水泥土搅拌桩软土地基土体动力特性的共振柱试验研究

Resonant column experimental study of dynamic properties of soft clay foundation with cement soil mixing piles

开展对水泥土搅拌桩软土地基土体试样的GDS(Global Distribution System)共振柱试验,研究不同剪应变、围压、水泥土置换率对土体动力特性的影响。结果表明,水泥土搅拌桩软土地基土体的动剪切模量G和阻尼比D随剪应变γ变化趋势与软黏土一致,在小应变范围内围压和置换率对土体的动剪切模量G和阻尼比D的影响显著,随着剪应变γ增大,围压和置换率的影响减弱;水泥土搅拌桩软土地基土体的最大动剪切模量G_(max)与围压表现出良好的线性关系,围压越大,提高水泥土的置换率对土体最大动剪切模量G_(max)增强效果越明显。研究结果可为地区水泥土搅拌桩软土地基土体动力参数的取值提供一定的参考。

Through the Global Distribution System (GDS) resonant column tests on soft clay foundation with cement soil mixing piles samples, the effects of shear strain, cell pressure and replacement ratio of cement soil on dynamic properties are analyzed. The test results shows that, the change tendency of the dynamic shear modulus G and damping ratio D of the cement soil mixing pile soft clay foundation is the same as that of soft clay, the dynamic shear modulus G and damping ratio D of the soil are significantly influenced by the cell pressure and the replacement ratio in the small strain range; the influence is weakened with the increase of strain. The Gmaxof soft clay foundation with cement soil mixing piles shows linear relationship with cell pressure; the enhancement effect on Gmaxof the replacement ratio is significant at high cell pressure. The results can provide a reference for the dynamic parameters of the soft clay foundation with cement soil mixing piles. © 2016, Science Press. All right reserved.