天然粗粒盐渍土大型路堤模型试验研究  

Large-scale model tests on embankment of crude coarse grained saline soil

作　　者：张莎莎[1,2] 杨晓华[1,2] 张秋美[1,2] 

机构地区：[1]长安大学公路学院,陕西西安710064 [2]长安大学特殊地区公路工程教育部重点试验室,陕西西安710064

出　　处：《岩土工程学报》2012年第5期842-847,共6页Chinese Journal of Geotechnical Engineering

基　　金：国家西部交通建设科技项目(200331879750);中央高校基本科研业务费专项资金资助项目(CHD2011JC41)

摘　　要：西北地区分布着大量的粗粒盐渍土,研究其作为路堤填料的适用性,可充分利用当地资源和节约公路工程建设费用。为了使试验结果更准确地反映工程实际情况,在对天然粗粒盐渍土进行不同方法的化学成分分析试验、模拟季节交替冻融循环试验、有(无)附加荷载单次降温盐胀试验及大型溶陷试验的基础上,开展了多次冻融循环条件下大型路堤模型试验。结果表明:两种化学成分分析试验—规范法和过5 mm筛法分别得到的易溶盐含量相差较大,过5 mm筛法能更准确指导实际工程的施工;随着含水率的增加,粗粒盐渍土的盐胀量和溶陷量亦逐渐增大,溶陷累加性较显著;50 kPa附加荷载抑制该天然粗粒盐渍土的盐胀量可达85%以上;经多次冻融循环后,大型路堤表面的最大盐胀率仅为0.44%;该天然粗粒盐渍土可用于上部路堤填料。In Northwest China,there is great deal of crude coarse grained saline soil.If it can be used as embankment fill,full use of local resources will be made and construction cost of highways saved.In order to make the test results more accurately and to reflect the actual working conditions,based on two different chemical analysis tests,experiments of freeze thaw cycles,salt expansion tests under（no） additional load and large-scale immersed tests,large-scale model tests on embankment under freeze thaw cycles are performed.It is shown that the soluble salt obtained by two different test methods（standard method and screening method of 5 mm） is quite different,and the results from the screening method of 5 mm can better guide the construction.With the increase of moisture content,the values of salt expansion and collapsibility gradually increase,and the cumulative characteristics of collapsibility are obvious.The amount of salt expansion for the saline soil under additional covering load is less than 15%,compared with that under no additional load.After several freeze-thaw cycles,the maximum expansion rate of the large-scale embankment model is only 0.44%.The crude coarse grained saline soil can be used for embankment fill.

关 键 词：道路工程 天然粗粒盐渍土 盐胀量 溶陷 模型试验 

分 类 号：TU448[建筑科学—岩土工程] U416[建筑科学—土工工程]