隧道爆破力学模型相似材料配比的正交试验

以砂岩作为模拟对象,研究满足隧道爆破力学模型试验要求的相似材料配比问题.基于正交试验法,选取石英砂、重晶石粉、石膏、水泥和水为相似材料,设置以石英砂/固体、水泥/石膏、重晶石粉/(重晶石粉+石英砂)的质量比为3个因素,每个因素3个水平,共9组配比的正交试验方案.通过室内试验,得到相似材料的密度、单轴抗压强度、弹性模量和声波波速的实测数据.试验结果表明:相似材料的物理力学参数分布范围较广,可满足不同隧道模型试验对相似材料的配比要求.利用极差敏感分析法分析各因素对相似材料参数的敏感性,并通过各因素对相似材料参数影响的直观分析图,分析各因素对相似材料物理力学参数的影响规律.对试验数据进行多元线性回归分析和室内试验,发现最优配合比下的相似材料与原型砂岩的单轴应力-应变曲线具有相似的脆性破坏特征;相似材料物理力学参数的设计值和实测值误差较小.

Orthogonal Test of Similar Materials Ratio in Tunnel Blasting Mechanical Model

Sandstone was used as the simulation object to study the ratio of similar materials that met the requirements of the tunnel blasting mechanical model test. Based on the orthogonal test method, quartz sand, barite powder, gypsum, cement, and water were selected as similar materials, and the mass ratio of quartz sand/solid, cement/gypsum, barite powder/(barite powder+quartz sand)were set as 3 factors, 3 levels of each factor, a total of 9 groups of orthogonal test schemes. Through laboratory tests, the data of density, uniaxial compressive strength, elastic modulus, and acoustic wave velocity of similar materials were measured. The test results show that the distribution range of physical and mechanical parameters of similar materials is wide, which can meet the requirements for the ratio of similar materials in different tunnel model tests. The sensitivity of each factor to similar material parameters is analyzed using range sensitivity analysis, and the in-fluence of each factor on the physical and mechanical parameters of similar materials is analyzed through the visual analysis of the influence of each factor on the similar material parameters. Multivariate linear regression analysis and laboratory tests were performed on the test data. It is found that the uniaxial stress-strain curves of similar materials at optimal mix ratios and prototype sandstone has similar brittle failure characteristics. The difference between design and measure values of the physical and mechanical parameters of the material is small.