自密实固化土基坑回填影响因素研究

Study on influencing factors of self-compacting solidified soil foundation pit backfilling

自密实固化土是将建筑废土与固化剂拌合后形成的一种土体,固化前土体由于具有很强的流动性,能较好地控制回填质量,固化后土体具有良好的密实度、强度和抗变形能力,可用于基坑肥槽回填。这种技术节省了建筑材料,又能废物利用,应用前景广阔。以南京河西某基坑工程为依托,对现场土样进行室内试验,掌握土体以及其固化后物理力学参数,采用ABAQUS有限元软件对基坑回填过程进行了数值模拟,研究了自密实固化土相关参数对周围环境以及回填土体表面沉降的影响;通过正交试验分析对回填土表面沉降影响最大的土体力学参数,并提出可以减小回填地表沉降的工程建议,可为实际基坑肥槽回填施工提供参考。

The self-compacting solidified soil is the kind of soil formed after mixing construction waste soil and curing agent.Before solidification,the soil has strong fluidity,which can control the backfill quality well.After solidification,the soil has good compactness,strength and deformation resistance,it can be used for backfilling of foundation pit fertilizer tank.This technology saves building materials and the waste is also used.It has broad application prospects.Based on the foundation pit project in Hexi,Nanjing,the indoor tests of the field soil samples were conducted to master the physical and mechanical parameters of the soil and its solidified soil in this paper.The finite element software ABAQUS was used to finish the numerical simulation on the backfilling process of the foundation pit.The relative parameters of the self-compacting solidified soil on the surrounding environment and the surface settlement of the backfill soil were studied.Through orthogonal tests,the soil mechanical parameters which have the greatest impact on the surface settlement of the backfill soil were analyzed.The engineering suggestions that can reduce the surface settlement of backfill were put forward,it could provide the reference for the actual backfill construction of foundation pit.