高填方土石混合料强夯振动响应及加固机理研究

基于土石混填料强夯加固的大型现场振动速度测试的试验成果,深入地分析了质点振速和波形在强夯过程中的传播及演化,以此研究了1000 kN·m夯击能作用下土石料填筑体的内部质点的振动响应及强夯加固机理。结果表明：土石料在强夯作用下土体内部仅有冲击波和振动波两种振动形态;提出了强夯起始加固临界振速的概念和确定方法,并给出相应的振速值;通过分析填筑体空间振速演化规律,阐述了粗粒土石混合料的强夯加固机理,将强夯过程分为加固发展阶段和加固退化阶段。为工程条件下强夯施工层厚给出指导性建议。

Vibration response and reinforcement mechanism of high-fill soil-stone mixtures by dynamic compaction

Based on the large-scale field tests on the vibration velocity caused by dynamic compaction in soil-aggregate mixtures, the propagation and evolution of particle amplitude and waveform in the process of dynamic compaction are analyzed, then the vibration response and reinforcement mechanism of the internal particles in soil-aggregate fills under the tamping energy of 1000 kN·m are studied. The results show that there are only two vibration forms, shock wave and vibration wave, in the soil-aggregate mixtures under the action of dynamic compaction. Then, the concept and method of the critical elastic vibration velocity of soil-aggregate mixtures are proposed, and the corresponding critical elastic vibration values are given. The expansion rules of each area with the times of ramming are given by the evolution laws of spatial vibration velocity. Finally, the reinforcement mechanism of dynamic compaction of coarse-grained soil-aggregate mixtures is expounded, the reinforcement process is divided into four stages, and the guiding suggestions for the layer thickness under dynamic compaction in the construction are proposed.