软土地基爆夯动力排水固结方法

Dynamic Drainage Consolidation Method by Explosive Ram in Soft Clay Foundation

宁启铁路DK172+000—DK172+200段软土路基固结处理现场试验结果表明,爆夯动力排水固结法(爆夯法)达到了快速固结的效果。由试验结果总结出爆夯法的作用原理,并提出处理工艺。依据爆夯法的作用原理,建立数值计算模型,并将三维动力固结问题转化为二维平面应变初边值问题。利用有限元法计算DK172+080土体表面沉降发展过程,计算结果与试验结果十分相近。试验和数值计算结果证明该方法可以有效地加快并加大软土地基的固结沉降,起到了较好的软土地基加固效果。影响爆夯作用的主要参数有上覆荷载、炸药单耗、爆炸次数、间隔时间。从作用机理、能量利用效率、有效加固深度和环境的影响等方面进行爆夯法与强夯法对比分析,认为爆夯法具有能量利用率高、有效加固深度大等特点。

The test result of Ningqi railway DK172＋ 000-DK172 ＋200 soft soil roadbed consolidation indicates that the method of dynamic drainage consolidation by explosive ramming （explosive ramming meth od） has achieved the purpose of quick eonsolidation. According to the action principle of dynamic consolidation by explosive ram summarized from the test result, we propose a corresponding processing technology and with the establishment of numerical calculation model, the three-dimensional dynamic consolidation questions are transformed into the two-dimensional surface strain initial value question. Using the finite element method, we fit the process of settlement of the DK172 ＋080 soil body surface, and find that the result of calculation is very close to test result. Experimentation and result of numerical calculation indicate that this method can effectively accelerate and strengthen the consolidation settlement of soft soil foundation. The main parameters influencing explosive ram function are pile loading, specific charge, times of blasting, and interval of exploding. The explosive ram method and heavy tamping method are contrasted from the influence factors such as action mechanism, energy utilization efficiency, effective strengthening depth and environmental influence, etc. We come to the conclusion that the energy utilization rate of dy namic consolidation by explosive ram is higher and effective strengthening depth is larger.