Rock anchor anchorage with anchoring system in horizontal fan-shaped distribution and construction method

Abstract

According to the rock anchor anchorage with the anchoring systems distributed in the horizontal fan shape and the construction method, a cable strand anchoring system and a prestress anchoring system are both arranged in the horizontal fan shape, and an inclined bridge main cable is led into the ground through an inclined hole and is converted into the horizontal direction after passing through a splay cable saddle hoisted upside down; and the cable strands reach the cable scattering chamber through the adit and are scattered into the cable strands which are laid in a fan-shaped mode, the cable strands penetrate through drill holes in the rock stratum to reach the front anchor hole and are tightly connected to the pre-stress anchoring system, and therefore loads are transmitted to the rock stratum to achieve the anchoring effect. The inclined hole and the horizontal hole are adopted as auxiliary channels, the anchoring system is horizontally arranged in a large-range rock stratum in a fan-shaped mode by excavating the fan-shaped anchor hole and the fan-shaped drill hole, and the method has the advantages of being convenient to construct, small in rock stratum damage, high in bearing performance and the like.

Description

Technical Field

[0001] The invention relates to the technical field of bridge engineering, in particular to a rock anchor with a horizontal fan-shaped distribution of an anchoring system and a construction method. Background Art

[0002] Tunnel anchors and rock anchors are the main anchor structures for suspension bridges. Tunnel anchors are formed by excavating anchor holes in the rock layer, pre-buried pipes and pouring concrete, while rock anchors are formed by drilling holes directly in the rock layer. Tunnel anchors and rock anchors have the same body shape, and the axis length of the anchor system that bears the load is generally more than 35m, but the latter has less rock excavation, so it has a better economic advantage.

[0003] The anchoring system of rock anchors includes a strand anchoring system and a prestressed anchoring system. The strand anchoring system spreads the main cable into strands for anchoring. After the strands are connected to the prestressed anchoring system, the load is transferred to the rock layer for bearing. The prestressed anchoring system of traditional rock anchors uses drilling through the rock layer. The holes on the front and rear anchor surfaces are symmetrically and closely arranged with quadrilaterals as the boundaries. The significant defects of this arrangement are as follows: First, the anchor body is long, and the distance between adjacent holes in the prestressed anchoring system is only a few tens of centimeters, which makes the deflection control of the holes extremely strict and the construction process very complicated; second, the holes in the prestressed anchoring system are too dense, which causes great damage to the rock layer during the construction process, weakening the bearing capacity of the anchoring system; third, the rock layer range that can be used by the prestressed anchoring system is not large, and stress concentration easily causes the rock layer to break. These defects restrict the engineering application of rock anchors, and their applicability is poor when the rock layer conditions are poor or the bridge load is large. Summary of the invention

[0004] In view of the defects of the prior art, the present invention provides a rock anchor with a horizontal fan-shaped distribution of an anchoring system and a construction method. The inclined hole and the flat hole are used as auxiliary channels. By excavating fan-shaped anchor holes and fan-shaped drill holes, the anchoring system is horizontally fan-shapedly arranged in a large range of rock strata. It has the characteristics of convenient construction, little damage to rock strata and high bearing capacity.

[0005] A rock anchor with a horizontal fan-shaped distribution of anchoring systems, comprising a cavern, a cable strand anchoring system and a prestressed anchoring system; the cavern comprises an inclined hole, a first flat hole, a loose cable chamber, a front anchor hole and a rear anchor hole; the cable strand anchoring system comprises a main cable, a rotating cable saddle, a loose cable saddle, a cable strand, a pull rod and a first borehole, the first borehole is a passage for the cable strand to pass through the rock layer from the loose cable chamber to the front anchor hole, and the first borehole is arranged in a fan-shaped manner; the prestressed anchoring system comprises a prestressed steel strand, a second borehole, and the second borehole is a prestressed steel strand. The steel bundle passes through the rock layer from the front anchor hole to the passage of the rear anchor hole, and the second borehole is laid out in a fan-shaped manner; the main cable enters the cave from the inclined hole, and after being turned by the turning saddle, it passes through the first horizontal hole to reach the scattered cable room, and is dispersed into cable strands by the scattered cable saddle located at the intersection of the inclined hole and the first horizontal hole. The cable strands pass through the first borehole in turn to reach the front anchor hole, and the anchor head of the cable strand in the front anchor hole is connected to one end of the pull rod, one end of the prestressed steel bundle is connected to the other end of the pull rod, and the other end of the prestressed steel bundle passes through the second borehole to reach the rear anchor hole and is locked.

[0006] Furthermore, the cave chamber also includes a second flat hole, a third flat hole, and a fourth flat hole. The second flat hole is a passage from the first flat hole to the third flat hole, and a passage from the first flat hole to the fourth flat hole. The third flat hole is a passage from the second flat hole to the front anchor hole, and the fourth flat hole is a passage from the second flat hole to the rear anchor hole.

[0007] Furthermore, the front anchor hole provides space for the construction of the prestressed anchor system, serving as a prestressed anchor cavern, cable strand anchor system and prestressed anchor system; the prestressed anchor system is connected in the front anchor hole to transfer the load, the front anchor hole is connected to the third flat hole, and is arranged in a horizontal fan shape; the rear anchor hole serves as the rear anchor surface of the prestressed anchor system, which is the part where the prestressed anchor system load is borne, the rear anchor hole is connected to the fourth flat hole, and is arranged in a horizontal fan shape. Furthermore,

[0008] Furthermore, the inclined hole, the first flat hole, the second flat hole, the third flat hole, the fourth flat hole, the front anchor hole and the rear anchor hole adopt a straight wall semicircular arch section.

[0009] Furthermore, the main cable is turned from an inclined direction to a horizontal direction at the turning saddle, and the deflection angle is less than 25°; a reinforced concrete base is provided on the upper part of the turning saddle, and the turning saddle is inverted and hoisted under the reinforced concrete base.

[0010] Furthermore, the cables of the strands and the cables of the main cable are continuous and uninterrupted, and the strands are dispersedly arranged with a rotation angle of 1° to 2° around the scattered cable saddle.

[0011] Furthermore, the prestressed anchoring system also includes a front anchor surface anchor, an anchor connector, a front anchor surface anchor pad, a rear anchor surface anchor pad and a rear anchor surface anchor; the front anchor surface anchor and the front anchor surface anchor pad are located in the front anchor hole and are used to fix one side of the prestressed steel bundle; the anchor connector is used to connect with the pull rod of the cable strand anchoring system, and the prestressed steel bundle is locked by the front anchor surface anchor after passing through the anchor connector; the rear anchor surface anchor and the rear anchor surface anchor pad are located in the rear anchor hole and are used to fix the other side of the prestressed steel bundle.

[0012] Furthermore, the positions of the first boreholes are constructed one by one using a drilling rig and a first protective pipe is installed, and the gap between the first borehole and the first protective pipe is filled with cement slurry.

[0013] Furthermore, the positions of the second boreholes are constructed one by one using a drilling rig and a second protective pipe is installed, and the gap between the second borehole and the second protective pipe is filled with cement slurry.

[0014] A method for constructing a rock anchor with a horizontal fan-shaped distribution of the anchoring system as described above comprises the following steps:

[0015] S1. Cavern excavation and support

[0016] The cavern includes an inclined cave, a first flat cave, a second flat cave, a third flat cave, a fourth flat cave, a cable room, a front anchor cave and a rear anchor cave; step S1 specifically includes:

[0017] (1) Excavate the inclined tunnel from the ground surface until the supporting inclined tunnel reaches the elevation where the horizontal rock anchor is located, i.e. the starting position of the first horizontal tunnel;

[0018] (2) Excavating the first flat tunnel from the bottom of the inclined tunnel and supporting the first flat tunnel;

[0019] (3) When the first level tunnel is excavated to the second level tunnel, the second level tunnel can be excavated and supported;

[0020] (4) When the excavation of the second level tunnel reaches the third level tunnel, the third level tunnel can be excavated and supported;

[0021] (5) When the second horizontal tunnel is excavated to the bottom, the fourth horizontal tunnel can be excavated and supported;

[0022] (6) When the first horizontal tunnel is excavated to the cable chamber, the cable chamber can be excavated and supported;

[0023] (7) When the third horizontal tunnel is excavated to the front anchor hole, the front anchor hole can be excavated and supported;

[0024] (8) When the fourth level tunnel is excavated to the rear anchor hole, the rear anchor hole can be excavated and supported;

[0025] S2. Civil construction and equipment assembly of cable anchoring system

[0026] Step S2 specifically includes:

[0027] S21. Civil construction of cable anchoring system

[0028] (1) Casting the reinforced concrete base of the saddle;

[0029] (2) Casting the reinforced concrete base of the loose cable saddle;

[0030] (3) In the cable-laying chamber, on the rock wall near the front anchor hole, the positions of all the first boreholes are calibrated using a total station, and the first protective pipes are constructed and installed one by one using a drilling rig, and the gaps between the first boreholes and the first protective pipes are filled with cement slurry;

[0031] S22, Equipment assembly of cable anchoring system

[0032] (1) Install the saddle on its reinforced concrete base;

[0033] (2) Installing the cable saddle on the reinforced concrete base of the cable saddle;

[0034] (3) The main cable enters the cave from the inclined hole, turns at the turning saddle, passes through the first flat hole to reach the cable-scattering room, and is dispersed into cable strands by the cable-scattering saddle. The cable strands pass through the first protective tube in turn to reach the front anchor hole;

[0035] (4) In the front anchor hole, connect the anchor head and the pull rod of the cable strand;

[0036] S3. Civil construction and equipment assembly of prestressed anchor system

[0037] Step S3 specifically includes:

[0038] S31. Civil construction of prestressed anchoring system

[0039] (1) In the front anchor hole, on the rock wall near the rear anchor hole, mark the positions of all the second boreholes, use a drilling rig to construct and install the second protective pipes one by one, and fill the gaps between the second boreholes and the second protective pipes with cement slurry;

[0040] S32. Equipment assembly of prestressed anchoring system

[0041] Taking a single prestressed anchor structure as an example, the installation process is as follows:

[0042] (1) The prestressed steel strand passes through the second protective pipe and reaches the rear anchor hole from the front anchor hole. The anchor surface anchor pad and the rear anchor surface anchor are installed in sequence at the rear of the second protective pipe in the rear anchor hole and locked;

[0043] (2) Install the front anchor surface anchor pad, anchor connector and front anchor surface anchor in sequence at the front part of the second protective pipe of the front anchor hole. The prestressed steel strand passes through the front anchor surface anchor pad, anchor connector and front anchor surface anchor in sequence. Use a jack to tension the prestressed steel strand. After tensioning, immediately lock the front anchor surface anchor.

[0044] (3) The second protective tube is sealed after being injected with anti-corrosion grease;

[0045] S4. Anchor system connection and maintenance

[0046] The tie rods on the cable anchorage system are tightly connected to the anchorage connectors on the prestressed anchorage system to achieve the transfer of the bridge main cable load;

[0047] The surfaces of the front anchor surface anchor and the rear anchor surface anchor, the front anchor surface anchor pad and the front anchor surface anchor pad and the exposed prestressed steel strands are waterproofed with polyurethane waterproof coating.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] 1. The present invention adopts an inverted hoisting saddle to deflect the direction of the main cable. The deflection angle of the main cable is small, and the load transmitted to the base and the rock formation is small, so it is not easy to be compressed and broken, thereby improving the stability of the system.

[0050] 2. The present invention adopts a horizontal fan-shaped distributed anchoring system, so that the front anchor hole and the rear anchor hole can adopt a small-sized section with a width and height of 3m. Compared with the conventional front anchor room and the rear anchor room with a large-sized section with a width and height of more than 10m, it has the advantages of better stability of the cave surrounding rock and less excavation and support engineering.

[0051] 3. The horizontal fan-shaped cables used in the present invention are dispersed by drilling through the rock strata, without the need for a large-scale cable dispersion chamber. The stability of the cave surrounding rock is better, and it has economic advantages such as small excavation and support engineering quantities.

[0052] 4. The present invention adopts a prestressed anchoring system with a horizontal fan-shaped arrangement. The distance between adjacent boreholes is relatively far, and the distance between the bottom of the holes can reach 1.5m or more, which effectively avoids the problem of being unable to install due to drilling construction deviation and can avoid damage to the rock formation caused by drilling construction.

[0053] 5. The present invention adopts a prestressed anchoring system with a horizontal fan-shaped arrangement, which makes full use of a large range of rock strata to bear the load, so it can bear a larger load and has a better bearing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A schematic diagram of the connection between the inclined hole and the flat hole of the rock anchor according to an embodiment of the present invention;

[0055] Figure 2 A schematic diagram of the connection between the inclined rock anchor hole and the front and rear anchor holes according to an embodiment of the present invention;

[0056] Figure 3 A horizontal structural diagram of the main structure of the rock anchor according to an embodiment of the present invention;

[0057] Figure 4 Cross-sectional view of the inclined hole, flat hole and anchor hole in the embodiment of the present invention;

[0058] Figure 5 A cross-sectional view of a cable chamber according to an embodiment of the present invention;

[0059] Figure 6 Schematic diagram of inverted hoisting of a rotating cable saddle according to an embodiment of the present invention;

[0060] Figure 7 A structural diagram of an anchoring system according to an embodiment of the present invention;

[0061] Figure 8 Distribution diagram of anchor plates and anchors in front anchor holes of prestressed anchoring systems according to embodiments of the present invention;

[0062] Fig. 9 Distribution diagram of the anchor plate and anchor of the rear anchor hole of the prestressed anchoring system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0063] 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.

[0064] See also Figure 1-9 An embodiment of the present invention provides a rock anchor with a horizontal fan-shaped distribution of an anchoring system. The rock anchor is constructed in a rock layer 2 below the ground surface 1 and includes a cavern 3, a cable anchoring system 4 and a prestressed anchoring system 5.

[0065] The cavern 3 comprises an inclined hole 31, a first flat hole 32, a second flat hole 33, a third flat hole 34, a fourth flat hole 35, a cable room 36, a front anchor hole 37 and a rear anchor hole 38. Figure 1 , Figure 2 and Figure 3 shown.

[0066] The inclined hole 31 is a passage from the ground surface 1 to the elevation where the horizontal rock anchor is located, and is connected to the first flat hole 32. The inclined hole 31 is a relatively closed space that can protect the main cable strand. The inclined hole 31 can be divided into an open hole and a dark hole according to the situation.

[0067] The first horizontal hole 32 is a passage from the inclined hole 31 to the cable chamber 36 , and a passage from the inclined hole 31 to the second horizontal hole 33 .

[0068] The second flat hole 33 is a passage from the first flat hole 32 to the third flat hole 34 , and a passage from the first flat hole 32 to the fourth flat hole 35 ;

[0069] The third flat hole 34 is a passage from the second flat hole 33 to the front anchor hole 37;

[0070] The fourth flat hole 35 is a passage from the second flat hole 33 to the rear anchor hole 38;

[0071] The cable saddle room 36 is the space where the cable saddle is located, and the main cable 41 is dispersed into cable strands. The cable saddle room 36 is close to the front anchor hole 37 and has an arc-shaped wall. Figure 3 shown.

[0072] The front anchor hole 37 provides a space for the construction of the prestressed anchor system 5, and serves as the front anchor surface of the prestressed anchor system 5. The prestressed steel strand 51 is tensioned and locked here, and the cable strand anchor system 4 is connected to the prestressed anchor system 5 here to transfer the load. The front anchor hole 37 is connected to the third flat hole 34 and is arranged in a horizontal fan shape.

[0073] The rear anchor hole 38 is the rear anchor surface of the prestressed anchor system 5 and is the part where the load of the prestressed anchor system 5 is borne. The rear anchor hole 38 is connected to the fourth flat hole 35 and is arranged in a horizontal fan shape.

[0074] The inclined tunnel 31, the first flat tunnel 32, the second flat tunnel 33, the third flat tunnel 34, the fourth flat tunnel 35, the front anchor tunnel 37 and the rear anchor tunnel 38 adopt straight wall semicircular arch cross-sections, and the tunnel width and height are both 3m. Figure 4 shown.

[0075] The cable chamber 36 is in the form of a rectangular section, with a tunnel width of 8m and a height of 3m. Figure 5 shown.

[0076] See also Figure 2 , Figure 3 , Figure 6 and Figure 7 The cable strand anchoring system 4 includes a main cable 41 , a rotating cable saddle 42 , a loose cable saddle 43 , a cable strand 44 , an anchor head 45 , a pull rod 46 , a first borehole 47 and a first protective tube 48 .

[0077] The main cable 41 is the main load-bearing structure of the suspension bridge. The bridge load is also transmitted to the rock anchor through the main cable 41. The main cable 41 is composed of multiple cables. As a non-replaceable component, it is made of high-strength plated steel wire and covered with a rust-proof sheath.

[0078] The turning cable saddle 42 is located at the intersection of the inclined tunnel 31 and the first flat tunnel 32. The main cable 41 turns from the inclined direction to the horizontal direction here. The deflection angle is generally less than 25°. A reinforced concrete base is provided on the upper part of the turning cable saddle 42. The turning cable saddle 42 is hoisted upside down under the reinforced concrete base. Figure 6 shown.

[0079] The main cable 41 spreads out into strands 44 after passing through the spread saddle 43 .

[0080] The strands 44 are the cables of the main cable 41. The cables of the strands 43 and the main cable 41 are continuous and uninterrupted. The strands 44 are distributed with the saddle 43 as the center and a rotation angle of 1° to 2°. As a non-replaceable component, the strands 43 are made of the same high-strength plated steel wire as the main cable 41 and are covered with a rust-proof sheath. Anchor heads 45 (such as Figure 7 shown).

[0081] One end of the pull rod 46 is connected to the anchor plate on the anchor head 45 of the cable strand 43, and the other end is connected to the anchor connector 53 of the prestressed anchor system 5, so as to realize the connection and load transfer between the cable strand anchor system 4 and the prestressed anchor system 5.

[0082] The first borehole 47 is a passage for the cable strand 44 to pass from the cable chamber 36 through the rock layer 2 to the front anchor hole 37. The first borehole 47 is arranged in a fan-shaped manner, and a first protective pipe 48 is used to protect the wall to maintain the stability of the surrounding rock. The gap between the first protective pipe 48 and the rock layer is filled with cement slurry.

[0083] The prestressed anchor system 5 adopts an anchor structure of a replaceable anchor system to facilitate replacement and maintenance during the bridge operation and maintenance phase. The prestressed anchor system 5 includes a prestressed steel strand 51, a front anchor surface anchor 52a, an anchor connector 53, a front anchor surface anchor pad 54a, a second borehole 55, a second protective pipe 56, a rear anchor surface anchor pad 54b and a rear anchor surface anchor 52b. The structural diagram of the prestressed anchor system 5 is shown in FIG. Figure 7 .

[0084] The prestressed steel strand 51 is the main force transmission structure in the anchoring system. The prestressed steel strand 51 is buried in the second protective pipe 56. The prestressed steel strand 51 adopts non-bonded epoxy-coated steel strands, which can be replaced as a whole strand at a later stage.

[0085] The front anchor surface anchor 52a and the front anchor surface anchor pad 54a are located in the front anchor hole 37 and are the main components for fixing one side of the prestressed steel strand 51. The mechanical anchoring provides the anchoring force. The front anchor surface anchor 52a and the front anchor surface anchor pad 54a are arranged as shown in FIG. Figure 8 shown.

[0086] The anchor connector 53 is used to connect with the pull rod 46 of the cable strand anchor system 4 to achieve load transfer.

[0087] The second borehole 55 is a passage for the prestressed steel strand 51 to pass through the rock layer 2 from the front anchor hole 37 to the rear anchor hole 38. The second borehole 55 is arranged in a fan-shaped manner and the second protective pipe 56 is used to protect the wall to maintain the stability of the surrounding rock. The gap between the second protective pipe 56 and the rock layer 2 is filled with cement slurry. The gap between the prestressed steel strand 51 and the second protective pipe 56 is filled with anti-corrosion grease, which can effectively prevent the corrosion of the prestressed steel strand 51.

[0088] The rear anchor surface anchor 52b and the rear anchor surface anchor pad 54b are located in the rear anchor hole 38 and are the main components for fixing the other side of the prestressed steel strand 51. The mechanical anchoring provides the anchoring force. A rubber gasket can be provided to increase the airtightness. The rear anchor surface anchor 52b and the rear anchor surface anchor pad 54b are distributed as follows: Fig. 9 shown.

[0089] The embodiment of the present invention further provides a method for constructing a rock anchor with a horizontal fan-shaped distribution of an anchoring system, which specifically adopts the following steps:

[0090] S1. Excavation and support of chamber 3

[0091] The cave chamber 3 includes an inclined hole 31 , a first flat hole 32 , a second flat hole 33 , a third flat hole 34 , a fourth flat hole 35 , a cable chamber 36 , a front anchor hole 37 and a rear anchor hole 38 .

[0092] (1) The inclined hole 31 is excavated from the ground surface until the inclined hole 31 is supported to the elevation where the horizontal rock anchor is located, that is, the starting position of the first horizontal hole 32.

[0093] (2) Excavating the first horizontal tunnel 32 from the bottom of the inclined tunnel 31 and supporting the first horizontal tunnel 32 .

[0094] (3) When the first horizontal tunnel 32 is excavated to the second horizontal tunnel 33, the second horizontal tunnel 33 can be excavated and supported.

[0095] (4) When the second horizontal tunnel 33 is excavated to the third horizontal tunnel 34, the third horizontal tunnel 34 can be excavated and supported.

[0096] (5) When the second horizontal tunnel 33 is excavated to the bottom, the fourth horizontal tunnel 35 can be excavated and supported.

[0097] (6) When the first horizontal tunnel 32 is excavated to the cable-scattering chamber 36, the cable-scattering chamber 36 can be excavated and supported.

[0098] (7) When the third horizontal tunnel 34 is excavated to the front anchor hole 37, the front anchor hole 37 can be excavated and supported.

[0099] (8) When the fourth horizontal tunnel 35 is excavated to the rear anchor hole 38, the rear anchor hole 38 can be excavated and supported.

[0100] S2. Cable anchoring system 4 civil construction and equipment assembly

[0101] S21. Civil construction of cable anchoring system 4

[0102] (1) Casting the reinforced concrete base of the cable saddle 42.

[0103] (2) Casting the reinforced concrete base of the loose cable saddle 43.

[0104] (3) In the cable chamber 36, on the rock wall near the front anchor hole 37, the positions of all the first boreholes 47 are calibrated using a total station, and the first protective pipes 48 are constructed and installed one by one using a drilling rig. The gaps between the first boreholes 47 and the first protective pipes 48 are filled with cement slurry.

[0105] S22, Equipment assembly of cable strand anchoring system 4

[0106] (1) The rotating cable saddle 42 is installed on its reinforced concrete base.

[0107] (2) Install the loose cable saddle 43 on its reinforced concrete base.

[0108] (3) The main cable 41 enters the cave through the inclined hole 31, turns at the turning saddle 42, passes through the first flat hole 32 to reach the cable distribution chamber 36, and is dispersed into cable strands 44 by the cable distribution saddle 43. The cable strands 44 pass through the first protective tube 48 in turn to reach the front anchor hole 37.

[0109] (4) In the front anchor hole 37, the anchor head 45 and the pull rod 46 of the cable strand 44 are connected.

[0110] S3. Prestressed anchor system 5 civil construction and equipment assembly

[0111] S31. Civil construction of prestressed anchor system 5

[0112] (1) In the front anchor hole 37, on the rock wall near the rear anchor hole 38, the positions of all the second bore holes 55 are marked, and the second protective pipes 56 are constructed and installed one by one using a drilling rig. The gaps between the second bore holes 55 and the second protective pipes 56 are filled with cement slurry.

[0113] S32, Equipment assembly of prestressed anchoring system 5

[0114] Taking a single prestressed anchor structure as an example, the installation process is as follows:

[0115] (1) The prestressed steel strand 51 passes through the second protective tube 56 and reaches the rear anchor hole 38 from the front anchor hole 37. At the rear of the second protective tube 56 in the rear anchor hole 38, the anchor surface anchor plate 54b and the rear anchor surface anchor 52b are installed in sequence and locked.

[0116] (2) The front anchor surface anchor plate 54a, the anchor connector 53 and the front anchor surface anchor 52a are sequentially installed in the front part of the second protective tube 56 of the front anchor hole 37, and the prestressed steel strand 51 passes through the front anchor surface anchor plate 54a, the anchor connector 53 and the front anchor surface anchor 52a in sequence. The prestressed steel strand 51 is tensioned by a jack, and the front anchor surface anchor 52a is locked immediately after the tensioning is completed.

[0117] (3) The second protective tube 56 is sealed after being injected with anti-corrosion grease.

[0118] S4. Anchor system connection and maintenance

[0119] The pull rod 46 on the cable strand anchoring system 4 is tightly connected to the anchoring connector 53 on the prestressed anchoring system 5 to achieve the transmission of the load of the main cable of the bridge.

[0120] The surfaces of the front anchor surface anchor 52a and the rear anchor surface anchor 52b, the surfaces of the front anchor surface anchor pad 54a and the front anchor surface anchor pad 54b and the exposed prestressed steel strand 51 are waterproofed with polyurethane waterproof coating.

[0121] The cable strand anchoring system and the prestressed anchoring system of the present invention are both arranged in a horizontal fan shape. The inclined main cable of the bridge is introduced into the ground through an inclined hole, turned to a horizontal direction after passing through an inverted hanging cable saddle, and reaches a cable sling chamber through a flat hole and spreads out into cable strands arranged in a fan shape. The cable strands pass through the drilled holes in the rock formation to reach the front anchor hole and are tightly connected to the prestressed anchoring system, thereby transferring the load to the rock formation to achieve an anchoring effect. The prestressed anchoring system can utilize a wide range of rock formations for construction and bearing, and has reliable bearing performance. The present invention avoids the defects of the traditional solution by adjusting the drilling distribution method without changing the drilling length.

[0122] 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 rock anchor with a horizontal fan-shaped anchoring system, comprising a cavern, a cable anchoring system and a prestressed anchoring system; characterized in that: The cave chamber includes an inclined hole, a first horizontal hole, a loose cable chamber, a front anchor hole and a rear anchor hole; the cable strand anchoring system includes a main cable, a rotating cable saddle, a loose cable saddle, a cable strand, a pull rod and a first borehole, wherein the first borehole is a passage for the cable strand to pass through the rock layer from the loose cable chamber to the front anchor hole, and the first borehole is arranged in a fan-shaped manner; the prestressed anchoring system includes a prestressed steel bundle and a second borehole, wherein the second borehole is a passage for the prestressed steel bundle to pass through the rock layer from the front anchor hole to the rear anchor hole, and the second borehole is arranged in a fan-shaped manner; the main cable enters the cave from the inclined hole, is turned by the rotating cable saddle, passes through the first horizontal hole to reach the loose cable chamber, is dispersed into cable strands by the loose cable saddle arranged at the intersection of the inclined hole and the first horizontal hole, and the cable strands pass through the first borehole in turn to reach the front anchor hole, wherein the anchor head of the cable strand is connected to one end of the pull rod, one end of the prestressed steel bundle is connected to the other end of the pull rod, and the other end of the prestressed steel bundle passes through the second borehole to reach the rear anchor hole and is locked.

2. The rock anchor with horizontal fan-shaped distribution of the anchoring system according to claim 1, characterized in that: The cave chamber also includes a second flat hole, a third flat hole, and a fourth flat hole. The second flat hole is a passage from the first flat hole to the third flat hole, and a passage from the first flat hole to the fourth flat hole. The third flat hole is a passage from the second flat hole to the front anchor hole, and the fourth flat hole is a passage from the second flat hole to the rear anchor hole.

3. The rock anchor with horizontal fan-shaped distribution of the anchoring system according to claim 2, characterized in that: The front anchor hole provides space for the construction of the prestressed anchoring system, serving as a prestressed anchoring cavern, a cable strand anchoring system and a prestressed anchoring system; the prestressed anchoring system is connected in the front anchor hole to transfer the load, the front anchor hole is connected to the third horizontal hole, and is arranged in a horizontal fan shape; the rear anchor hole serves as the rear anchor surface of the prestressed anchoring system, is the part where the prestressed anchoring system load is borne, the rear anchor hole is connected to the fourth horizontal hole, and is arranged in a horizontal fan shape.

4. The rock anchor with horizontal fan-shaped distribution of the anchoring system according to claim 2, characterized in that: The inclined hole, the first flat hole, the second flat hole, the third flat hole, the fourth flat hole, the front anchor hole and the rear anchor hole adopt straight wall semicircular arch sections.

5. The rock anchor with horizontal fan-shaped distribution of the anchoring system according to claim 1, characterized in that: The main cable is turned from an inclined direction to a horizontal direction at the turning saddle, and the deflection angle is less than 25 degrees; a reinforced concrete base is provided on the upper part of the turning saddle, and the turning saddle is inverted and hoisted under the reinforced concrete base.

6. The rock anchor with horizontal fan-shaped distribution of the anchoring system according to claim 1, characterized in that: The cables of the strands and the cables of the main cable are continuous and uninterrupted, and the strands are dispersedly arranged with the scattered cable saddle as the center and a rotation angle of 1° to 2°.

7. The rock anchor with horizontal fan-shaped distribution of the anchoring system according to claim 1, characterized in that: The prestressed anchoring system also includes a front anchor surface anchor, an anchor connector, a front anchor surface anchor pad, a rear anchor surface anchor pad and a rear anchor surface anchor; the front anchor surface anchor and the front anchor surface anchor pad are located in the front anchor hole and are used to fix one side of the prestressed steel bundle; the anchor connector is used to connect with the pull rod of the cable strand anchoring system, and the prestressed steel bundle is locked by the front anchor surface anchor after passing through the anchor connector; the rear anchor surface anchor and the rear anchor surface anchor pad are located in the rear anchor hole and are used to fix the other side of the prestressed steel bundle.

8. The rock anchor with horizontal fan-shaped distribution of the anchoring system according to claim 1, characterized in that: The positions of the first boreholes are constructed one by one using a drilling rig and a first protective pipe is installed, and the gap between the first borehole and the first protective pipe is filled with cement slurry.

9. The rock anchor with horizontal fan-shaped distribution of the anchoring system according to claim 1, characterized in that: The positions of the second boreholes are constructed one by one using a drilling rig and a second protective pipe is installed, and the gap between the second borehole and the second protective pipe is filled with cement slurry.

10. A method for constructing a rock anchor with a horizontal fan-shaped distribution of the anchoring system according to any one of claims 1 to 9, characterized in that: The steps include: S1. Cavern excavation and support The cavern includes an inclined cave, a first flat cave, a second flat cave, a third flat cave, a fourth flat cave, a cable room, a front anchor cave and a rear anchor cave; step S1 specifically includes: (1) Excavate the inclined tunnel from the ground surface until the supporting inclined tunnel reaches the elevation where the horizontal rock anchor is located, i.e. the starting position of the first horizontal tunnel; (2) Excavating the first flat tunnel from the bottom of the inclined tunnel and supporting the first flat tunnel; (3) When the first level tunnel is excavated to the second level tunnel, the second level tunnel can be excavated and supported; (4) When the excavation of the second level tunnel reaches the third level tunnel, the third level tunnel can be excavated and supported; (5) When the second horizontal tunnel is excavated to the bottom, the fourth horizontal tunnel can be excavated and supported; (6) When the first horizontal tunnel is excavated to the cable chamber, the cable chamber can be excavated and supported; (7) When the third horizontal tunnel is excavated to the front anchor hole, the front anchor hole can be excavated and supported; (8) When the fourth level tunnel is excavated to the rear anchor hole, the rear anchor hole can be excavated and supported; S2. Civil construction and equipment assembly of cable anchoring system Step S2 specifically includes: S21. Civil construction of cable anchoring system (1) Casting the reinforced concrete base of the saddle; (2) Casting the reinforced concrete base of the loose cable saddle; (3) In the cable-laying chamber, on the rock wall near the front anchor hole, the positions of all the first boreholes are calibrated using a total station, and the first protective pipes are constructed and installed one by one using a drilling rig, and the gaps between the first boreholes and the first protective pipes are filled with cement slurry; S22, Equipment assembly of cable anchoring system (1) Install the saddle on its reinforced concrete base; (2) Installing the cable saddle on its reinforced concrete base; (3) The main cable enters the cave from the inclined hole, turns at the turning saddle, passes through the first flat hole to reach the cable-scattering room, and is dispersed into cable strands by the cable-scattering saddle. The cable strands pass through the first protective tube in turn to reach the front anchor hole; (4) In the front anchor hole, connect the anchor head and the pull rod of the cable strand; S3. Civil construction and equipment assembly of prestressed anchor system Step S3 specifically includes: S31. Civil construction of prestressed anchoring system (1) In the front anchor hole, on the rock wall near the rear anchor hole, mark the positions of all the second boreholes, use a drilling rig to construct and install the second protective pipes one by one, and fill the gaps between the second boreholes and the second protective pipes with cement slurry; S32. Equipment assembly of prestressed anchoring system Taking a single prestressed anchor structure as an example, the installation process is as follows: (1) The prestressed steel strand passes through the second protective pipe and reaches the rear anchor hole from the front anchor hole. The anchor surface anchor pad and the rear anchor surface anchor are installed in sequence at the rear of the second protective pipe in the rear anchor hole and locked; (2) Install the front anchor surface anchor pad, anchor connector and front anchor surface anchor in sequence at the front part of the second protective pipe of the front anchor hole. The prestressed steel strand passes through the front anchor surface anchor pad, anchor connector and front anchor surface anchor in sequence. Use a jack to tension the prestressed steel strand. After tensioning, immediately lock the front anchor surface anchor. (3) The second protective tube is sealed after being injected with anti-corrosion grease; S4. Anchor system connection and maintenance The tie rods on the cable anchorage system are tightly connected to the anchorage connectors on the prestressed anchorage system to achieve the transfer of the bridge main cable load; The surfaces of the front anchor surface anchor and the rear anchor surface anchor, the front anchor surface anchor pad and the front anchor surface anchor pad and the exposed prestressed steel strands are waterproofed with polyurethane waterproof coating.

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