松香基相似材料抗剪强度指标试验研究

采用松香作为胶结剂的相似材料是地质力学模型试验中常用的一种相似材料。为研究松香基相似材料骨料组成、松香用量、石蜡用量等影响因素对其抗剪强度指标的影响,设计了三因素四水平的正交试验。制作了16组不同配比的试样,通过直剪试验测得其黏聚力和内摩擦角,并对试验结果进行了极差分析。结果表明,松香基相似材料的黏聚力受松香用量的影响最大,随着松香用量的增加,黏聚力有大幅增长;内摩擦角受骨料组成影响最大,粗骨料比例越高,内摩擦角越大。通过调节配比,可使黏聚力在68 kPa~270 kPa之间波动,内摩擦角在29°~58°之间波动。该研究成果可为地质力学模型试验中相似材料的制备提供参考。

Experimental Study on the Shear Strength Indexes of Resin-Based Equivalent Material

Resin-based material is a kind of widely used equivalent material in geo-mechanical model test. In order to investigate the influence of material composition on shear strength indexes, an orthogonal test is designed and 16 groups of samples with different matching are manufactured. The three factors, each has four levels, in the orthogonal test are the proportion of resin, the proportion of coarse aggregate and the proportion of paraffin. The shear strength indexes of the material are tested, including cohesive force and internal friction angle, and the test result is analyzed by range analysis. Results show that key factor for the cohesive force is the proportion of resin. Larger resin proportion leads to larger cohesive force. The proportion of paraffin also affects the material’s cohesive force to a certain extent. The more paraffin used, the lager cohesive obtained. It was also indicated that the internal friction angle is mostly influenced by the proportion of aggregates. And more coarse aggregate corresponds to larger internal friction angle. The cohesive force and internal friction angle of resin-based equivalent material can be adjusted by changing the matching in a large variation range. In this paper, the variation ranges are 68 kPa~270 kPa and 29°~58° respectively, which can meet different demands of different geo-mechanical tests.