强夯消除黄土湿陷性的机理  

Mechanism of Eliminating Collapsibility of Loess by Dynamic Compaction

作　　者：靳彤舟 倪万魁[1] 穆彦仕 马海涵 王海曼 荣誉 JIN Tong-zhou;NI Wan-kui;MU Yan-shi;MA Hai-han;WANG Hai-man;RONG Yu(School of Geology Engineering and Geomatics,Chang'an University,Xi'an 710054,China)

机构地区：[1]长安大学地质工程与测绘学院,西安710054

出　　处：《科学技术与工程》2025年第11期4724-4732,共9页Science Technology and Engineering

基　　金：国家自然科学基金(41931285)。

摘　　要：强夯法是消除黄土地基湿陷性的有效方法之一。为了研究强夯消除黄土湿陷性的机理,对铜川市天然黄土和夯芯黄土进行了颗分试验、湿陷试验、扫描电镜试验和土-水特征曲线(soil-water characteristic curve, SWCC)试验,以分析强夯在黄土粒度组成、微观结构特征和非饱和特征方面的影响,以及这些因素与湿陷性的关系。结果表明:在强夯作用下,铜川地区黄土中黏粒含量显著增加,当黏粒含量大于36.2%时,黄土不再具有湿陷性。强夯导致坍塌的大中孔隙形成了小微孔隙,土颗粒排列更为紧密,湿陷性减小。夯芯黄土SWCC曲线过渡段斜率大于天然黄土过渡段斜率,这是因为强夯作用下形成的黏粒作为胶结物质,一方面增加了胶结强度,另一方面填充于孔隙中,提高了黄土的密实度。最终对比发现,SWCC曲线拟合参数a与小微孔隙面积占比和湿陷系数间有良好的相关性。黄土的湿陷性可间接地由SWCC曲线特征判断得出。Dynamic compaction is one of the effective methods to eliminate collapsibility of loess foundation.In order to study the mechanism of eliminating loess collapsibility by dynamic compaction,particle size test,collapsibility test,scanning electron microscope test and soil-water characteristic curve(SWCC)test were conducted on undistributed loess and compacted loess in Tongchuan City.The above experimental data was used for analyzing the effect of dynamic compaction on the particle size distribution,microstructural and unsaturated characteristic of loess,as well as the relation between these factors and collapsibility.It is shown that the clay content of the loess in Tongchuan area increases significantly under dynamic compaction.It is found that when the clay content is greater than 36.2%,the loess is no longer collapsible.It is observed that dynamic compaction leads to the formation of small and micro pores from collapsed macropores and mesopores.As a consequence,the density of particles increases and the collapsibility decreases.The slope of the SWCC curve desaturation section of compacted loess is greater than that for undistributed loess.This is because clay particles formed under dynamic compaction act as cementation materials,which is considered to increase the strength of cementation on the one hand,and to be filled in the pores on the other hand,increasing the density of loess.Finally,the results show that the SWCC curve fitting parameter a is related to the proportion of micro-pore area and the collapsibility coefficient.The collapsibility of loess can be judged indirectly from the characteristics of the SWCC curve.

关 键 词：黄土湿陷 强夯作用 粒径级配 微观结构 土-水特征曲线 

分 类 号：TU444[建筑科学—岩土工程]