An anchor bolt high prestressing device and using method

Abstract

The invention provides a bolt high prestress applying device and a use method, which belong to the technical field of surrounding rock support. The device includes hydraulic oil high-pressure oil injection system, anchor rod pulling system, high torque application system, hydraulic oil pressure relief system, hydraulic oil high-pressure oil injection system, anchor rod drawing system, high torque application system, hydraulic oil pressure relief system on the base. The base is made of high-strength steel material. Through the action of high oil pressure, the device can not only apply high prestress to the anchor rod, but also apply high torque pretightening to the anchor nut, reconstruct the stress state of the surrounding rock, and change the two-dimensional stress after excavation into three-dimensional Stress, to achieve the purpose of improving the performance of surrounding rock, improving the loose structure, strengthening the weak layer, realizing the rapid reinforcement of complex loose and broken surrounding rock underground, and enhancing the ability of soft broken rock mass to resist deformation.

Description

technical field [0001] The invention relates to the technical field of surrounding rock support, in particular to a bolt high prestress applying device and a use method. Background technique [0002] Bolt support is the most widely used support method in underground roadways, road bridge tunnels, and underground rock mass engineering. Commonly used are pipe joint anchors, grouting anchors, and resin anchors. The bolt support technology has also gradually developed from the early passive support to the current rich support system, including full-length anchor support, long bolt support, high prestress active support, etc. The support function has also developed from the early suspension function to support functions such as composite beams, composite arches, and span reduction. At present, resin bolt support is the most widely used, which mainly uses the cementation effect of resin to fix the bolt at the bottom of the borehole, and adds nuts and backing plates to the exposed...

AI Technical Summary

Problems solved by technology

However, with the existing bolt construction and installation technology, the bolt still plays a passive support role. Since the high prestress cannot be achieved, the active support function of the bolt is difficult to realize. The specific problems are as follows: (1) During the rod installation process, the pre-tightening force is often achieved by manual pre-tightening by support workers. The pre-stress application of the anchor rod is relatively random, and the torque range achieved by manual use of a wrench is 100N·M~200N·M; (2 ) Although there is a bolter drilling rig that can be used for bolt installation and pre-tightening, the torque of the drilling rig is relatively low, up to 150N·M, which is not enough to provide sufficient pre-tightening torque, resulting in insufficient pre-stress of the bolt and limited improvement in the strength of the surrounding rock; ( 3) Existing high prestress application equipment is rarely used in anchor bolts, and is mostly used in anchor cable support, and the equipment is heavy, large in size, and complex in construction, which is not suitable for rapid installation and pretension of anchor bolts; (4) simple When the prestress is increased by increasing the torque, the relationship between the torque and the prestress is greatly affected by the construction situation; (5) When the high pullout force is achieved and the prestress is applied alone, it is difficult to tighten the nut, the preload is small, and the prestress is prone to occur. stress decay

Images