摘要
Many geotechnical structures,such as the subgrade of high-speed railway,are extremely sensitive to micro deformations.As one of the most commonly used indexes in China to evaluate the potential swelling level of expansive soils,the effectiveness and accuracy of free swelling ratio should be highly required.However,due to the deficiency of geotechnical test regulations for the free swelling ratio test,non-negligible variation difference is often observed among the test results of the same type of soil samples.Thus,a series of laboratory tests are conducted to figure out the influences of soil particle size,initial soil temperature,and wet-dry circulation on the free swelling ratio of expansive soils.The results show that the initial soil temperature exerts an obvious influence on free swelling ratio and a relative weak influence on soil mass of expansive soil with the micro soil particle size(d<0.075 mm),and the correlation becomes unclear when soil particle size is within the range of 0.075 mm≤d<0.500 mm.A larger particle size of expansive soils induces a larger free swelling ratio and soil mass in the soil measuring cup regardless of initial soil temperature.However,the enlarging amplitude decreases as the particle size of expansive soils increases.There is a progressive enlargement of free swelling ratio at the first two wet-dry cycles and then it attenuates gradually when the number of wetdry cycles further increases.
因现行土工试验标准对自由膨胀率试验方法的细节规定存在不足,导致相同土样的试验结果存在影响土体膨胀等级评定的波动性问题,为此,本文进行了系列土工试验,发现土样初始温度的变化对粒径小于0.075 mm膨胀土的自由膨胀率具有较明显的影响。自由膨胀率随着土颗粒粒径的增加而增大,但增大幅度逐级减小。原状膨胀土自由膨胀率随着干湿循环次数的增加而呈现出先增大后减小并最终逐渐趋于稳定的变化趋势。
作者
WANG Liang-liang
WANG Zhao-teng
DING Zhi-ping
LIN Yu-liang
LEI Xiao-qin
LIU Zhi-jun
王亮亮;王照腾;丁志平;林宇亮;雷小芹;柳志军(School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou 221116,China;State Key Laboratory for Geomechanics&Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221116,China;Xuzhou Design Institute,China Railway Shanghai Design Institute Group Co.,Ltd.,Xuzhou 221000,China;School of Civil Engineering,Central South University,Changsha 410075,China;Key Lab Mt Hazards&Earth Surface Proc,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610041,China)
基金
Project(2016M591957) supported by the China Postdoctoral Science Foundation
Projects(51878667,51678571)supported by the National Natural Science Foundation of China
Project(2017XKQY050) supported by the Fundamental Research Funds for the Central Universities,China。
作者简介
Corresponding author:WANG Liang-liang,PhD,Lecturer,Tel:+86-18112202342,E-mail:wlltm0304@163.com,ORCID:https://orcid.org/0000-0002-6119-9303。
