砂石桩与强夯地基处理效果的动力触探评价

DPT Evaluation of the Effects Sand-Gravel Columns and Dynamic Compaction Treated Soils

拟建的武汉王家墩堆山公园位于软弱地基上,采用砂石桩+强夯联合固结预压法进行地基处理。为了初步检验设计方案的可行性,选取了2块区域进行试验并进行整体效果评价,其中采用动力触探试验对桩间土在处理前后力学性能的变化进行评价。通过对比研究地基处理前后桩间土在同一深度的动探贯入击数的变化,发现砂石桩施工完成后,地基土体的强度整体均有所提高,而强夯处理后,深层土体的强度有所提高,表层土体强度反而有所降低。

The proposed Wangjiadun Duishan Park is on the soft soils. The combination of sand-gravel columns and dynamic compaction methods are found to be most economical. To verify the feasibility of this soil improvement concept, the pilot study was conducted at two locations. The effect of the improvement was evaluated by the Dynamic Penetration Test （DPT） method. The DPT testing was performed at soils between sand-gravel columns. From the DPT blow count changes before and after the improvement, it is concluded that the shear strength of the composite soil mass was improved after the installation of the sandgravel columns. After the dynamic compaction, the shear strength of the deep deposited soils increased but the soil strength at shallow depth decreased.