Prestressed expanded-head anti-floating anchor rod and construction method

Abstract

The invention belongs to the technical field of rock-soil anchoring, and relates to a prestressed expanded-head anti-floating anchor rod and a construction method.The variable-diameter reinforcement cage is installed on the anchoring section of an anchor rod body, the outer side of the free section of the anchor rod body is sleeved with an anti-corrosion lantern ring, an anchor rod centering device is arranged on the free section of the anchor rod body, and the upper portion of the anchor rod body is sleeved with a second steel sleeve; the bottom of the second steel sleeve is connected with the top of the anti-corrosion lantern ring, and the top of the second steel sleeve is aligned with the bottom face of the anchor pit in parallel and connected with a stress diffusion anchor disc which is fixed through a fastening nut. The anchor rod impermeable layer is arranged between the building foundation bottom plate and the foundation waterproof layer, and the grouting pipe is arranged on one side of the anchor rod body; when the variable-diameter reinforcement cage is unfolded, the contact area of the anchor rod body and an anchoring body can be increased, bonding of the anchor rod body and the anchoring body is enhanced, the uplift bearing capacity of the anchor rod is improved, cracking of anchoring section concrete is effectively controlled, and the integrity of the anchor rod is enhanced. The variable-diameter reinforcement cage is opened by means of grouting pressure and the gravity of the device, and construction is simple and fast.

Description

Technical field: [0001] The invention belongs to the technical field of rock and soil anchoring, and relates to a variable-diameter prestressed enlarged head anti-floating anchor and a construction method, which are used to provide higher pullout resistance, better corrosion resistance and stronger control Shapeshifting ability. Background technique: [0002] In recent years, with the rapid development of my country's infrastructure construction, the foundation of high-rise buildings is buried deeper and deeper. As the main medium bearing the self-weight of the structure, the rock-soil mass is rich in a large number of pores and fissures, and the groundwater contained in it produces buoyancy on the foundation of the building. When the buoyancy generated is greater than the self-weight of the structure, an upward instability accident will occur . As one of many anti-floating measures, the anti-floating anchor has the advantages of simple construction technology, simple main...

AI Technical Summary

Problems solved by technology

[0003] The anti-floating anchor is a concealed project for long-term support, and corrosion is the most influential factor on the durability of the anchor. The durability of the anchor directly determines the service life of the anchor structure. After the free end or anchor end of the anchor is corroded, Its pull-out bearing capacity will be greatly reduced, which will pose a threat to personal property. In the prior art, there are few durability design methods and supporting anti-corrosion measures for prestressed metal anchor rods in corrosive environments. Therefore, a bearing capacity is designed. Prestressed anti-floating anchor rods with high strength and good corrosion resistance are technical problems that need to be solved urgently

[0004] The methods commonly used in the prior art to improve the bearing capacity of metal anti-floating anchors mainly include the following: (1) increasing the number of pores, (2) increasing the number of anchor rod bodies in a single anchor hole, (3) applying prestress; Brush the anti-corrosion paint on the free section of the anchor rod body to improve the corrosion resistance of the metal anti-floating anchor rod. For example, CN11005376A discloses a variable diameter steel cage to expand the anchor rod system to enhance the bearing capacity of the anchor rod, but the corrosion of the rib body is not considered. And the deployment of the reinforcement cage is complicated; CN205348172B discloses a method for increasing the bearing capacity by improving the contact and bonding between the anchor rod and the soil, without anti-corrosion treatment, and the deformation of the anchorage section of the anchor rod is relatively large, although these two methods are in a certain To a certain extent, the bearing capacity of the anti-floating anchor is improved, but the anti-corrosion problem of the metal anchor is not considered, and there are problems of large deformation of the anchorage section of the anchor and complicated construction

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