砂砾卵石土高速公路路基填筑试验研究

为研究砂砾卵石土混合料作为路基填料压实后的压实效果，通过室内筛分试验、重型击实试验、CBR试验得到砂砾卵石土的颗粒级配组成，最大干密度、最佳含水率与粗颗粒含量的关系，CBR值与粗颗粒含量、击实次数的关系。试验结果表明，最大干密度随着粗颗粒含量的增加先增大后减小，CBR值随着粗颗粒含量的增加而增大。进一步分析砂砾卵石土作为路基填筑材料的压实机制，通过现场碾压试验，确定砂砾卵石土路基填筑施工工艺，利用压实度、CBR、弯沉、回弹模量等现场检测手段和现场沉降观测数据检验压实效果，通过比较分析各种检测方法的可靠性，提出适合砂砾卵石土压实质量的检测方法，运用统计学方法得到沉降差检测标准值，确定采用碾压遍数与沉降差双重控制保证压实质量，得到一些有益的结论。

Test research on compaction effect of expressway embankment with sand-gravel-cobble mixture

The research on expressway embankment with sand-gravel-cobble mixture is in discussing.In order to research on the compaction effect of expressway embankment with sand-gravel-cobble mixture,the screening test,heavy compaction test and California bearing ratio(CBR) test in laboratory have been carried out;and through these tests the grain composition of sand-gravel-cobble mixture,the relation between maximum dry density and coarse particle content,the relation between best water content with coarse particle content and the relation between CBR value with coarse particle content or compaction times are obtained.The results show that the maximum dry density first increases and then decreases when the coarse particle content increases;and CBR value increases when the coarse particle content increases.Then compaction mechanism of sand-gravel-cobble mixture used in embankment filling is analyzed.Based on compaction test in field,the construction technology of embankment with sand-gravelcobble mixture is obtained.The compaction effect is detected by using compaction degree,CBR,deflection,modulus of resilience and settlement discrepancy.In the end,the suitable detection methods of embankment with sand-gravel-cobble mixture are suggested by analyzing the reliability of every detection method;and the standard value of settlement discrepancy is obtained based on statistics theories,and determined using both settlement discrepancy and compaction times to guarantee compaction.Some useful conclusions are obtained.