不同方法缩尺后粗粒料强度和变形特性研究

Study on Strength and Deformation Characteristics of Coarse Aggregate After Different Grading Scale Methods

对某原型级配堆石料采用剔除法(TC)和混合法(HH)两种缩尺方法进行缩尺,对缩尺后的两种粗粒料试样(分别简称TC料和HH料)进行三轴固结排水剪切试验。结果表明:围压相同时,TC料的峰值应力(σ1-σ3)f与内摩擦角均高于HH料的相应值;TC料有着较强的剪胀性;相同围压下,与HH料相比,TC料具有较小的破坏应变εaf与相变处体变εv0及较高的相变应力比M0;同一粒径下,TC料割线弹性模量约为HH料的1.03～1.39倍。当颗粒最大粒径增大时,TC料的割线体积模量的增幅小于HH料的相应值。随着颗粒最大粒径的增大,两种缩尺方法所得的弹性模量参数K有所增大而变形模量指数n减小。

Two grading scale methods in the Chinese standard,exclusion method and hybrid method, are used to scale a kind of coarse aggregate. Triaxial consolidation drainage shear tests have been performed on samples of different particle sizes. The results show that when the confining pressure is the same,the peak stress (σ1-σ3)f and friction angle φ obtained by the exclusion method are higher than that obtained by the hybrid method. Coarse-grained material acquired by the exclusion method has a stronger dilatancy. Besides,under the same confining pressure,compared with coarse-grained material obtained by the hybrid method,both εaf and εv0 obtained by the exclusion method are smaller and its M0 is higher. Lastly,under the same particle size,the secant elastic modulus obtained by the exclusion method is about 1.03 to 1.39 times higher than that obtained by the hybrid method. When the particle size increases,the bulk modulus obtained by the exclusion method increases less than that obtained by the hybrid method and the elastic modulus parameter K obtained by the two scale methods increases and the deformation modulus index n decreases.