冻融循环下钢渣砂土混合料的小应变动力特性参数研究

Small strain dynamic characteristic parameters of steel slag sand mixture under freeze-thaw cycles

利用GDS-RCA共振柱系统进行钢渣砂土混合料的小应变动力特性研究,分析了不同围压、配合比以及冻融循环次数的情况下动剪切模量和阻尼比的变化规律。通过试验得到了3种配合比、4种冻融循环次数在3种围压下的动剪切模量和阻尼比的曲线,采用Hardin-Drnevich双曲线进行拟合分析并对最大动剪切模量的经验模型进行预测。结果表明:钢渣砂土混合料的动剪切模量均随围压的提高而增大,随应变的增大而减小,随冻融循环次数的增加而降低;阻尼比随围压的提高而减小,随应变的增大而增大,随冻融循环次数的增加而增大;在3种配合比中,当钢渣掺量为40%时最大动剪切模量最大,不同钢渣掺量对阻尼比的影响较小。验证了钢渣砂土混合料在冻土地区地基处理中应用的可行性。

Using GDS-RCA resonant column system to study the small strain dynamic characteristics of sand with steel slag,the change law of dynamic shear modulus and damping ratio under different mix ratio,confining pressure and number of freeze-thaw cycles was analyzed.The curves of dynamic shear modulus and damping ratio under three confining pressures were obtained through experiments for three mix ratios and four freeze-thaw cycles,the Hardin-Drnevich dual curve is used to fit analysis and predict the maximum dynamic shear modulus.The dynamic shear modulus of the steel slag sand mixture increases with the increase of confining pressure,decreases with the increase of strain,and decreases with the increase of freeze-thaw cycles.The damping ratio decreases with the increase of confining pressure,increases with the increase of strain,and increases with the increase of freeze-thaw cycles.The maximum dynamic shear modulus of the sample is the largest when the steel slag content is 40%,and the different steel slag content has little effect on the damping ratio.The feasibility of using steel slag sand mixture in frozen soil region foundation treatment is verified.