摘要
利用改进的ZC-2015型渗气仪对不同类型的原状风干和重塑的马兰黄土进行渗气试验,分析土样体积、渗径、干密度、取样深度等对渗气率ka的影响,并利用扫描电镜(SEM)试验得到的孔隙结构参数解释黄土渗气特性。结果表明:渗气率ka不仅是气体渗透特性的衡量指标,也是描述非饱和马兰黄土孔隙和结构特征的重要参数。不同体积的土样由于尺寸效应,其渗气率随着土样体积的增大而增大。另外,渗气率随着渗径、干密度的增大而减小。对比3种不同类型黄土的透气性试验结果和电镜照片,并结合统计的孔隙结构参数,得出渗气率在区域和深度上有一定的规律,区域上黄土颗粒中黏粒含量增高,总孔隙和大孔隙面积减小,土体有效渗气孔隙减少,重塑黄土的渗气率随着取土深度的增加有微小的减小。
A series of tests on undistured dry soil and remoulded Malan loess were conducted by using improved ZC-2015 air permeameter.Gas permeability experiments analyzed the effects of soil volume,permeability diameter,dry density and sampling depth on air permeability（ka）,and loess permeability was explained by the pore structure parameters,which were obtained by electron microscopy in SEM tests.The results showed that ka was not only aquantitative index of the gas seepage,but also was an important parameter that describing the pore and structure characteristics of unsaturated Malan loess.Due to the size effect in different soil volumes of loess,and their permeability increased with the increasing of volume of soil samples.In addition,ka decreased with the increasing of dry density and permeability diameter.Comparing the test results and the SEM photographs of three different types of Malan loess,and combining with the statistics of the pore structure parameters,we can conclude that kahas a certain regularity in area and depth.Regionally,the content of clay particles in the soil particles increased,while the total pore and macropore area decreased,and the effective seepage porosity decreased,and kaof remolded soil with the increase of soil depth has a little decrease.
作者
刘锦阳
李喜安
张凯旋
郭泽泽
简涛
LIU Jinyang1, LI Xian1,2 , ZHANG Kaixuan1 , GUO Zeze1 , JIAN Tao1(1. School of Geological Engineering and Geomatics, Chang ＇ an University, Xi ＇ an 71 O054 ; 2. Open Research Laboratory of Geotechnical Engineering,Ministry of Land and Resources, X i ＇ an 71005)
出处
《水土保持学报》
CSCD
北大核心
2018年第1期141-146,共6页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目(41172255
41572264
41440044)
关键词
渗气率
土样体积
渗径
干密度
扫描电镜试验
air permeability
soil volume
permeability diameter
dry density
SEM tests
