CN111663444A - Suspension bridge tunnel anchor and rock mass anchor combined type anchorage structure and construction method - Google Patents
Suspension bridge tunnel anchor and rock mass anchor combined type anchorage structure and construction method Download PDFInfo
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- CN111663444A CN111663444A CN202010599756.8A CN202010599756A CN111663444A CN 111663444 A CN111663444 A CN 111663444A CN 202010599756 A CN202010599756 A CN 202010599756A CN 111663444 A CN111663444 A CN 111663444A
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- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
- E01D19/00—Structural or constructional details of bridges
- E01D19/14—Towers; Anchors ; Connection of cables to bridge parts; Saddle supports
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- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
- E01D21/00—Methods or apparatus specially adapted for erecting or assembling bridges
Abstract
The invention provides a suspension bridge tunnel anchor and rock mass anchor combined type anchorage structure and a construction method. The composite anchorage structure comprises a main cable access hole arranged in a suspension bridge site area, a cable scattering saddle chamber, a front anchor chamber and a rear anchor chamber which are formed by sequential construction of the main cable access hole, wherein a front anchor solid, an anchor plug body, a rear anchor body and a plurality of anchor cables are arranged between the front anchor chamber and the rear anchor chamber; and the main cable of the suspension bridge is connected with the corresponding anchor cable after being connected into the hole from the main cable and drawn into the cable saddle scattering chamber and then scattered by the cable saddle scattering chamber. The invention enlarges the rock mass bearing range, improves the bearing capacity of the anchorage, can reduce the size of the anchorage hole, and can be suitable for rock masses with poor engineering quality level.
Description
Technical Field
The invention belongs to the technical field of bridge engineering, and relates to a suspension bridge anchorage structure, in particular to a suspension bridge tunnel anchor and rock mass anchor combined type anchorage structure and a construction method.
Background
The conventional suspension bridge anchorage structure mainly comprises a gravity type anchorage, a tunnel type anchorage, a gravity type anchorage (tunnel type anchorage) + a composite anchorage of an anchor cable, a rock mass anchor, a rock mass and reinforced concrete plate type anchorage, a concrete beam type rock anchor and the like. The gravity type anchorage is used in a soft rock foundation, the tension of a main cable is resisted by the friction force between the dead weight and the foundation, the construction amount of earth and stone excavation and concrete is large, and the influence on the ecological environment is also large. Tunnel type anchorages are usually built in harder or complete rock masses, most of the pulling force in the main cable is transmitted to surrounding rocks through anchor bodies, the influence of earth and stone excavation, concrete construction amount and ecological environment on the heavy force type anchorages is small, but the tunnel type anchorages required by bridges loaded by large tonnage are still large, and the tunnel excavation and concrete pouring amount are also large. The similar scale model of tunnel type anchorage draws the experiment and shows that the load is transmitted to the country rock only with the mode of cutting and rubbing through the lateral wall all around of the middle rear portion of anchor body for the major part of main rope pulling force, and about 70% of main rope pulling force is accounted for, and the anchor body bearing capacity can not be improved by a wide margin to extension anchor body, and the country rock self can not fully bear the weight of, and the tunnel type anchorage country rock safety and stability coefficient of building is more than 7, and some reaches 10 ~ 50 even. The combined type anchorage of the tunnel type anchorage and the anchor cable is characterized in that the rear part of the gravity type anchorage or the tunnel type anchorage is additionally provided with the anchor cable to transmit partial load to a rock mass, the output force of the anchor cable and the anchor body is not easy to coordinate, the durability of the anchor cable is difficult to guarantee, and the stress is not uniform.
In order to solve the problems that the output force of an anchor cable and an anchor body is not easy to coordinate and the engineering quantity of earth and stone is large, the patent of the publication No. CN 105648921B discloses a construction method of a suspension bridge rock body and reinforced concrete slab composite anchor. The rock mass anchor, the rock mass and reinforced concrete slab combined type anchorage and the concrete beam type rock anchor need a large number of anchor cables for perforation, so that the integrity of the rock mass is weakened, the anchor is only suitable for I-III rock masses with higher engineering quality grades, the application is less, and the experience is insufficient.
With the needs of national economic development and traffic engineering construction, a suspension bridge with double-layer, dual-purpose use of highway and railway, large span and large tonnage bearing not only can emerge, the tension of a single main cable reaches or exceeds 5 ten thousand tons, and individually or even approaches 10 ten thousand tons, which provides higher requirements for the bearing capacity of an anchorage, and the anchorage is adopted, so that the anchorage quantity or the number of anchor cables must be increased. However, the suspension bridge is limited by lines and landforms, tunnel type anchorages are often required to be built in IV-V rock masses with low engineering quality level, large-span and large-tonnage bridge bearing anchorages with large volume are provided with anchor holes with the height of more than 24m, the hole forming is extremely difficult, great potential safety hazards exist, the hole digging and concrete volume is greatly increased, the investment is huge, the construction period is long, and the risk is high.
Disclosure of Invention
The invention provides a composite anchorage structure of a suspension bridge tunnel anchor and a rock mass anchor and a construction method thereof according to the defects of the prior art, wherein the composite anchorage keeps the bearing characteristic of the traditional tunnel type anchorage body, effectively utilizes the rock mass around the anchorage body, reduces the section size of an anchorage body chamber, reduces the hole digging and concrete amount, correspondingly improves the bearing capacity of the anchorage and reduces the construction cost.
In order to achieve the technical purpose, the technical scheme provided by the invention is a suspension bridge tunnel anchor and rock mass anchor combined type anchorage structure, the combined type anchorage structure comprises a main cable access hole arranged in a suspension bridge site area, a cable scattering saddle chamber, a front anchor chamber and a rear anchor chamber which are formed by sequential construction through the main cable access hole, a front anchor solid, an anchor plug body, a rear anchor body and a plurality of anchor cables are arranged between the front anchor chamber and the rear anchor chamber, the front anchor solid is arranged on the front anchor surface of the anchor plug body, the area of the front anchor solid is larger than that of the front anchor surface of the anchor plug body, the rear anchor body is arranged on the rear anchor surface of the anchor plug body, the area of the rear anchor body is larger than that of the rear anchor plug body, and the plurality of anchor cables penetrate through the anchor plug body and rock mass around the anchor plug body from the front anchor body and are fixed on the rear anchor body through the; main cables of the suspension bridge are connected into the hole from the main cable and are drawn into the cable saddle scattering chamber, and then are scattered into main cable strands with the same number as the anchor cables through the cable saddle scattering chamber, and each main cable strand is connected with the corresponding anchor cable through the anchoring connector.
The further technical scheme of the invention is as follows: the cross section of the anchor plug body is in an urban portal shape, a horseshoe shape or a round shape, and the cross section area of the anchor plug body is gradually increased from the front anchor surface to the rear anchor surface to form a wedge-shaped body with a small front part and a big rear part; the anchor plug body and the rear anchor body form a tunnel anchor, the front anchor body is separated from the anchor plug body, and the front anchor body, the rear anchor body and rock mass around the anchor plug body form a rock mass anchor wrapped outside the tunnel anchor under the action of the anchor cable.
The invention has the following excellent technical scheme: the front anchor body and the rear anchor body are of an integral reinforced concrete structure, the front anchor body is arranged on the periphery of the front anchor surface of the anchor plug body, and the rear anchor body is connected with the anchor plug body through an arc-shaped or hemispherical curved surface body.
The invention has the following excellent technical scheme: backfilling concrete in a region of the front anchor chamber corresponding to the front anchor body and larger than the front anchor surface of the anchor plug body to form a front anchor chamber reinforcing body; the anchor plugs are uniformly distributed in a rock mass between the anchor plug body and the front anchor solid body and the rear anchor body outer edge connecting line on the periphery of the anchor plug body in an annular manner, and form a rock mass anchor wrapped outside the tunnel anchor together with the rock mass on the periphery of the anchor plug body and between the front anchor solid body and the rear anchor body outer edge connecting line; the anchor plug is internally embedded with anchor cable pipes, the front anchor body, the rock mass around the anchor plug body, the rear anchor body and the front anchor chamber reinforcing body are internally provided with anchor cable holes, the anchor cable pipes are arranged in the anchor cable holes, the anchor cable pipes in the rock mass and the anchor cable pipes in the front anchor chamber reinforcing body are connected in the front anchor chamber reinforcing body in a fillet or arc tangent mode, and a plurality of anchor cables penetrate through the anchor plug body and the rock mass around the front reinforcing body and the anchor plug body from the front anchor face and the anchor cable pipes of the front anchor chamber reinforcing body respectively and are fixed on the rear anchor body through an anchor.
The invention has the following excellent technical scheme: the anchor cables penetrate through the anchor cable pipes and the anchor cable holes to the rear anchor chamber and are anchored on the rear anchoring body by using an anchor device, the front ends of the anchor cables in the tunnel anchor are fixed on the front anchor surface of the tunnel anchor by using the anchor device, the anchor cables in the rock mass anchor are fixed on the reinforcing body of the front anchor chamber, and each main cable strand is connected with the corresponding anchor device through an anchoring connector; the front anchor chamber reinforcing body is a reinforcing structure formed by backfilling reinforced concrete after the main cable strands and the anchor cables are connected on the front end face of the front anchor chamber reinforcing body.
In the invention, the resultant force line of the anchor plug body is superposed with the resultant force line of the main cable, and the section resultant force point of the front anchor body and the section resultant force point of the rear anchor body are both on the main cable resultant force line.
The invention provides a construction method of a suspension bridge tunnel anchor and rock mass anchor combined type anchorage structure, which is characterized by comprising the following specific steps of:
(1) determining the position of a front anchor chamber according to a design drawing and construction lofting, excavating a main cable access hole on a single-side or double-side mountain slope of the suspension bridge, and excavating an urban portal-shaped cable saddle scattering chamber, a front anchor solid chamber, an anchor body chamber and a rear anchor chamber by smooth blasting; the size of the anchor body chamber is constructed according to the size of the anchor plug body and the size of the rear anchor body, the front anchor chamber is expanded from the bottom of the cable saddle chamber to be consistent with the width of the front anchor solid chamber, the rear anchor chamber is consistent with the width of the part of the anchor body chamber corresponding to the rear anchor body, and the cross section of the anchor body chamber is in an urban portal shape, a horseshoe shape or a circular shape;
(2) carrying out shotcreting and grouting reinforcement on the broken surrounding rock of the front anchor chamber, carrying out primary shotcreting support on the front anchor solid chamber and the anchor body chamber, grouting local small ducts, erecting a steel arch frame on the surrounding rock section to support the surrounding rock, carrying out shotcreting and grouting reinforcement on the surrounding rock of the rear anchor chamber, and lining a main cable with concrete for connecting the main cable into the hole, the cable saddle chamber, the front anchor chamber and the rear anchor chamber;
(3) after the excavation of the anchor body chamber and the rear anchor chamber is finished and the bottom is cleaned, an anchor cable pipe and a steel bar are accurately positioned and installed in the anchor body chamber, the anchor cable pipe extends to the front anchor surface in a radial straight line mode, and the resultant force point is located in the center of the cable scattering saddle; embedding a grouting pipe between the anchor plug body and the rock contact surface, installing a rear anchor surface template, integrally pouring micro-expansion concrete in a layered mode, vibrating tightly, and curing the concrete to form an integrated anchor body structure consisting of the anchor plug body and a rear anchor body;
(4) according to design drawings and construction layout, indoor reinforcing steel bars of the front anchoring body are manufactured and installed, steel pipes are embedded in drilling positions, concrete is poured, after the strength of the concrete reaches design strength, anchor cable holes are drilled from the embedded steel pipes to the rear anchoring face through a drilling machine, and the rock body is broken and is reinforced through grouting during the process, so that the integrity and the bearing capacity of the rock body are improved.
(5) Installing an anchor cable in the anchor cable hole, installing an anchor cable pipe outside the front anchoring body in the rock mass to a front anchoring chamber, and backfilling a region, corresponding to the front anchoring body, of the front anchoring chamber, which is larger than the front anchoring surface of the anchor plug body by using reinforced concrete to form a front anchoring chamber reinforcing body;
(6) excavating a cable saddle foundation in a cable saddle dispersing chamber, pouring a cable saddle reinforced concrete base, installing a cable saddle after the cable saddle reaches the design strength, drawing a main cable of the suspension bridge, dispersing the cable saddle into main cable strands with the same number as the anchor cables, and connecting the anchor cables with the main cable strands one by using anchor connectors;
(7) after the anchor plug body concrete reaches the design strength, an anchor is installed on the surface of the rear anchor body, the anchor cables are symmetrically stretched from the center anchor cable to the outer ring layer by layer, after a single anchor cable reaches the design load, the single anchor cable is anchored to the anchor plug body by the anchor until all the anchor cables are stretched and anchored, and finally, oil bodies for corrosion prevention and lubrication of the anchor cables are poured into the anchor cable pipes, so that the construction of the composite anchor structure is completed.
The middle part of the composite anchorage is an inverted wedge-shaped anchor plug body with a small front part and a large rear part and an urban door opening-shaped or circular or horseshoe-shaped cross section, the front end surface of the anchor plug body is provided with a front anchor solid with an area larger than that of the front end surface of the anchor plug body, the rear end surface of the anchor plug body is provided with a rear anchor body with an area larger than that of the rear end surface of the anchor plug body, anchor cables are distributed in rock masses around the anchor plug body and the anchor plug body, the front anchor solid is separated from the anchor plug body, the anchor plug body and the rear anchor body are integrally cast with reinforced concrete, a front anchor chamber expanding part outside the front anchor surface of the anchor plug body is filled with the reinforced concrete to form a front anchor chamber reinforcing body, and the front anchor solid, the rear anchor body and the rock masses between the front anchor; the anchorage structure not only keeps the bearing characteristic of the traditional tunnel type anchorage body, but also effectively utilizes the rock mass around the anchor plug body, reduces the size of the section of the anchor hole, reduces the amount of hole excavation and concrete and correspondingly improves the bearing capacity of the anchorage. Compared with the traditional tunnel type anchor body, the combined type anchor has the advantages that the length of the combined type anchor is shorter under the same surrounding rock grade and bearing capacity, the length of a cavern can be shortened, and the section of the cavern is reduced, so that the cavern digging amount and the concrete amount are reduced, the construction cost is reduced, and the construction period is shortened.
Drawings
Figure 1 is a vertical cross-sectional view of a tie back construction of the present invention;
FIG. 2 is a cross-sectional view A-A of FIG. 1;
fig. 3 is a sectional view B-B of fig. 1.
In the figure: the method comprises the following steps of 1-main cable access hole, 2-cable saddle scattering chamber, 3-front anchor chamber, 4-front anchor body, 5-anchor plug body, 6-rear anchor body, 7-rear anchor chamber, 8-main cable, 9-cable saddle scattering, 10-anchor cable, 11-main cable strand, 12-anchor connector, 13-rock mass, 14-anchor device, 15-anchor cable hole, 16-anchor cable pipe and 17-front anchor chamber reinforcement body.
Detailed Description
The following will clearly and completely describe the embodiments of the present invention with reference to the accompanying drawings.
Fig. 1 to 3 are drawings of a composite anchorage structure of a suspension bridge tunnel anchor and a rock mass anchor in the embodiment, which are drawn in a simplified manner and are only used for clearly and concisely explaining the embodiment of the invention. The following claims presented in the drawings are specific to embodiments of the invention and are not intended to limit the scope of the claimed invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it is to be understood that the terms "upper", "lower", "inside", "outside", "left", "right", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, or the orientations or positional relationships that the products of the present invention are conventionally placed in use, or the orientations or positional relationships that are conventionally understood by those skilled in the art, and are used for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.
In the embodiment, the composite anchorage structure of the suspension bridge tunnel anchor and the rock mass anchor is provided, as shown in fig. 1 to 3, and comprises a main cable access hole 1 arranged in a suspension bridge site area, a cable scattering saddle chamber 2, a front anchor chamber 3 and a rear anchor chamber 7 which are formed by sequentially constructing the main cable access hole 1, a front anchor solid 4, an anchor plug body 5, a rear anchor body 6 and a plurality of anchor cables 10 are arranged between the front anchor chamber 3 and the rear anchor chamber 7, the cross section of the anchor plug body 5 is in an urban door hole shape or a horseshoe shape or a circular shape, and the cross section area of the anchor plug body is gradually increased from the front anchor face to the rear anchor face to form a wedge-shaped body with a small front part and a large rear part; the front anchor solid 4 is arranged on the front anchor surface of the anchor plug body 5, the area of the front anchor solid is larger than that of the front anchor surface of the anchor plug body 5, the rear anchor body 6 is arranged on the rear anchor surface of the anchor plug body 5, the area of the rear anchor body is larger than that of the rear anchor surface of the anchor plug body 5, the cross sections of the front anchor solid 4 and the rear anchor body 6 are the same as that of the anchor plug body 5, and the contact surface of the rear anchor body 6 and the anchor plug body 5 is an arc-shaped or hemispherical curved surface body. The anchor plug body 5 and the rear anchor body 6 are of an integrated reinforced concrete structure to form a tunnel anchor, the front anchor solid 4 is arranged on the periphery of the front side of the front anchor surface of the anchor plug body 5, and concrete is backfilled in a region of the front anchor chamber 3 corresponding to the front anchor solid 4 larger than the front anchor surface of the anchor plug body 5 to form a front anchor chamber reinforcing body 17; a plurality of anchor cables 10 respectively penetrate through the anchor plug body 5 and rock bodies 13 around the front reinforcing body 4 and the anchor plug body 5 from the front anchor face and the anchor cable pipe 16 of the front anchor chamber reinforcing body 17 and then are fixed on the rear anchoring body 6 through an anchorage device 14, the front ends of the anchor cables 10 in the tunnel anchor are fixed on the front anchor face of the tunnel anchor through the anchorage device, and the anchor cables 10 in the rock anchor are fixed on the front anchor chamber reinforcing body 17. A plurality of anchor cables 10 are uniformly distributed in an annular shape in the anchor plug body 5 and the rock mass 13 between the front anchor solid 4 on the periphery of the anchor plug body 5 and the outer edge connecting line of the rear anchor body 6, and form a rock mass anchor with the rock mass 13 between the front anchor solid 4 on the periphery of the anchor plug body 5 and the outer edge connecting line of the rear anchor body 6; the anchor cables distributed in the anchor plug body 5 penetrate through anchor cable pipes pre-installed in the anchor plug body 5, the anchor cables distributed in a rock body 13 on the periphery of the anchor plug body 5 penetrate through anchor cable pipes 16 pre-drilled in anchor cable holes 15 in the rock body 13, the front ends of the anchor cables 10 are fixed on the front end face of the front anchor body 4 through anchors 14 respectively, the anchor cables 10 in the rock body 13 penetrate through the anchor cable pipes 16 in the front anchor chamber reinforcing body 17, and the anchor cable pipes 16 in the rock body and the anchor cable pipes 16 in the front anchor chamber reinforcing body 17 are connected in the front anchor chamber reinforcing body 17 in a fillet or arc tangent mode. Main cables 8 of the suspension bridge are led into the cable saddle scattering chamber 2 from the main cable access hole 1 and then are scattered into main cable strands 11 with the same number as the anchor cables 10 through the cable saddle scattering 9, and each main cable strand 11 is connected with the corresponding anchor cable 10 through the anchoring connector 12. The resultant force line of the anchor plug body 5 is superposed with the resultant force line of the main cable 8, and the cross section resultant force point of the front anchor body 4 and the cross section resultant force point of the rear anchor body 6 are both on the resultant force line of the main cable 8.
The construction method of the suspension bridge tunnel anchor and rock mass anchor combined type anchorage structure in the invention is described in detail below by combining a concrete engineering example, wherein the example comprises combined type anchorages arranged on mountains on one side or two sides of a suspension bridge. The engineering geological conditions and the physical and mechanical parameters of the rock mass and the concrete are as follows: the method comprises the following steps of 1, slicing rock, weak weathering to strong weathering, poor rock integrity, crushing to breaking, no development of underground water, no controllability and adverse structural plane, wherein the quality level of rock engineering is mostly IV level, and the local part is V level; the severe gamma of the rock mass is 2.48g/cm3Saturated uniaxial compressive strength R of rock massc15-30 MPa, and the average value E of the deformation modulus of the rock masso7.5MPa, Poisson ratio mu of 0.27, and allowable bearing capacity [ f ] of rock massa]0.75MPa, 0.85 f 'of rock shearing strength, 0.55MPa of c and 0.45 f of shearing strength, 0.75 f' of rock and concrete shearing strength, 0.50MPa of c and 0.40 f of shearing strength, and 2.7 × 10 of single main cable5kN, 109 main cable strands, 127 strands, galvanized high-strength steel wires: diameter phi 5mm, standard strength Rj bThe construction is carried out by the PPWS method under 1960 MPa. Anchor body concrete: design designation C40, micro-expanded; the number of the anchor cable pipes is 109, the anchor cable pipes are all seamless steel pipes, the inner diameter of each pipe is phi 12cm, and the quality of each anchor cable pipe is Q345.
Anchorage structural style and size: main cable access section length 25m, scattered cable saddle room length 5m, city portal shape: width × height ═ 7m × 8 m; the anchor plug body is in an urban portal shape and has the length of 45m (including the length of the rear anchor body of 5 m); the front anchor chamber is shaped like an urban cave and is 10m long; front anchor surface: the tunnel is of an urban portal shape, and the width x the height is 6m x 8m (the corresponding tunnel anchor surface is of an urban portal shape, and the width x the height is 7.8m x 9.8 m); a rear anchor chamber: 2.5m in length; rear anchor: the thickness of the curved surface body is 8.71m, the width of the curved surface body is 16.24m multiplied by 18.24m, the radius of the curved surface body is 9.12m, and the radius of a circular arc tangent to the side surface of the anchor plug body and the curved surface is 2.00 m; front anchor solid: the thickness is 3m, the shape of an urban portal is 14m multiplied by 16 m; the angle between the combined force line of the main cable and the anchor body and the horizontal plane is 37 degrees.
The concrete construction steps are as follows:
(1) determining the position of a front anchor chamber according to a design drawing and construction lofting, excavating a main cable access hole 1 on a single-side or double-side mountain slope of the suspension bridge, and excavating an urban portal-shaped cable saddle scattering chamber 2, a front anchor chamber 3, a front anchor solid chamber, an anchor body chamber and a rear anchor chamber 7 through smooth blasting; the size of the anchor body chamber is constructed according to the size of the anchor plug body and the size of the rear anchor body, the front anchor chamber is expanded from the bottom of the cable saddle chamber to be consistent with the width of the front anchor solid chamber, the rear anchor chamber is consistent with the width of the part of the anchor body chamber corresponding to the rear anchor body, and the cross section of the anchor body chamber is in an urban portal shape, a horseshoe shape or a circular shape; carrying out shotcreting and grouting reinforcement on broken surrounding rocks of the front anchor chamber 3, carrying out primary shotcreting support on an anchor plug body chamber, carrying out grouting on local small guide pipes, erecting a steel arch frame on a surrounding rock section to support the surrounding rocks, carrying out shotcreting and grouting reinforcement on the surrounding rocks of the rear anchor chamber 7, and lining a main cable access hole 1, a cable saddle chamber 2, the front anchor chamber 3 and the rear anchor chamber 7 with concrete;
(2) after the excavation of the anchor body chamber 5 and the rear anchor body 5 is finished and the bottom is cleaned, 27 anchor cable pipes 16 and steel bars are accurately positioned and installed in the rear anchor body 5 and the anchor plug chamber 5, the anchor cable pipes 16 extend to the front anchor surface in a radial straight line mode, and the resultant force point is located in the center of the cable scattering saddle 9. The grouting pipe is embedded between the contact surface of the anchor plug body 5 and the rock body 13, the rear anchor surface template is installed, the micro-expansion concrete is integrally poured in a layered mode, the vibration is dense, and the concrete is maintained to form the integrated anchor plug body consisting of the anchor plug body 5 and the rear anchor body 6.
(3) According to design drawings and construction layout, steel bars are arranged in the front anchoring body 4, a steel pipe with the pipe inner diameter phi of 15cm is embedded in a drilling position, holes with the number of 82 are formed, concrete is poured, after the concrete strength reaches the design strength, anchor cable holes 13 are drilled from the embedded steel pipe to the rear anchoring surface through a drilling machine, the rock is crushed and broken in the process, and rock with poor integrity is subjected to grouting reinforcement, so that the integrity and the bearing capacity of the rock are improved.
(4) Installing anchor cables 10 in the anchor cable holes 13, installing anchor cable pipes in the rock body outside the front anchor bodies 4 of the anchor cables 10 to the front anchor chamber 3, and then filling enlarged parts of the front anchor chamber 3 with reinforced concrete to form front anchor chamber reinforcing bodies 17.
(5) Excavating a scattered cable saddle 9 foundation in the scattered cable saddle chamber 2, pouring a scattered cable saddle 9 reinforced concrete base, installing the scattered cable saddle 9 after the designed strength is reached, then drawing in a suspension bridge main cable 8, dispersing the suspension bridge main cable into 109 main cable strands 11 through the scattered cable saddle 9, and connecting the anchor cables 10 with the main cable strands 11 one by one in a one-to-one correspondence mode by using anchoring connectors;
(6) after the concrete of the anchor plug body 5 reaches the design strength, a P-shaped anchor is arranged on the surface of the rear anchoring body 6, the anchor cables are symmetrically stretched towards the outer ring layer by layer from the center anchor cable, after a single anchor cable reaches the design load, the single anchor cable is anchored on the anchor plug body by an anchor 14 until all the anchor cables are stretched and anchored, and finally, oil bodies for corrosion prevention and lubrication of the anchor cables are poured into the anchor cable pipes 16.
In the anchorage in the embodiment, the anchorage plug body with a smaller section size is wrapped by the rock mass, the anchorage plug body is separated from the front anchorage body, the bearing mechanism of the traditional tunnel anchor is reserved, meanwhile, under the action of the rear anchorage body which is large in area and is an arc-shaped body, the tunnel anchor and the rock mass anchor can bear in a synergic mode, the bearing area of the anchorage plug is increased by the outer edge part of the rear anchorage body, the stress diffusion effect of the arc-shaped body overcomes the limitation that the plate (beam) type anchorage only utilizes the rock mass right in front to bear, the stress concentration of surrounding rocks is reduced, and the bearing range of the surrounding rocks is further expanded. The composite anchorage can be built in surrounding rock with poor lithology, although a large number of anchor cables are drilled, the amount of concrete is less compared with that of anchor holes dug in traditional tunnels, the construction cost is low, the construction period is short, and the construction risk is low.
The above description is only one embodiment of the present invention, and the description is specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.
Claims (6)
1. The utility model provides a suspension bridge tunnel anchor and rock mass anchor combined type anchorage structure which characterized in that: the composite anchorage structure comprises a main cable access hole (1) arranged in a bridge site area of a suspension bridge, a scattered cable saddle chamber (2), a front anchor chamber (3) and a rear anchor chamber (7) which are formed by sequentially constructing the main cable access hole (1), a front anchor solid (4), an anchor plug body (5), a rear anchor body (6) and a plurality of anchor cables (10) are arranged between the front anchor chamber (3) and the rear anchor chamber (7), the front anchor solid (4) is arranged on the front anchor surface of the anchor plug body (5), the area of the front anchor solid is larger than that of the front anchor surface of the anchor plug body (5), the rear anchor body (6) is arranged on the rear anchor surface of the anchor plug body (5), the area of the rear anchor solid is larger than that of the rear anchor surface of the anchor plug body (5), and the plurality of anchor cables (10) pass through rock masses (5) and (13) around the anchor plug body (5) from the front anchor body (4) and are fixed on the rear anchor body (6) through an anchorage device (14); main cables (8) of the suspension bridge are led into the cable-scattering saddle chamber (2) from the main cable access hole (1) and then are scattered into main cable strands (11) with the same number as the anchor cables (10) through the cable-scattering saddle (9), and each main cable strand (11) is connected with the corresponding anchor cable (10) through the anchoring connector (12).
2. The suspension bridge tunnel anchor and rock mass anchor combined type anchorage structure of claim 1, characterized in that: the cross section of the anchor plug body (5) is in an urban portal shape, a horseshoe shape or a circular shape, and the cross section area of the anchor plug body is gradually increased from the front anchor surface to the rear anchor surface to form a wedge-shaped body with a small front part and a large rear part; the anchor plug body (5) and the rear anchor body (6) form a tunnel anchor, the front anchor body (4) is separated from the anchor plug body (5), and the front anchor body, the rear anchor body (6) and rock mass (13) around the anchor plug body (5) form a rock mass anchor wrapped outside the tunnel anchor under the action of the anchor cable (10).
3. The suspension bridge tunnel anchor and rock mass anchor combined type anchorage structure of claim 1 or 2, characterized in that: the cross sections of the front anchor body (4) and the rear anchor body (6) are the same as the cross section of the anchor plug body (5), the anchor plug body (5) and the rear anchor body (6) are of an integrated reinforced concrete structure, the front anchor body (4) is arranged around the front side of the front anchor surface of the anchor plug body (5), and the rear anchor body (6) is connected with the anchor plug body (5) through an arc-shaped or hemispherical curved surface body.
4. The suspension bridge tunnel anchor and rock mass anchor combined type anchorage structure of claim 2, characterized in that: backfilling concrete in a region of the front anchor chamber (3) corresponding to the front anchor solid (4) and larger than the front anchor surface of the anchor plug body (5) to form a front anchor chamber reinforcing body (17); the anchor cables (10) are uniformly distributed in an annular shape in a rock mass (13) between the anchor plug body (5) and the outer edge connecting lines of the front anchor body (4) and the rear anchor body (6) on the periphery of the anchor plug body (5), and form a rock mass anchor wrapped outside the tunnel anchor with the rock mass (13) on the periphery of the anchor plug body (5) and between the front anchor body (4) and the outer edge connecting lines of the rear anchor body (6); anchor cable pipes (16) are pre-buried in the anchor plug body (5), anchor cable holes (15) are formed in the front anchor body (4), rock mass (13) around the anchor plug body (5), the rear anchor body (6) and the front anchor chamber reinforcing body (17), the anchor cable pipes (16) are installed in the anchor cable holes (15), the anchor cable pipes (16) in the rock mass (13) and the anchor cable pipes (16) in the front anchor chamber reinforcing body (17) are connected in the front anchor chamber reinforcing body (17) in a fillet or arc tangent mode, and a plurality of anchor cables (10) penetrate through the anchor plug body (5) and the rock mass (13) around the front anchor body (4) and the anchor plug body (5) respectively and then are fixed on the rear anchor body (6) through the anchor (14).
5. The suspension bridge tunnel anchor and rock mass anchor combined type anchorage structure of claim 2, characterized in that: the anchor cables (10) penetrate through the anchor cable pipes and the anchor cable holes to the rear anchor chamber (7) and are anchored on the rear anchoring body (6) through anchor devices, the front ends of the anchor cables (10) in the tunnel anchor are fixed on the front anchor surface of the tunnel anchor through anchor devices (14), the anchor cables (10) in the rock anchor are fixed on the front anchor chamber reinforcing body (17), and each main cable strand (11) is connected with the corresponding anchor device (14) through an anchoring connector (12); the front anchor chamber reinforcing body (17) is a reinforcing structure formed by backfilling reinforced concrete after the main cable strands (11) and the anchor cables (10) are connected on the front end face of the front anchor body (4).
6. A construction method of a suspension bridge tunnel anchor and rock mass anchor combined type anchorage structure is characterized by comprising the following specific steps:
(1) determining the position of a front anchor chamber according to a design drawing and construction lofting, excavating a main cable access hole on a single-side or double-side mountain slope of the suspension bridge, and excavating an urban portal-shaped cable saddle scattering chamber, a front anchor solid chamber, an anchor body chamber and a rear anchor chamber by smooth blasting; the size of the anchor body chamber is constructed according to the size of the anchor plug body and the size of the rear anchor body, the front anchor chamber is expanded from the bottom of the cable saddle chamber to be consistent with the width of the front anchor solid chamber, the rear anchor chamber is consistent with the width of the part of the anchor body chamber corresponding to the rear anchor body, and the cross section of the anchor body chamber is in an urban portal shape, a horseshoe shape or a circular shape;
(2) carrying out shotcreting and grouting reinforcement on the broken surrounding rock of the front anchor chamber, carrying out primary shotcreting support on the front anchor solid chamber and the anchor body chamber, grouting local small ducts, erecting a steel arch frame on the surrounding rock section to support the surrounding rock, carrying out shotcreting and grouting reinforcement on the surrounding rock of the rear anchor chamber, and lining a main cable with concrete for connecting the main cable into the hole, the cable saddle chamber, the front anchor chamber and the rear anchor chamber;
(3) after the excavation of the anchor body chamber and the rear anchor chamber is finished and the bottom is cleaned, an anchor cable pipe and a steel bar are accurately positioned and installed in the anchor body chamber, the anchor cable pipe extends to the front anchor surface in a radial straight line mode, and the resultant force point is located in the center of the cable scattering saddle; embedding a grouting pipe between the anchor plug body and the rock contact surface, installing a rear anchor surface template, integrally pouring micro-expansion concrete in a layered mode, vibrating tightly, and curing the concrete to form an integrated anchor body structure consisting of the anchor plug body and a rear anchor body;
(4) according to design drawings and construction layout, indoor reinforcing steel bars of the front anchoring body are manufactured and installed, steel pipes are embedded in drilling positions, concrete is poured, after the strength of the concrete reaches design strength, anchor cable holes are drilled from the embedded steel pipes to the rear anchoring face through a drilling machine, and the rock body is broken and is reinforced through grouting during the process, so that the integrity and the bearing capacity of the rock body are improved.
(5) Installing an anchor cable in the anchor cable hole, installing an anchor cable pipe outside the front anchoring body in the rock mass to a front anchoring chamber, and backfilling a region, corresponding to the front anchoring body, of the front anchoring chamber, which is larger than the front anchoring surface of the anchor plug body by using reinforced concrete to form a front anchoring chamber reinforcing body;
(6) excavating a cable saddle foundation in a cable saddle dispersing chamber, pouring a cable saddle reinforced concrete base, installing a cable saddle after the cable saddle reaches the design strength, drawing a main cable of the suspension bridge, dispersing the cable saddle into main cable strands with the same number as the anchor cables, and connecting the anchor cables with the main cable strands one by using anchor connectors;
(7) after the anchor plug body concrete reaches the design strength, an anchor is installed on the surface of the rear anchor body, the anchor cables are symmetrically stretched from the center anchor cable to the outer ring layer by layer, after a single anchor cable reaches the design load, the single anchor cable is anchored to the anchor plug body by the anchor until all the anchor cables are stretched and anchored, and finally, oil bodies for corrosion prevention and lubrication of the anchor cables are poured into the anchor cable pipes, so that the construction of the composite anchor structure is completed.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN112681132A (en) * | 2020-11-18 | 2021-04-20 | 中交一公局集团有限公司 | Positioning support of suspension bridge prestressed anchoring system and construction method |
| CN113700513A (en) * | 2021-08-03 | 2021-11-26 | 武汉科技大学 | Combined type tunnel anchorage structure |
| CN114922085A (en) * | 2022-06-09 | 2022-08-19 | 湖南科技大学 | Assembly type tunnel anchor system and construction method |
| CN116657506A (en) * | 2023-07-27 | 2023-08-29 | 中国建筑第六工程局有限公司 | Method for arranging cable crane gravity anchors of highway and rail dual-purpose suspension bridge in deep soil layer |
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2020
- 2020-06-28 CN CN202010599756.8A patent/CN111663444A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112681132A (en) * | 2020-11-18 | 2021-04-20 | 中交一公局集团有限公司 | Positioning support of suspension bridge prestressed anchoring system and construction method |
| CN113700513A (en) * | 2021-08-03 | 2021-11-26 | 武汉科技大学 | Combined type tunnel anchorage structure |
| CN114922085A (en) * | 2022-06-09 | 2022-08-19 | 湖南科技大学 | Assembly type tunnel anchor system and construction method |
| CN116657506A (en) * | 2023-07-27 | 2023-08-29 | 中国建筑第六工程局有限公司 | Method for arranging cable crane gravity anchors of highway and rail dual-purpose suspension bridge in deep soil layer |
| CN116657506B (en) * | 2023-07-27 | 2023-11-14 | 中国建筑第六工程局有限公司 | Method for arranging cable crane gravity anchors of highway and rail dual-purpose suspension bridge in deep soil layer |
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