Horizontally pushing liftingjack of direct shear tests are operated on rock mass shear strength test. - center point group analysis is used for treating shear test data.
用平推法直剪试验进行岩体抗剪断强度试验，用-点群中心法处理直剪试验数据。
2
Job security: electric jack has lift the self-locking protection device that, when beyond top heave range will automatically stop lifting, safe and reliable.
工作安全：电动千斤顶具有升降自锁的保护装置，当超出顶举范围时将自动停止升降，安全可靠。
3
Electric jack slab and under arms over thick, using reinforced optimization strong design, make jacklifting smoothly, won't be out of shape.