25000 kN·m超高能级强夯处理大厚度填土地基现场试验研究

Application of 25000 kN·m ultra high energy level dynamic compaction in the treatment of large thickness filled soil foundation

超高能级强夯是处理深厚湿陷性黄土地基、大厚度非均匀碎石回填地基的有效方法,但缺乏工程应用经验的积累。为评估25000 kN·m能级强夯处理大厚度新近素填土地基的效果,依托榆林某工业园区场平工程,开展了现场试夯试验,通过平板载荷试验和标准贯入试验检测夯后地基的承载力和密实度。试验结果表明:夯后地基的承载力特征值不低于260 kPa,夯后是夯前的2.6倍以上;在地基22 m深度范围内,夯后地基土的标贯击数是夯前的1.8~8.8倍,根据承载力指标判断的有效加固深度约为20 m。相关成果可为超高能级强夯处理类似大厚度素填土地基提供参考。

Ultra high energy level dynamic compaction proves to be an effective treatment for improving deep collapsible loess foundation and thick,non-uniform gravel backfill foundation.However,it lacks sufficient engineering application experiences.To assess the impact of high energy level 25000 kN·m dynamic compaction on the treatment of thick recently filled soil foundation,on-site trial compaction tests were carried out in the leveling project of an industrial park in Yulin.The bearing capacity and density of the compacted foundation were tested through plate loading tests and standard penetration tests.The results show that the characteristic value of the bearing capacity of the compacted foundation is no less than 260 kPa,more than 2.6 times its pre-compaction characteristic value.Within the depth of 22 m,the standard penetration blow count of the compacted foundation soil is 1.8-8.8 times compared to pre-compaction levels.Based on the bearing capacity index,an estimated effective reinforcement depth of approximately 20 m was determined.The relevant findings can provide valuable references for the treatment of similar thick plain fill foundation using ultra high energy level in dynamic compaction.