沧州地面沉降区黏性土次固结系数的试验研究  

Experimental Study on Secondary Consolidation Coefficient of Clayey Soil in Cangzhou Land Subsidence Zone

作　　者：李晨 齐剑峰 解勇杰 郭海朋 王云龙[2,3] LI Chen;QI Jianfeng;XIE Yongjie;GUO Haipeng;WANG Yunlong(Hebei GEO University,Shijiazhuang 050031,China;Hebei Cangzhou Groundwater and Land Subsidence National Observation and Research Station,Cangzhou 061000,China;China Institute of Geo-Environment Monitoring,Beijing 100081,China)

机构地区：[1]河北地质大学城市地质与工程学院,河北石家庄050031 [2]河北沧州平原区地下水与地面沉降国家野外科学观测研究站,河北沧州061000 [3]中国地质环境监测院,北京100081

出　　处：《河北地质大学学报》2024年第6期74-83,共10页Journal of Hebei Geo University

基　　金：科技基础资源调查专项(2022FY101800);国家自然科学基金(U2344225)。

摘　　要：黏性土层次固结变形是地面沉降的重要原因,次固结系数是次固结变形的重要参数。通过获取不同深度的黏性土原状土样和制备的重塑土样,开展次固结试验,分析了黏性土的e-lg(t)曲线和固结压力、时间对次固结系数的影响,进而建立反映次固结系数时间效应的关系式。结果表明:次固结阶段的孔隙比随时间的变化曲线呈非线性变化,当固结压力大于和小于先期固结压力时,曲线分别呈现上凸、上凹形态;次固结系数受固结压力和时间影响,发现当超固结比大于1和超固结比小于等于1时,次固结系数分别随着时间的增加逐渐减小、增大;建立了当超固结比大于1时次固结系数的经验公式,并利用试验数据进行了验证。研究结果可为沧州地区次固结变形的计算提供依据。The consolidation deformation of clayey soil layer is an important cause of ground settlement,and secondary consolidation coefficient is an important parameter of secondary consolidation deformation.Secondary consolidation tests were carried out by obtaining undisturbed clay samples of different depths and prepared remodeled soil samples,and the effects of e-lg(t)curve,load and time on secondary consolidation coefficients were analyzed,and then the relationship formula reflecting the time effect of secondary consolidation coefficients was established.The results show that:the curve of pore ratio during the secondary consolidation stage shows a non-linear variation with time.When the consolidation pressure is greater than and less than the initial consolidation pressure,the curve shows an upward convex and upward concave shape,respectively.The coefficient of secondary consolidation is influenced by consolidation pressure and time.It is found that when the over consolidation ratio is greater than 1 and the over consolidation ratio is less than or equal to 1,the coefficient of secondary consolidation gradually decreases and increases with time,respectively.We have established an empirical formula for the coefficient of secondary consolidation when the over consolidation ratio is greater than 1,and verified it using experimental data.The research results can provide a basis for the calculation of secondary consolidation deformation in the Cangzhou area.

关 键 词：地面沉降区 黏性土 次固结系数 固结 时间效应 

分 类 号：P315.9[天文地球—地震学]