In order to measure elastic modulus of rock in a borehole
Type BEM-1-D76 Jack was developed by our institute. In this paper
working principle
targets and measuring method of this jack are introduced. It's practical applications in a region with high stress are given. In addition
the jack are compared with other similar jacks in abroad. It is shown that Type BEM-1-D76 Jack is a new effective instrument for measuring deformation behavior of rock mass.