Fast tensioning anchor cable structure and construction method thereof

Abstract

The invention discloses a fast tensioning anchor cable structure. The fast tensioning anchor cable structure comprises anchor cable steel strands, a primary grouting pipe, a secondary grouting pipe, aguiding member and binding members, wherein the anchor cable steel strands are arranged in drilling holes; the primary grouting pipe extends into the drilling holes and is used for performing primarygrouting on the surrounding rock, 1-3m from openings of the drilling holes, in the drilling holes to form a primary grouting part used for closing the openings of the drilling holes; the secondary grouting pipe extends into the drilling holes and is used for performing secondary grouting on other areas not subjected to primary grouting in the drilling holes; the guiding member is disposed in thedrilling for the anchor cable steel strands to pass through to guide the anchor cable steel strands to enter into the drilling holes; and the binding members are used for binding the anchor cable steel strands disposed in the drilling holes. The gripping force and anchoring force between the steel strands and a grouting body are effectively increased, meanwhile, the consolidation time of the grouting body is greatly reduced, so that the anchor cable construction is completed within 15 hours, and a fast tensioning anchor cable supporting structure is provided for a weak surrounding rock long-span tunnel with short self-stabilization time.

Description

technical field [0001] The invention relates to the field of geotechnical engineering, in particular to a fast-tensioning anchor cable structure and a construction method thereof. Background technique [0002] Since the anti-rust oil on the surface of the steel strand is difficult to remove during on-site construction, the grip force between the steel strand and the grouting body is greatly reduced, so the steel strand and the grouting body often appear when the prestressed anchor cable is stretched. The slippage of the grouting body in the anchoring section causes the prestress to fail to meet the design requirements, and the current solution is to lengthen the length of the grouting body in the anchoring section, thereby increasing the gripping force between the steel strand and the grouting body , to prevent the two from slipping, but this method increases the length of the grouting body and leads to high construction costs; in addition, in the prior art, the strength of ...

AI Technical Summary

Problems solved by technology

[0002] Since the anti-rust oil on the surface of the steel strand is difficult to remove during on-site construction, the grip force between the steel strand and the grouting body is greatly reduced, so the steel strand and the grouting body often appear when the prestressed anchor cable is stretched. The slippage of the grouting body in the anchoring section causes the prestress to fail to meet the design requirements, and the current solution is to lengthen the length of the grouting body in the anchoring section, thereby increasing the gripping force between the steel strand and the grouting body , to prevent the two from slipping, but this method increases the length of the grouting body and leads to high construction costs; in addition, in the prior art, the strength of the grouting body needs to reach more than 30Mpa before the anchor cable is tensioned, while the cement mortar injection It takes at least 20 days for the strength of the slurry to reach 30Mpa. Therefore, the entire anchor cable construction takes about one month from drilling, anchor cable installation, grouting, grout consolidation, and anchor cable tensioning.

For large-span weak surrounding rock tunnels, the self-stabilization time is short, and there is an urgent need for a fast-tensioning anchor cable that can provide a prestressed anchor cable structure for the tunnel surrounding rock in a relatively short period of time.

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