A prestressed anchor cable structure for tunnel anti-seepage and construction method thereof

Abstract

The present invention discloses a prestressed anchor cable structure for tunnel anti-seepage and a construction method thereof, wherein the prestressed anchor cable structure comprises an unbonded prestressed steel strand, a pier seat, a steel pad and an anchor. The unbonded prestressed steel strand is wound around the outside of the tunnel in the circumferential direction; the pier seat is arranged in a reaction arch groove, the reaction arch groove is arranged in a reaction archway, the reaction archway is located below the tunnel, and the two ends of the unbonded prestressed steel strand pass through the pier seat in opposite directions; the two ends of the unbonded prestressed steel strand are each locked with the pier seat through an anchor; the two ends of the unbonded prestressed steel strand are each passed through a steel pad, and the steel pad is located between the anchor and the pier seat. Compared with the prior art, the present invention can put the entire cross-section of the tunnel support structure in a compressed state by applying prestress to the unbonded prestressed steel strand, greatly improve the tensile bearing performance of the support structure, delay or even eliminate the cracking phenomenon of the support structure, and avoid leakage engineering accidents in the tunnel.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel engineering, and in particular to a prestressed anchor cable structure for tunnel anti-seepage and a construction method thereof. Background Art

[0002] With the rapid development of urban underground space and transportation engineering, a large number of urban subways and tunnel projects have been built. The mining method has been widely used in tunnel engineering due to its own advantages. However, since the tunnel is basically buried deep below the surface and is in a complex stress state, and the concrete tensile strength is low, the tunnel is prone to cracking due to the support structure during operation, inducing groundwater to leak into the tunnel. This will not only cause the tunnel operating environment to be humid, causing serious safety hazards to the passage of vehicles in the tunnel, but also easily cause the bearing capacity of the support structure to be reduced due to the corrosion of the steel bars of the support structure by groundwater, inducing accidents such as tunnel collapse. In addition, due to tunnel leakage, the tunnel is pumped and drained all year round, which will consume a lot of maintenance costs. Therefore, the anti-seepage of the tunnel support structure has always been an extremely important link in the tunnel construction process. Summary of the invention

[0003] The purpose of the present invention is to provide a prestressed anchor cable structure for tunnel anti-seepage and a construction method thereof, which are used to prevent the support structure of a tunnel excavated by a mining method from cracking and avoid the occurrence of leakage accidents.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention discloses a prestressed anchor cable structure for tunnel anti-seepage, comprising:

[0006] Unbonded prestressed steel strands, the unbonded prestressed steel strands are wound around the outside of the tunnel in a circumferential direction;

[0007] A pier seat, wherein the pier seat is arranged in a reaction arch groove, the reaction arch groove is arranged in a reaction archway, the reaction archway is located below the tunnel, and two ends of the unbonded prestressed steel strand pass through the pier seat in opposite directions;

[0008] Anchors, both ends of the unbonded prestressed steel strands are locked with the pier seat by means of the anchors;

[0009] Steel pads, each end of the unbonded prestressed steel strand passes through a steel pad, and the steel pads are located between the anchor and the pier seat.

[0010] The present invention also discloses a construction method of the above-mentioned prestressed anchor cable structure for tunnel anti-seepage, comprising the following steps:

[0011] S1. Excavate the tunnel to the tunnel wall and reaction archway required by the design, and excavate the reaction arch groove at the designed position at the bottom of the tunnel;

[0012] S2. Install the pier formwork and steel bars at the center of the reaction arch groove mileage, and preliminarily place the unbonded prestressed steel strands along the circumference near the tunnel wall at the reaction arch groove mileage, and make the two ends of the unbonded prestressed steel strands pass through the two sides of the pier formwork respectively;

[0013] S3. According to the design requirements, on the inner side of the unbonded prestressed steel strand, close to the tunnel wall, tie the outer longitudinal steel bars, weld the steel arch frame, tie the inner longitudinal steel bars in sequence, then adjust the tension and position of the unbonded prestressed steel strand and fix it preliminarily; then pour the concrete of the tunnel support structure, pier and reaction arch groove;

[0014] S4. After the strength of the supporting structure and pier base concrete reaches the design requirements, steel pads and anchors are inserted into the unbonded prestressed steel strands on both sides of the pier base in sequence. At the same time, the unbonded prestressed steel strands are tensioned synchronously on both sides of the pier base, locked according to the designed prestress value, and then the reaction archway concrete is poured.

[0015] Compared with the prior art, the present invention has achieved the following technical effects:

[0016] 1. The present invention uses non-bonded prestressed steel strands to apply prestress. The non-bonded prestressed steel strands have good flexibility and are very convenient to install along the axial direction of the tunnel wall;

[0017] 2. The present invention utilizes the piers in the reaction arch groove at the bottom of the tunnel to symmetrically tension the unbonded prestressed steel strands, which makes the construction very convenient;

[0018] 3. The present invention applies prestress to the unbonded prestressed steel strands, so that the entire cross-section of the tunnel support structure can be placed under compression, greatly improving the tensile bearing capacity of the support structure, delaying or even eliminating cracking of the support structure, and avoiding leakage engineering accidents in the tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a side view of the prestressed anchor cable structure used for tunnel anti-seepage in this embodiment;

[0021] Figure 2 for Figure 1 AA section view;

[0022] Figure 3 for Figure 1 BB cross-section diagram;

[0023] Explanation of the reference numerals: 11-unbonded prestressed steel strand; 12-pier; 13-steel pad; 14-anchor; 21-steel arch frame; 22-inner longitudinal reinforcement; 23-outer longitudinal reinforcement; 24-concrete; 31-reaction archway; 32-reaction arch groove; 41-tunnel; 42-tunnel wall. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] The purpose of the present invention is to provide a prestressed anchor cable structure for tunnel anti-seepage and a construction method thereof, which are used to prevent the support structure of a tunnel excavated by a mining method from cracking and avoid the occurrence of leakage accidents.

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] like Figure 1-3 As shown, this embodiment provides a prestressed anchor cable structure for tunnel waterproofing, including an unbonded prestressed steel strand 11, a pier 12, a steel pad 13 and an anchor 14.

[0028] Among them, the unbonded prestressed steel strand 11 is circumferentially wound around the outside of the tunnel 41; the pier seat 12 is arranged in the reaction arch groove 32, the reaction arch groove 32 is arranged in the reaction archway 31, the reaction archway 31 is located below the tunnel 41, and the two ends of the unbonded prestressed steel strand 11 pass through the pier seat 12 in opposite directions; the two ends of the unbonded prestressed steel strand 11 are each locked with the pier seat 12 by an anchor 14; the two ends of the unbonded prestressed steel strand 11 each pass through a steel pad 13, and the steel pad 13 is located between the anchor 14 and the pier seat 12.

[0029] By applying prestress to the unbonded prestressed steel strands 11, this embodiment can put the entire cross-section of the tunnel support structure in a compressive state, greatly improve the tensile bearing capacity of the support structure, delay or even eliminate the cracking of the support structure, and avoid leakage engineering accidents in the tunnel 41.

[0030] This embodiment also provides a construction method of the above-mentioned prestressed anchor cable structure for tunnel anti-seepage, comprising the following steps:

[0031] S1. Tunnel excavation: excavate the tunnel 41 to the tunnel wall 42 and reaction arch 31 required by the design, and excavate the reaction arch groove 32 at the designed position at the bottom of the tunnel 41.

[0032] S2. Preliminary installation of prestressed anchor cables: Install the pier seat 12 template and steel bars at the center of the reaction arch groove 32 mileage, and preliminarily place the unbonded prestressed steel strands 11 along the circumferential direction near the tunnel wall 42 at the reaction arch groove 32 mileage, and make the two ends of the unbonded prestressed steel strands 11 pass through the two sides of the pier seat 12 template respectively.

[0033] S3. Support structure and concrete construction: According to the design requirements, on the inner side of the unbonded prestressed steel strand 11, close to the tunnel wall 42, the outer longitudinal steel bars 23, the welded steel arch frame 21, and the inner longitudinal steel bars 22 are tied in sequence, and then the tension and position of the unbonded prestressed steel strand 11 are adjusted and preliminarily fixed; then the concrete 24 of the tunnel support structure, pier 12 and reaction arch groove 32 is poured.

[0034] S4. Prestressed tensioning construction: After the strength of the concrete 24 of the supporting structure and the pier 12 has been cured to meet the design requirements, the steel pads 13 and anchors 14 are sequentially inserted into the unbonded prestressed steel strands 11 on both sides of the pier 12, and the unbonded prestressed steel strands 11 are simultaneously tensioned on both sides of the pier 12, locked according to the designed prestress value, and then the concrete 24 of the reaction archway is poured.

[0035] The present specification uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A construction method for a prestressed anchor cable structure for tunnel anti-seepage, characterized in that: A prestressed anchor cable structure for tunnel anti-seepage is used, and the prestressed anchor cable structure for tunnel anti-seepage includes: Unbonded prestressed steel strands, the unbonded prestressed steel strands are wound around the outside of the tunnel in a circumferential direction; A pier seat, wherein the pier seat is arranged in a reaction arch groove, the reaction arch groove is arranged in a reaction archway, the reaction archway is located below the tunnel, and two ends of the unbonded prestressed steel strand pass through the pier seat in opposite directions; Anchors, both ends of the unbonded prestressed steel strands are locked with the pier seat by means of the anchors; Steel pads, each end of the unbonded prestressed steel strand passes through a steel pad, and the steel pads are located between the anchor and the pier seat; The construction method of the prestressed anchor cable structure for tunnel anti-seepage comprises the following steps: S1. Excavate the tunnel to the tunnel wall and reaction archway required by the design, and excavate the reaction arch groove at the designed position at the bottom of the tunnel; S2. Install the pier formwork and steel bars at the center of the reaction arch groove mileage, and preliminarily place the unbonded prestressed steel strands along the circumference near the tunnel wall at the reaction arch groove mileage, and make the two ends of the unbonded prestressed steel strands pass through the two sides of the pier formwork respectively; S3. According to the design requirements, on the inner side of the unbonded prestressed steel strand, close to the tunnel wall, tie the outer longitudinal steel bars, weld the steel arch frame, tie the inner longitudinal steel bars in sequence, then adjust the tension and position of the unbonded prestressed steel strand and fix it preliminarily; then pour the concrete of the tunnel support structure, pier and reaction arch groove; S4. After the strength of the supporting structure and pier base concrete reaches the design requirements, steel pads and anchors are inserted into the unbonded prestressed steel strands on both sides of the pier base in sequence. At the same time, the unbonded prestressed steel strands are tensioned synchronously on both sides of the pier base, locked according to the designed prestress value, and then the reaction archway concrete is poured.

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