Tendon prestressing device for pre-tensioning method and construction method thereof

By combining the structure and construction method of the pre-tensioned cable prestressed device, the problems of early deformation and low grouting efficiency in large-span tunnels with weak surrounding rock were solved, realizing active support of the surrounding rock and long-term effectiveness of the prestressed structure, thus improving the overall stability of the tunnel.

CN116906099BActive Publication Date: 2026-07-24SOUTHWEST JIAOTONG UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
SOUTHWEST JIAOTONG UNIV
Filing Date
2023-09-05
Publication Date
2026-07-24

AI Technical Summary

Technical Problem

Existing technologies cannot effectively control the early deformation of large-span tunnels in weak surrounding rock. Traditional prestressed anchor bolts are small in size and have low grouting efficiency, resulting in high risks to the stability of the tunnel structure. Moreover, once the anchor section cracks, it is prone to failure.

Method used

The pre-tensioned cable prestressing device is adopted. Through the combination structure of anchor cable, outer pipe, grouting inner pipe and clamping plate, grouting is performed after applying pre-tightening force to achieve active support and early deformation control of the surrounding rock. The anchor cable is made of multi-strand steel strands and high-bonding-strength resin anchoring agent, combined with early-strength rapid-setting micro-expansion grouting material to fill the cracks.

Benefits of technology

It significantly improves the shear strength and bearing capacity of the surrounding rock, controls early deformation, improves grouting efficiency, ensures the long-term effectiveness of the prestressed structure, and prevents the loosening of the surrounding rock and structural failure.

✦ Generated by Eureka AI based on patent content.

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Abstract

The application relates to a pre-tensioning method pipe cable prestressing device and a construction method thereof. The pre-tensioning method pipe cable prestressing device comprises an anchor cable, a backing plate is sleeved on the anchor head of the anchor cable and is anchored with surrounding rock, the anchor cable on the side away from the anchor head is sequentially divided into a pipe cable section, a grouting section and an anchoring section from outside to inside, an outer pipe is sleeved on the periphery of the pipe cable section, a plurality of grouting inner pipes are arranged between the pipe cable section and the outer pipe, the plurality of grouting inner pipes are distributed in a circular array with the anchor cable as the center, a clamping plate is detachably arranged on the pipe cable section and is used for tightly clamping the grouting inner pipes on the inner wall of the outer pipe, the grouting inner pipes pass through the backing plate outward, and a lock head abutting against the backing plate is arranged on the anchor head of the anchor cable. The application has the beneficial effects that the surrounding rock of the tunnel can be actively supported, the deformation of the surrounding rock in the anchoring area can be timely controlled, the grouting efficiency can be improved while the shear strength and the bearing capacity of the surrounding rock are improved.
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