The excavation unloading activities in deep hard rock tunnels often induce high-intensity rockburst disasters

which has become a key issue affecting the safety construction of tunnels. The physical model test is an important method to study the deep tunnel excavation

and the properties of model materials have great influences on the testing results. Thus

it is the key to prepare materials suitable for the physical model test. Based on the development of the traditional rockburst model materials

this paper introduces the rockburst proneness index and brittleness evaluation index. Combing with the orthogonal design method and sensitivity analysis

the experiments were carried out to investigate the rockburst model materials with low-strength and high-brittleness. We analyzed five influencing factors

including the quartz sand content

barite content

water content and the mass ratio of high-strength gypsum and cement. Each factor was set at five levels

a total of 25 matching schemes. The material strength

mechanical parameters

rockburst proneness index and brittleness evaluation index of model materials were measured in each matching scheme

and the variation of these parameters and indexes were studied under different design levels. Finally

the relationships among the influencing factors

rockburst proneness and brittleness of the selected rockburst model materials were discussed. The results show that: 1) According to the rockburst proneness index and brittleness evaluation index

the prepared model materials meet the requirements of the physical model tests. 2) It is important to control the contents of barite powder and water and to adjust the mass ratio of high-strength gypsum to cement properly.