自重湿陷性黄土地区复合地基处理对比试验研究

Experimental study on composite ground treatment in self-heavy collapsible loess area

为探究不同成桩方法和桩体材料对自重湿陷性黄土处理效果的影响,结合兰州中川机场新建航站楼项目,设计不同试验方案,从湿陷性处理效果、地基承载力及土体挤密情况三个方面进行了对比研究,筛选出最佳处理方案。通过对比分析可知,不同处理方案都能满足消除黄土湿陷性的要求;施工工艺对地基承载能力几乎无影响,桩体材料对其影响较大,灰土桩处理区域承载能力比素土桩处理区域高14%左右;桩体材料相同时,沉管挤密桩对土体的挤密效果优于预成孔夯扩挤密桩,四种方案中素土沉管挤密桩处理区域的挤密效果最佳,从桩体压实效果分析,灰土挤密桩压实度明显优于素土挤密桩,压实系数离散程度更小。

In order to explore the effect of different compaction methods and different material of piles on collapsible loess treatment,based on the case study of the new terminal project of Zhongchuan Airport in Lanzhou,some different experimental schemes are designed to compare the treatment effect on collapse,the ground bearing capacity and the soil mass after compaction,so as to get the optimal treatment plan.The main conclusions are that the different treatment methods could eliminate the collapsibility;the construction process has little impact on the ground bearing capacity,and the bearing capacity of the lime-soil pile is about 14%higher than that of the soil pile;when the pile shaft material is the same,the soil compaction effect of compaction piles with sinking tube is better than that with pre-bored hole.Among the four schemes,the compaction effect of soil pile with sinking pipe is best.The pile shaft compaction effect of lime-soil compaction piles is obviously better than that of soil compaction piles,and the compaction coefficient is less discrete.