WO2023071327A1

WO2023071327A1 - Fabricated flexible damping screw anchor foundation and power transmission tower

Info

Publication number: WO2023071327A1
Application number: PCT/CN2022/107732
Authority: WO
Inventors: 孟克; 赵戈; 邵国栋; 陈小军; 宋克英
Original assignee: 中国电建集团山东电力建设第一工程有限公司
Priority date: 2021-10-27
Filing date: 2022-07-26
Publication date: 2023-05-04
Also published as: CN114059574B; CN114059574A

Abstract

The present invention relates to the technical field of power transmission line engineering. Disclosed are a fabricated flexible damping screw anchor foundation and a power transmission tower. The technical solution comprises: a damping bearing platform and a plurality of screw anchor groups; the screw anchor group comprises a plurality of anchor rod sections; the adjacent anchor rod sections are connected by screw anchor discs; flexible connecting sections are mounted between the top of the first anchor rod section and the damping bearing platform to form soft connection, and a horizontal force borne by the anchor rod is reduced. According to the present invention, the damping bearing platform and the screw anchor groups are connected together by means of the flexible connecting sections, so that the horizontal force borne by the anchor rod can be reduced. Moreover, the damping bearing platform and the flexible connecting sections work in conjunction to achieve the effects of damping and energy consumption.

Description

An assembled flexible shock-absorbing spiral anchor foundation and transmission tower

technical field

The invention relates to the technical field of power transmission line engineering, in particular to an assembled flexible shock-absorbing spiral anchor foundation and a power transmission tower.

Background technique

The cap and the spiral anchor of the existing spiral anchor foundation are usually welded (hardly connected), and the shaking of the transmission tower may easily cause the joint between the cap and the spiral anchor to break, resulting in extensive damage to the concrete part of the cap. Moreover, the anchor plate welding workload of the existing spiral anchor foundation is relatively large. The inventor found that the bearing capacity of the spiral anchor foundation when only bearing horizontal force is only 14% of the bearing capacity when only bearing uplift force. When the horizontal force changes from 0 to 15kN, the uplift bearing capacity drops by more than 50%. If the bolt diameter becomes smaller, the influence of horizontal force on the uplift bearing capacity will be more obvious. Therefore, it should be avoided that the spiral anchor foundation bears excessive horizontal force, otherwise, it will be difficult to give full play to the advantages of the spiral anchor foundation.

The prior art discloses a flexible slab foundation-screw anchor composite foundation. Since the main column has bending resistance and the base plate is large in size (the width of the slab is 4m-10m), most of the horizontal force is borne by the slab foundation. When the connecting cap connects multiple spiral anchor foundations together, due to the small size of the cap (width 1.5m left to right), the lateral stiffness is limited, part of the horizontal force of the foundation force is borne by the cap, and part of it is transmitted to the Spiral anchor section. The horizontal force borne by the screw anchor part cannot be ignored, and the bearing capacity of the screw anchor foundation cannot be fully exerted at this time. Especially when the backfill soil is not fully compacted, the upper cap can produce a certain horizontal displacement, and the horizontal force borne by the anchor rod is larger.

technical problem

The foundation force of the transmission tower includes vertical force and horizontal force, and the horizontal force generally accounts for 10% to 25% of the vertical force. The transmission tower is subjected to wind load all the year round, and the wind load is a kind of dynamic load. Under the action of wind load, the transmission tower is prone to shaking, which causes the bottom foundation to bear a large horizontal force.

technical solution

In view of the deficiencies in the prior art, the purpose of the present invention is to provide an assembled flexible shock-absorbing spiral anchor foundation and transmission tower, which connects the shock-absorbing cap and the spiral anchor group together through a flexible connecting section, which can reduce the size of the anchor bolt. horizontal force; and the shock-absorbing platform cooperates with the flexible connection section to achieve the effect of shock-absorbing and energy-dissipating.

In order to achieve the above object, the present invention is achieved through the following technical solutions:

In the first aspect, an embodiment of the present invention provides an assembled flexible shock-absorbing spiral anchor foundation, including a shock-absorbing platform and a plurality of spiral anchor groups, the spiral anchor groups include a plurality of anchor rod segments, adjacent anchor rods The sections are connected by a spiral anchor plate; a flexible connection section is installed between the top of the anchor section of the first section and the shock absorbing platform to reduce the horizontal force of the anchor.

As a further implementation, the flexible connecting section includes at least two flexible pipes sleeved together, one end of the flexible pipe is connected to the shock-absorbing platform through the first connecting plate, and the other end is connected to the connecting head through the second connecting plate;

Damping material is filled between adjacent flexible pipes.

As a further implementation, the connecting head is detachably connected to the anchor rod section; the first connecting plate and the second connecting plate are circular plates, and both diameters are larger than the diameter of the outermost flexible pipe.

As a further implementation manner, an elastic pad is provided inside the shock-absorbing platform, and a plurality of blocking blocks are evenly arranged on the elastic pad in the circumferential direction.

As a further implementation, the blocking block includes an external resistance block and an internal resistance block, and several stiffeners are connected between the external resistance block and the internal resistance block; the elastic pad is arranged in the area surrounded by the internal resistance block.

As a further implementation, the external resistance block and the internal resistance block are respectively perpendicular to the shock absorbing platform, and the height of the external resistance block is greater than the height of the internal resistance block;

The length of the external resistance block is longer than that of the internal resistance block, and each external resistance block is connected with at least two internal resistance blocks.

As a further implementation manner, the shock absorbing platform includes a platform bottom plate and a platform top plate, and the platform bottom plate and the platform top plate are connected by anchor bolts.

As a further implementation manner, the elastic pad is arranged between the bottom plate of the platform and the top plate of the platform, and the anchor bolts are arranged outside the elastic pad.

As a further implementation, the top of the platform top plate is fixed with a first backing plate sleeved on the outside of the anchor bolt and a second backing plate located above the first backing plate; There is a spring; the top of the second backing plate is provided with a nut.

In the second aspect, the embodiment of the present invention also provides a power transmission tower, including the flexible shock-absorbing spiral anchor foundation, and the main body of the power transmission tower is installed on the flexible shock-absorbing spiral anchor foundation.

Beneficial effect

1) In one or more embodiments of the present invention, a flexible connection section is provided at the connection part of the shock absorbing platform and the spiral anchor group, and this part realizes the soft connection between the shock absorbing platform and the spiral anchor part, and the lateral stiffness of this part is small , allowing a certain level of lateral deformation of the upper cap, which significantly reduces the horizontal force borne by the bolt; and the flexible connection section is filled with damping material, which has a certain energy dissipation effect and can give full play to the high vertical bearing capacity of the screw anchor foundation The advantages.

(2) An elastic pad is provided inside the shock-absorbing cap of one or more embodiments of the present invention, and the shock-absorbing effect is played by the elastic pad; and a blocking block is arranged on the outside of the elastic pad, and the blocking block includes an external resistance block and an internal resistance block , the internal resistance block acts as a limit to the elastic pad, and the external resistance block acts as a limit to the top plate of the cap, so as to ensure the shock absorption effect of the shock-absorbing cap.

(3) The elastic pad in one or more embodiments of the present invention is placed in the area surrounded by the inner resistance block, and the top plate of the cap is connected with the anchor bolt through the reserved anchor bolt hole, and is fastened by a nut to realize the foundation cap Prefabricated assembly production saves on-site construction time and costs, shortens on-site construction period, and improves construction efficiency.

(4) The spiral anchor group in one or more embodiments of the present invention splices multiple anchor rod segments through the spiral anchor plate, and the spiral anchor group can be spliced in segments according to the bearing capacity requirements, etc., to meet the needs of different projects; The spiral anchor group adopts the splicing type and can be spliced with the flexible connecting section, which solves the problems of low horizontal bearing capacity of the spiral anchor foundation and heavy anchor plate welding workload in the prior art.

Description of drawings

Figure 1 is a front view of the present invention according to one or more embodiments;

Figure 2 is a cross-sectional view of the present invention according to one or more embodiments;

Fig. 3 is the A-A sectional view of Fig. 2;

Fig. 4 is a schematic structural diagram of a spiral anchor plate according to one or more embodiments of the present invention;

Fig. 5(a) is a schematic structural diagram of a flexible connecting section according to one or more embodiments of the present invention;

Fig. 5(b) is a top view of the first connecting plate according to one or more embodiments of the present invention;

Fig. 5(c) is a B-B sectional view of Fig. 5(a).

Among them, 1. Shock absorbing cap, 1-1. Internal resistance block, 1-2. Cap bottom plate, 1-3. Stiffener, 1-4. External resistance block, 1-5. Cap top plate, 1- 6. First backing plate, 1-7. Spring, 1-8. Second backing plate, 1-9. Anchor bolt, 1-10. Elastic pad, 1-11. Connector, 1-12. Mounting hole, 2. First anchor section, 3. Second anchor section, 4. Third anchor section, 5. Anchor tip, 6. Spiral anchor plate, 7. Bolt, 8. Bolt hole, 9. Flexible connection section , 9-1. First connecting plate, 9-2. Second connecting plate, 9-3. Flexible tube, 9-4. Damping material, 9-5. Connecting head, 9-6. Bolt hole.

Embodiments of the present invention

This embodiment provides an assembled flexible shock-absorbing spiral anchor foundation, as shown in Figure 1 and Figure 2, including a shock-absorbing platform 1, a flexible connecting section 9, a spiral anchor group, a blocking block, and an elastic pad 1-10, The bottom of the shock-absorbing platform 1 is provided with a plurality of spiral anchor groups, and each spiral anchor group is connected to the shock-absorbing platform 1 through a flexible connecting section 9, and the flexible connection between the spiral anchor group and the shock-absorbing platform 1 is realized through the flexible connecting section 9 , to reduce the horizontal force on the bolt.

Further, as shown in Figure 5(a), the flexible connecting section 9 includes a first connecting plate 9-1, a second connecting plate 9-2, a flexible pipe 9-3 and a connecting head 9-5, and the flexible pipe 9-3 One end is fixed with the first connecting plate 9-1, and the other end is fixed with the second connecting plate 9-2; the flexible pipe 9-3 is provided with a plurality of different diameters, as shown in Figure 5 (c), the flexible pipe 9-3 starts from A multi-layer structure is formed from inside to outside, and the space between adjacent flexible pipes 9-3 is filled with damping material 9-4, which has the effect of auxiliary energy consumption and shock absorption.

The flexible pipe 9-3 is made of flexible metal material, and in this embodiment, the flexible pipe 9-3 is made of mild steel. The length of the flexible pipe 9-3 is set according to actual use requirements.

The first connecting plate 9-1 is connected with the shock absorbing platform 1, the second connecting plate 9-2 is connected with the connecting head 9-5, and is connected with the screw anchor group through the connecting head 9-5. The connecting head 9-5 of this embodiment is a hollow circular tube, which is connected with the screw anchor group by bolts 7 .

In this embodiment, the first connecting plate 9-1 and the second connecting plate 9-2 are circular steel plates, and the diameters of the two are larger than the diameter of the outermost flexible pipe 9-3 to increase the contact with the shock absorbing platform 1. contact surface to form a stable connection. As shown in FIG. 5( b ), a number of bolt holes 9-6 are opened in the circumferential direction of the first connecting plate 9-1, and the connection with the shock absorbing platform 1 is realized by screwing bolts into the bolt holes 9-6.

It can be understood that, in other embodiments, the first connecting plate 9-1 and the second connecting plate 9-2 may also be in other shapes, such as rectangular plates whose length is greater than the diameter of the outermost flexible pipe 9-3.

By arranging a multi-layer flexible pipe 9-3 between the first connecting plate 9-1 and the second connecting plate 9-2, under the basic force, the first connecting plate 9-1 and the second connecting plate 9-2 Misalignment can occur under a small force, so that the lower helical anchor group bears a small horizontal force. When designing the flexible connecting section 9, the horizontal force borne by the anchor rod can be preset first, and then the flexible pipe 9-3 can be designed.

In this embodiment, a flexible connection section 9 is provided at the connection between the shock absorbing platform 1 and the spiral anchor group, which realizes the soft connection between the shock absorbing platform 1 and the spiral anchor group. This part has small lateral stiffness, allowing the upper shock absorbing platform 1 to A certain level of lateral deformation can significantly reduce the horizontal force borne by the bolt, and has a certain energy dissipation effect, which can give full play to the advantages of the high vertical bearing capacity of the spiral anchor foundation.

In this example, the horizontal force borne by the anchor rod is studied through the refined numerical analysis of the flexible shock-absorbing spiral anchor foundation, as shown in Table 1.

Table 1 Comparison table of bolt bearing capacity

the

Among them, SJ-A is a conventional spiral anchor foundation, and SJ-B is a flexible shock-absorbing spiral anchor foundation. It can be seen that the horizontal force borne by a single anchor is reduced by 89.8%, and the uplift bearing capacity of a single anchor is increased by 51.9%. , give full play to the advantages of high vertical bearing capacity of a single screw anchor foundation.

Further, an elastic pad 1-10 is arranged inside the shock-absorbing platform 1, and a plurality of blocking blocks are evenly arranged in the circumferential direction of the elastic pad 1-10. The shock-absorbing platform 1 includes a platform bottom plate 1-2 and a platform top plate 1-5, an elastic pad 1-10 is arranged between the platform bottom plate 1-2 and the platform top plate 1-5, and a blocking block is fixed on the bearing platform. The upper surface of the base plate 1-2, the outer side of the elastic pad 1-10.

In this embodiment, the bottom plate 1-2 of the platform and the top plate 1-5 of the platform are both rectangular plates, and the size of the bottom plate 1-2 of the platform is larger than that of the top plate 1-5 of the platform, so that the blocking block can support the elastic pad at the same time. 1-10 and bearing platform top plate 1-5 play a position-limiting effect.

In this embodiment, rubber pads are used for the elastic pads 1-10, so that the shock-absorbing platform 1 can play a shock-absorbing role. Of course, in other embodiments, the elastic pads 1-10 can also use other elastic materials. Steel is selected for the shock absorbing platform 1 to increase its bearing capacity; for example, the shock absorbing platform 1 is made of Q355 steel.

Furthermore, the platform bottom plate 1-2 and the platform top plate 1-5 are connected by anchor bolts 1-9. As shown in FIG. 3 , bolt holes are respectively provided at the corresponding positions near the edge of the platform bottom plate 1-2 and the platform top plate 1-5 for the installation of the anchor bolts 1-9. And the layout of the bolt holes should have a certain distance from the edge of the elastic pad 1-10, and avoid the installation position of the blocking block.

Further, the top of the platform top plate 1-5 is fixed with a first backing plate 1-6, and the first backing plate 1-6 is sleeved on the anchor section where the anchor bolt 1-9 exceeds the top of the platform top plate 1-5. A backing plate 1-6 is provided with a second backing plate 1-8, and a spring 1-7 is arranged between the first backing plate 1-6 and the second backing plate 1-8; Outside the anchor section, a nut is provided on the top of the second backing plate 1-8, through which the second backing plate 1-8, the spring 1-7 and the first backing plate 1-6 fix the anchor bolt 1-9.

In this embodiment, the anchor bolts 1-9 are evenly and symmetrically arranged around the shock absorbing platform 1, and the bottom of the anchor bolts 1-9 is connected to the bottom plate of the platform 1-2 through plug welding, so that the superstructure load can be effectively transferred to the shock absorbing bearing. Station 1. The first backing plate 1-6, the second backing plate 1-8, and the spring 1-7 can be made of steel, wherein the first backing plate 1-6 is spot welded to the platform top plate 1-5.

Further, the blocking block includes an external resistance block 1-4 and an internal resistance block 1-1, the internal resistance block 1-1 acts as a limit to the elastic pad 1-10, and the external resistance block 1-4 acts as a limit to the platform top plate 1 -5 acts as a limiter; several stiffeners 1-3 are connected between the external resistance block 1-4 and the internal resistance block 1-1.

As shown in Figure 3, in this embodiment, both the external resistance block 1-4 and the internal resistance block 1-1 are arranged as rectangular blocks, and the length and height of the external resistance block 1-4 are greater than that of the internal resistance block 1-1 length and height. The external resistance block 1-4 and the internal resistance block 1-1 are vertically fixed to the base plate 1-2 respectively. Each external resistance block 1-4 is connected to a plurality of internal resistance blocks 1-1 through stiffeners 1-3, and the internal resistance blocks 1-1 are evenly arranged along the circumferential direction of the elastic pad 1-10, that is, the elastic pad 1-10 is arranged inside Within the area enclosed by block 1-1.

In this embodiment, the internal resistance block 1-1 and the external resistance block 1-4 are connected to the base plate 1-2 by welding, and the stiffener 1-1 between the internal resistance block 1-1 and the external resistance block 1-4 3 is connected with both by welding. The components are firmly connected by welding.

Further, the spiral anchor group includes a plurality of anchor rod segments, and adjacent anchor rod segments are connected by a spiral anchor disc 6 . As shown in Figure 4, both ends of the spiral anchor plate 6 are provided with bolt holes 8, and the bolt 7 is screwed into the bolt holes 8 to realize the connection with the anchor section; through the splicing form of the spiral anchor plate 6 and the anchor section, It is convenient for the assembly of the spiral anchor plate 6 .

In this embodiment, the spiral anchor plate 6 is forged in advance according to the bearing capacity requirements, which reduces the welding workload. The anchor plate in the forged spiral anchor plate adopts variable thickness treatment, the root thickness is large, and the edge thickness is small, which is beneficial Cut the soil, reducing the screw anchor's entry torque. At the same time, the size of the forged spiral anchor plates at different positions can be replaced according to the needs of the bearing capacity, so that the diameters of the spiral anchor plates in the same spiral anchor group are different, easy to disassemble and assemble, avoiding a large number of welding, convenient and practical.

The number of anchor sections depends on the specific construction requirements. In this embodiment, four anchor sections are taken as an example, that is, the first anchor section 2, the second anchor section 3, and the third anchor section are arranged sequentially from top to bottom. The rod segment 4 and the anchor rod tip 5, wherein the connecting head 9-5 of the first anchor rod segment 2 and the flexible connecting segment 9 is connected by a bolt 7, and the anchor rod tip 5 is the most end of the anchor rod.

The construction method of this embodiment is:

Connect the flexible connecting section 9 to the bottom of the platform bottom plate 1-2, fix the internal resistance block 1-1 and the external resistance block 1-4 on the upper surface of the platform bottom plate 1-2 by welding, and the internal resistance block 1-1 and the external resistance block 1-1 Stiffeners 1-3 are welded between the resistance blocks 1-4. After the elastic pad 1-10 is placed in the area surrounded by the internal resistance block 1-1, connect the platform top plate 1-5 with the platform bottom plate 1-2 through the anchor bolt 1-9, and tighten the nuts.

Complete the assembly of the spiral anchor group according to the bearing capacity, and use large-scale machinery to screw the spiral anchor group into the soil layer of the construction site to ensure that the elevation of all the spiral anchor groups after construction is consistent; connect the upper end of the first anchor section 2 with the flexible connecting section 9 connections.

Embodiment two:

This embodiment provides an assembled flexible shock-absorbing spiral anchor foundation. The flexible shock-absorbing spiral anchor foundation adopts the structure described in Embodiment 1, and a connecting piece 1-11 is installed on one side of the cap top plate 1-5, and through the connection The piece 1-11 is connected with the upper structure; multiple mounting holes 1-12 are opened on the connecting piece 1-11 to form multiple fixing points.

In this embodiment, the connecting piece 1-11 is an angle steel connecting piece, and the angle steel connecting piece is welded together with the platform top plate 1-5.

Embodiment three:

This embodiment provides an assembled flexible shock-absorbing spiral anchor foundation, which is different from Embodiment 1 in that prestressed steel bars are set in the spiral anchor plate 6 to further enhance the strength and rigidity of the spiral anchor plate 6. Other structures and embodiments One is the same and will not be repeated here.

Embodiment four:

This embodiment provides a power transmission tower, including the flexible shock-absorbing spiral anchor foundation described in Embodiment 1, the main body of the power transmission tower is installed on the shock-absorbing support platform 1 of the flexible shock-absorbing spiral anchor foundation.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, there may be various modifications and changes in the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

Claims

An assembled flexible shock-absorbing spiral anchor foundation is characterized in that it includes a shock-absorbing cap and a plurality of spiral anchor groups, the spiral anchor group includes a plurality of anchor rod sections, and adjacent anchor rod segments are connected by a spiral anchor plate; A flexible connecting section is installed between the top of the anchor section and the shock absorbing platform to reduce the horizontal force of the anchor; the flexible connecting section includes at least two flexible pipes sleeved together, and one end of the flexible pipe is connected through the first The plate is connected to the shock-absorbing bearing platform, and the other end is connected to the connecting head through the second connecting plate; damping material is filled between adjacent flexible pipes.
An assembled flexible shock-absorbing spiral anchor foundation according to claim 1, wherein the connecting head is detachably connected to the anchor section; the first connecting plate and the second connecting plate are circular plates, and Both diameters are larger than the diameter of the outermost flexible pipe.
The assembled flexible shock-absorbing spiral anchor foundation according to claim 1, wherein an elastic pad is arranged inside the shock-absorbing platform, and a plurality of blocking blocks are evenly arranged in the circumferential direction of the elastic pad.
An assembled flexible shock-absorbing spiral anchor foundation according to claim 3, wherein the blocking block includes an external resistance block and an internal resistance block, and several stiffeners are connected between the external resistance block and the internal resistance block; The pad is arranged in the area enclosed by the internal resistance block.
An assembled flexible shock-absorbing spiral anchor foundation according to claim 4, characterized in that, the external resistance block and the internal resistance block are respectively perpendicular to the shock-absorbing platform, and the height of the external resistance block is greater than that of the internal resistance block high;

The length of the external resistance block is longer than that of the internal resistance block, and each external resistance block is connected with at least two internal resistance blocks.
The assembled flexible shock-absorbing spiral anchor foundation according to claim 1, wherein the shock-absorbing platform includes a platform bottom plate and a platform top plate, and the platform bottom plate and the platform top plate are connected by anchor bolts.
The assembled flexible shock-absorbing spiral anchor foundation according to claim 6, wherein the elastic pad is arranged between the bottom plate of the platform and the top plate of the platform, and the anchor bolts are arranged outside the elastic pad.
An assembled flexible shock-absorbing spiral anchor foundation according to claim 6, characterized in that, the top of the platform top plate is fixed with a first backing plate sleeved on the outside of the anchor bolt, and a second backing plate above the first backing plate. Two backing plates; a spring is arranged between the first backing plate and the second backing plate; a nut is arranged on the top of the second backing plate.
A power transmission tower, characterized in that it comprises the flexible shock-absorbing spiral anchor foundation according to any one of claims 1-8, and the main body of the power transmission tower is installed on the flexible shock-absorbing spiral anchor foundation.