# Development of a Model Material for Dynamic Geotechnical Model Tests
## 1 Introduction  
China is located at the intersection of the Pacific Rim and the Eurasian seismic belt. Earthquakes cause many secondary disasters, such as rock slope collapses and landslides. It is particularly important to analyse the dynamic response and evolution of rock slopes under earthquake loading [1; 2; 3; 4]. In recent years, many methods have been proposed to study the deformation and failure characteristics of rock slopes during earthquakes, among which the most important method is the dynamic testing of geotechnical models. By using a geotechnical model to simplify the actual engineering of a geological slope, the response to earthquakes is monitored over time, and the nonlinear characteristics of slope deformation and failure are analysed [5; 6; 7; 8]. It is very difficult to collect rock specimens for these geotechnical model tests, so the key to their success is to select appropriate model materials similar to those in the field so that the model test effectively reflects the actual geological phenomena [9; 10; 11].  
At present, many achievements have been made in the research of model materials, and good results have been achieved in model experiments. Gypsum mixtures were developed by ISMES and LNEC in Portugal. [PERSON] et al. [12] developed the MIB material, which is composed of barite powder, rubber film ferric concentrate powder and rosin alcohol solution. [PERSON] [13] and [PERSON] et al. [14] developed the NIOS material, whichis composed of fine magnetite powder, river sand, and binder based on gypsum or cement. In addition, [PERSON] [15], [PERSON] [16], [PERSON] [17] and [PERSON] [18] used iron powder, barite powder, quartz sand, rosin alcohol solution and other materials (IBSCM) to simulate most rock mass materials, from soft rock to hard rock. Studies on model materials in model tests are relatively complete. Many scholars have conducted studies on rock masses similar to limestone [19], marl [20,21] and conglomerate [22] through static physico-mechanical parameters. However, current studies do not take into account dynamic effects in the geotechnical model tests. Static physico-mechanical parameters are used to determine the proportions of the components in model materials, which then affects the accuracy of the model geotechnical tests for dynamic failure. Meanwhile, in the process of dynamic physical model tests and research, it is time consuming to configure model materials, resulting in slow progress and low efficiency of testing and research.  
The efficient and orderly configuration of model sandstone materials will improve the efficiency of research. In this paper, by combining the results of previous studies, the similarity criterion and many mechanical tests of model materials, the sensitivity of dynamic and static parameters to the proportions of components in model materials was analysed and multiple linear regression analysis was used to establish a quantitative relation between physico-mechanical parameters and the proportions of components in model materials. Finally, a sandstone slope along the Duxiang Expressway was taken as an example, and the model material's configuration was similar to that of the slope.