0~20次)的组合条件下,获得含水率、主应力差-应变、强度参数的变化规律.试验结果表明:相同冻融次数时,剪切强度随围压增大而增大;相同围压下土的内摩擦角、黏聚力和剪切强度随冻融次数的增加呈现先减小后增大的趋势;含水率随冻融次数的增加先升高后降低.转折点对应冻融次数在7次左右.采用超固结效应机理对冻融过程特性变化进行分析.
Abstract
Take subgrade soil from Huangpu Road near Dalian Maritime University as research object, compression tests were carried out in different confining pressures and different times of freezingthawing cycles using SLB1 triaxial apparatus, and the effects of freezingthawing on subgrade soil were studied . Under the condition of combination of different confining pressures(0~800kPa) and different times of freezingthawing cycles (0~20), the change law of moisture content, principal stress differencestrain and strength parameter is obtained. Results show that under the same times of freezingthawing cycles,shear strength increases with increasing of confining pressure. Under the same confining pressure, internal frictional angle, cohesive strength and shear strength present the tendency of reducing first and then increasing with the increase of the times of freezingthawing cycles, however moisture content presents the tendency of increasing first then reducing with the increase of the times of freezingthawing cycles. The turning point is about in the position of 7 times. Over consolidation effect mechanism is used to analyze the characteristic change of frozenthaw process.
关键词
路基土 /
冻融循环 /
静三轴压缩实验 /
强度参数
Key words
subgrade soil /
freezing-thawing cycles /
static triaxial compression test /
strength parameter
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参考文献
[1] 齐吉琳, 张建明, 朱元林. 冻融作用对土结构性影响的土力学意义[J].岩石力学与工程学报, 2004, 23(增2):2690- 2694.
QI Ji-lin, ZHANG Jian-ming,ZHU Yuan-lin. Influence of freezingthawing on soil structure and its soil mechanics significance[J]. Chinese Journal of Rock Mechanics and Engineering,2004,23(Supp. 2):2690–2694. (in Chinese)
[2]齐吉琳, 马巍. 冻融作用对超固结土强度的影响[J]. 岩土工程学报, 2006, 28(12):2082-2086.
QI Ji-lin,MA Wei. Influence of freezingthawing on strength of overconsolidated soils[J]. Chinese Journal of Geotechnical Engineering,2006,28(12):2082–2086.(in Chinese)
[3]VIKLANDER P. Permeability and volume changes in till due to cyclic freezethaw[J]. Canadian Geotechnical Journal, 1998, 35(3):471-477.
[4]ZHANG S J, LAI Y M, ZHANG X F, et al. Study on the damage propagation of surrounding rock from a coldregion tunnel under freezethaw cycle condition[J]. Tunnelling and Underground Space Technology, 2004, 19(3):295-302.
[5]钱家欢, 殷宗泽. 土工原理与计算[M]. 北京:中国水利水电出版社, 1996:48.
[6]CHAMBERLAIN E J, GOW A J. Effect of freezing and thawing on the permeability and structure of soils[J]. Engineering Geology, 1981, 15(1/4):73-92.
基金
国家自然科学基金资助项目(51079010);大连市交通科技项目(2011—10);中央高校基本科研业务费资助项目(2012TD015)