尾矿粉土动力变形特性试验研究

采用GDS动三轴试验仪,对某尾矿坝的尾矿粉土筑坝料进行了动模量与阻尼比试验,研究了尾矿粉土的动应力-动应变特性,分析了围压和固结比对最大动剪切模量、动剪切模量比和阻尼比的影响,并基于沈珠江动力本构模型,提出了可以将固结比影响归一化的最大动剪切模量和模量衰减的修正公式。试验结果表明:随着围压和固结比增大,尾矿粉土的动弹性模量增大,阻尼比减小;随着动应变的增大,动剪切模量比逐渐减小,阻尼比变大;该修正公式可以将固结比和围压对最大动剪切模量和模量衰减的影响归一化,能较准确地反映尾矿粉土的动力变形特性。

Experimental Study on Dynamic Deformation Characteristics of Tailings Silt

The dynamic modulus damping ratio of the tailings silt damming material of a tailings dam was tested using the GDS dynamic triaxial apparatus. The dynamic stress-strain characteristics of tailings silt were examined, and the effect of confining pressure and consolidation ratio on the maximum dynamic shear modulus as well as dynamic shear modulus ratio and damping ratio were analyzed. Moreover, the modified formulae for the maximum dynamic shear model and modulus attenuation which could normalize the influence of consolidation ratio was proposed based on Zhujiang Shen’s dynamic constitutive model. Test results demonstrated that with the rising of confining pressure and consolidation ratio, the dynamic elastic modulus of tailings silt increased while damping ratio decreased. With the augment of dynamic strain, the dynamic shear modulus ratio reduced while damping ratio increased. The modified formulae could normalize the effects of consolidation ratio and confining pressure on the maximum dynamic shear modulus and modulus attenuation, and thus accurately reflecting the dynamic deformation characteristics of tailings silt.