黑棉土路基病害特征及成因机制分析  

Analysis on the disease characteristics and formation mechanisms of subgrade on black cotton soil

作　　者：程永振[1,2] 黄晓明 Cheng Yongzhen;Huang Xiaoming(School of Transportation,Southeast University,Nanjing 210096,China;Faculty of Architecture and Civil Engineering,Huaiyin Institute of Technology,Huai an 223001,China)

机构地区：[1]东南大学交通学院,南京210096 [2]淮阴工学院建筑工程学院,淮安223001

出　　处：《东南大学学报（自然科学版）》2020年第4期677-683,共7页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51778139);江苏省建设系统科技资助项目(2019ZD001021)。

摘　　要：为分析黑棉土路基的主要病害及成因,测试了路基开裂位置基底黑棉土的含水率和路基弯沉,计算了地基胀缩变形量,研究了路堤高度、黑棉土埋深和换填深度对地基变形量的影响.结果表明:深宽裂缝是黑棉土路基的主要病害形式;路堤自重对黑棉土胀缩变形的抑制作用不明显,地基变形主要发生在黑棉土大气影响深度范围内;地基换填材料渗透性大,不能阻止雨水入渗到基底黑棉土中,黑棉土地基发生了显著的胀缩变形;黑棉土换填深度接近大气影响深度时,地基变形量方可满足规范要求;排水顺畅路段雨季后路基弯沉小于设计值,反之,路基强度不能满足设计要求;地基换填深度不足、换填材料渗透性大与路基防排水设计缺陷是诱发黑棉土路基开裂的主要原因.In order to analyze the main diseases and causes of subgrade on black cotton soil(BCS),the moisture content of BCS beneath foundation at the location of subgrade cracking and subgrade deflection were tested.The expansion and shrinkage deformation of the foundation were calculated.The effects of embankment height,buried depth of BCS and its replacement depth on the foundation deformation were studied.The results indicate that deep and wide cracks are the main diseases of the subgrade on BCS.The inhibitory effect of the embankment weight on the swell-shrinkage deformation of BCS is not obvious.The foundation deformation occurs mainly in the range of the influence depth of BCS by the air.The permeability of the foundation replacement material is large,which cannot prevent the rainwater from permeating into BCS below base.Hence,the BCS foundation has undergone remarkable swell-shrinkage deformation.The foundation deformation meets the standard requirements while the replacement depth of BCS is close to the influence depth of BCS by the air.The subgrade deflection is less than design value in the highway with a smooth drainage,otherwise the subgrade strength cannot meet the design requirements.The insufficient replacement depth of the foundation,high permeability of the replacement materials and the design defect of the subgrade waterproofing and drainage are main causes for inducing subgrade cracks.

关 键 词：黑棉土 路基开裂 含水率 地基变形 路基弯沉 

分 类 号：U416.1[交通运输工程—道路与铁道工程]