高速公路路基填料承载比影响因素研究

Study on influence factors of California Bearing Ratio (CBR) of expressway subgrade materials

路基填料的承载比(CBR值)是土体抗局部剪切力(潜在强度)的反映,评价其路用性能的重要指标。为了研究影响粘性土CBR值的主要因素,结合河北省青(岛)银(川)高速公路工程实际,对15组填料进行了物理、理学试验。根据土样塑性指数相同,而CBR值差异很大的实验结果,从土体的颗粒组成、矿物成分以及粘土矿物成分几方面研究了其对填料CBR值的影响。得出有益的结论:在标准的试验方法和相同的试验条件下,对塑性指数相同的土体而言,影响CBR值的主要因素是土体中矿物类型及其含量的多少,其次为粘粒组颗粒曲线分布情况及粘粉比m。粘粉比m越大,CBR值越小。

The California Bearing Ratio （CBR） denoted the potential strength of subgrade material and was an important index to evaluate its performance in expressway. In order to study the main influence factors of the CBR value of clay, the physical and chemical tests of fifteen groups of subgrade materials from the Qingdao-Yinchuan Expressway in Hebei Province were done, Based on the result of tests, that there was obvious difference between CBR values of clays with the same plastic index, the influence factors of CBR of expressway subgrade materials were studied, such as distribution of particle sizes of soils, mineral component and clay mineral component, and useful conclusions were gained. The main influence factors of CBR of expressway subgrade materials were the type and content of minerals component and the shape of distribution curve of particle sizes of soils. The CBR value decreased with the increase of clay-silt ratio.