A pressure type anchor rod foundation and a construction method

Abstract

This invention relates to the field of power facility technology and discloses a pressure-type anchor foundation and its construction method. The pressure-type anchor foundation includes: anchor bolts, a truss foundation, and a connecting plate. Multiple anchor bolts are installed on the bedrock, symmetrically distributed along their central axis. The anchoring sections of the anchor bolts are fixedly connected to the bedrock via grouting. The truss sections of the anchor bolts serve as the main columns of the truss foundation, with diagonal braces and truss sections forming a spatial truss structure. The connecting plate at the top of the anchor bolts is used to connect the tower legs of the tower. The anchor bolts simultaneously function as both anchor bolts and main columns of the truss, achieving integration of the anchor bolts and the truss foundation. This results in a structure without redundancy or connection nodes, maximizing material utilization, shortening the force transmission path, improving load transfer efficiency, and significantly reducing the risk of node failure. The pressure-type anchor foundation provided by this invention solves the problems of long force transmission paths and low load transfer efficiency in existing steel truss foundation anchor foundations.

Description

Technical Field

[0001] This invention relates to the field of power facility technology, specifically to a pressure-type anchor foundation and its construction method. Background Technology

[0002] Rock anchor foundations are environmentally friendly power transmission line foundations that use cement mortar or fine aggregate concrete to bond the anchor bars to the rock mass, creating a unified structure. This type of foundation fully utilizes the high strength and low deformation properties of the original rock mass, exhibiting excellent load-bearing capacity. It avoids the damage to the rock base and vegetation caused by manual rock drilling and blasting, resulting in significant environmental benefits. Furthermore, rock anchor foundations (excluding the pile cap) require minimal earthwork excavation and produce virtually no waste soil, reducing the consumption of materials such as concrete, steel, and formwork. The reduced transportation volume and high degree of mechanization in construction lower labor intensity, save costs, and shorten the construction period, making it a promising option for power transmission line projects in mountainous areas.

[0003] In the existing technology, the prefabricated steel truss foundation anchor bolt foundation uses a truss structure to replace the large-volume foundation. The truss foundation assembled from metal profiles is fixed to the foundation by anchor bolts, and the anchor bolts and the truss foundation are connected by nodes.

[0004] However, transmission line tower foundations bear not only alternating tensile and compressive loads but also significant horizontal loads. Uplift resistance and overturning resistance are often key control conditions in design calculations. In the aforementioned scheme, the anchor bolt and truss foundation are two independent components, requiring a connection node between them. The force transmission path is: anchor bolt → connection node → truss foundation → tower leg. This results in discontinuous force transmission with multiple links, a long path, and low load transfer efficiency. Each link is a potential weak point, hindering true collaborative operation. Furthermore, the connection node, with its complex structure, bears additional bending moments and shear forces under horizontal forces, making it the weakest link. Summary of the Invention

[0005] This invention provides a pressure-type anchor foundation and its construction method to solve the problems of long force transmission paths and low load transfer efficiency in existing steel truss foundation anchor foundations.

[0006] In a first aspect, the present invention provides a pressure-type anchor foundation, comprising: an anchor, a truss base, and a connecting plate; multiple anchors are provided on the bedrock, the multiple anchors being centrally symmetrically distributed, the portion of the anchor exposed in the bedrock being provided with a truss section, and the portion of the anchor extending into the bedrock being provided with an anchoring section, the anchoring section being fixedly connected to the bedrock by grouting; the truss section serves as the main column of the truss base, the truss base is provided with diagonal bracing, the first end of the diagonal bracing is connected to the top of the truss section of one of the anchors, the other end of the diagonal bracing is connected to a fixing member on the bedrock, the diagonal bracing and the truss section forming a spatial truss structure; the connecting plate is provided on the top of the anchor, the connecting plate being used to connect the tower legs of the tower.

[0007] Beneficial effects: The anchoring section at the bottom of the anchor rod is fixedly connected to the bedrock through grouting. The truss section at the top of the anchor rod serves as the main column of the truss foundation. The truss section and the diagonal bracing form a spatial truss structure. When the tower is subjected to uplift and horizontal forces, the load is transferred to the connecting plate through the tower leg, and then to the anchor rod through the connecting plate. Under the action of uplift force, the anchor rod is under tension. The anchoring section transfers the load to the bedrock through grouting. Under the action of horizontal force, the compressive stress of the diagonal bracing and the external load are superimposed. The horizontal resistance is provided by the stiffness of the diagonal bracing. The anchor rod extends directly from the underground anchoring section to the ground surface to form a truss structure. The anchor rod simultaneously serves as both the anchoring rod body and the main column of the truss, realizing the integration of the anchor rod and the foundation. There is no redundant structure, no connection nodes, and the material utilization rate is maximized. There are only two force transmission links: the anchor rod and the tower leg. The force transmission path is short, the load transmission efficiency is improved, and the risk of node failure is greatly reduced. The pressure-type anchor foundation provided by this invention solves the problems of long force transmission path and low load transfer efficiency in existing steel truss foundation anchor foundations.

[0008] In one alternative implementation, the plurality of anchor bolts are arranged axially symmetrically and obliquely to form an umbrella-like structure.

[0009] Beneficial effects: The inclined arrangement of anchor bolts can decompose the horizontal force into a tensile force along the anchor bolt axis and a component force perpendicular to the anchor bolt. The axial tensile force is transmitted to the bedrock through the grouting body by the anchoring section of the anchor bolt, which can share part of the horizontal force and improve the overall horizontal resistance.

[0010] In one alternative embodiment, the anchor bolt has a free section in the middle, which is located between the anchoring section and the truss section. The gap between the free section and the bedrock is filled with a filler material, which is used to absorb the deformation and sway of the free section.

[0011] Beneficial effects: The inclined anchor decomposes the horizontal force into a tensile force along the anchor's axis and a component force perpendicular to the anchor. The component force perpendicular to the anchor causes the anchor to sway slightly, producing slight bending deformation and vibration. The filler absorbs the bending deformation and sway of the free section, playing a buffering role. The anchor simultaneously undertakes three functions: anchoring rod, buffer component, and main column of truss, further enhancing the overall horizontal resistance.

[0012] In one optional embodiment, a pressure plate is provided at the bottom of the anchoring section, the pressure plate is welded to the bottom end face of the anchoring section, and the pressure plate abuts against the grouting body around the anchoring section.

[0013] Beneficial effects: When the anchor rod is under tension, the bearing plate welded to the bottom end face of the anchor rod converts the tension into pressure on the grout. After the grout is under pressure, it transfers the load to the bedrock, achieving pressure-type anchoring with the bedrock.

[0014] In one alternative embodiment, the surface of the anchoring section is provided with a shear connector, which is used to increase the adhesion between the anchoring section and the grouting body.

[0015] Beneficial effects: Shear connectors can compensate for the problems of smooth surface and insufficient adhesion of the anchoring section, prevent slippage at the interface between the anchoring section and the grouting body, ensure that the anchor rod and the grouting body work together, and at the same time, shear connectors provide adhesive shear resistance, forming a composite anchoring system that combines mechanical bearing and adhesive shear resistance with the bearing plate at the bottom of the anchor rod, thereby improving the overall load-bearing capacity.

[0016] In one optional embodiment, a sealing device is provided at the point where the anchor rod penetrates the bedrock. The sealing device includes a flexible water-stop ring and a sleeve. The sleeve is pre-embedded in the anchor hole in the bedrock, the anchor rod passes through the sleeve, and the flexible water-stop ring is disposed in the annular gap between the sleeve and the anchor rod.

[0017] Beneficial effects: The flexible water-stop ring fills the annular gap between the anchor rod and the sleeve, allowing the anchor rod to swing slightly under horizontal force while preventing the loss of filler material in the free section of the anchor rod and the infiltration of groundwater.

[0018] In one optional embodiment, the diagonal brace is a prestressed compression bar, the diagonal brace includes a first support rod and a second support rod, and an adjustment assembly is provided between the first support rod and the second support rod. The adjustment assembly moves the first support rod and the second support rod relatively away from each other, so as to extend the diagonal brace.

[0019] Beneficial effects: The first support rod connects to the truss section of an anchor rod, and the second support rod connects to the fixing component on the bedrock. The diagonal bracing actively extends via an adjusting assembly, generating an outward thrust as a prestressed compression member. This thrust acts on the main column node of the anchor rod, ensuring that each anchor rod generates prestress synchronously, resulting in good overall prestress uniformity and high construction efficiency. Unlike traditional truss diagonal bracing, which only serves as a stabilizing support, the diagonal bracing transforms from a passive support to an active force-bearing member, significantly improving material utilization. After prestressing is applied, the diagonal bracing, as a prestressed compression member, remains under compression, while the truss section of the anchor rod, as a tension member, remains under tension. Together, they form a stable, self-balancing prestressed system that resists external loads. Simultaneously, the inclined anchor rods decompose the horizontal force into axial tension and vertical components. The anchor rods bear the axial tension, while the free section buffers the vibration generated by the vertical component through filling material. This triple mechanism significantly enhances horizontal resistance.

[0020] In one optional embodiment, the adjusting assembly includes: a first connecting part, a second connecting part, and an adjusting sleeve. The first connecting part is disposed on the first support rod; the second connecting part is disposed on the second support rod; the first end of the adjusting sleeve is provided with a first threaded part that is threadedly connected to the first connecting part, and the second end of the adjusting sleeve is provided with a second threaded part that is threadedly connected to the second connecting part. The first threaded part and the second threaded part rotate in opposite directions.

[0021] Beneficial effect: By rotating the adjusting sleeve, the first and second threaded parts with opposite rotation directions cause the first and second connecting parts to drive the first and second support rods away from each other, thereby causing the diagonal brace to actively extend.

[0022] Secondly, the present invention also provides a construction method for the pressure-type anchor foundation described in the above embodiments, comprising the following steps: Drill holes in the bedrock to form anchor holes; The anchor rod is lowered into the anchor hole, with the anchoring section of the anchor rod below the bedrock surface and the truss section of the anchor rod above the bedrock surface; Grouting is performed at the bottom of the anchor hole to form a grout body, which wraps around the anchoring section of the anchor rod. The grout body is cured to the design strength to ensure that the anchoring section is fixedly connected to the bedrock. The truss section serves as the main column of the truss foundation. Diagonal bracing is installed on the diagonal bracing. The diagonal bracing is connected to the truss section through node connectors and bolts. The bolts are first initially tightened, and then the anchor rods are prestressed before the bolts are finally tightened to lock them in place. Install a connecting plate on top of the anchor bolt, and then install the tower legs on the mounting plate.

[0023] Beneficial effects: The anchor bolts are inserted into the anchor holes in the bedrock, and the anchoring section is fixedly connected to the bedrock through the cast-in-place structure. The truss section and the diagonal bracing form a truss foundation. The anchor bolts continuously penetrate from the underground anchoring section to the ground truss section, resulting in a short force transmission path. On-site, the node connectors, diagonal bracing, and anchor bolts are initially connected by bolts. After applying prestress to the anchor bolts, the bolts are tightened to lock them in place. No on-site welding is required, ensuring quality control and rapid construction. Because the pressure-type anchor bolt foundation described in the above embodiment is used, it possesses any of the aforementioned advantages.

[0024] In one alternative embodiment, a pressure plate is welded to the bottom of the anchor rod before it is lowered into the anchor hole, and a shear connector is welded to the surface of the anchoring section.

[0025] Beneficial effects: The cast-in-place structure binds the anchor section, shear connector, and bottom bearing plate of the anchor rod to the bedrock as one unit, forming the main load transfer area. The bearing plate at the bottom of the anchor rod provides pressure-type anchoring, and the shear connector provides bonded shear resistance, forming a composite anchoring system with a significantly better bearing capacity than the traditional single anchoring mechanism.

[0026] In one alternative embodiment, the free section of the anchor rod is also lowered into the anchor hole in the bedrock. After the grouting body has been cured to the design strength, filler is added to the gap between the free section and the bedrock until it is flush with the bottom bedrock surface. A sealing device is installed where the anchor rod exits the bedrock.

[0027] Beneficial effects: Under the action of horizontal force, the anchor rod is allowed to produce slight bending deformation and sway, avoiding stress concentration, while preventing the loss of filler material in the free section and the infiltration of groundwater.

[0028] In one alternative implementation, during the application of prestress, a through-hole jack is installed on top of the anchor rod to tension the anchor rod upwards. After reaching the designed prestress value, the nut of the bolt is tightened.

[0029] Beneficial effects: By using a through-hole jack to generate pre-tension stress synchronously in each anchor rod, and then tightening all the node bolts to lock them, a fixed pre-stress state is formed, the overall pre-stress is uniform, and the construction efficiency is high.

[0030] In one alternative implementation, during the application of prestress, the adjusting assembly extends the diagonal brace by rotating the adjusting sleeve. The jacking force generated by the diagonal brace acts on the main column node of the truss section, causing the anchor rod to generate pre-tension stress. After reaching the design prestress value, the nut of the locking bolt is tightened.

[0031] Beneficial effects: By adjusting the active extension of the diagonal bracing, the diagonal bracing acts as a prestressed compression member, generating an outward jacking force. This jacking force acts on the main column node of the anchor rod, causing each anchor rod to generate prestress synchronously, resulting in good overall prestress uniformity and high construction efficiency. The diagonal bracing is always under compression, forming a stable self-balancing prestressing system with the tensioned anchor rod. The diagonal bracing changes from passive support to active force bearing, significantly improving material utilization. Attached Figure Description

[0032] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of a pressure-type anchor foundation according to an embodiment of the present invention.

[0034] Explanation of reference numerals in the attached figures: 1. Bedrock; 2. Anchor bolt; 21. Truss section; 22. Anchoring section; 23. Free section; 3. Diagonal brace; 31. First support rod; 32. Second support rod; 33. Adjustment assembly; 4. Connecting plate; 5. Tower leg; 6. Pressure plate; 7. Sealing device. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] The following is combined Figure 1 The following describes embodiments of the present invention.

[0037] According to an embodiment of the present invention, a pressure-type anchor foundation is provided, comprising: an anchor 2, a truss base, and a connecting plate 4; multiple anchors 2 are provided on bedrock 1, the multiple anchors 2 are centrally symmetrically distributed, the portion of the anchor 2 exposed in the bedrock 1 is provided with a truss section 21, the portion of the anchor 2 extending into the bedrock 1 is provided with an anchoring section 22, the anchoring section 22 is fixedly connected to the bedrock 1 by grouting; the truss section 21 serves as the main column of the truss base, the truss base is provided with a diagonal brace 3, the first end of the diagonal brace 3 is connected to the top of the truss section 21 of one of the anchors 2, the other end of the diagonal brace 3 is connected to a fixing member on the bedrock 1, the diagonal brace 3 and the truss section 21 form a spatial truss structure; the connecting plate 4 is provided on the top of the anchor 2, the connecting plate 4 is used to connect the tower legs 5 of the tower.

[0038] In use, the anchoring section 22 at the bottom of the anchor rod 2 is fixedly connected to the bedrock 1 via grouting. The truss section 21 at the top of the anchor rod 2 serves as the main column of the truss support. The truss section 21 and the diagonal brace 3 form a spatial truss structure. When the tower is subjected to upward and horizontal forces, the load is transmitted to the connecting plate 4 through the tower leg 5, and then to the anchor rod 2 through the connecting plate 4. Under the action of the upward force, the anchor rod 2 is under tension, and the anchoring section 22 transmits the load to the bedrock 1 through the grouting. Under the action of horizontal force, the compressive stress of the diagonal brace 3 and the external load are superimposed, and the horizontal resistance is provided by the stiffness of the diagonal brace 3. The anchor 2 extends directly from the underground anchoring section 22 to the ground to form a truss structure. The anchor 2 also serves as the dual function of the anchoring rod and the main column of the truss, realizing the integration of the anchor 2 and the truss foundation. There is no redundant structure, no connection nodes, and the material utilization rate is maximized. There are only two force transmission links: the anchor 2 and the tower leg 5. The force transmission path is short, the load transfer efficiency is improved, and the risk of node failure is greatly reduced. The pressure-type anchor foundation provided in this embodiment solves the problems of long force transmission path and low load transfer efficiency of existing steel truss foundation anchor 2 foundations.

[0039] Specifically, the anchor rod 2 can be made of H-beams or I-beams, or it can be made of box-section steel or steel pipe. Box-section steel has good torsional resistance and is suitable for working conditions with large horizontal forces; steel pipe section is easy to protect against corrosion and is suitable for corrosive geological conditions.

[0040] Specifically, the diagonal brace 3 is a steel component, including angle steel or channel steel.

[0041] Specifically, the grouting body is formed by injecting non-shrink high-strength grouting material.

[0042] Specifically, the fixing component on the bedrock 1 can be a steel pipe sleeve for inserting the anchor rod 2, or a special pre-embedded component fixed on the bedrock.

[0043] In one embodiment, a plurality of anchor bolts 2 are arranged symmetrically and obliquely to form an umbrella-like structure. The oblique arrangement of the anchor bolts 2 decomposes the horizontal force into a tensile force along the axial direction of the anchor bolt 2 and a component force perpendicular to the anchor bolt 2. The axial tensile force is transmitted to the bedrock 1 by the anchoring section 22 of the anchor bolt 2 through grouting, thus sharing part of the horizontal force and improving the overall horizontal resistance. Alternatively, as an alternative embodiment, the anchor bolts 2 can also be installed vertically.

[0044] In one embodiment, the anchor rod 2 has a free section 23 in its middle, which is located between the anchoring section 22 and the truss section 21. A filler is placed between the free section 23 and the bedrock 1 to absorb the deformation and sway of the free section 23. The inclined anchor rod 2 decomposes the horizontal force into a tensile force along the axial direction of the anchor rod 2 and a component force perpendicular to the anchor rod 2. The component force perpendicular to the anchor rod 2 causes slight swaying, resulting in slight bending deformation and vibration. The filler absorbs the bending deformation and sway of the free section 23, acting as a buffer. The anchor rod 2 simultaneously fulfills three functions: anchoring rod, buffer component, and main truss column, further enhancing the overall horizontal resistance. Alternatively, as an alternative embodiment, the gap between the free end and the bedrock 1 can be left empty.

[0045] Specifically, the filler is preferably sand and fine sand, but graded crushed stone, expansive soil, or a mixture of high-damping rubber particles can also be used. Graded crushed stone has good drainage performance and is suitable for working conditions with high groundwater levels; the high-damping rubber particle mixture has damping energy dissipation function and is suitable for working conditions with large wind vibrations.

[0046] In one embodiment, a pressure-bearing plate 6 is provided at the bottom of the anchoring section 22. The pressure-bearing plate 6 is welded to the bottom end face of the anchoring section 22, and the pressure-bearing plate 6 abuts against the grouting body surrounding the anchoring section 22. When the anchor rod 2 is under tension, the pressure-bearing plate 6 welded to the bottom end face of the anchor rod 2 converts the tension into pressure on the grouting body. After being compressed, the grouting body transfers the load to the bedrock 1, achieving pressure-type anchoring with the bedrock 1. Alternatively, as an alternative embodiment, the pressure-bearing plate 6 can be omitted, and anchoring can be achieved through the adhesion between the anchoring section 22 and the grouting body itself.

[0047] Specifically, the pressure plate 6 is made of Q345 steel plate, and the thickness is preferably, but not limited to, 20mm~30mm. The pressure plate 6 is provided with grouting holes and venting holes.

[0048] In one embodiment, a shear connector is provided on the surface of the anchoring section 22 to increase the adhesion between the anchoring section 22 and the grout. The shear connector compensates for the smooth surface and insufficient adhesion of the anchoring section 22, preventing slippage at the interface between the anchoring section 22 and the grout, ensuring the coordinated operation of the anchor rod 2 and the grout. Simultaneously, the shear connector provides adhesive shear resistance, forming a composite anchoring system combining mechanical bearing and adhesive shear resistance with the bearing plate 6 at the bottom of the anchor rod 2, thus improving the overall load-bearing capacity. Alternatively, as an alternative embodiment, the shear connector can be omitted, and pressure anchoring can be achieved solely through the bearing plate 6 at the bottom of the anchor rod 2.

[0049] Specifically, the shear connector is made of studs or perforated steel plates (PBL shear keys). When the anchor rod 2 is made of H-beams or I-beams, the shear connector is welded to the flange and web surfaces of the anchoring section 22.

[0050] In one embodiment, a sealing device 7 is provided where the anchor rod 2 exits the bedrock 1. The sealing device 7 includes a flexible water-stop ring and a sleeve. The sleeve is pre-embedded in the anchor hole of the bedrock 1, and the anchor rod 2 passes through the sleeve. The flexible water-stop ring is disposed in the annular gap between the sleeve and the anchor rod 2. The flexible water-stop ring fills the annular gap between the anchor rod 2 and the sleeve, allowing the anchor rod 2 to swing slightly under horizontal force while preventing the loss of filler material and groundwater infiltration from the free section 23 of the anchor rod 2.

[0051] Specifically, the flexible waterstop ring is a rubber waterstop ring.

[0052] In one embodiment, the diagonal brace 3 is a prestressed compression member, comprising a first support rod 31 and a second support rod 32. An adjustment component 33 is provided between the first support rod 31 and the second support rod 32, which moves the first support rod 31 and the second support rod 32 away from each other, thereby allowing the diagonal brace 3 to extend. The first support rod 31 connects to a truss section 21 of an anchor rod 2, and the second support rod 32 connects to a fixing member on the bedrock 1. The adjustment component 33 allows the diagonal brace 3 to actively extend, generating an outward jacking force as a prestressed compression member. This jacking force acts on the main column node of the anchor rod 2, causing each anchor rod 2 to generate prestress synchronously, resulting in good overall prestress uniformity and high construction efficiency. Unlike traditional truss diagonal braces that only serve as stable supports, the diagonal brace 3 changes from passive support to active stress, significantly improving material utilization. After prestressing is applied, the diagonal brace 3, acting as a prestressed compression member, remains under compression, while the truss section 21 of the anchor rod 2, acting as a tension member, remains under tension. Together, they form a stable, self-balancing prestressing system to resist external loads. Simultaneously, the inclined anchor rod 2 decomposes the horizontal force into axial tension and vertical components. The anchor rod 2 bears the axial tension, while the free section 23 buffers the vibration generated by the vertical component through filler material. This triple mechanism significantly enhances the horizontal resistance. Alternatively, as an alternative implementation, the diagonal brace 3 can be set to a fixed length, with prestressing applied via external equipment such as jacks.

[0053] In one embodiment, the adjusting assembly 33 includes a first connecting portion, a second connecting portion, and an adjusting sleeve. The first connecting portion is disposed on the first support rod 31; the second connecting portion is disposed on the second support rod 32. The first end of the adjusting sleeve has a first threaded portion threadedly connected to the first connecting portion, and the second end of the adjusting sleeve has a second threaded portion threadedly connected to the second connecting portion. The first and second threaded portions rotate in opposite directions. Rotating the adjusting sleeve causes the first and second threaded portions, with their opposite rotation directions, to move the first and second connecting portions away from each other, thereby causing the diagonal brace 3 to actively extend. Alternatively, as an alternative embodiment, the adjusting assembly 33 can also be configured as a sliding sleeve structure, with a locking structure to lock the extension amount of the sliding sleeve.

[0054] According to an embodiment of the present invention, in another aspect, a construction method is also provided for the pressure-type anchor foundation described in the above embodiments, comprising the following steps: Drill holes in bedrock 1 to form anchor holes; The anchor rod 2 is lowered into the anchor hole, with the anchoring section 22 of the anchor rod 2 located below the surface of the bedrock 1 and the truss section 21 of the anchor rod 2 located above the surface of the bedrock 1. Grouting is performed at the bottom of the anchor hole to form a grout body, which wraps the anchoring section 22 of the anchor rod 2. The grout body is cured to the design strength so that the anchoring section 22 is fixedly connected to the bedrock 1. Truss section 21 serves as the main column of the truss foundation. Diagonal bracing rods 3 are installed on it. The diagonal bracing rods 3 are connected to truss section 21 through node connectors and bolts. The bolts are first initially tightened, and then the anchor rods 2 are prestressed before the bolts are finally tightened to lock them in place. Install the connecting plate 4 on the top of the anchor bolt 2, and install the tower leg 5 on the mounting plate.

[0055] During construction, the anchor rod 2 is inserted into the anchor hole of the bedrock 1, the anchoring section 22 is fixedly connected to the bedrock 1 through the cast-in-place body, the truss section 21 and the diagonal brace 3 form a truss support, and the anchor rod 2 continuously penetrates from the underground anchoring section 22 to the ground truss section 21, resulting in a short force transmission path. On-site, the node connectors, diagonal brace 3 and anchor rod 2 are initially connected by bolts. After applying prestress to the anchor rod 2, the bolts are tightened to lock it in place. No on-site welding is required, the quality is controllable, and the construction speed is fast.

[0056] In one embodiment, before the anchor rod 2 is lowered into the anchor hole, a bearing plate 6 is welded to the bottom of the anchor rod 2, and a shear connector is welded to the surface of the anchoring section 22. The cast-in-place structure binds the anchoring section 22 of the anchor rod 2, the shear connector, and the bearing plate 6 to the bedrock 1, forming the main load transfer area. The bearing plate 6 at the bottom of the anchor rod 2 provides pressure-type anchoring, and the shear connector provides bonded shear resistance, forming a composite anchoring system with significantly better load-bearing capacity than traditional single anchoring mechanisms.

[0057] In one embodiment, the free section 23 of the anchor rod 2 is also lowered into the anchor hole of the bedrock 1. After the grout has cured to the design strength, filler is added to the gap between the free section 23 and the bedrock 1 until it is flush with the surface of the bottom bedrock 1. A sealing device 7 is installed where the anchor rod 2 exits the bedrock 1. Under the action of horizontal force, the anchor rod 2 is allowed to undergo slight bending deformation and swaying to avoid stress concentration, while preventing the loss of filler material from the free section 23 and the infiltration of groundwater.

[0058] In one embodiment, during the application of prestress, a through-hole jack is installed on the top of the anchor rod 2 to tension the anchor rod 2 upwards. After reaching the designed prestress value, the nuts on the bolts are tightened. The through-hole jack causes each anchor rod 2 to generate prestress synchronously, and then all the bolts at the nodes are tightened to lock it, forming a fixed prestress state. The overall prestress is uniform, and the construction efficiency is high.

[0059] It should be noted that the method of applying stress using a through-hole jack is suitable for working conditions where the number of anchor bolts 2 is small, such as when there are four or fewer anchor bolts 2.

[0060] In one embodiment, during the application of prestress, the adjusting component 33 extends the diagonal brace 3 by rotating the adjusting sleeve. The jacking force generated by the diagonal brace 3 acts on the main column node of the truss section 21, causing the anchor rod 2 to generate pre-tension stress. After reaching the design prestress value, the nut of the locking bolt is tightened. By actively extending the diagonal brace 3 through the adjusting component 33, the diagonal brace 3, as a prestressed compression member, generates an outward jacking force. This jacking force acts on the main column node of the anchor rod 2, causing each anchor rod 2 to generate prestress synchronously, resulting in good overall prestress uniformity and high construction efficiency. The diagonal brace 3 is always under compression, forming a stable self-balancing prestressing system with the tensioned anchor rod 2. The diagonal brace 3 changes from passive support to active stress, significantly improving material utilization.

[0061] It should be noted that the method of using the active extension of the diagonal brace 3 as a prestressed compression bar is suitable for working conditions where there are a large number of anchor rods 2, such as when there are six or more anchor rods 2.

[0062] The working principle is as follows: During the construction phase, the anchor rod 2, equipped with a bearing plate 6 and shear connectors, is lowered into the anchor hole of the bedrock 1. The anchoring section 22 of the anchor rod 2 is below the surface of the bedrock 1, and the truss section 21 of the anchor rod 2 is above the surface of the bedrock 1. Grouting is performed at the bottom of the anchor hole to form a grout body, which wraps around the anchoring section 22 of the anchor rod 2. After the grout body is cured to the design strength, sand or other filler materials are filled into the gap between the free section 23 and the bedrock 1, and a sealing device 7 is installed. The truss section 21 serves as the main column of the truss foundation, and diagonal bracing rods 3 are installed. The diagonal bracing rods 3 pass through the nodes. The connectors and bolts are connected to the truss section 21. The bolts at the nodes are in a partially tightened state and not fully locked. The adjusting sleeve of the rotating adjustment component 33 causes the diagonal brace 3 to actively extend. The diagonal brace 3, acting as a prestressed compression member, generates an outward jacking force. This jacking force acts on the main upright node of the anchor rod 2, forcing each anchor rod 2 to undergo tensile deformation along its axial direction, forming prestress. The prestress is transmitted downward along the anchor rod 2 to the bearing plate 6 at the bottom of the anchoring section 22, and is converted into pressure on the grout. After being compressed, the grout transmits the pressure to the surrounding bedrock 1. After the anchor rod 2 reaches the designed prestress, the bolts are finally tightened to lock it in place, fixing the prestress state. The diagonal brace 3 is under compression, the anchor rod 2 is under tension, and the grout is under compression. The three interact to form a stable self-balancing prestressed system. A connecting plate 4 is installed on the top of the anchor rod 2, and the tower leg 5 of the tower is connected through the installation plate.

[0063] During the working load stage, when the tower is subjected to upward and horizontal forces, the load is transferred to the connecting plate 4 through the tower leg 5, and then to each anchor rod 2 through the connecting plate 4. Under the action of the upward force, the anchor rod 2 is further tensioned, and the bearing plate 6 at the bottom further compresses the grout. After being compressed, the grout transfers the load to the bedrock 1. Due to the prestressing already applied, the foundation deforms very little in the early stage of loading. Under the action of the horizontal force, the inclined anchor rod 2 decomposes the horizontal force into a tensile force along the axial direction of the anchor rod 2 and a component force perpendicular to the anchor rod 2. The axial tensile force is transferred to the grout to be borne by the bearing plate 6; the vertical component force causes the anchor rod 2 to bend slightly, which is absorbed by the filling material of the free section 23. The ground sealing device 7 allows the anchor rod 2 to swing slightly while preventing sand and soil loss. The diagonal brace 3, as a prestressed compression member, is always under compression and forms a self-balancing system with the tensioned anchor rod 2 to jointly resist external loads. When an external horizontal force acts on the truss foundation, the compressive stress of the diagonal brace 3 is superimposed on the external load, and the stiffness of the diagonal brace 3 provides additional horizontal resistance.

[0064] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A pressure-type anchor foundation, characterized in that, include: Anchor bolts (2), multiple anchor bolts (2) are provided on the bedrock (1), the multiple anchor bolts (2) are symmetrically distributed in the center, the part of the anchor bolt (2) exposed on the bedrock (1) is provided with a truss section (21), the part of the anchor bolt (2) extending into the bedrock (1) is provided with an anchoring section (22), the anchoring section (22) is fixedly connected to the bedrock (1) by grouting body; The truss platform uses the truss segment (21) as the main column of the truss platform. The truss platform is provided with diagonal bracing (3). The first end of the diagonal bracing (3) is connected to the top of the truss segment (21) of the anchor rod (2). The other end of the diagonal bracing (3) is connected to the fixing member on the bedrock (1). The diagonal bracing (3) and the truss segment (21) form a spatial truss structure. A connecting plate (4) is provided on the top of the anchor rod (2), and the connecting plate (4) is used to connect the tower legs (5) of the tower.

2. The pressure-type anchor foundation according to claim 1, characterized in that, Multiple anchor rods (2) are arranged symmetrically and obliquely to form an umbrella-shaped structure.

3. The pressure-type anchor foundation according to claim 2, characterized in that, The anchor rod (2) has a free section (23) in the middle. The free section (23) is located between the anchoring section (22) and the truss section (21). The gap between the free section (23) and the bedrock (1) is filled with a filler material, which is used to absorb the deformation and sway of the free section (23).

4. The pressure-type anchor foundation according to claim 1, characterized in that, The bottom of the anchoring section (22) is provided with a pressure plate (6), which is welded to the bottom end face of the anchoring section (22), and the pressure plate (6) is in contact with the grouting body around the anchoring section (22).

5. The pressure-type anchor foundation according to claim 4, characterized in that, The anchoring section (22) is provided with a shear connector on its surface, which is used to increase the adhesion between the anchoring section (22) and the grouting body.

6. The pressure-type anchor foundation according to claim 1, characterized in that, A sealing device (7) is provided at the point where the anchor rod (2) passes through the bedrock (1). The sealing device (7) includes a flexible water-stop ring and a sleeve. The sleeve is pre-embedded in the anchor hole of the bedrock (1). The anchor rod (2) passes through the sleeve. The flexible water-stop ring is set in the annular gap between the sleeve and the anchor rod (2).

7. The pressure-type anchor foundation according to any one of claims 1 to 6, characterized in that, The diagonal brace (3) is a prestressed compression bar. The diagonal brace (3) includes a first support rod (31) and a second support rod (32). An adjustment component (33) is provided between the first support rod (31) and the second support rod (32). The adjustment component (33) moves the first support rod (31) and the second support rod (32) away from each other so that the diagonal brace (3) can be extended.

8. The pressure-type anchor foundation according to claim 7, characterized in that, The adjustment component (33) includes: The first connecting part is disposed on the first support rod (31); The second connecting part is provided on the second support rod (32); An adjusting sleeve is provided with a first threaded portion at its first end that is threadedly connected to the first connecting portion, and a second threaded portion at its second end that is threadedly connected to the second connecting portion. The first threaded portion and the second threaded portion rotate in opposite directions.

9. A construction method, characterized in that, For a pressure-type anchor foundation according to any one of claims 1-8, the following steps are included: Drill holes in the bedrock (1) to form anchor holes; The anchor rod (2) is lowered into the anchor hole. The anchoring section (22) of the anchor rod (2) is below the surface of the bedrock (1), and the truss section (21) of the anchor rod (2) is above the surface of the bedrock (1). Grouting is performed at the bottom of the anchor hole to form a grout body. The grout body wraps the anchoring section (22) of the anchor rod (2). The grout body is cured to the design strength so that the anchoring section (22) is fixedly connected to the bedrock (1). The truss section (21) serves as the main column of the truss foundation. Diagonal bracing (3) is installed on the truss section (21) through node connectors and bolts. The bolts are first initially tightened, and then the anchor rod (2) is prestressed before the bolts are finally tightened to lock the prestressed state. Install a connecting plate (4) on the top of the anchor bolt (2), and install the tower leg (5) on the mounting plate.

10. The construction method according to claim 9, characterized in that, Before the anchor rod (2) is lowered into the anchor hole, a pressure plate (6) is welded to the bottom of the anchor rod (2), and a shear connector is welded to the surface of the anchoring section (22).

11. The construction method according to claim 9, characterized in that, The free section (23) of the anchor rod (2) is lowered into the anchor hole of the bedrock (1). After the grouting body is cured to the design strength, filler is added to the gap between the free section (23) and the bedrock (1) until it is flush with the bottom bedrock (1) surface. A sealing device (7) is installed at the point where the anchor rod (2) passes through the bedrock (1).

12. The construction method according to any one of claims 9-11, characterized in that, During the application of prestress, a through-type jack is installed on the top of the anchor rod (2) to tension the anchor rod (2) upwards. After reaching the designed prestress value, the nut of the bolt is tightened.

13. The construction method according to any one of claims 9-11, characterized in that, During the application of prestress, the adjusting component (33) extends the diagonal brace (3) by rotating the adjusting sleeve. The thrust generated by the diagonal brace (3) acts on the main column node of the truss section (21), causing the anchor rod (2) to generate prestress. After reaching the design prestress value, the nut of the locking bolt is tightened.

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