花岗岩地区河谷相软土路基处治与沉降变形特性  

Treatment and Settlement Deformation Characteristics of Valley Soft Soil Subgrade in Granite Area

作　　者：古鹏翔 刘先林 骆俊晖 张涛[3] GU Pengxiang;LIU Xianlin;LUO Junhui;ZHANG Tao(Guangxi Sanglu Highway Co..Ltd.,Nanning 530021,China;Guangui Communication Design Group Co.,Ltd..Nanning 530029,China;Faculty of Engineering.China University of Geosciences(Wuhan),Wuhan 430074,China)

机构地区：[1]广西阳鹿高速公路有限公司,广西南宁530021 [2]广西交通设计集团有限公司,广西南宁530029 [3]中国地质大学(武汉)工程学院,湖北武汉430074

出　　处：《安全与环境工程》2020年第2期149-154,161,共7页Safety and Environmental Engineering

基　　金：广西交通科技项目(20140203);国家自然科学基金项目(41807260)。

摘　　要：针对广西地区高速公路沿线工程地质情况,采用换填法和水泥搅拌桩法对花岗岩地区河谷相软土路基进行处治,通过现场荷载试验和路基沉降监测,分析了两种软土路基处治方法的适用性和此类软土路基的沉降变形特性。结果表明:就地取材的换填法处治适用于软土厚度较小路段(小于3 m),水泥搅拌桩法适用于软土厚度较大且工后沉降控制严格路段(大于3 m),两种方法处治后的软土路基承载力均满足相关规范要求;换填法治理路段沉降主要发生在软土路基部分,上部填土沉降较小;水泥搅拌桩法治理路段软土路基沉降发展与土体含水量和压缩特性密切相关,加载初期(约1个月)软土路基沉降量增幅和增速均较大,累计沉降量可达总沉降量的一半,路基沉降经历了发生、发展和稳定三个阶段。Based on the engineering geology conditions of the highways in Guangxi province,this paper uses two different methods,namely the replacement method and the cement deep-mixing method to treat the valley soft soil subgrade in granite area.The paper also conducts a series of in-situ loading tests and subgrade settlement monitoring to investigate the applicability of such two methods and the characteristics of settlement.The results show that the replacement method of local construction materials is suitable for the road section with small thickness of soft soils(less than 3 m).The cement deep-mixing method shows good performance in the section of large thickness of soft soils(more than 3 m)which needs strict control of post-construction settlement.The bearing capacity of subgrade achieves the requirements detailed in the design standards after treatment.For the case of replacement,settlement is mainly resulted from the soft soil subgrade,while up filling has a small quantity of settlement.The evolution of subgrade settlement in the section of using the cement deep-mixing method is closely related to the moisture content and the compression behaviors of soft soils.At the initial stage of loading(approximately one month),both the increment and the increasing rate are large,and the cumulative settlement can reach half of the total settlement.The settlement has experienced three stages of occurrence-development-stable with the applied loading.

关 键 词：花岗岩地区 河谷相软土 路基沉降 工程性质 地基处理 换填法 水泥搅拌桩法 

分 类 号：X935[环境科学与工程—安全科学] TU447[建筑科学—岩土工程]