含砾砂岩CBR值的影响因素研究

CBR值是评定土基(或其他路面材料)承载能力的重要参数,其大小取决于许多因素。通过对不同粒径范围的含砾砂岩进行CBR试验,分析了颗粒粒径、矿物成分、泡水时间和击实次数等因素对CBR值的影响,并利用双因素无重复分析法对上述影响因素进行了显著性分析。结果表明:含砾砂岩经压实后浸水仍不易软化,强度稳定,在南方强降雨地区,可用来填筑路基;矿物组成、泡水时间和击实次数对含砾砂岩的CBR值影响较大,粒径大小和干密度对CBR值的影响相对较小;当难以通过增大夯实功来提高路基的填筑强度时,可通过增加粗颗粒的含量来实现路基承载强度的提高。

Analysis on Effect Factors of CBR of Gravel-Bearing Sandstone

CBR is the key parameter to evaluate the load-carrying capacity of subgrade, which depends on many factors. By CBR tests on gravel-bearing sandstones of different particles, analyses the influence factors such as particle component, mineral component, immersion time and striking times, and analyses the prominent property of the above factors by means of nonrepeative double factors variance analysis. The results show that the compacted gravel-bearing sandstone after immerdion is difficult to be soften and has stable strength, which can be used to fill subgrade in southern heavy rainfall area, and the main influence factors of CBR is mineral component, immersion time and the compaction times, the impacts of particle size and dry density is relatively small. While it is difficult to improve the filling strength by increasing tamp power, increasing the content of coarse particles is a way to improve load-carrying capacity of subgrade.