Multi-level back-grasp-type hollow anchor rod and construction method thereof

Abstract

The invention discloses a multi-level back-grasp-type hollow anchor rod. The multi-level back-grasp-type hollow anchor rod comprises an anchoring rod with a grouting passage inside, an anchor head is fixed at the lower end of the anchoring rod, a plurality of back-grasp buckles are fixed on the anchoring rod, a grout outlet is formed in the anchor head, and the parts, at the upper side of the back-grasp buckles, of the anchoring rod and the parts, at the lower side of the back-grasp buckles, of the anchoring rod are provided with grout outlets and air return holes respectively, and the grout outlets and the air return holes are communicated with the grouting passage. Compared with the construction method of a hard rock body and a soil body, the construction method of the multi-level back-grasp-type hollow anchor rod comprises the steps of (a) preparation of equipment, (b) measurement and distribution of holes, (c) drilling, (d) hole cleaning and detection, (e) inserting of the anchor rod, (f) installation of a grout stop plug, (g) screwing of nuts and (h) grouting, and the anchor rod is directly inserted through the anchor head according to the construction method of a soft soil body, sand and water. The multi-level back-grasp-type hollow anchor rod and the construction method of the multi-level back-grasp-type hollow anchor rod increase the contact area and anchoring force between the anchor rod and the hole wall and prevent the anchor rod from falling out and injuring people. A uniform cement mortar layer can be formed around the anchor rod through the grout outlets and the air return holes, the damage of corrosion is avoided, and the purpose of long-time supporting is achieved.

Description

technical field [0001] The invention belongs to the technical field of rock-soil stability support for tunnel engineering, slope engineering, and deep foundation pit engineering, and more specifically relates to a multi-stage pouring system that can effectively increase the anchoring force and form a uniform thickness of cement mortar. Grab-type hollow anchor rod and its construction method. Background technique [0002] A large number of anchors are used in tunnel construction, slope protection and foundation pit protection. The anchoring force per unit length of the anchor is often related to the contact area between the anchor and the rock mass. For common anchors, the radial range of anchoring is affected by the diameter of the anchor. However, increasing the diameter of the bolt too much will cause waste of material. And when supporting at the top of the tunnel, if the anchor rod is installed in the upward direction, there will be an accident in which the anchor rod f...

AI Technical Summary

Problems solved by technology

[0002] A large number of anchors are used in tunnel construction, slope protection and foundation pit protection. The anchoring force per unit length of the anchor is often related to the contact area between the anchor and the rock mass. For common anchors, the radial range of anchoring is affected by the diameter of the anchor. However, increasing the diameter of the bolt too much will cause waste of material

And when supporting the top of the tunnel, if the anchor rod is installed in the upward direction, there will be accidents where the anchor rod falls out and hurts people.

Drilling holes in sandy soil and water often has the problem that it is not easy to form holes and the anchor rods are not easy to install.

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