Extrusion reaming anchor rod and construction method

Abstract

The invention discloses an extrusion anchor rod with larger pulling resistance and a construction method of the extrusion anchor rod. The anchor rod is formed in the way that after mechanical hole forming is conducted, an anchor rod main reinforcing bar is added, and grouting and cementing are conducted. After grouting, an anchor rod anchoring body is formed and comprises a main anchor rod body ofa standard anchoring section and multiple anchor rod diameter expansion bodies of an embedded extrusion and expanding section; the diameter expansion bodies are formed by compacting side-wall rock and earth mass by an extrusion reamer; the anchor rod diameter expansion bodies are arranged at intervals in the longitudinal direction of the main anchor rod body, and each anchor rod diameter expansion body comprises multiple protrusions which are symmetrically arranged; the maximal diameter formed by the anchor rod diameter expansion bodies is not less than twice the diameter of the main anchor rod body. The construction method comprises the steps of advance hole forming, sequential extrusion and reaming, anchor bar installing, grouting, and stretching and drawing for locking. Extrusion and reaming are conducted by a drilling tool according to designed spacing, and the diameter of the anchoring body is increased in section, so that the purposes of compacting the side wall of the anchoringbody, and improving the strength of the rock and earth mass are achieved; meanwhile, an embedded reaming body section is formed, the single stress mode of the anchor rod body is improved, thus the anti-pulling capability of the anchor rod is effectively improved, the labor is saved, and the engineering cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of building foundation anchoring, in particular to the technical field of design and construction of anchor rods in anchoring construction, and particularly relates to an extrusion reaming anchor rod and a construction method. Background technique [0002] In construction engineering, transportation engineering, water conservancy and hydropower engineering, mining engineering and other projects closely related to national defense and people's livelihood, rock-soil anchoring technology is widely used in the field of rock-soil reinforcement due to its simple structure, convenient construction, and low cost. Bearing capacity is an important parameter in geotechnical anchoring engineering. How to improve the pull-out bearing capacity of anchor rods is particularly critical in geotechnical anchoring engineering. [0003] According to the calculation formula of the anchoring body and the uplift bearing capacity of...

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Problems solved by technology

[0004] Existing methods for enlarging the cross-section of the anchoring body include secondary high-pressure grouting, bagging, rotary spraying, blasting, etc., but there are also many deficiencies, such as: secondary high-pressure grouting and blasting are difficult Control the expansion shape of the anchorage section; the effects of the bladder method and the rotary grouting method are affected by factors such as the formation, the size of the bladder, and the grouting pressure, and the process is relatively complicated; in addition, the shortcomings of the above methods are that they will affect the rock and soil Produce different degrees of disturbance, thereby reducing the strength of the rock and soil around the anchor

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