强夯能量利用率反演及加固影响范围研究

强夯法具有高效的地基处理能力而被广泛应用，但加固地基的同时会对周围工程结构和环境产生一定的振动危害。以能量转换原理为基础，近似将夯击能分为振动波能和土体塑性功两部分，通过建立的强夯椭球体分区加固模型，导出塑性功计算格式，提出利用监测强夯夯坑深度变化信息来反演强夯能量利用率的反演方法，并导出了相应的反演公式。依据加固压实区和加固影响区椭球体分布假设和夯坑深度变化监测结果，给出了强夯加固范围和影响范围大小的计算思路和方法。以北京园博园回填土地基强夯加固工程为背景，利用现场监测试验信息对强夯能量利用率和加固范围及影响范围进行了反演分析和计算。分析表明，文中方法不仅能够有效地反演出强夯能量利用率和计算出强夯加固范围和影响范围，且可利用分析结果能够方便地估算地基强夯加固时的有效夯击次数，进行加固方案设计等。通过分析结果与现场地基测试结果的比较，验证了文中方法的有效性和实用性。

Research on inversion of energy efficiency and compacted and affected scope of dynamic compaction

Dynamic compaction method is widely used for its high efficiency in foundation treatment. But the vibration caused by dynamic compaction will threaten the surroundings especially the structures around. Base on the fact that the tamping energy is approximately divided into vibrational energy and plastic work of soil, the formula of plastic work is derived according to the proposed ellipsoid partition model of dynamic compaction, and the inversion method of the energy efficiency is given by monitoring the information such as depth of tamping pits；also the inversion formula is derived. According to the ellipsoid distribution hypothesis of the affected zone and compacted zone, associated with the monitoring data of the depth of tamping pits, the calculation method of compacted scope and affected scope is given. Finally, under the background of the Beijing Garden Expo Park backfill soil reinforcement project, the compacted scope and affected scope as well as energy efficiency of dynamic compaction are calculated and inversed according to the field monitoring information. The result shows that the method in this paper can not only inverse the energy efficiency and calculate the compacted scope and affected scope, but also provide a reference to estimate the effective number of tamping in the design of reinforcement scheme. By comparing the analytical results with the foundation testing results, the effectiveness and practicability of the method in this paper are verified.