陕西榆林地区风积沙工程特性试验研究  

Experimental Study on Engineering Characteristics of Aeolian Sandin Yulin Area of Shaanxi Province

作　　者：刘光秀 李玉根 郑文[1,2] 马小莉 徐德衡 LIU Guangxiu;LI Yugen;ZHENG Wen;MA Xiaoli;XU Deheng(School of Architecture Engineering,Yulin University,Yulin 719000,Shaanxi China;Key Laboratory for Special Soil Mechanics and Engineering of Yulin,Yulin 719000,Shaanxi China;College of Architecture and Civil Engineering,Xi’an University of Science&Technology,Xi’an 710054,Shaanxi China)

机构地区：[1]榆林学院建筑工程学院,陕西榆林719000 [2]榆林市特殊土力学与工程重点实验室,陕西榆林719000 [3]西安科技大学建筑与土木工程学院,西安710054

出　　处：《河南科学》2020年第8期1242-1248,共7页Henan Science

基　　金：国家自然科学基金项目(51868075);陕西省自然科学基金项目(2019JQ-349);榆林市科技局科技计划项目(2019-80-2);国家级大学生创新训练项目(201911395002)。

摘　　要：以陕西榆林地区境内毛乌素沙漠南缘地表风积沙土为研究对象,对其进行颗粒级配、密度、含水量、微结构及化学成分等理化学性质研究,通过标准击实试验、干振法、饱水振法研究风积沙土的压实特性,通过压缩试验、直剪试验研究风积沙土的压缩特性、强度特性.试验结果表明:榆林地区地表风积沙土颗粒较均匀,粒径主要分布在0.25~0.075 mm之间,粉粒、黏粒含量较少,多属于级配不良的细砂;风积沙的击实试验曲线形状呈先凹后凸形的驼峰型曲线,当处于干燥状态和含水量为12%情况下均可被压实;在一定振动条件下,风积沙的最大干密度值具有最佳振动时间,沙颗粒随着振动时间的延长出现先振实、然后振松、再振实的循环现象;风积沙压缩系数小于0.1 MPa-1,压缩模量≥20 MPa,属于低压缩性土.风积沙的内摩擦角值与干密度大小和含水量有直接关系,在同一含水量下,风积沙的内摩擦角值随着干密度的增加而增加;在同一干密度下,内摩擦角随值着含水量的增加有所降低,但影响较小.Taking the aeolian sandy soil on the south edge of Maowusu Desert in Yulin area of Shaanxi Province as the research object,the physical and chemical properties of the aeolian sandy soil,such as particle gradation,density,moisture content,microstructure and chemical composition were studied.The compaction characteristics of aeolian sandy soil were studied by standard compaction test,dry vibration method and full water vibration method.The compression characteristics and strength characteristics of aeolian sandy soil were studied by compression test and direct shear test.The results show that the particles of aeolian sand in Yulin area are relatively uniform,the particle size is mainly distributed between 0.25-0.075 mm,the content of silt and clay is less,and most of them belong to poorly graded fine sand;the compaction test curve of aeolian sand is a hump curve of concave and convex shape,which can be compacted when it is in dry state and water content is 12%.Under certain vibration conditions,the maximum dry density of aeolian sand has the best vibration time.With the extension of vibration time,the sand particles is first vibrated and compacted,then vibrated and loosened,and then vibrated and compacted.The compression coefficient of aeolian sand is less than 0.1 MPa-1,and the compression modulus≥20 MPa,which belongs to low compressibility soil.The internal friction angle of aeolian sand is directly related to the dry density and water content.Under the same water content,the internal friction angle of aeolian sand increases with the increase of dry density;under the samedry density,the internal friction angle decreases with the increase of water content,but the effect is small.

关 键 词：风积沙 颗粒级配 击实曲线 压缩系数 内摩擦角 

分 类 号：TU451[建筑科学—岩土工程] U416.166[建筑科学—土工工程]