细粒土路基填料承载比试验技术要求及影响因素

分析了美国、英国、日本和我国交通行业标准对承载比(CBR)试验要求的异同,强调了承载比试验的操作技术及注意事项,并对试验中的一些问题进行了有益的探讨。为了研究影响黏性土CBR值的主要因素,结合在建高速公路15组填料进行了物理、力学试验。分别从土体的颗粒组成、矿物成分以及黏土矿物成分等几方面研究了黏性土填料CBR值的影响。结果显示,在标准的试验方法和相同的试验条件下,当土体的塑性指数相同时,影响CBR值的因素主要是土体中矿物类型及其含量的多少,其次为黏粒组颗粒曲线分布情况及黏粉比m。

Technological requirements and influence factors of California bearing ratio of expressway subgrade materials

The similarities and differences of California bearing ratio(CBR) test requirements in America,Britain,Japan and China are analyzed;The test technology and proceeding are emphasized.The CBR denotes the potential strength of subgrade material and it is the important index of evaluating its using performance in expressway.In order to study the main influence factors of the CBR value of clay,the physics and chemistry tests of fifteen groups of subgrade materials,taking from the Qingdao-Yinchuan Expressway in Hebei Province,are done.Based on the result of tests,which there are obvious difference between CBR value with the same plastic index clay,the influence factors of CBR of expressway subgrade materials,such as distribution of particle sizes in soils,mineral component and clay mineral component,are studied.The useful conclusions are drawn as follows: the main influence factors of CBR of expressway subgrade material are the type of mineral component and its content;secondly are the distribution curve shape of particle sizes in soils.