软岩流变相似材料的研制及物理模型试验应用

目前能合理模拟软岩流变效应的相似材料很少，而采用模型试验法研究软岩工程的长期流变效应也处于探索阶段。为给软岩流变模型试验提供合适的相似材料，研制出一种以铁粉、重晶石粉和石英砂为骨料，松香酒精溶液为胶结剂，液压油为黏滞剂的软岩流变相似材料。该相似材料强度低，流变性强，不仅可模拟软岩的瞬时弹塑性性质，也能较好模拟软岩的流变特性。假定骨料比例恒定，调节松香酒精溶液浓度m和液压油含量w，开展了一系列梯度配比试验。研究表明：（1）该相似材料的主要瞬时强度变形参数和西原模型流变参数均受m和w两因素的双重影响；（2）松香酒精溶液浓度越大，试样强度越大，流变性越小；（3）液压油含量越大，试样强度越小，流变性越明显；（4）相比松香酒精溶液浓度m，液压油含量w对西原模型各参数的影响更大，起主控作用。最终，将该相似材料应用于神华新街软弱砂质泥岩煤矿盾构斜井的长期流变模型试验中，试验结果表明：该材料瞬时力学性能和流变特性均达到试验要求，为试验取得良好结果提供了材料保证。

Development of rheology similar material of soft rock and its application in model test

At present, there are few similar materials that can reasonably simulate the rheological behavior of soft rock. It is also still in the exploratory stage to study the long-term rheological behavior of soft rock engineering based on the model test method. In this paper, a new rheological similar material of soft rock was developed, which compose of the iron powder, barite powder and quartz sand as aggregate, the rosin alcohol solution as binder and the hydraulic oil as viscous agent. This material processes a low strength and a significantly rheological property, which can not only simulate the transient elastoplastic properties of soft rock, but also simulate the rheological properties well. With a constant aggregate proportion, a series of gradient compounding tests were conducted by adjusting the concentration of rosin alcohol solution m and the content of hydraulic oil w. The tests results indicate that the main parameters associated with the instantaneous strength and deformation of the similar material as well as the rheological parameters of Nishihara model are all affected by the factors m and w. The higher the concentration of the rosin solution, the larger the strength and the smaller the rheology of samples are. A higher hydraulic oil content leads to lower strength and more obvious rheological behavior. Compared with the concentration of the rosin alcohol solution m, the hydraulic oil content w exerts more remarkable influence on the parameters of Nishihara model. Finally, the developed similar material was applied to the model test of the shield inclined shaft in the weak sandy mudstone in Shenhua Xinjie coal mine. The model test results show that, the instantaneous mechanical properties and rheological properties of the material meet the test requirements, which provides guarantee for good results.