Dynamic compaction treatment technology research of red clay soil embankment in southern mountains

Abstract

High liquid limit soil generally adopted in expressway embankment construction of southern mountains, which often expresses some characteristics including high moisture content, high porosity ratio, low permeability, high compressibility, certain disintegration, and so on. Spring soil phenomenon and inhomogeneous compaction have effects on the quality of embankment construction, just because the water in soil is difficult to evaporate. Based on the study of reinforcement mechanism for high liquid limit soil, in situ tests for dynamic compaction treatment in Yizhang—Fengtouling expressway embankment were developed. The reliable and economical dynamic compaction treatment methods and the construction technology for large range high liquid limit soil embankment in southern mountains expressway were discussed. In the process, convenient measurement methods were adopted to evaluate the treatment effects. The test results show that the dynamic compaction method has good treatment effects on the local red clay embankment. The embankment compaction degree is improved with compactness coming to 90% around tamping pits and compactness over 95% in tamping pits interior after tamping. The bearing capacity, the physical mechanic-property and the shear strength for soil are obviously improved, which are enhanced with cohesive strength increasing over 10 kPa and compression modulus increasing over 3 MPa.

Keywords

dynamic compaction / embankment / high liquid limit soil / in situ test / reinforcement mechanism

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