分别对灰砂配比为1∶4,1∶8,1∶10和1∶12的4种尾砂胶结充填体进行了力学试验,得出了其应力-应变曲线.分析了不同配比充填体变形与破坏特征,用损伤力学建立了4种不同配比充填体损伤本构方程.经验算对比,所建立的损伤本构方程与试验结果吻合.尾砂胶结充填体损伤研究表明,不同配比的充填体表现出不同的损伤特性,充填体配比越低,达到峰值应力时的损伤值越小;峰值应力后,损伤增长越快,破坏过程越突然.根据岩体开挖释放能量与充填体蓄积应变能相近的原则,探讨了充填体与岩体的合理匹配.充填体与岩体的匹配系数与原岩应力、岩体弹性模量、充填体弹性模量及充填体损伤参数相关.为了便于工程实际应用,对充填体力学试验结果进行了回归分析,得出了充填体强度设计公式,并研究了深部矿床不同开采深度所要求的充填体强度.
Four kinds of backfill with cement-tailing ratio of 0.250, 0.125, 0.100 and 0.083 respectively were tested; and their stress-strain curves were obtained. Analyzing the deformation and failure characters of different backfills, their damage constitutive equations investigated with damage mechanics whose calculating results coincide with experiment results well were proposed. The results of damage analysis show that there have different damage characters in different backfills, e. g. the lower the cement-tailing ratio the lower the damage value when stress reaches to peak value; the lower the content of cement the more rapid in damage and the more abrupt in failure process after peak value of stress. According to the principle that releasing energy from excavated rock mass corresponds with cumulative energy of deformation in backfill; the reasonable matches between backfill and rock mass whose coefficient correlates with earth stress, elastic modulus of rock mass, elastic modulus of backfill and damage parameters of backfill respectively were researched. In order to apply it to engineering conveniently, regressing the experimental results of backfill, a design formula of strength for cemented backfill was put forward; and the required strengths of backfill in deep deposit were researched.