To study the rock joint parameters

joint space and joint angle of rock fragmentation by full face rock tunnel boring machine (TBM) disc cutter

the test of high-strength gypsum specimen penetrated by wedge indentation is applied. Data of penetration depth and loads during the loading process are collected. Shooting with the camera in real time

photograph of the specimen surface damage and failure mode of the development process are taken. The results show that: when joint angle is constant

a greater joint space needs a greater penetration load when loading value drops

it also needs greater penetration power and crack propagation energy; when joint angle equals to 0 and 90

anti-invasive factor is consistent. When the joint angle equals to 30 and 60

with the increase of joint space

anti-invasive factor increases. When the joint spacing is constant

with the increase of the angle

the peak load

penetration power and crack propagation energy decrease and then increase. When joint angle equals to 30

the values are the minimum. According to a morphological analysis after the destruction of specimens

it is found that the spatial characteristics of joints crack obviously control the crack mode and have significant limitations for the damage region .