高能级强夯加固深厚杂填土地基现场试验研究  

Field Test Research on Strengthening Deep and Thick Backfilled Foundation Soil by 12 000 k N·m High Energy Dynamic Compaction

作　　者：王家磊 韩进宝 马新岩 吴云峰 李海鹏 Wang Jialei;Han Jinbao;Ma Xinyan;Wu Yunfeng;Li Haipeng(China Airport Planning&Design Institute Co.Ltd.,Beijing 100029,P.R.China;Xinjiang Airport Group Co.Ltd.,Urumqi 830016,P.R.China)

机构地区：[1]民航机场规划设计研究总院有限公司,北京100029 [2]新疆机场(集团)有限责任公司,乌鲁木齐830016

出　　处：《地下空间与工程学报》2021年第4期1154-1163,1189,共11页Chinese Journal of Underground Space and Engineering

摘　　要：高能级强夯法是解决深厚杂填土地基承载力不足和工后沉降问题的重要工程手段之一。鉴于现有研究中对深厚杂填土地基的高能级强夯参数、夯实加固特征少有探讨,理论成果、工程经验不足,使杂填土在山区大型填方工程中的推广使用严重受限,以某高填方机场工程为依托,围绕厚层杂填土地基开展了多组现场高能级(12 000 k N·m)强夯试验,揭示了杂填土地基的强夯加固机理并结合多种现场检测试验对夯实效果、夯密特征进行了对比,为深厚杂填土地基强夯参数和夯实检验方法的选择指明了方向。结果表明:卵砾石深厚杂填土地基在12 000 kN·m高能级强夯作用下,土性明显改善;在"主夯16加固夯14满夯5"单点夯击次数下浅表卵砾石层的夯实、整体地基土层均匀性的改良以及工程节支方面明显优于"主夯10加固夯12满夯3"强夯方案;存在最佳单点夯击次数,当夯击数超过这一数值时,额外的夯击对地基土性改良不利;杂填土地基由于成分复杂、空间高度不连续,现场波速试验不适用于此类地基土层质量的检测;受土性影响,杂填土地基夯密收敛标准略高于行业规范中的一般规定,为满足场地地基密实度要求,厚层杂填土地基强夯工艺须满足最后两击平均夯沉量不大于0.1 m、浅表卵砾石垫层固体体积率不小于85%、夯后杂填土密实度为密实及以上。最后,结合试验结果对强夯方案进行了优化,得到了深厚杂填土地基高能级强夯处理的推荐参数和现场检测方案。High energy dynamic compaction is one of the important engineering methods to solve the problem of insufficient compactness and settlement of the thick miscellaneous filling foundation. In view of the wide use of miscellaneous fill in large-scale landfill projects in mountainous areas is seriously limited because of the lack of discussion on high energy dynamic compaction parameters and characteristics of compaction in the existing researches,and the lack of theoretical achievements and engineering experience. On-site high energy dynamic compaction experiments on heavy miscellaneous fill foundation were carried out based on a high-fill airport project,the reinforcement mechanism of dynamic compaction on miscellaneous fill foundation was revealed,and the compaction effect and compaction characteristics through various on-site inspection tests were compared.The conclusions point out the direction for the choice of dynamic compaction parameters and compaction testing methods for the heavy miscellaneous fill foundation. The results show that,under high energy dynamic compaction effect of 12 000 k N·m,the engineering properties of the foundation consist of gravel and miscellaneous were significantly improved. The scheme that the number of single-point compaction is "chief ramming 16-reinforcement ramming 14-full tamping 5"is superior to the other scheme that the number of single-point compaction is"chief ramming 10-reinforcement ramming 12-full tamping 3"in compaction of shallow gravel layer,improvement of uniformity of whole foundation and engineering savings. There is an optimal number of single point compaction,corresponding to the " saturation state" of the whole compaction of foundation. Additional compaction is not conducive to the improvement of foundation properties when the compaction number exceeds the value. The field wave velocity test is unsuitable for detecting the soil quality of heavy miscellaneous fill foundation due to its complex composition and discontinuity in space. Influenced by soil property,t

关 键 词：高能级强夯法 杂填土 地基处理 影响深度 强夯参数 

分 类 号：TU472.1[建筑科学—结构工程]