CN107165186A - A kind of power transmission tower single anchor cable mat foundation and construction method - Google Patents

Abstract

The invention discloses a single-anchor cable slab foundation for a power transmission tower, which includes a load-bearing plate, an anchor hole, a prestressed anchor cable and concrete filled in the anchor hole. The prestressed anchor cable includes a steel strand, a telescopic anchor, a steel pipe sleeve and The steel cable and the telescopic anchor include an upper connecting plate, a lower connecting plate, a spring connecting the upper connecting plate and the lower connecting plate, and at least two sets of connecting rod assemblies. The connecting rod assemblies are symmetrically arranged on both sides of the upper connecting plate. The anchor cable resists the vertical downward pressure, horizontal force and uplift force given by the transmission tower, reduces the size of the anchor hole, reduces the amount of undisturbed soil excavation and spoil, and reduces the impact of large-scale excavation on the environment. The invention also provides a single-anchor cable-slab foundation construction method for transmission towers, which has a high degree of mechanization during construction, shortens the construction period, improves construction efficiency, and reduces construction costs.

Description

Single-anchor cable-slab foundation and construction method for transmission tower

technical field

The invention belongs to the field of transmission tower foundations, in particular to a single-anchor cable-slab foundation for transmission towers.

Background technique

At present, in areas with thick overburden, traditional transmission line foundations are mainly used, such as "big excavation", "excavation and bottom expansion", "cast-in-situ piles" and other foundations, but these traditional foundations have defects, and large excavation The excavation area of the foundation is large and occupies a lot of land; the construction of the excavated foundation is relatively difficult; the cost of the cast-in-situ pile foundation is relatively high.

The underground part of the traditional foundation occupies a large space. When there are high constraints on the occupied space of the underground part of the foundation, due to the limitation of the calculation model of the conventional slab foundation, the area of the large underground slab is often large, and it is easy to fail to meet the application conditions; Although the cast-in-situ pile foundation covers a much smaller area, for areas with high environmental requirements or inconvenient transportation, when using cast-in-place pile foundations, due to the limitation of construction technology, there are certain requirements for the site and transportation conditions, often due to inability to quickly A good solution will cause environmental pollution.

The traditional foundation mainly relies on the whole foundation to resist the uplift force, downward pressure and horizontal force, but when resisting a certain control load, the local part of the traditional foundation is often not stressed or the force is small, resulting in waste of materials, increasing the cost of the foundation, and making Traditional foundations are more expensive.

Contents of the invention

The technical problem to be solved by the present invention is to provide a single-anchor cable-slab foundation for transmission towers which is convenient for construction.

In order to solve the above technical problems, the present invention adopts the following technical solutions: a single-anchor cable slab foundation for a power transmission tower, including a load-bearing plate, an anchor hole located below the load-bearing plate, and a prestressed anchor fixed in the anchor hole through the load-bearing plate cable and concrete filled in the anchor hole, the prestressed anchor cable includes steel strands passing through the load-bearing plate, telescopic anchors connected to the bottom of the steel strands, steel pipe sleeves sleeved outside the telescopic anchors, and steel pipe sleeves that pull the steel pipe sleeves to move up and down The steel cable and the telescopic anchor include an upper connecting plate, a lower connecting plate, a spring connecting the upper connecting plate and the lower connecting plate, and at least two sets of connecting rod assemblies. The connecting rod assemblies are arranged symmetrically on both sides of the upper connecting plate. The connecting rod and the lower connecting rod, the upper connecting rod and the lower connecting rod are respectively hinged with the upper connecting plate and the lower connecting plate.

Further, the load-bearing plate is provided with communication holes for steel strands and steel cables to pass through, and the upper end of the load-bearing plate is provided with a fixed plate, and at least three through holes communicated with the communication holes are arranged on the fixed plate, and the steel strands and steel cables Pass through different through holes respectively.

Further, the through hole is rounded and truncated, and a split wedge-shaped chuck for clamping the steel strand or steel cable is fixed in the through hole.

Further, there are two steel cables, the lower ends of the two steel cables are provided with suspension rings, and the upper ends of the steel pipes are symmetrically provided with two hooks respectively matched with the suspension rings.

Further, the through holes include a fixing hole arranged in the center of the fixing disc for the steel strand to pass through, pulling holes and ventilation holes on both sides of the fixing hole for the steel cable to pass through.

Further, the steel strand is connected to the upper connecting plate through a wedge-shaped clamp.

Further, the load-bearing plate is a reinforced concrete structure, including several cross-set steel plates and concrete wrapped outside the steel plates.

Further, the four corners of the load-bearing plate are provided with screw holes, and the internal threads of the screw holes are connected with anchor bolts.

Further, there are four sets of connecting rod assemblies, and the four sets of connecting rod assemblies are centrally symmetrical.

The present invention also provides a construction method for a single-anchor cable slab foundation for a power transmission tower, the steps are as follows:

(1) Dig a foundation pit for placing the load-bearing plate on the selected ground, drill the anchor hole vertically downward at the bottom of the foundation pit, and use reaming equipment to ream the bottom of the anchor hole into a spherical shape;

(2) Connect the upper connecting plate and the steel strand, and put the prestressed anchor cable sleeved on the outside of the telescopic anchor into the anchor hole;

(3) Use support rods and other instruments to extend into the anchor hole to resist the top of the upper connecting plate, pull the steel cable upward, and the steel cable drives the steel pipe sleeve to move upward, so that the telescopic anchor protrudes from the steel pipe sleeve in the spherical hole at the bottom of the anchor hole. And expand outward, and then take out the support rod;

(4) Inject concrete into the anchor hole, so that the concrete in the anchor hole and the prestressed anchor cable are condensed into one;

(5) Place a steel plate in the foundation pit and pour concrete to form a bearing plate;

(6) Place the fixed plate on the top of the condensed load-bearing plate, and use the split wedge chuck to lock the steel strand and the steel cable on the fixed plate.

Compared with prior art, the beneficial effect of the present invention is:

1. Dig a foundation pit for the load-bearing plate on the selected ground, drill the anchor hole vertically downward at the bottom of the foundation pit, use reaming equipment to expand the bottom of the anchor hole into a spherical shape, and connect the steel pipe sleeve to the telescopic The prestressed anchor cable on the outer side of the anchor is put into the anchor hole. At this time, the connecting rod assembly is against the inner wall of the steel pipe sleeve, the lower connecting plate is pushed by the hinged upper connecting rod and lower connecting rod, and the spring between the upper connecting plate and the lower connecting plate Pulled by the lower connecting plate, it is in a stretched state; use support rods and other instruments to extend into the anchor hole to resist the top of the upper connecting plate, pull the steel cable upward, and the steel cable drives the steel pipe sleeve to move upward, so that the telescopic anchor is at the bottom of the anchor hole. The steel pipe sleeve protrudes from the spherical hole, and the spring retracts, driving the lower connecting plate to move in the direction of the upward connecting plate, so that the hinged upper and lower connecting rods expand outward, then take out the support rod, inject concrete into the anchor hole, and make the anchor The concrete in the hole and the prestressed anchor cable are condensed into one, and the steel plate is placed in the foundation pit and concrete is poured to form a load-bearing slab, and a fixed plate is placed on the top of the condensed load-bearing slab, and the steel strand and The steel cable is locked on the fixed plate; the load-bearing plate resists the vertical downward pressure, horizontal force and bending moment given by the transmission tower, and prevents the foundation from lateral slipping and overturning. The lower part of the load-bearing plate wraps the concrete sphere of the telescopic anchor Using the underground expansion structure to resist the uplift force of the transmission tower due to factors such as wind loads can make the upper transmission tower have better resistance to dynamic loads. The spring-type telescopic anchor structure can be freely expanded and expanded, which is convenient for transportation and construction. Prestressed anchors The cable mainly transmits the uplift force. Such a prestressed anchor cable has clear foundation load transmission and clear foundation force, which reduces the size of the anchor hole, reduces the amount of undisturbed soil excavation and spoil, and reduces the impact of large-scale excavation on the environment. damage, thereby protecting the ecological environment; at the same time, the high degree of mechanization of the foundation construction makes the construction period short, improves the construction efficiency, and reduces the construction cost.

2. The steel strand and the load-bearing plate are connected through the fixed plate, which increases the contact area between the steel strand and the load-bearing plate to prevent excessive stress concentration. Through the holes, the steel strands and cables are fixed in different through holes.

3. The split-type wedge-shaped chuck is convenient for clamping the steel strand and the steel cable. The wedge-shaped chuck has a self-locking function in the process of clamping the steel strand, which is not easy to cause slippage. At the same time, the wedge-shaped chuck effectively prevents the wire rope from Wear and tear on the fixed disc; the rounded truncated through-hole and the wedge-shaped chuck cooperate to fix the wedge-shaped chuck in the through-hole to prevent the wedge-shaped chuck from slipping.

4. Two symmetrical hooks on both sides of the steel strand cooperate with the lifting rings, so that when the steel cable lifts the steel pipe sleeve, both sides of the steel pipe sleeve are pulled, the force is more uniform, and the pulling of the steel pipe sleeve is more convenient and labor-saving.

5. The through hole includes a fixing hole set in the center of the fixing plate for the steel strand to pass through, a pulling hole and a ventilation hole on both sides of the fixing hole for the steel cable to pass through, and the ventilation hole makes the moist gas in the concrete under the fixing plate free. Discharge in time to prevent the concrete from being too wet and affecting the strength of the concrete.

6. The steel strand is connected to the upper connecting plate through the wedge-shaped chuck, so that the fixed position of the steel strand and the upper connecting plate can be installed, and the installation is more convenient. At the same time, different sizes can be connected to the steel strand according to different sizes of anchor holes. The telescopic anchor has a wider range of application.

7. The load-bearing plate is a reinforced concrete structure. The rigidity of the steel plate is large, so that the strength of the load-bearing plate is high. The concrete is poured outside the steel plate to protect the steel plate, so that the durability and fire resistance of the load-bearing plate are obviously better than those of pure steel structure. The load-bearing plate can give full play to the physical and mechanical properties of the steel plate and concrete, save materials and reduce the cost.

8. By installing the anchor bolts at the four corners of the load-bearing plate, the load-bearing plate can bear more uniform force when it bears the downward pressure and the uplift force, and prevents the load-bearing plate from being damaged by uneven force.

9. There are four sets of connecting rod assemblies, and the four sets of connecting rod assemblies are symmetrical about the center of the spring, so that the connecting rod assemblies extend from four directions to the anchor hole, so that after pouring concrete, the telescopic anchor is wrapped in all directions. The force is more even.

Compared with the prior art, the present invention resists the vertical downward pressure, horizontal force, bending moment and uplift force given by the transmission tower through the load-bearing plate and the prestressed anchor cable, thereby reducing the size of the anchor hole and reducing the original state. The amount of soil excavation and spoil volume can reduce the damage caused by large-scale excavation to the environment, thereby protecting the ecological environment. At the same time, the degree of mechanization during construction is high, which makes the construction period short, improves construction efficiency, and reduces construction costs.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and specific embodiment:

Fig. 1 is the perspective view of bearing plate and prestressed anchor cable expansion state;

Fig. 2 is the schematic diagram of the expanded state of bearing plate and prestressed anchor cable buried in the ground;

Fig. 3 is the schematic diagram of the shrinkage state of the prestressed anchor cable buried in the anchor hole;

Figure 4 is a partial sectional view of the bearing plate;

Figure 5 is an exploded view of Figure 4;

FIG. 6 is an enlarged view of part B of FIG. 5 .

Among them: 1. Bearing plate; 11. Steel plate; 12. Connecting hole; 2. Anchor hole; 3. Prestressed anchor cable; 31. Steel strand; 32. Telescopic anchor; 321. Upper connecting plate; 322. Lower connecting plate; 323, spring; 324, connecting rod assembly; 3241, upper connecting rod; 3242, lower connecting rod; 33, steel pipe sleeve; 331, hook; 34, steel cable; 341, suspension ring; 4, fixed plate; 41, fixed hole; 42. Pull hole; 43. Vent hole; 5. Wedge chuck; 6. Anchor bolt.

detailed description

Referring to Fig. 1 to Fig. 6, an embodiment of a single-anchor cable slab foundation for a power transmission tower of the present invention will be further described.

As shown in Figures 1 to 4, a single-anchor cable slab foundation for a power transmission tower includes a load-bearing plate 1, an anchor hole 2 located below the load-bearing plate 1, and a prestressed anchor hole 2 that passes through the load-bearing plate 1 and is fixed in the anchor hole 2. The anchor cable 3 and the concrete filled in the anchor hole 2, the prestressed anchor cable 3 includes a steel strand 31 passing through the bearing plate 1, a telescopic anchor 32 connected to the bottom end of the steel strand 31, and a telescopic anchor 32 sleeved outside the telescopic anchor 32. The steel pipe sleeve 33 and the steel cable 34 that pulls the steel pipe sleeve 33 to move up and down, the load-bearing plate 1 is provided with a connecting hole 12 for the steel strand 31 and the steel cable 34 to pass through, and the upper end of the load-bearing plate 1 is provided with a fixed plate 4, a fixed plate 4 At least four through holes communicating with the communication holes 12 are arranged on the top, and the steel strand 31 and the load-bearing plate 1 are linked by the fixed plate 4, and the fixed plate 4 increases the contact area between the steel strand 31 around the load-bearing plate 1 to prevent the occurrence of Due to excessive stress concentration, the steel strand 31 and the steel cable 34 respectively pass through different through holes, so that the steel strand 31 and the steel cable 34 are fixed in different through holes.

The load-bearing plate 1 resists the vertical downward pressure, horizontal force and bending moment given by the transmission tower, and prevents the foundation from lateral slipping and overturning. The concrete sphere at the lower part of the load-bearing plate 1 that wraps the telescopic anchor 32 uses the underground expansion structure to resist power transmission The uplifting force of the tower due to wind load and other factors can make the upper transmission tower have better resistance to dynamic loads. The spring 323 telescopic anchor 32 structure can be freely expanded and expanded, which is convenient for transportation and construction. The prestressed anchor cable 3 mainly transmits Such a prestressed anchor cable 3 has clear foundation load transmission and clear foundation stress, which reduces the size of the anchor hole 2, reduces the amount of undisturbed soil excavation and spoil, and reduces the impact of large-scale excavation on the environment. Destruction, thereby protecting the ecological environment; the foundation construction has a high degree of mechanization, which makes the construction period short, improves construction efficiency, and reduces construction costs.

As shown in Figure 5, the through hole includes a fixing hole 41 arranged in the center of the fixing disc 4 for the steel strand 31 to pass through, a pulling hole 42 and a ventilation hole 43 positioned on both sides of the fixing hole 41 for the steel cable 34 to pass through, and simultaneously The air hole 43 makes the moisture gas in the concrete at the bottom of the fixed plate 4 discharge in time, preventing the concrete from being too wet and affecting the strength of the concrete. There are two steel cables 34, the lower ends of the two steel cables 34 are provided with suspension rings 341, and the upper ends of the steel pipes are symmetrically provided with two hooks 331 respectively matched with the suspension rings 341, and two symmetrical hooks on both sides of the steel strand 31 331 cooperates with suspension ring 341, makes steel cable 34 when lifting steel pipe cover 33, both sides of steel pipe cover 33 all receive pulling, and the force is more even, and pulling steel pipe cover 33 is more convenient and labor-saving.

The through hole is rounded and truncated, and the split wedge chuck 5 for clamping the steel strand 31 or the steel cable 34 is fixed in the through hole. The split wedge chuck 5 is convenient for clamping the steel strand 31 and the steel cable 34, The wedge-shaped collet 5 has a self-locking function in the process of clamping the steel strand 31 and the steel cable 34, which is not easy to cause slippage. The through hole of the through hole is matched with the wedge-shaped chuck 5, and the wedge-shaped chuck 5 in the through hole is fixed to prevent the wedge-shaped chuck 5 from slipping.

As shown in Figure 6, the telescopic anchor 32 includes an upper connecting plate 321, a lower connecting plate 322, a spring 323 connecting the upper connecting plate 321 and the lower connecting plate 322, and at least two groups of connecting rod assemblies 324, and the connecting rod assemblies 324 are arranged symmetrically on the upper connecting plate. 321 on both sides, the link assembly 324 includes a hinged upper link 3241 and a lower link 3242, the upper link 3241 and the lower link 3242 are respectively hinged with the upper link 321 and the lower link 322, and the steel strand 31 passes through the wedge The collet 5 is connected with the upper connecting plate 321, so that the fixed position of the steel strand 31 and the upper connecting plate 321 is installed, and the installation is more convenient. The telescopic anchor 32 has a wider application range. There are four groups of connecting rod assemblies 324, and the four groups of connecting rod assemblies 324 are center-symmetrical around the spring 323, so that the connecting rod assemblies 324 extend from four directions to the anchor hole 2, so that the wrapped The concrete telescopic anchor 32 is more evenly stressed in all directions.

The load-bearing plate 1 is a reinforced concrete structure, including several cross-set steel plates 11 and concrete wrapped outside the steel plate 11. The rigidity of the steel plate 11 is large, so that the strength of the load-bearing plate 1 is relatively high. The concrete is poured outside the steel plate 11. Play a protective role, so that the durability and fire resistance of the load-bearing plate 1 are significantly better than those of pure steel structure. The four corners of the load-bearing plate 1 are provided with screw holes, and the internal threads of the screw holes are connected with anchor bolts 6. The foot bolts 6 are installed at the four corners of the load-bearing plate 1, so that the load-bearing plate 1 is stressed more evenly when it bears the downward pressure and the pulling force, and prevents the load-bearing plate 1 from being damaged by uneven force.

The present invention also provides a construction method for a single-anchor cable slab foundation for a power transmission tower, the steps are as follows:

(1) On the selected ground, dig a foundation pit for placing the bearing plate 1, drill the anchor hole 2 vertically downwards at the bottom of the foundation pit, and use the reaming equipment to ream the bottom of the anchor hole 2 into a spherical shape;

(2) Connect the upper connecting plate 321 and the steel strand 31, put the steel pipe sleeve 33 in the prestressed anchor cable 3 on the outside of the telescopic anchor 32 and put it into the anchor hole 2. At this time, the connecting rod assembly 324 and the inner wall of the steel pipe sleeve 33 In contrast, the lower connecting plate 322 is pushed by the hinged upper connecting rod 3241 and the lower connecting rod 3242, and the spring 323 between the upper connecting plate 321 and the lower connecting plate 322 is pulled by the lower connecting plate 322 and is in a stretched state;

(3) Utilize support rods and other instruments to extend into the anchor hole 2 to resist the top of the upper connecting plate 321, pull the steel cable 34 upward, and the steel cable 34 drives the steel pipe sleeve 33 to move upward, so that the telescopic anchor 32 is spherical at the bottom of the anchor hole 2. A steel pipe sleeve 33 protrudes from the hole, and the spring 323 retracts, driving the lower connecting plate 322 to move in the direction of the upper connecting plate 321, so that the hinged upper connecting rod 3241 and the lower connecting rod 3242 expand outward, and then take out the supporting rod;

(4) Inject concrete into the anchor hole 2, so that the concrete in the anchor hole 2 and the prestressed anchor cable 3 are condensed into one;

(5) Place the steel plate 11 in the foundation pit and pour concrete to form the bearing plate 1;

(6) Place the fixed disk 4 on the top of the condensed bearing plate 1 , and lock the steel strand 31 and the steel cable 34 on the fixed disk 4 by using the split wedge chuck 5 .

The above descriptions are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions under the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principles of the present invention should also be regarded as the protection scope of the present invention.

Claims (10)

1. a kind of list anchor cable mat foundation of power transmission tower, it is characterised in that：Anchor hole including bearing plate, below bearing plate, Prestress anchorage cable fixed in anchor hole and the concrete being filled in anchor hole are stretched into through bearing plate, the prestress anchorage cable includes Steel strand wires through bearing plate, the flexible anchor for being connected to steel strand wires bottom, the steel pipe socket being socketed in outside flexible anchor and pull steel The cable wire that pipe sleeve is moved up and down, the flexible anchor includes the spring and extremely of upper connective plate, lower linking plate, connection upper connective plate and lower linking plate Few two groups of link assemblies, the link assembly is symmetricly set on upper connective plate both sides, and the link assembly includes the upper company being hinged Bar and lower link, upper connecting rod and lower link are hinged with upper connective plate and lower linking plate respectively.

2. a kind of power transmission tower according to claim 1 list anchor cable mat foundation, it is characterised in that：Set on the bearing plate The intercommunicating pore passed through for steel strand wires and cable wire is equipped with, the bearing plate upper end, which is provided with fixed disk, fixed disk, sets at least three The individual through hole connected with intercommunicating pore, the steel strand wires and cable wire pass through from different through holes respectively.

3. a kind of power transmission tower according to claim 2 list anchor cable mat foundation, it is characterised in that：The through hole is rounding The split type templin chuck for clamping steel strand wires or cable wire is fixed with platform shape, through hole.

4. a kind of power transmission tower list anchor cable mat foundation according to claim 1,2 or 3, it is characterised in that：The cable wire Be provided with two, the lower ends of two cable wires is provided with suspension ring, the upper end of the steel pipe be symmetrically arranged with two respectively with suspension ring The hook of cooperation.

5. a kind of power transmission tower according to claim 4 list anchor cable mat foundation, it is characterised in that：The through hole includes setting Put the fixing hole passed through in fixed disk center for steel strand wires, the pulling hole passed through positioned at fixing hole both sides for cable wire and passage.

6. a kind of power transmission tower according to claim 1 list anchor cable mat foundation, it is characterised in that：The steel strand wires pass through Templin chuck is connected with upper connective plate.

7. a kind of power transmission tower according to claim 1 list anchor cable mat foundation, it is characterised in that：The bearing plate is steel Tendon concrete structure, including several steel plates arranged in a crossed manner and the concrete being wrapped in outside steel plate.

8. a kind of power transmission tower according to claim 1 list anchor cable mat foundation, it is characterised in that：The four of the bearing plate Angle is provided with screw, and screw internal thread is connected with foundation bolt.

9. a kind of power transmission tower according to claim 1 list anchor cable mat foundation, it is characterised in that：The link assembly is set Four groups are equipped with, four groups of link assemblies are centrosymmetric.

10. a kind of power transmission tower construction method of single anchor cable mat foundation, it is characterised in that step is as follows：

(1) foundation ditch for placing bearing plate is dug on selected ground, anchor hole is bored vertically downwards in the bottom of foundation ditch, uses reaming Equipment is by the bottom reaming globulate of anchor hole；

(2) connection upper connective plate and steel strand wires, the prestress anchorage cable that steel pipe socket is socketed on the outside of flexible anchor are put into anchor hole；

(3) top for propping up upper connective plate is stretched into anchor hole using apparatuses such as support bars, cable wire is pulled up, cable wire drives steel pipe socket Move up so that flexible anchor stretches out steel pipe socket in the spherical pore of anchor hole bottom, and expands outwardly, and then takes out support bar；

(4) concrete is injected into anchor hole so that concrete and prestress anchorage cable in anchor hole condense integral；

(5) steel plate is placed in foundation ditch and concrete, basis of formation upper plate is poured into a mould；

(6) fixed disk is placed at the top of the bearing plate of condensation, is locked steel strand wires and cable wire using split type templin chuck On fixed disk.