Research on CBR Evaluation Method and Classification Scheme for Expansive Soils Fill
|School||Changsha University of Science and Technology|
|Course||Road and Railway Engineering|
|Keywords||Expansive soil filler Improve the CBR test Improve the CBR value CBR amount of expansion Consistency Classification index system|
The Changsha University expansive soil research group in Yunnan, Hunan and Guangxi provinces, four highway closed package cover expansive soils with different expansion and contraction level the successful construction of the the Kudan embankment entity Engineering made good engineering Treatment effects and the economic and ecological environmental benefits. To promote the Treatment for the promotion of new technologies and to ensure the strength and stability of the roadbed must correctly evaluate the strength of expansive soils used as roadbed filler and ancillary filler classification index system. Essential characteristics CBR strength for expansive soils tend to reach the existing roadbed design specification requirements (≥ 3%) of the phenomenon, the three aspects of the overburden pressure and sample preparation moisture from the flooding in parts, a comprehensive analysis of standard CBR test method unreasonable evaluation expansive soil filler strength of expansive soils, the cover fill core the embankment entities Engineering based on the closed package in the actual working conditions, study and propose a set of evaluation expansive soil such special soil real strength improvements The CBR Test Method: heavy compaction standards, soaking wet the best parts of the moisture content, change the specimen top of flooding for the lateral flooding and increased overburden pressure. Two soil types (expansive soil and non-expansive soils) six soil samples were taken CBR standard method to improve the method of comparative tests, analyze test results, verify the rationality and feasibility of improved test methods. The same actual departure from the project, to follow the principle of combining inheritance and innovation, in-depth study of the expansive soil engineering properties and directly used as embankment filler main factors: strength, deformation and construction performance. Basis Indoor lot of expansive soil engineering construction experience with the performance test results and existing entities, use research to improve the CBR test, CBR strength of using a modified CBR expansion amount and consistency of the three indicators to establish expansive soil embankment filler classification and grading The index system. The test results show that the three typical expansive soil-related indicators, this article index classification system can truly reflect the essential characteristics of expansive soil and engineering properties as roadbed filler and obtain indicators parameters of the test is simple, fast, and can greatly broaden expansive soil with for the range of use of the filler. The classification of the establishment of the index system improved CBR test method proposed and expansive soil directly used as roadbed filler expansive soil embankment design and construction to provide the basis and reference for engineers.