膨胀土填料分类指标体系的合理性验证

Rationality Verification of Index Classification Scheme of Expansive Soils Used as Filler

为进一步检验膨胀土填料分类指标体系的合理性,对在建广西百隆高速路上3种膨胀土系统开展了基本土性和各种强度、变形等路用性能试验,全面分析测试结果并对照新填料分类体系,3种土样均满足以改进CBR值、改进CBR膨胀量和稠度为指标的分级标准,都可直接用于下路堤填筑。据此,按物理处治技术原理并结合工程实施条件,采取粘土包边膨胀土夹层填芯方案,将性质最差的1号土分2阶段填筑于ZK176+135～+410路段,共消耗膨胀土60 000 m3,跟踪检测表明,路堤施工质量良好。通过系统试验和修建工程实体验证了膨胀土填料三指标分类体系的合理性。

In order to further verify the rationality of the classification of expansive soil used as filler, a series of tests on soil properties, strength and deformation of road performance were performed for three kinds of expansive soil in Baise-Longlin expressway in Guangxi. In terms of testing results and the new classification criteria of expansive soil used as embankment filler determined by modified CBR strength, modified CBR swelling rate and consistency, it is concluded that the indices for the three kinds of expansive soils all satisfy the requirements. Therefore, the expansive soils can be directly used as embankment filler. According to the testing results of soil properties and the principle of physical treatment technique and combined with practical condition of the project construction, a technology of both embankment sides enveloped by non-expansive clay and a filling method like ＂ sandwich＂ were utilized. The expansive soil No. 1 which has the poorest engineering behavior among the three kinds of soil sample was selected to fill the embankments of ZK176 ＋ 135 -ZK176 ＋ 410. The consumption of expansive soil was more than 60 000 cubic meter in all. The results of following detection show that this engineering technology has good application effect for subgrade construction. Accordingly, the applicability of the three-index classification scheme for expansive soils as embankment filler was verified by laboratory tests and practical projects.