沙漠地区高速公路风积沙路基湿压法施工工艺与质量控制

Construction Technology and Quality Control of Wet CompactionMethod for Aeolian Sand Subgrade of Expressway in Desert Area

风积沙是新疆沙漠地区最丰富的材料,为了就地取材将其用于道路工程建设中,在对风积沙颗粒特性及其路基压实特性分析的基础上,提出风积沙路基湿压法施工工艺及其质量控制要点,并对施工后的质量进行检测。结果表明:风积沙的不均匀系数<5.0、曲率系数<1.0,但其在最佳含水率时CBR实测值均超过规范大于8%的规定;建议风积沙路基施工含水率控制在13%±2%、下路床以下的松铺系数为1.27、虚铺厚度为45 cm,且宜采用22 t双驱动振动压路机碾压4遍以上;风积沙填料含水量接近最佳含水量时成团状且不散开,检测点处压实度代表值、弯沉值、回弹模量均满足规范要求值,表明风积沙填料可用于高速公路路基施工。

In order to use aeolian sand,the most abundant material in Xinjiang desert area,as the local materials in road engineering construction the construction technology and quality control points of wet compaction method for aeolian sand subgrade was put forward and the construction quality was tested based on the analysis of the characteristics of aeolian sand particles and compaction of its subgrade.The results show that,the non-uniformity coefficient of aeolian sand is less than 5.0 and curvature coefficient is less than 1.0,while the measured value of CBR at the optimal water content is more than the specification standard(8%);the optimal water content of aeolian sand subgrade(13%±2%),the loose paving coefficient under the lower roadbed(1.27),the virtual paving thickness(45 cm)and rolling times of 22 t double drive vibratory roller(more than 4 times)are suggested.When the water content of aeolian sand is close to the optimal one,it is agglomerated and does not disperse,and the representative value of compactness,deflection value and modulus of resilience at the detection point all meet the requirements of the specification,which indicates that aeolian sand can be used for expressway subgrade construction.