A constant-resistance energy-absorbing bolt for strengthening large-deformation rock mass

Abstract

The invention discloses a constant-resistance energy-absorbing anchor rod for strengthening a large-deformation rock body. The constant-resistance energy-absorbing anchor rod for strengthening the large-deformation rock body comprises a rod body, a constant-resistance energy-absorbing device, a nut and a tray, wherein the rod body is a smooth rod body with a round section; two ends of the rod body are provided with threads; the middle section of the rod body is wrapped by a plastic sleeve; the constant-resistance energy-absorbing device is arranged on the head part of the anchor rod and consists of a diameter-expanding cylinder, a conical cylinder, an anchorage device and a protective cover; the head of the rod body passes through the anchorage device to be connected with the diameter-expanding cylinder and the conical cylinder; and the protective cover is wrapped out of the diameter-expanding cylinder, the conical cylinder and the anchorage device. The constant-resistance energy-absorbing anchor rod can improve the capacity of the anchor rod in absorbing rock strain energy by utilizing the constant-resistance energy-absorbing device, is applicable to strengthening large-deformation surrounding rock of underground engineering or large-deformation rock creeping on the side slope under the high stress condition, has large ultimate elongation quantity, high and constant initial resistance and a simple structure, is convenient to manufacture and construct.

Description

technical field [0001] The invention relates to bolt reinforcement technology, in particular to a constant-resistance energy-absorbing bolt suitable for strengthening large-deformation rock mass. Background technique [0002] In underground engineering and slope engineering, anchor rod is a supporting component that is widely used and has good reinforcement effect. With the increase of underground projects, the buried depth of underground projects is getting bigger and bigger. For example, the underground caverns of Jinping II Power Station and the Hongtoushan Copper Mine in Liaoning have a buried depth of more than 1000m. At this time, the surrounding rock of underground projects is Under high stress conditions, it often shows the characteristics of large deformation, such as geological disasters such as large deformation of soft rock, rock burst or gas outburst. However, the ultimate tensile length of the existing bolts is small. When the surrounding rock of the undergrou...

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Problems solved by technology

However, there are many defects in the existing bolts, such as Kang Hongpu's patent "tubular friction stretchable bolt", the announcement number is CN87207128U, its resistance is relatively small, and it is difficult to give full play to the reinforcement effect of the bolt; at the same time, the existing The resistance of large-deformation bolts is often uneven, and its resistance changes continuously with the increase of deformation, making it difficult to better play its anchoring role in the early or late stage of surrounding rock deformation; secondly, the deformable section of the existing large-deformation bolts Often arranged near the anchor tray, it is easy to have an adverse interaction with the secondary lining construction, such as the "anchor relief member" invented by Cao Junzhi et al., the announcement number is CN201448117U, and its relief structure is located at the outer anchor head , the exposure length is large, and the yielding length is only about 2cm; in addition, the existing large-deformation bolt body is often in direct contact with the air, and its anti-corrosion and durability are poor. When the surrounding rock undergoes long-term deformation, it is prone to corrosion and loses its Large deformation capacity, such as the patent "serrated shell-shaped yielding anchor rod" with the announcement number CN2149480Y

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