炉渣粉煤灰回填地基的强夯设计参数研究

针对人工回填料——高炉渣粉煤灰,研究其各主要施工参数对强夯效果的影响,为强夯施工参数设计提供了更加科学的参考标准,实现方案的合理性和成本的经济性。以高炉渣粉煤灰回填地基为研究对象,对强夯法加固地基的设计参数进行了数值模拟。依托包头钢铁集团新体系高炉矿渣地基处理项目,在FLAC~(3D)软件的基础上,选定夯击能、夯击次数,夯锤直径、夯点间距作为强夯施工研究参数,通过控制单一变量对不同施工参数下的强夯法加固地基的位移和应力变化进行探究。分析得出了夯击参数对强夯加固的影响规律,并对加固效果进行了详细的评价。结果表明:选取的夯击能越大,夯锤中心的土体产生的竖向位移越大;随着夯击次数的增加,土体的影响深度逐渐增大,当超过最佳夯击次数后,就显得毫无意义;夯锤直径越大,作用面积越大,土体变形范围越大。因此,合理的选取强夯间距可以增强地基的整体强夯效果。

Study on design parameter of dynamiccompaction for foundation backfilled with blastfurnace slag fly ash

Aiming at the artificial backfill material—blast furnace slag fly ash， the influences of its main construction parameters on the effect of dynamic compaction are studied herein， from which a more scientific reference standard for the design of the construction parameter for dynamic compaction is provided，and then the scheme reasonability and the cost economic efficiency are realized as well. By taking the foundation backfilled with blast furnace slag fly ash as the study objective， the design parameters for the foundation reinforced with the method dynamic compaction is numerically simulated. Based on the foundation treatment project made with blast furnace slag for the new system of Baotou Iron and Steel Group，the changes of the displacement and stress of the foundation reinforced with dynamic compaction method under various construction parameters are explored through controlling the relevant single variable by selecting the tamping energy， the tamping number， the diameter of tamping hammer and the spacing of tamping points as the parameters to be studied for the dynamic compaction construction on the basis of the software of FLAC3D. The law of the influence from the tamping parameter is obtained from the analysis concerned，and then the reinforcement effect is evaluated in detail. The result shows that the larger the selected tamping energy is， the larger the vertical displacement of the soil mass occurred within the tamping center is to be，while the impacted depth of the soil mass gradually increases and is to be insignificant when the optimum tamping number is exceeded. The larger the tamping diameter is，the larger the affected area is to be and the range of the soil mass deformation is to be as well. Therefore，reasonable selection of the tamping spacing for dynamic compaction can enhance the overall dynamic compaction effect of foundation.