不同含水率和压力下煤矸石改良膨胀土微观评价  

Microscopic evaluation of expansive soil modified by coal gangue under different water contents and pressures

作　　者：张雁[1,2] 朱红星 殷潇潇 ZHANG Yan;ZHU Hongxing;YIN Xiaoxiao(College of Energy and Transportation Engineering, Inner Mongolia Agricultural University, Huhhot 010018, China;Department of Civil & Environmental Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada;Chengfa Investment Group, Qingdao, Shandong 266555, China)

机构地区：[1]内蒙古农业大学能源与交通工程学院,呼和浩特010018 [2]滑铁卢大学土木与环境工程学院,加拿大滑铁卢N2L3G1 [3]城发投资集团有限公司,山东青岛266555

出　　处：《中国科技论文》2021年第12期1354-1360,共7页China Sciencepaper

基　　金：国家自然科学基金资助项目(51669025)。

摘　　要：为了从微观角度评价煤矸石(coal gangue,CG)对膨胀土(expansive soil,ES)的改良效果,通过膨胀率试验确定CG的最佳掺量,通过压汞试验测得土样在不同含水率和压力下的孔隙率、累积孔隙体积、累积孔隙密度和总孔隙体积参数,并对各孔隙特征参数进行分析。结果表明:当CG掺量为7%时,ES的膨胀率明显减小;当含水率分别为20%、50%、80%时,掺量为7%的煤矸石改良膨胀土(7%CG-ES)孔隙率比ES分别减小了9.2%、7.4%、5.8%;随着含水率的增大,土样内部的小孔隙向大孔隙转变,CG可在一定程度上抑制这种现象,使土体密实度相对增大;由土样的总孔隙体积参数分析得出,7%CG-ES的遇水膨胀敏感性明显小于ES。研究结果可为膨胀土路基灾害处置提供参考。In order to evaluate the improvement effect of coal gangue(CG)on expansive soil(ES)from the micro point of view,the optimal content of CG was determined through the expansion rate test.The porosity,cumulative pore volume,cumulative pore density and total pore volume parameters of soil samples under different water contents and pressures were measured through mercury injection test,and the pore characteristic parameters were analyzed.The results show that the expansion rate of ES decreases obviously when the content of CG is 7%.When the moisture content is 20%,50%and 80%,the porosity of 7%coal gangue modified expansive soil(7%CG-ES)is 9.2%,7.4%and 5.8%lower than ES respectively.With the increase of water content,the small pores in the soil sample change to large pores.CG can inhibit this phenomenon to a certain extent and increase the compactness of the soil relatively.By analyzing the total pore volume parameters of soil samples,it is concluded that the water swelling sensitivity of 7%CG-ES is obviously less than that of ES.The research results can provide reference for the disaster treatment of expansive soil subgrade.

关 键 词：岩土工程 改良膨胀土 含水率 抗压强度 孔隙参数 

分 类 号：TU411[建筑科学—岩土工程]