某铁路车站软土地基的沉降变形特性  

Settlement characteristics of soft soil in the railway station

作　　者：柴跃进 

机构地区：[1]中铁六局集团有限公司,北京100036

出　　处：《铁道科学与工程学报》2013年第4期95-99,共5页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51108462);湖南省科技厅工业支撑计划项目(2011GK3127);湖南省发改委批准立项项目(湘发改高技[2012]1493号)

摘　　要：通过理论计算和沉降施工监测表明,软土地基在附加荷载下沉降大,地基沉降主要是路堤填土造成的。加固前软弱地基固结时间长,需加固后12a才能满足铁路工后沉降不大于20cm要求。淤泥层采用塑料排水带(真空预压)加固后,固结时间大大缩短,在加固后240d就能满足工后沉降小于20cm和沉降速率小于5cm/a要求。由于理论计算与实际施工条件有差异,再加上软土地基本身的复杂性,实测沉降与理论沉降计算值两者并不完全一致,实际沉降值略大于计算值,实际沉降值在大致地基加固后2a后才趋于稳定,时间长于计算值。有限元计算和实测值表明:地面沉降变形最大点位于地面线中心点,路肩次之,往路基两侧边坡坡脚处沉降量最小。研究结论可为类似工程施工参考。According to theoretical calculation and constrution monitoring of settlement, it shows that the soft soil has great settlement in the action of additional load, including filling which is the main reason of settlement, rail structure and train. Consolidation time of soft soil before treatment was so long that it would take 12 years to sat isfy the demand of the post construction settlement of subgrade which must be less than 20 cm. Consolidation time of the soil after treatment with plastic plate for drainage（vacuum preloading） became so short that it would take only 240 d to meet the demand of the settlement of subgrade after acceptance which still includes the settle ment velocity being less than 5 cm/a. Due to the difference between the calculation hypothesis and practical con struction condition and the complexity of the formation of soft soil, measured settlement value was not completely coincide with the calculated value. Measured settlement value was a little greater than the calculated value and the measured value would become stable in about 2 years that was longer than the calculated value. It shows that the the greatest setterment position obtained by either calculation using finite element method or measurement lies in central line of subgrade surface, and the settltment of verge takes second place. The least settlement is at the toe of the embankment slope. The conclusions can be construction. regarded as reference to the similar soft soil in design and

关 键 词：沉降 理论计算 现场监测 软土地基 铁路 

分 类 号：TU416[建筑科学—岩土工程]