长春地区黏性土中孔隙水压力折减性研究

Study on Pore Water Pressure Reduction in Clay Soil in Changchun Area

以长春轨道交通工程(第三期建设规划)为依托,分别采用X射线衍射、扫描电镜(SEM)以及压汞实验对长春地区不同深度黏性土土样的矿物成分、微观结构和孔隙特征进行分析。进而结合现场孔隙水压力长期监测结果,对黏性土层折减情况进行归纳总结。结果显示,长春地区黏性土矿物组成的主要成分吸附性较强且有亲水性;微观孔隙结构多以小孔隙为主,并且随深度增加,小孔隙减少,微孔隙增加,孔隙趋向均一化;主要产生孔隙水压力折减的地层为硬塑状态黏性土层,软塑及可塑状态黏性土层基本不折减。

Based on Changchun Rail Transit Project(PhaseⅢConstruction Plan),the mineral composition,microstructure and pore characteristics of clayey soil samples with different depths in Changchun area were analyzed by X-ray diffraction,scanning electron microscopy(SEM)and mercury intrusion test.Based on the long-term monitoring results of pore water pressure in situ,the reduction of cohesive soil layer is summarized.The results show that the main mineral components of clayey soil in Changchun area have strong adsorptivity and hydrophilicity;the micro-pore structure is mainly small pore,and with the increase of depth,the small pore decreases,the micro-pore increases,and the pore tends to be homogeneous;the main pore water pressure reduction layer is hard-plastic clayey soil layer,and the soft-plastic and plastic clayey soil layer is basically not reduced.