Double-cable single-anchor tunnel type anchorage and construction method

Abstract

According to the double-cable single-anchor tunnel type anchorage and the construction method, two main cables of a bridge penetrate through an inclined hole with the axis parallel to the direction of the main cables to be led into the ground, after the direction of the main cables is deflected through a cable rotating saddle, the main cables penetrate through the inclined hole with the axis obliquely intersecting with the direction of the main cables and converge in a saddle chamber in the middle, and the side wall of the saddle chamber is provided with a transversely-installed splay cable saddle; the main cable is dispersed into a plurality of cable strands, the cable strands are dispersed in the front anchor chamber and anchored to a single wedge-shaped concrete anchor body, and the anchor body fully utilizes surrounding rock to jointly bear loads. The two main cables of the bridge are anchored to the same anchor body, and the anchor has the advantages of being convenient to construct, low in manufacturing cost, good in bearing performance and the like.

Description

Technical Field

[0001] The invention relates to the technical field of bridge engineering, in particular to a double-cable single-anchor tunnel anchorage and a construction method. Background Art

[0002] Tunnel anchorage is a ground anchorage structure that bears the load of the main cable of a suspension bridge. Compared with gravity anchorage, it has significant advantages such as less environmental impact and lower cost. Suspension bridges generally have two main cables, located on both sides of the bridge deck, so there are generally two anchorages to bear the load of the two main cables respectively.

[0003] Most existing tunnel anchors use a double-anchor solution with a rock wall between the anchors. The construction of the anchor hole causes great disturbance to the rock wall, which limits the construction progress and affects the bearing capacity of the anchor body. Some researchers have proposed excavating the rock wall and filling it with concrete to connect the two anchor bodies into a whole, but this will form a larger underground cavern, which will cause great difficulties in rock excavation support and surrounding rock stability. Summary of the invention

[0004] In view of the defects of the prior art, the present invention provides a double-cable single-anchor tunnel anchorage and construction method. The double main cables of the bridge are introduced into the rock layer below the surface through an inclined hole, deflected after passing through the cable saddle, converged in the saddle room and dispersed into multiple cable strands by the scattered cable saddle. The cable strands are connected to the steel strands and transfer the load to a single anchor body to achieve the anchoring effect. The present invention is convenient to construct, has little disturbance to the surrounding rock, reduces the number of anchor bodies by half, and has the characteristics of low cost and good bearing performance.

[0005] A double-cable single-anchor tunnel anchorage is buried in a stratum below the surface, comprising a cavern, a cable strand connection structure and an anchoring structure; the cavern comprises a first inclined cavern, a second inclined cavern, a third inclined cavern, a fourth inclined cavern, a saddle chamber, a front anchor chamber, an anchor cavern and a rear anchor chamber; the cable strand connection structure comprises two main cables of a suspension bridge, namely a first main cable and a second main cable; the first inclined cave connects the surface to the second inclined cavern, the second inclined cave connects the first inclined cave to the saddle chamber, the first inclined cave and the second inclined cave provide a passage for the first main cable to pass through and realize downward turning; the third inclined cave connects the surface to the fourth inclined cave, the fourth inclined cave connects the third inclined cave to the saddle chamber, the third inclined cave and the fourth inclined cave provide a passage for the second main cable to pass through and realize upward turning; after passing through the saddle chamber, the first main cable and the second main cable are respectively dispersed into a plurality of first cable strands and a plurality of second cable strands in the front anchor chamber, the plurality of first cable strands and the plurality of second cable strands are anchored by the anchoring structure, and the anchor cave provides a construction space for the anchoring structure.

[0006] Furthermore, the axis of the first inclined hole is parallel to the direction of the first main cable, the second inclined hole is obliquely intersected with the first inclined hole and the saddle room at a small angle of 30° to 45°, and the axis of the second inclined hole is parallel to the direction of the deflected first main cable; the axis of the third inclined hole is parallel to the direction of the second main cable, the fourth inclined hole is obliquely intersected with the third inclined hole and the saddle room at a small angle of 30° to 45°, and the axis of the fourth inclined hole is parallel to the direction of the second main cable after deflection.

[0007] Furthermore, the cable strand connection structure further includes a first rotation cable saddle, a second rotation cable saddle, a first rotation cable saddle base, and a second rotation cable saddle base;

[0008] The first rotating cable saddle is located at the connection between the first inclined hole and the second inclined hole, and is used to deflect the direction of the first main cable. The first rotating cable saddle is provided with a first rotating cable saddle base, and the first rotating cable saddle base is fastened to the rock wall;

[0009] The second turning saddle is located at the connection of the third inclined hole and the fourth inclined hole, and is used to deflect the direction of the second main cable. A second turning saddle base is provided at the second turning saddle, and the second turning saddle base is fastened to the rock wall.

[0010] Furthermore, the cable strand connection structure further includes a first loose cable saddle, a second loose cable saddle, a first loose cable saddle base, a second loose cable saddle base, a first cable strand and a second cable strand;

[0011] The first cable saddle is located in the saddle room and is arranged transversely on a cave wall on one side of the saddle room. A first cable saddle base is provided at the bottom of the first cable saddle. The first cable saddle base is fastened to the rock wall. The first main cable is dispersed into a plurality of first cable strands after passing through the first cable saddle.

[0012] The second cable saddle is located in the saddle room and is arranged transversely on the cave wall on the other side of the saddle room. A second cable saddle base is provided at the second cable saddle. The second cable saddle base is fastened to the rock wall. The second main cable is dispersed into multiple second cable strands after passing through the second cable saddle.

[0013] Furthermore, the anchoring structure includes a front anchor, a steel strand, an anchor body and a rear anchor. The first cable strand and the second cable strand are respectively connected to the steel strand of the anchoring system through connectors to transfer the bridge load to the anchoring system. The front anchor locks the steel strand to the front anchor surface of the anchor body, and the rear anchor locks the steel strand to the rear anchor surface of the anchor body.

[0014] Furthermore, the front anchor includes a first front anchor and a second front anchor, and the rear anchor includes a first rear anchor and a second rear anchor; one end of the steel strand clamped by the first front anchor is connected to the first strand to transfer the load to the anchor body; one end of the steel strand clamped by the second front anchor is connected to the second strand to transfer the load to the anchor body; the first rear anchor corresponds to the first front anchor, and the other end of the steel strand clamped by the first front anchor is locked to the rear anchor surface of the anchor body, and the second rear anchor corresponds to the second front anchor, and the other end of the steel strand clamped by the second front anchor is locked to the rear anchor surface of the anchor body.

[0015] Furthermore, the anchor body is a load-bearing component, which contacts the rock layer and forms a joint body to jointly bear the bridge load. The anchor body is a wedge-shaped body that is small in the front and large in the back, and is cast with concrete material in the anchor hole.

[0016] Furthermore, the anchoring structure also includes a protective tube, which is buried in the anchor body and provides a passage for the steel strand to pass through.

[0017] A method for constructing the double-cable single-anchor tunnel anchorage as described above comprises the following steps:

[0018] Step S1: The caverns are excavated and supported in sequence to form a space. Step S1 includes:

[0019] Step S11, the first inclined hole is entered from the ground surface, and excavation support is provided to the bottom of the second inclined hole; the third inclined hole is entered from the ground surface, and excavation support is provided to the bottom of the fourth inclined hole;

[0020] Step S12, using the first and second inclined tunnels as personnel access and air intake channels, and the third and fourth inclined tunnels as machinery access and exhaust channels, excavating the support saddle room, the front anchor room, the anchor hole and the rear anchor room in sequence;

[0021] Step S2: anchoring structure construction and component installation. Step S2 includes:

[0022] Step S21, use total station to measure, steel pipe as support, locate and bury all protective pipes, and then install anchor pads of all front anchors and all rear anchors. Make concrete molds and cast anchor bodies in compartments, and maintain until the concrete is completely solidified;

[0023] Step S22, installing, tensioning and locking all steel strands: the steel strands pass through the protective tube, first install the anchor clips and anchor rings of the rear anchor, then install the anchor clips and anchor rings of the front anchor, and use tensioning equipment to tension and lock the steel strands;

[0024] Step S23, all front anchors are divided into first front anchors and second front anchors, and all rear anchors are divided into first rear anchors and second rear anchors;

[0025] Step S3: cable strand connection structure construction and component installation. Step S3 includes:

[0026] Step S31, casting and constructing the first rotation cable saddle base and the second rotation cable saddle base, and installing the first rotation cable saddle and the second rotation cable saddle;

[0027] Step S32, casting and constructing the first loose cable saddle base and the second loose cable saddle base, and installing the first loose cable saddle and the second loose cable saddle;

[0028] Step S33, the first main cable enters the hole, passes through the first cable spreading saddle and then reaches the first cable turning saddle, and is dispersed into a plurality of first cable strands;

[0029] Step S34, the second main cable enters the hole, passes through the second turning saddle and reaches the second spreading saddle, and is spread into a plurality of second cable strands;

[0030] Step S35: All first cable strands are connected to the steel strands of the first front anchor, and all second cable strands are connected to the steel strands of the second front anchor.

[0031] Furthermore, it also includes: Step S4, anchor protection and maintenance: applying anti-corrosion grease to the surface of the anchor and the exposed surface of the steel strand, and performing performance monitoring and maintenance during the operation and maintenance stage.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The present invention adopts an inclined hole parallel to and obliquely intersecting the main cable axis to introduce the main cable into the ground. After being deflected by the transversely arranged cable saddle, the main cable is merged into the middle saddle chamber. The saddle chamber and the number of large caverns such as the front anchor chamber, anchor hole and rear anchor chamber behind it are only one, the excavation and support engineering of the cavern is less, the construction progress is improved, and the economic benefits are better.

[0034] 2. The technical solution provided by the present invention anchors the two main cables of the bridge to the same anchor body. Compared with the traditional technical solution of two anchor bodies, the number of anchor bodies is reduced by half, the amount of concrete used is significantly reduced, and it has obvious economic advantages.

[0035] 3. The anchor body of the present invention adopts a wedge-shaped body with a similar cross-sectional width-to-height ratio. Compared with a wider anchor hole in which two anchors are connected to form an anchor, it has better surrounding rock stability and more reliable bearing performance.

[0036] 4. The two inclined holes used in the present invention are respectively used as passages for personnel and machinery to enter and exit and as passages for air intake and exhaust, and have the characteristics of convenient construction, high safety and good ventilation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a main structural diagram of an oblique cross section of a double-cable single-anchor tunnel-type anchorage according to an embodiment of the present invention;

[0038] Figure 2 This is a main structural diagram of a vertical section of a double-cable single-anchor tunnel-type anchorage according to an embodiment of the present invention;

[0039] Figure 3 It is the layout diagram of the cavern according to the embodiment of the present invention;

[0040] Figure 4 It is a cross-sectional view of an inclined hole according to an embodiment of the present invention;

[0041] Figure 5 It is a cross-sectional view of a saddle chamber according to an embodiment of the present invention;

[0042] Figure 6 This is a schematic diagram of the connection between the inclined hole and the saddle room according to an embodiment of the present invention;

[0043] Figure 7 This is a schematic diagram of the transverse arrangement of the loose cable saddle according to an embodiment of the present invention;

[0044] Figure 8 It is a schematic diagram of the front anchor surface section and anchorage section of the anchor structure according to an embodiment of the present invention;

[0045] Fig. 9 It is a schematic diagram of the anchor surface section and anchorage section after the anchoring structure according to an embodiment of the present invention;

[0046] Fig.10 This is a schematic diagram of the buried pipe installation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0048] See also Figure 1 and Figure 2 An embodiment of the present invention provides a double-cable single-anchor tunnel anchor, which is buried in a stratum 2 below the surface 1 and includes a cavern 3, a cable strand connection structure 4 and an anchoring structure 5.

[0049] Please also read Figure 3 to Figure 6 The cave chamber 3 includes a first inclined cave 31a, a second inclined cave 31b, a third inclined cave 31c, a fourth inclined cave 31d, a saddle chamber 32, a front anchor chamber 33, an anchor hole 34 and a rear anchor chamber 35.

[0050] The first inclined hole 31a is connected to the ground surface 1 and the second inclined hole 31b, providing a passage for the first main cable 41a to pass through. The axis of the first inclined hole 31a is parallel to the direction of the first main cable 41a.

[0051] The second inclined hole 31b connects the first inclined hole 31a to the saddle room 32, providing a passage for the first main cable 41a to pass through. The second inclined hole 31b is obliquely intersected with the first inclined hole 31a and the saddle room 32 at a small angle of 30° to 45°. The axis of the second inclined hole 31b is parallel to the direction of the deflected first main cable 41a.

[0052] The third inclined hole 31c is connected to the ground surface 1 and the fourth inclined hole 31d, providing a passage for the second main cable 41b to pass through. The axis of the third inclined hole 31c is parallel to the direction of the second main cable 41b.

[0053] The fourth inclined hole 31d connects the third inclined hole 31c to the saddle room 32, providing a passage for the second main cable 41b to pass through. The fourth inclined hole 31d is obliquely intersected with the third inclined hole 31c and the saddle room 32 at a small angle of 30° to 45°. The axis of the fourth inclined hole 31d is parallel to the direction of the deflected second main cable 41b.

[0054] The saddle chamber 32 provides a space for the first and second saddles 44a and 44b to be housed.

[0055] The front anchor chamber 33 provides a space for the first cable strand 46a and the second cable strand 46b to be dispersed, and is a space for the construction and subsequent maintenance of the anchor structure 5.

[0056] The anchor hole 34 is a space for constructing the anchor structure 5 .

[0057] The rear anchor chamber 35 is a space for the construction and subsequent maintenance of the anchor structure 5 .

[0058] See also Figure 1 , Figure 2 and Figure 7 The cable strand connection structure 4 includes a first main cable 41a, a second main cable 41b, a first rotation saddle 42a, a second rotation saddle 42b, a first rotation saddle base 43a, a second rotation saddle base 43b, a first loose cable saddle 44a, a second loose cable saddle 44b, a first loose cable saddle base 45a, a second loose cable saddle base 45b, a first cable strand 46a, and a second cable strand 46b.

[0059] The first main cable 41a and the second main cable 41b are two main cables of the suspension bridge, which are main components for transmitting bridge loads and are made of high-strength steel strands.

[0060] The first rotating saddle 42a is located at the connection between the first inclined hole 31a and the second inclined hole 31b, and is used to deflect the direction of the first main cable 41a. The first rotating saddle 42a is provided with a first rotating saddle base 43a. The first rotating saddle base 43a is made of reinforced concrete and is fastened to the rock wall.

[0061] The second turning saddle 42b is located at the connection between the third inclined hole 31c and the fourth inclined hole 31d, and is used to deflect the direction of the second main cable 41b. A second turning saddle base 43b is provided at the second turning saddle 42b. The second turning saddle base 43b is made of reinforced concrete and is fastened to the rock wall.

[0062] The first cable saddle 44a is located in the saddle chamber 32 and is arranged transversely on a side wall of the saddle chamber 32. A first cable saddle base 45a is provided at the bottom of the first cable saddle 44a. The first cable saddle base 45a is made of reinforced concrete and is fastened to the rock wall. The first main cable 41a passes through the first cable saddle 44a and is dispersed into a plurality of first cable strands 46a.

[0063] The second cable saddle 44b is located in the saddle chamber 32 and is arranged transversely on the cave wall on the other side of the saddle chamber 32. A second cable saddle base 45b is provided at the second cable saddle 44b. The second cable saddle base 45b is made of reinforced concrete and is fastened to the rock wall. The second main cable 41b passes through the second cable saddle 44b and is dispersed into a plurality of second cable strands 46b.

[0064] The first strand 46 a is a dispersed steel strand of the first main cable 41 a . There are a plurality of first strands 46 a , which are connected to the steel strands 52 of the anchor system 5 through connectors and transfer the bridge load to the anchor system 5 .

[0065] The second strand 46 b is a dispersed steel strand of the second main cable 41 b . There are a plurality of second strands 46 b , which are connected to the steel strands 52 of the anchor system 5 through connectors and transfer the bridge load to the anchor system 5 .

[0066] See also Figure 8-10 The anchoring structure 5 includes a front anchor 51, a steel strand 52, a protective tube 53, an anchor body 54 and a rear anchor 55. The front anchor 51 includes a first front anchor 51a and a second front anchor 51b, and the rear anchor 55 includes a first rear anchor 55a and a second rear anchor 55b.

[0067] The front anchor 51 locks the steel strand 52 to the front anchor surface of the anchor body 54. The main components are the anchor pad, the clip and the anchor ring. The front anchor 51 is divided into a first front anchor 51a and a second front anchor 51b. The steel strand 52 clamped by the first front anchor 51a is connected to the first strand 46a, and the load is transferred to the anchor body 54. The steel strand 52 clamped by the second front anchor 51b is connected to the second strand 46b, and the load is transferred to the anchor body 54.

[0068] The steel strand 52 is a component for transferring the internal load of the anchoring system 5, and transfers the load of the main cable 5 to the anchor body. The steel strand 52 passes through the anchor body 54 from the front anchor surface to the rear anchor surface.

[0069] The protective tube 53 is buried in the anchor body 54 to provide a passage for the steel strand 52 to pass through. The protective tube 53 is made of steel material.

[0070] The anchor body 54 is a load-bearing component, which contacts with the rock layer 2 and forms a joint body to jointly bear the bridge load. The anchor body 54 is a wedge-shaped body with a small front and a large back, and is cast in the anchor hole 34 with concrete material.

[0071] The rear anchor 55 locks the steel strand 52 to the rear anchor surface of the anchor body 54. The main components are an anchor pad, a clip and an anchor ring. The rear anchor 55 is divided into a first rear anchor 55a and a second rear anchor 55b. The first rear anchor 55a corresponds to the first front anchor 51a, and the second rear anchor 55b corresponds to the second front anchor 51b.

[0072] The embodiment of the present invention further provides a method for constructing the above-mentioned dual-cable single-anchor tunnel anchorage, comprising the following steps:

[0073] Step S1, the cavern 3 is excavated and supported in sequence to form a space.

[0074] Step S11: Enter the first inclined hole 31a from the ground surface, excavate and support to the bottom of the second inclined hole 31b, and enter the third inclined hole 31c from the ground surface, excavate and support to the bottom of the fourth inclined hole 31d.

[0075] Step S12, using the first inclined tunnel 31a and the second inclined tunnel 31b as personnel entrance and exit and air intake channels, the third inclined tunnel 31c and the fourth inclined tunnel 31d as machinery entrance and exit and exhaust channels, and excavating the support saddle chamber 32, the front anchor chamber 33, the anchor hole 34 and the rear anchor chamber 35 in sequence.

[0076] Step S2: constructing the anchoring structure 5 and installing components.

[0077] Step S21: Use total station to measure and steel pipe as support to locate and bury all protective pipes 53, and then install anchor pads of all front anchors 51 and all rear anchors 55. Make concrete molds and cast anchor bodies 54 in compartments, and maintain until the concrete is completely solidified.

[0078] Step S22, install, tension and lock all steel strands 52. Take one steel strand 52 as an example, the steel strand 52 passes through the protective tube 53, first install the anchor clip and anchor ring of the rear anchor 55, then install the anchor clip and anchor ring of the front anchor 51, and use tensioning equipment to tension the steel strand 52 and lock it.

[0079] Step S23: All front anchors 51 are divided into first front anchors 51a and second front anchors 51b, and all rear anchors 55 are divided into first rear anchors 55a and second rear anchors 55b.

[0080] Step S3: constructing the cable strand connection structure 4 and installing components.

[0081] Step S31, casting and constructing the first rotating cable saddle base 43a and the second rotating cable saddle base 43b, and installing the first rotating cable saddle 42a and the second rotating cable saddle 42b.

[0082] Step S32: Cast and construct the first loose-cable saddle base 45a and the second loose-cable saddle base 45b, and install the first loose-cable saddle 44a and the second loose-cable saddle 44b.

[0083] Step S33: The first main cable 41a enters the hole, passes through the first spreading saddle 44a, and then reaches the first turning saddle 42a, and is dispersed into a plurality of first cable strands 46a.

[0084] Step S34: The second main cable 41b enters the hole, passes through the second turning saddle 42b, and reaches the second dispersing saddle 44b, and is dispersed into a plurality of second cable strands 46b.

[0085] Step S35: All first cable strands 46a are connected to the steel strands 52 of the first front anchor 51a, and all second cable strands 46b are connected to the steel strands 52 of the second front anchor 51b.

[0086] Step S4: anchor protection and maintenance.

[0087] Anti-corrosion grease is applied to the surface of the anchor and the exposed steel strand, and performance monitoring and maintenance are carried out during the operation and maintenance phase.

[0088] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A double-cable single-anchor tunnel anchorage, characterized in that: It is buried in the stratum below the surface, and includes a cavern, a cable-strand connection structure and an anchoring structure; the cavern includes a first inclined cavern, a second inclined cavern, a third inclined cavern, a fourth inclined cavern, a saddle chamber, a front anchor chamber, an anchor hole and a rear anchor chamber; The cable strand connection structure includes two main cables of the suspension bridge, namely, a first main cable and a second main cable. The first inclined hole connects the ground surface to the second inclined hole, the second inclined hole connects the first inclined hole to the saddle room, the first inclined hole and the second inclined hole provide a passage for the first main cable to pass through and realize downward turning; the third inclined hole connects the ground surface to the fourth inclined hole, the fourth inclined hole connects the third inclined hole to the saddle room, the third inclined hole and the fourth inclined hole provide a passage for the second main cable to pass through and realize upward turning; after passing through the saddle room, the first main cable and the second main cable are respectively dispersed into multiple first cable strands and multiple second cable strands in the front anchor room, the multiple first cable strands and the multiple second cable strands are anchored by the anchoring structure, and the anchor hole provides construction space for the anchoring structure.

2. The double-cable single-anchor tunnel anchorage according to claim 1, characterized in that: The axis of the first inclined hole is parallel to the direction of the first main cable, the second inclined hole is obliquely intersected with the first inclined hole and the saddle room at a small angle of 30° to 45°, and the axis of the second inclined hole is parallel to the direction of the deflected first main cable; the axis of the third inclined hole is parallel to the direction of the second main cable, the fourth inclined hole is obliquely intersected with the third inclined hole and the saddle room at a small angle of 30° to 45°, and the axis of the fourth inclined hole is parallel to the direction of the second main cable after deflection.

3. The double-cable single-anchor tunnel anchorage according to claim 1, characterized in that: The cable strand connection structure further includes a first rotation cable saddle, a second rotation cable saddle, a first rotation cable saddle base, and a second rotation cable saddle base; The first rotating cable saddle is located at the connection between the first inclined hole and the second inclined hole, and is used to deflect the direction of the first main cable. The first rotating cable saddle is provided with a first rotating cable saddle base, and the first rotating cable saddle base is fastened to the rock wall; The second turning saddle is located at the connection of the third inclined hole and the fourth inclined hole, and is used to deflect the direction of the second main cable. A second turning saddle base is provided at the second turning saddle, and the second turning saddle base is fastened to the rock wall.

4. The double-cable single-anchor tunnel anchorage according to claim 1, characterized in that: The cable strand connection structure further includes a first loose cable saddle, a second loose cable saddle, a first loose cable saddle base, a second loose cable saddle base, a first cable strand and a second cable strand; The first cable saddle is located in the saddle room and is arranged transversely on a cave wall on one side of the saddle room. A first cable saddle base is provided at the bottom of the first cable saddle. The first cable saddle base is fastened to the rock wall. The first main cable is dispersed into a plurality of first cable strands after passing through the first cable saddle. The second cable saddle is located in the saddle room and is arranged transversely on the cave wall on the other side of the saddle room. A second cable saddle base is provided at the second cable saddle. The second cable saddle base is fastened to the rock wall. The second main cable is dispersed into multiple second cable strands after passing through the second cable saddle.

5. The double-cable single-anchor tunnel anchorage according to claim 1, characterized in that: The anchoring structure includes a front anchor, a steel strand, an anchor body and a rear anchor. The first cable strand and the second cable strand are respectively connected to the steel strand of the anchoring system through connectors to transfer the bridge load to the anchoring system. The front anchor locks the steel strand to the front anchor surface of the anchor body, and the rear anchor locks the steel strand to the rear anchor surface of the anchor body.

6. The double-cable single-anchor tunnel anchorage according to claim 5, characterized in that: The front anchor includes a first front anchor and a second front anchor, and the rear anchor includes a first rear anchor and a second rear anchor; one end of the steel strand clamped by the first front anchor is connected to the first strand to transfer the load to the anchor body; one end of the steel strand clamped by the second front anchor is connected to the second strand to transfer the load to the anchor body; the first rear anchor corresponds to the first front anchor, and the other end of the steel strand clamped by the first front anchor is locked to the rear anchor surface of the anchor body, and the second rear anchor corresponds to the second front anchor, and the other end of the steel strand clamped by the second front anchor is locked to the rear anchor surface of the anchor body.

7. The double-cable single-anchor tunnel anchorage according to claim 5, characterized in that: The anchor body is a load-bearing component that contacts the rock layer and forms a joint body to jointly bear the bridge load. The anchor body is a wedge-shaped body that is small in the front and large in the back, and is cast with concrete material in the anchor hole.

8. The double-cable single-anchor tunnel anchorage according to claim 5, characterized in that: The anchoring structure also includes a protective tube, which is buried in the anchor body and provides a passage for the steel strand to pass through.

9. A method for constructing a double-cable single-anchor tunnel anchorage as claimed in any one of claims 1 to 8, characterized in that The steps include: Step S1: The caverns are excavated and supported in sequence to form a space. Step S1 includes: Step S11, the first inclined hole is entered from the ground surface, and excavation support is provided to the bottom of the second inclined hole; the third inclined hole is entered from the ground surface, and excavation support is provided to the bottom of the fourth inclined hole; Step S12, using the first and second inclined tunnels as personnel access and air intake channels, and the third and fourth inclined tunnels as machinery access and exhaust channels, excavating the support saddle room, the front anchor room, the anchor hole and the rear anchor room in sequence; Step S2: anchoring structure construction and component installation. Step S2 includes: Step S21, use total station to measure, steel pipe as support, locate and bury all protective pipes, and then install anchor pads of all front anchors and all rear anchors. Make concrete molds and cast anchor bodies in compartments, and maintain until the concrete is completely solidified; Step S22, installing, tensioning and locking all steel strands: the steel strands pass through the protective tube, first install the anchor clips and anchor rings of the rear anchor, then install the anchor clips and anchor rings of the front anchor, and use tensioning equipment to tension and lock the steel strands; Step S23, all front anchors are divided into first front anchors and second front anchors, and all rear anchors are divided into first rear anchors and second rear anchors; Step S3: cable strand connection structure construction and component installation. Step S3 includes: Step S31, casting and constructing the first rotation cable saddle base and the second rotation cable saddle base, and installing the first rotation cable saddle and the second rotation cable saddle; Step S32, casting and constructing the first loose cable saddle base and the second loose cable saddle base, and installing the first loose cable saddle and the second loose cable saddle; Step S33, the first main cable enters the hole, passes through the first cable spreading saddle and then reaches the first cable turning saddle, and is dispersed into a plurality of first cable strands; Step S34, the second main cable enters the hole, passes through the second turning saddle and reaches the second spreading saddle, and is spread into a plurality of second cable strands; Step S35: All first cable strands are connected to the steel strands of the first front anchor, and all second cable strands are connected to the steel strands of the second front anchor.

10. The method for constructing a double-cable single-anchor tunnel anchorage according to claim 9, characterized in that: It also includes: Step S4, anchor protection and maintenance: applying anti-corrosion grease to the surface of the anchor and the exposed steel strand surface, and performing performance monitoring and maintenance during the operation and maintenance phase.

Images