干湿循环下煤矸石改良膨胀土表面特性研究  

Study on Surface Characteristics of Expansive Soil Ameliorated by Coal Gangue Under Dry-Wetting Cycle

作　　者：罗秀云 张雁[2] 朱红星 Luo Xiuyun;Zhang Yan;Zhu Hongxing(Inner Mongolia Autonomous Region Transportation Bureau of Xinghe County,Ulanqab,Inner Mongolia 013650;College of Energy and Transportation Engineering,Inner Mongolia Agricultural University,Hohhot,Inner Mongolia 010018)

机构地区：[1]内蒙古自治区乌兰察布市兴和县交通运输局,内蒙古乌兰察布013650 [2]内蒙古农业大学能源与交通工程学院,内蒙古呼和浩特010018

出　　处：《非金属矿》2022年第1期31-33,36,共4页Non-Metallic Mines

基　　金：国家自然科学基金(52169023,51669025);内蒙古自治区研究生教育教学改革与实践项目(YJG20181012901)。

摘　　要：利用煤矸石改良解决膨胀土干燥开裂造成的工程灾害,通过不同煤矸石粉掺量的膨胀土收缩试验,确定煤矸石粉的最佳掺量,对干湿循环下土样表面的裂隙图像进行分析,检测土样表面及裂隙面的粗糙度,根据土样表面特性分析煤矸石抑制膨胀土收缩裂隙发育的机理。结果表明,在干湿循环下,当煤矸石粉掺量为9%时,膨胀土收缩性得到较好的抑制,裂隙面积率随时间增加呈现出先快速增大后逐渐稳定趋势,煤矸石粉可有效延迟膨胀土裂隙发育时间;土样表面粗糙度小于裂隙面粗糙度,掺入煤矸石粉使膨胀土样内部粗糙度增大,裂隙面积率降低,从而约束膨胀土样收缩变形。In order to reduce the cracking of expansive soil, coal gangue is used to improve and solve the engineering disaster of expansive soil.Based on the shrinkage test of expansive soil with different coal gangue powder content, the optimal dosage of coal gangue powder was determined.Through the cracking image on the surface of expansive soil sample under the dry-wet cycle and the roughness detection of soil sample surface and crack surface, the mechanism of coal gangue inhibiting the development of expansive soil shrinkage crack was revealed from the surface characteristics of soil sample. The results show that under the dry-wetting cycle, the shrinkage is well inhibited when the coal gangue powder content is 9%. With the increase of time, the crack area ratio increases rapidly at first and then gradually stabilizes. The coal gangue powder can effectively delay the crack development time of expansive soil. The surface roughness of the soil sample is less than that of the crack surface, and the addition of gangue powder raises the internal roughness of the expansive soil sample, reduce the crack area ratio and restricts the shrinkage deformation of the expansive soil sample.

关 键 词：膨胀土 煤矸石 裂隙率 粗糙度 表面特性 

分 类 号：TU443[建筑科学—岩土工程]