中文摘要：

取自广西武鸣的一种红黏土粗粒含量高,胶结作用明显,工程性质特殊。通过对三种不同级配的武鸣红黏土进行击实试验及CBR试验,结合其矿物组成,比较了粗粒含量以及含水率变化对填筑性能的影响。研究结果表明：天然武鸣红黏土颗粒组成中砾粒和粉粒含量较多,不同级配的击实土在最优含水率时,其浸水后的CBR均为最大值,虽然级配不同浸水后CBR值下降幅度不同,但三种土样浸水后CBR均趋向一个稳定的值,这一规律受红黏土的土质特点以及浸水前后土间毛细力、范德华力及化学胶结力变化所控制;饱和度较高时,武鸣红黏土的工程性能主要受控于土中的黏粒及具有黏粒特性的粉粒级团粒结构,大于0.5mm粗粒组的存在并不能提高泡水后CBR强度以及改善水稳定的范围,无法产生类似于掺加粗粒料对土性改良的效果。在最优含水率附近,天然级配的武鸣红黏土CBR满足规范对路堤及路床填料的要求。

英文摘要：

The laterite samples taken from Wuming are strongly cemented and contain many aggregates contributing to the accumulation of coarse grains. The soil samples are divided into three groups by grain size grade： the compaction tests and CBR tests are performed to analyze the effects of the mineral composition, the content of coarse grain and the change of moisture on the filling natures. It is found that thecontent of coarse grain has obvious impact on maximum dry density. The CBR reaches its maximum value at optimum moisture content but the reduction of CBR for the soil with the size ＇smaller than 0.5mm is much less than that of the other two. All the three soils almost reach a close value after soaking process. This phenomenon results from the capillary force, the Van der Waals force and the chemical cemented force greatly change in soaking process. During the high saturation degree the engineering properties of Wuming laterite are controlled by the structures of the clay grain and the silt lumpy aggregate. The coarse grain group greater than 0. 5mm couldn＇ t improve the CBR strength after soaking and the scope of water stability. That is it couldn＇ t bring the effect like mixing coarse grains. Under the condition with optimum moisture content the CBR of the Wtlming laterite with the nature grain composition meets the filling requirements of the road subgrade from the codes.