榆林地区风积沙的工程分类

为了研究榆林地区风积沙的工程技术分类,依托陕西省榆林市境内穿越风积沙地区的国道210陕蒙段和省道204榆靖段的改扩建工程,采集沿线风积沙样,对沙样进行了筛分、含泥量、液塑限等试验,分析了筛分试验结果和级配指标,确定了风积沙分类的划分依据,对榆林地区风积沙进行了工程分类,并通过击实和强度试验,进行了验证性分析。研究结果表明:榆林地区风积沙颗粒粒径主要分布在0.075mm~0.3mm之间,陕蒙段风积沙的砂粒含量整体大于榆靖段;沙样区分应采用方孔筛颗粒分析,确定0.15mm为风积沙分类的关键筛孔;依据0.15mm筛孔通过率,将该地区风积沙划分为3类,即A类(通过率小于30%)、B类(通过率在30%~60%之间)和C类(通过率大于60%);建立细度模数和0.15mm筛孔通过率的关系,进一步说明了0.15mm筛孔通过率作为分类指标的合理性;水泥稳定3种风积沙的最佳含水率、最大干密度和7d无侧限抗压强度具有明显的区别,验证了文中风积沙分类方法的实用性。

Engineering Classification of Aeolian Sand in Yulin Area

In order to study the engineering technological classification of aeolian sand in Yulin area,in the paper relyingon the reconstruction projects of the Shaanxi to Inner Mongolia sectionof the nationalroad 210and theYulin-Jingbian sectionof the provincial road 204crossing the aeolian sand area in YulinCity,Shaanxi Province,and aeolian sand samples are collected along the two roads.Through the tests ofthe sieving,silt content and liquid plastic limit,the sieving test results and grading indicators areanalyzed,the classification index of aeolian sand is established,then the aeolian sands in Yulin area areclassified which is verified through the tests of compaction and compressive strength.The results showthat the aeolian sand particles of the Yulin area are mainly distributed among 0.075mm and 0.3mm,andthe sand particles content in aeolian sand of the Shaanxi-Inner Mongolia section is more than that in the Yulin-Jingbian section.The sand samples should be distinguished by the square-hole sieve and the 0.15mm should beregarded as the key sieve size for aeolian sand classification.According to the passing percent at 0.15mmsieve size,the aeolian sands in Yulin area are classified into three categories:A-category(passing percentis less than 30%),B-category(passing percent range is 30%~60%),and C-category(passing percent is more than 60%).By establishing the relationship between fineness modulus and the passing percent at0.15mm sieve size,the rationality of 0.15 mm sieve passing percent as a classification index is furtherverified.The optimum water content,maximum dry density and 7dcompressive strength of cementstabilized three categories of aeolian sand are different obviously,through which the practicability of theaeolian sand classification method is verified.