基于大型直剪试验的高炉矿渣粉煤灰混合料力学特性研究
Research on Mechanical Properties of Blast Furnance Slag Fly Ash Mixture Based on Large-scale Direct Shear Experiment

依托包钢新体系2 250 mm热轧车间的地基处理工程对混合料的力学特性进行研究；借助大型直剪仪对不同围压和含水率的混合料进行直剪试验，分析了混合料在不同条件下的抗剪强度、力学参数以及从混合料剪切“翻滚？蔡？跃”现象的角度对相应的剪应力？布羟形灰乒叵登？线上下波动情况进行分析；通过线性回归分析得到含水率与粘结力和内摩擦角的关系曲线。结果表明：当含水率相同时，随着法向应力的增加，混合料的抗剪强度峰值逐渐增大；相同法向应力作用下，随着含水率的增加，混合料的抗剪强度逐渐降低；随着含水率的增加，粘结力和内摩擦角逐渐降低，并且含水率的变化对粘结力的影响程度较内摩擦角大；当剪切位移处于试样长度的1/60~1/10时，剪切“翻滚？蔡？跃”现象最为明显，相应的剪应力？布羟形灰魄？线所出现的上下波动幅度也最大。
The mechanical properties of mixture were studied based on a new system of Baotou Steel 2 250 mm hot-rolling workshop ground treatment engineering. By means of large-scale direct shear apparatus, direct shear tests of mixture with different confining pressures and moisture contents were carried out. The shear strength and mechanical parameters of mixture under different conditions were analyzed. The fluctuations of shear stress？？shear displacement curves were analyzed from perspective of shear “roll-jump” phenomenon of mixture. The relationship curves of moisture content, cohesive force and internal friction angle were obtained through linear regression analysis. The results show that the peak value of shear strength of mixture increases gradually with increase of normal stress when moisture content is the same. Under the same normal stress，shear strength of mixture decreases gradually with increase of moisture content. The cohesive force and internal friction angle decrease gradually with increase of water content. The impact of moisture content change on cohesive force is greater than internal friction angle. When the shear displacement is 1/60-1/10 of specimen length, shear “roll-jump” phenomenon is most obvious, and the fluctuations of shear stress？？shear displacement curves are greatest