基于正交设计的岩质相似材料配比试验研究

Experimental Study on Mix Proportion of Rock Similar Material Based on Orthogonal Design

以铁矿粉、重晶石粉、粉细砂为主材料,松香、酒精为黏结剂,石膏粉为调节剂,配制振动台模型试验中的岩质相似材料。基于正交设计方法,通过直接剪切试验与单轴压缩试验,对影响岩质相似材料物理力学参数的各配比因素进行了极差分析和方差分析。结果表明,不同配比相似材料的物理力学参数取值范围较广,能够满足大部分模型试验中对岩质相似材料的要求。相似材料的黏聚力随黏结剂浓度的增加而大致呈线性增长;相似材料的内摩擦角随石膏粉含量的增加而减小,随着黏结剂浓度、粉细砂含量的增加而增大;相似材料的弹性模量随黏结剂浓度、铁粉与重晶石粉含量的增加而大致呈线性增长。以福州市金鸡山隧道围岩的黏聚力、摩擦角和弹性模量为目标,选用12#配比作为振动台模型试验中模拟中风化粗粒花岗岩层的相似材料。

Taking iron ore powder, barite powder and fine sand as base materials, taking rosin, ethanol and gypsum as bonding agents and regulating agent respectively, the rock similar material used in shaking table model test is prepared. According to orthogonal design method, the range analysis and variance analysis of different mix proportions for physical and mechanical properties of rock similar material are conducted through direct shear test and uniaxial compression test： The result shows that （1） the physical and mechanical properties of rock similar materials with different mix proportions vary within a large range, which can satisfy the requirements for rock similar material in most model tests, and the cohesion of rock similar material increases linearly with the increases of concentration of bonding agent; （2） the internal friction angle of rock similar material decreases with the increases of content of gypsum, while it increases with the increases of concentration of bonding agent and the content of find sand ; （3） the elastic modulus of rock similar material increases linearly with the increases of concentration of bonding agent, contents of iron ore powder and barite powder. According to the cohesion, the friction angle and the elastic modulus of surrounding rock mass in Jinjishan Tunnel, the mix weathered grained granite proportion No. 12 is selected for the rock similar material to simulate moderately in the shaking table model test.