振冲法处理饱和粉土地基的工后孔隙比研究  

Study of post-treated void ratio of saturated silt subgrade treated with vibroflotation

作　　者：周元强[1] 徐强[2] 沈锦儒[1] 

机构地区：[1]江苏省电力设计院,南京211102 [2]江苏省电力公司宿迁供电公司,江苏宿迁223800

出　　处：《岩土力学》2013年第S1期406-412,共7页Rock and Soil Mechanics

摘　　要：孔隙比是评价粉土密实程度的重要指标,研究表明饱和粉土地基的液化指数与孔隙比有关。对于振冲法处理严重液化的饱和粉土地基,只要工后孔隙比降到0.75以下,就能达到消除液化的目的。利用试验成果,通过振冲桩施工前后土体的三相组成分析,量化振冲碎石桩的挤密、振实功效,推导出饱和粉土经振冲法处理后的工后孔隙比估算方法,估算结果与实测值的误差在±1.5%以内。利用该方法可以迅速接近最佳的桩距、桩径组合,为节省试验费用和加快试验进度提供可靠的依据。Void ratio is one of the most important evaluation indicator of the silt compactness;the study shows that there are certain corresponding relations between liquefaction indexes and void ratio of saturated silt subgrade treated with vibroflotation;when the post-treated void ratio drops to bellow 0.75,the liquefaction of saturated silt subgrade could be eliminated.Based on the testing result and three-phase composition analysis of soil before and after the vibroflotation,the vibration effectiveness and compaction effectiveness of vibro replacement stone column are quantified;and the estimate method of post-treated void ratio is also derived.Compared with measured values,the estimate values calculated through the estimate method have errors within ± 1.5%.Meanwhile,the estimate method of post-treated void ratio are used to rapidly approach the optimal combination of pile spacing and pile diameter,so as to provide a reliable basis for saving the cost and speeding up the progress of pile testing.

关 键 词：饱和粉土 振冲法 液化 工后孔隙比 估算法 

分 类 号：TU43[建筑科学—岩土工程]