膨胀土路基压实和承载强度研究

依托广西崇左~上思二级公路建设项目,在室内试验和现场修建试验路段相结合进行大量数据采集的基础上,较深入地分析弱膨胀土路基填筑中压实度、压实功、含水量、CBR等的特点及其关系。同一种膨胀土,击实功越大,最大干密度越大,最佳含水量越小。不同种类的膨胀土,在相同击实功下,膨胀性越小CBR越大。同一种膨胀土,击实功越大,CBR越大,但最大CBR所对应的含水量都大致相等。项目所在地,干旱季节大部分弱膨胀土的天然含水量大致都在15%~18%之间,这正好与该地区弱膨胀土CBR达到最大值时的含水量相对应。而且,这个含水量区间虽比标准击实时的最佳含水量要大4%~7%,但只要不超出这个区间的上限,在现场路基施工时就可通过增加压实功很易使其达到压实度要求。

Research on Compaction and Load Strength of Expansive Soil Subgrade

Relying on the project construction of the second-class road from Chongzuo to Shangsi in Guangxi Province,on the basis of lots of data gathered from the combination of lab.tests and field constructing test section,the characters and relationship between degree of compaction,compaction effect,water content and CBR of weak expansive soil when is filled in subgrade are analyzed.For the same kind of expansive soil,the more compaction effect is,the bigger maximum dry density is,and the smaller optimum water content is.For different kind of expansive soils,when at the same compaction effect,the smaller the expansibility is,the bigger CBR is.As well as for the same kind of expansive soil,the more compaction effect is,the bigger CBR is,but the water content correspond to maximum CBR is equivalent approximately.On the project area,nature water content of most weak expansive soil is about 15% to 18%,that is correspond to water content when weak expansive soil's CBR gets to maximum,furthermore,although span of water content is more 4% to 7% than optimum water content of normal compaction,as long as it doesn't overstep the upper limit,it's easy to meet degree of compaction with more compaction effect when at field subgrade construction.