细粒含量对砂性土压实特性影响的试验研究

Experimental Research on Influence of Fine Particle Content on Compaction Characteristics of Sandy Soil

砂土作为一种比较特殊的路基填料,其压实特性对路基施工方式和施工质量有重要影响。随着细粒含量的增加,砂土填料可能呈现出不同的压实特性。根据现行《铁路土工试验规程》,用低液限粉土对一系列掺配不同细粒含量的细砂进行重型击实试验,研究细粒含量对砂土击实特性的影响。结果表明:细粒含量对砂土的击实特性有显著影响,随着细粒含量的变化,砂土的击实曲线可分为三种典型类型:随机小幅波动的类直线型、横写"S"型、单驼峰型,后两种击实特性曲线的临界细粒含量约在30%;细粒含量超过30%的砂土具有良好的击实特性,可作为一种良好的路基填料。

Sandy soil,as a kind of special material for subgrade filling,has the compaction characteristics significantly impacting the method and quality of subgrade construction.With the increase of fine particle content,this sandy filling material may present different compaction characteristics.According to the current Code for Soil Test of Railway Engineering,the heavy compaction tests were conducted on the fine sand in different fines content with low liquid limit silt to study the influence of fine particle content on the compaction characteristics of sandy soil.The result shows that the fine particle content has a significant influence on the compaction characteristics of sandy soil,and with the change of fines content,the compaction curve can be divided into three typical types:like-straight-line with random slight fluctuation,“S”written transversely,and single hump type,wherein the last two types of curve are of the critical fines content about 30%;the sandy soil having the fines content more than 30%has such good compaction characteristics to be a favorable material for subgrade filling.