某机场自重湿陷性黄土场地地基处理试验研究

FOUNDATION TREATMENT OF SELF WEIGHT COLLAPSE LOESS OF REMOVAL AIRPORT PROJECT

为消除某机场迁建工程自重湿陷性黄土场地的湿陷性,达到减小高填方场地工后沉降的目的,选用灰(素)土挤密桩、孔内深层强夯挤密桩(DDC)及强夯法对6个场地进行试验,获得了诸多物理力学参数,分析不同方法处理的效果。结果表明灰土和素土挤密桩在消除黄土湿陷性上均能达到目标,从环保和经济角度考虑可以优先选用素土挤密桩;挤密桩和DDC桩的挤密系数基本呈现上部和下部较小,中间较大的趋势,而强夯法处理的压实系数随着深度增加逐渐减小;强夯法的压实系数基本上大于挤密桩和DDC桩的挤密系数;DDC处理区域,若干点的湿陷系数大于0.015,重要黄土地基处理工程应慎重采用该种方法;从经济和效率角度考虑,强夯法要优于挤密桩和DDC法,大面积施工中建议采用强夯法。

In order to eliminate collapsibility of self weight collapse loess of removal airport project in Yan＇an and decrease sedimentation of high-fill site, some physical mechanics index of six test sites were acquired by using lime-soil （original soil） compaction pile, down-hole dynamic compaction and dynamic compaction, effectiveness of 3 kinds of foundation treatment was analyzed. The test results showed, lime-soil （original soil） can achieve the purpose of eliminating collapsibility, from an environmental and economic point, original soil compaction pile will be given the priority. Compaction coefficient of compaction pile and DDC pile basically shows that the upper and lower part of pile is small, the larger and the intermediate pile is large, while degree of compaction of the dynamic compaction decreases with the depth increasing, degree of compaction of dynamic compaction method is greater than the compaction coefficient of compaction pile and DDC pile basically. In DDC treatment area, some points are greater than 0.015, so important engineering projects should be careful using this method. From point of economy and efficiency, the dynamic compaction method is superior to the compaction pile and DDC method, the large area construction should be suggested to use dynamic compaction.