吉林建筑大学学报

我国挖方废弃渣土的改良对于资源循环、绿色环保尤为重要。自密实流动土可作为一种理想的盾构渣土改良目标。针对郑州地区产生的挖方废弃渣土进行改良处理。采用渣土、水泥、泡沫以及活性氧化镁作为原材料，其中活性氧化镁和泡沫二者混合掺加来协同改良渣土，取得了明显的改良效果。通过调整泡沫掺量和氧化镁掺量调配出流动度和泌水率符合要求的流动化回填土。通过图像三轴试验分析固化试样后的应力-应变关系、云图变形的变化规律。结果表明：在3%泡沫掺量和3%活性氧化镁掺量下，改良效果最好，其流动性和力学性能均满足相关规范要求。试验制备出流动度为200～320 mm，泌水率整体不超过5%,28 d抗压强度在0.3～0.75 MPa范围内的流动性回填土，这对挖方废弃渣土的合理配置和资源的有效利用提供了合理的依据。

The improvement of our excavation waste soil is particularly important for resource recycling and greening. Self compacting flowable soils can be an ideal target for shield spoil improvement. It is aimed at improving the treatment of excavation waste sludge produced by shield structure in Zhengzhou area. The material was made of slag soil, cement, rosin-type plant foamer and activated magnesium oxide. Where the active magnesium oxide and foamer both mixed and blended to collaboratively improved the slag soil, achieved significant improvements. Fluidized backfill with satisfactory fluidity and bleeding rate was prepared by adjusting the content of foam and magnesium oxide. The stress-strain relationship and the variation of nephogram deformation were analyzed by image triaxial test. It was shown that at 3% and 5% foam dosing and 3% active magnesium oxide dosing, it was optimal for improving the flowability and mechanical properties of the mix. Test preparation of mobility of 200～320 mm, the overall water secretion rate does not exceed 5%, 28 d compressive strength in the range of 0.3～0.75 MPa flow engineering soil. This provides a rational basis for the rational allocation of excavated waste spoils, as well as the effective utilization of resources.