工程岩体Ⅲ级围岩相似材料配比试验研究

Experimental Study on Proportioning of Similar Materials for Surrounding Rock of Class III

目前超大跨扁平地下洞室模型试验的围岩相似材料缺少合适的配制方法,以工程岩体中Ⅲ级围岩的物理力学参数作为相似材料配比目标,采用重晶石粉和石英砂作为骨料,高强石膏粉和水作为胶结剂,洗衣液作为调节剂,基于正交理论设计了3因素5水平的正交试验方案,制作了25组不同的配比,通过大量的直剪试验和单轴压缩试验分别测得试样的黏聚力c和内摩擦角φ以及试样的抗压强度σ(c)和弹性模量E,并采用极差分析法进行了敏感因素分析。试验结果表明:所配制的相似材料物理力学参数变化范围广,能满足大部分岩质岩体模型试验的强度要求;材料含量的变化对物理力学参数的影响规律明显,可为配比不同模型试验的相似材料提供指导。

At present, there is a lack of suitable preparation method for similar materials of surrounding rock in model test of super large-span flat underground caverns. The physical and mechanical parameters for surrounding rock of class III in engineering are taken as the target for proportioning test with similar materials. Barite powder and quartz sand were used as aggregate, high-strength gypsum powder and water were used as cementing agent, and laundry detergent was used as regulator. The experimental scheme was designed based on the orthogonal test theory. The scheme took three different factors with five different levels of each factor in account. It was made up of 25 sets of samples with different proportions. The cohesive force and internal friction angle of samples were measured by a large number of direct shear tests. The compressive strength and elastic modulus were measured by uniaxial compression test. Moreover, the sensitive factors were analyzed by range analysis method. The test results show that the prepared similar materials have a wide range of physical and mechanics parameters, which can meet the requirement for strength of most rocky similar material of model test. The change of material content has obvious influences on physical and mechanical parameters, which can provide guidance for proportioning of similar materials of different model tests.