湿陷性黄土地基基础方案比选研究

Comparison and Selection of Collapsible Loess Foundation Schemes

【目的】基于EPC项目设计阶段,分析湿陷性黄土地基基础采用的2种技术方案。【方法】以钻孔灌注基础和强夯法2种处理方案进行技术和经济方面比较,比较两种方法在处理本项目湿陷性黄土地基的适用性。【结果】经对比分析发现,钻孔灌注桩基础不用考虑消除湿陷性黄土的湿陷性且能满足上部结构承载力要求,沉降变形小,但造价高、工期长;强夯法能够消除土层的湿陷性,提高土层的承载力,而且造价低、工期短。【结论】综合比较本项目确定强夯地基处理方案,强夯法在处理非自重湿陷性黄土轻微~中等湿陷等级土层有良好的处理效果,可消除湿陷性,提高土层地基承载力,使得满足设计要求,便于施工、节省工期、降低成本。

[Purposes]Based on the EPC project design phase,this paper analyzes two kinds of technical solutions for collapsible loess foundation.[Methods]The technical and economic aspects of drilling and dynamic compaction were compared,and the applicability of the two methods in the treatment of collapsible loess foundation of this project was compared.[Findings]Through comparative analysis,it is found that the bored pile foundation does not need to consider eliminating the collapsibility of collapsible loess and can meet the bearing capacity requirements of the superstructure.The settlement deformation is small,but the cost is high and the construction period is long.Dynamic compaction can eliminate the collapsibility of the soil layer,improve the bearing capacity of the soil layer,and the cost is low and the construction period is short.[Conclusions]By comprehensive comparison,this project determines the dynamic compaction foundation treatment scheme.The dynamic compaction method has a good treatment effect on the non-self-weight collapsible loess with slight to medium collapsible grade soil layer,which can eliminate the collapsibility and improve the bearing capacity of soil layer,so as to meet the design requirements,facilitate construction,save time and reduce cost.