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有效围压、固结比、含砾量和颗粒破碎对砂砾土动剪切模量和阻尼比影响的规律已有较丰富的研究成果,但有关颗粒形状影响的研究鲜见报道。利用英国GDS公司的扭剪仪,对级配相同的圆砾砂砾土和角砾砂砾土进行动三轴对比试验,研究相对密度为45%,不同围压下颗粒形状对砂砾土动剪切模量和阻尼比的影响,发现:有效围压大于300 k Pa或剪应变幅值大于7×10-4时,圆砾砂砾土比角砾砂砾土具有更大的动剪切模量;对于最大动剪切模量,圆砾砂砾土和角砾砂砾土均存在砾石(粒径大于5 mm)含量P5的一个阀值P5cr,且角砾砂砾土的砾石含量阀值P5cr较圆砾砂砾土的大,当P5为阀值P5cr时,砂砾土的最大动剪切模量达到极大值;剪应变幅值大于2×10-4时,角砾砂砾土的阻尼比比圆砾砂砾土的大。
The laws of effective confining pressure, consolidation ratio, gravel content and particle breakage on the dynamic shear modulus and damping ratio of gravel soil have been relatively abundant. However, few studies on the influence of particle shape have been reported. Using the torsional shears of GDS Company of the United Kingdom, a dynamic triaxial comparison test was conducted between gravelly gravel soil and gravel gravel soil with the same grading density. The relative density of 45% Volume and damping ratio. It is found that the gravel gravel soil has larger dynamic shear modulus than the gravel gravel soil when the effective confining pressure is more than 300 kPa or the shear strain amplitude is more than 7 × 10-4. For the maximum The dynamic shear modulus, the gravel gravel soil and the gravel gravel soil both have a threshold value P5cr of the content P5 of gravel (grain size greater than 5 mm), and the gravel content threshold P5cr of the gravel gravel soil is higher than that of the gravel gravel soil When P5 is the threshold P5cr, the maximum dynamic shear modulus of gravel soil reaches its maximum. When the shear strain amplitude is more than 2 × 10-4, the damping ratio of gravel gravel soil is larger than that of gravel gravel soil.