Steel structure column foot resisting tension shear and compression shear interaction and construction method

Abstract

The application discloses a steel structure column foot resisting tension-shear and compression-shear interaction and a construction method, and belongs to the technical field of steel structure engineering. The application solves the problems of the complex structure, low error tolerance and difficulty in effectively adapting to tension-shear and compression-shear interaction of the existing steel structure column foot. The application comprises a bottom steel plate, a top steel plate fixed to the lower end of the upper steel structure column, the top steel plate being arranged in parallel and spaced apart above the bottom steel plate and forming a preset gap, grouting material filled and solidified in the preset gap, a contact surface formed between the bottom steel plate and the top steel plate, and at least one bolt, the rod body of the bolt penetrating through the top steel plate and the bottom steel plate, and the top steel plate, the grouting material and the bottom steel plate being fastened into an integrated whole by the pre-tightening force of the bolt. The pre-tightening force of the bolt is greater than the maximum vertical tension design value of the column foot during the service period. The column foot is clear in stress and reliable in force transmission, can absorb the elevation and flatness deviation through on-site grouting of the grouting material, significantly improves the fatigue resistance and seismic performance, and is particularly suitable for steel structure engineering subjected to horizontal reciprocating load.

Description

Technical Field

[0001] This invention belongs to the field of steel structure engineering technology, specifically relating to a steel structure column base joint suitable for bearing horizontal reciprocating loads and having high adaptability to installation accuracy, and specifically relating to a steel structure column base and construction method for resisting tensile shear and compressive shear interaction. Background Technology

[0002] Steel column bases are critical force-transfer nodes connecting the superstructure and foundation, and their performance directly affects the safety and reliability of the overall structure. In structures such as industrial plants, large public buildings, and bridges, column bases not only bear vertical pressure but also need to resist horizontal shear forces caused by wind, earthquakes, etc., and may even bear upward tensile forces. Traditional steel structure column bases are mainly divided into hinged column bases and rigid column bases. Hinged column bases primarily transmit vertical forces and horizontal shear forces, but have weak bending resistance. Rigid column bases (such as exposed, embedded, and encased types) can transmit bending moments, shear forces, and axial forces, but they are usually complex in construction, require a large amount of on-site welding, and have extremely high requirements for construction precision. Furthermore, they are prone to localized damage or anchor bolt failure when subjected to cyclic loads in high-intensity seismic zones. Especially when dealing with on-site installation errors, traditional column bases have limited adjustment capabilities, often requiring cutting or shims, which affects construction efficiency and joint quality.

[0003] Therefore, there is an urgent need for a type of steel column base that can effectively resist the interaction of tension, compression, and shear, while also being able to be prefabricated in the factory, easy to assemble on site, have strong fault tolerance, and have a clear stress distribution. Summary of the Invention

[0004] One object of the present invention is to solve at least the above-mentioned problems and / or defects, and to provide at least the advantages described below.

[0005] Another objective of this invention is to provide a steel structure column base that resists the interaction of tension and shear, compression and shear. This column base has a clear force path, reliably withstanding the combined or reciprocating action of pressure, tension, and shear forces. Furthermore, by incorporating adjustable elliptical bolt holes and a grouting layer, it can effectively absorb and adapt to on-site installation errors, achieving high-precision and high-efficiency prefabricated construction.

[0006] This invention addresses the problems of traditional steel structure column bases, such as easy separation of the grout layer from the steel plate, unclear force transmission path, and severe reduction in shear bearing capacity when subjected to the interaction of tensile and shear forces. It also solves the problems of stringent requirements for absolute precision during on-site construction, difficulty in absorbing installation errors, large welding volume, and low construction efficiency.

[0007] This addresses the problems of insufficient strength of existing column base grout, poor bonding at the contact surface due to shrinkage deformation, and low preload of ordinary bolts, which are prone to loosening and cannot maintain sufficient contact pressure under tension and shear conditions.

[0008] This addresses the problem of difficulty in accurately and quickly adjusting the elevation and level of the top steel plate during column base installation, and the inability to accurately set the preset gap thickness, which leads to uneven grout layer thickness and affects load-bearing performance.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: A steel structural column base resistant to alternating tensile and compressive shear forces, comprising: The bottom steel plate is fixedly installed on the foundation. The top steel plate is fixedly installed at the lower end of the upper steel structure column, and the top steel plate is placed parallel to the bottom steel plate directly above it, forming a preset gap between the two. Grouting material, which fills and solidifies in the preset gap between the bottom steel plate and the top steel plate, and forms a contact surface with the upper surface of the bottom steel plate and the lower surface of the top steel plate; At least one bolt, the shank of which passes through a first through hole in the top steel plate and a corresponding second through hole in the bottom steel plate, the head of the bolt or nut pressing against the upper surface of the top steel plate or the lower surface of the bottom steel plate, and fastening the top steel plate, the grouting material and the bottom steel plate together by applying a preload; Wherein, the design value of the preload applied to the bolt is greater than the design value of the maximum vertical tensile force that the bolt may bear under the design load combination, so that when the vertical tensile force and the horizontal shear force work together, the contact surface between the grout and the bottom steel plate and the top steel plate always maintains a compressed state, that is, the contact surface can still maintain sufficient compression force, thereby bearing all or part of the horizontal shear force through the static friction between the contact surfaces.

[0010] Preferably, in the steel structure column base subjected to the interaction of tensile shear and compressive shear, the grouting material is a high-strength grouting material with a compressive strength of not less than 60 MPa, and the high-strength grouting material is a cement-based or epoxy-based grouting material with micro-expansion characteristics. At least one bolt is a high-strength bolt.

[0011] Preferably, in the steel structure column base with tensile and compressive shear interaction, the periphery of the bottom steel plate is provided with at least 3 threaded through holes, and a leveling load-bearing bolt is inserted in the threaded through holes. The top of the leveling load-bearing bolt abuts against the lower surface of the top steel plate. The elevation and levelness of the top steel plate are adjusted by rotating the leveling load-bearing bolt, and the thickness of the preset gap is set.

[0012] Preferably, in the steel structure column base with tensile and compressive shear interaction, the second through hole opened on the bottom steel plate is an elliptical elongated hole, the first through hole opened on the top steel plate is an elliptical elongated hole, and the major axis directions of the elliptical elongated holes on the bottom steel plate and the top steel plate are orthogonal to each other. A pre-embedded sleeve is inserted into the first through hole and the second through hole. The outer wall of the pre-embedded sleeve is coated with a release agent. The pre-embedded sleeve is pulled out after the high-strength grout has initially set. The high-strength bolt is installed after the high-strength grout has been cured to the design strength.

[0013] Preferably, in the steel structure column base with tensile shear and compressive shear interaction, at least one grouting hole and at least one venting hole are provided on the top steel plate and / or the bottom steel plate. The grouting hole is used to inject the high-strength grout into the preset gap, and the venting hole is used to discharge the air in the preset gap.

[0014] Preferably, in the steel structure column base with tensile and compressive shear interaction, the bottom steel plate is fixedly connected to the foundation by pre-embedded anchor bolts or welding; The top steel plate is fixedly connected to the upper steel structure column by welding or bolting.

[0015] Preferably, in the steel structure column base with tensile and compressive shear interaction, the thickness of the preset gap can be adjusted by the amount of high-strength grout injected on site to absorb the elevation error and flatness deviation of the foundation.

[0016] Preferably, in the steel structure column base with tensile and compressive shear interaction, the high-strength bolts are equipped with a long-term preload maintenance device. This device includes an elastic compensation element located below the bolt head or nut. The elastic compensation element automatically releases elastic potential energy to maintain the contact surface clamping force when the bolt preload decays.

[0017] Preferably, in the steel structure column base with the interaction of tensile shear and compressive shear, the bolt shank and the wall of the elliptical elongated hole are provided with a radial clearance adjustment and progressive shear bearing structure. This structure ensures that the bolt does not form shear bearing contact with the hole wall in the initial state, and gradually establishes contact to share the shear force when the horizontal shear force exceeds the static friction force.

[0018] A construction method for a steel structure column base subjected to tensile-shear and compressive-shear interaction as described in any one of the claims includes the following steps: The base steel plate is fixedly installed on the foundation; The top steel plate is fixedly installed at the lower end of the upper steel structure column; The upper steel structure column with the top steel plate is hoisted to the top of the bottom steel plate. The elevation and level of the top steel plate are adjusted by screwing the leveling load-bearing bolts set around the bottom steel plate, so as to set the thickness of the preset gap between the top steel plate and the bottom steel plate. A sleeve coated with a release agent is inserted into the first through hole opened on the top steel plate and the corresponding second through hole opened on the bottom steel plate; High-strength grout is injected into the preset gap under pressure until the high-strength grout continuously overflows from the vent holes opened on the top steel plate and / or bottom steel plate. After the high-strength grout has initially set, the sleeve is pulled out to form bolt holes; After the high-strength grout has cured to the design strength, high-strength bolts are inserted into the bolt holes and a pre-tightening force is applied. The design value of the pre-tightening force is greater than the design value of the maximum vertical tensile force that the column base will bear during service.

[0019] Compared with the prior art, the present invention has the following advantages: 1. Clear force distribution and reliable performance: The force transmission paths of the two main working conditions, compression shear and tension shear, are clearly distinguished. The high-strength bolt preload ensures that the grouting material can still participate in shear resistance under tension conditions. The overall fatigue resistance and cyclic load resistance of the joint are excellent.

[0020] 2. High degree of prefabrication and convenient construction: Major components such as bottom steel plate, top steel plate, and high-strength bolts can be produced in the factory in a standardized manner. On-site, only positioning, pouring high-strength grout and tightening bolts are required, which greatly reduces on-site welding and improves construction quality and speed.

[0021] 3. High tolerance for errors and high adaptability: The force transmission layer is formed by injecting high-strength grout on site. The gap thickness can be precisely adjusted according to the actual installation situation, effectively absorbing the elevation error and unevenness of the foundation during structural installation, and reducing the stringent requirements for absolute precision on site.

[0022] 4. Wide applicability: It is particularly suitable for large steel structures that are subjected to horizontal reciprocating forces such as earthquakes and waves, as well as engineering scenarios with high requirements for installation efficiency and quality control.

[0023] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0024] Figure 1 This is a detailed drawing of a steel column base subjected to the interaction of tensile shear and compressive shear in one embodiment of the present invention.

[0025] Figure 2 This is a detailed drawing of the column base in one embodiment of the present invention.

[0026] Bottom steel plate 1, top steel plate 2, grouting hole 21, vent hole 22, high-strength grouting material 3, high-strength bolt 4, upper steel structure column 5, foundation 6, leveling load-bearing bolt 7, sleeve 8, release agent 9. Detailed Implementation

[0027] The present invention will now be described in further detail so that those skilled in the art can implement it based on the description.

[0028] It should be noted that, unless otherwise specified, the experimental methods described in the following implementation plan are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified.

[0029] This invention discloses a steel structure column base resistant to alternating tensile and compressive shear forces, relating to the field of steel structure engineering. The column base includes a bottom steel plate 1, a top steel plate 2, high-strength grout 3 filling the gap between the two, and high-strength bolts 4 connecting the steel plates. When compressive and shear forces act together, the steel plate and grout 4 work together to bear the load; when tensile and shear forces act together, the tensile force is borne by the high-strength bolts 4, while the preload of the bolts ensures that the grout 4 is continuously compressed, thus providing the frictional force required for shear resistance. This column base forms an adjustable force transmission layer through on-site grouting, effectively absorbing installation errors and realizing an efficient construction mode of factory prefabrication and on-site assembly. It has advantages such as clear force distribution, good seismic performance, high fault tolerance, and convenient construction, and is particularly suitable for large steel structures subjected to horizontal reciprocating loads.

[0030] According to one embodiment of the present invention, a steel structure column base resistant to tensile-shear and compressive-shear interactions includes a bottom steel plate 1, a top steel plate 2, high-strength grout 3, and high-strength bolts 4. The high-strength grout 3 fills and solidifies within a predetermined gap between the bottom steel plate 1 and the top steel plate 2. The high-strength bolts 4 penetrate corresponding predetermined through holes on the top steel plate 2 and the bottom steel plate 1, and are reliably connected by applying a preload. The bottom steel plate 1 and the top steel plate 2 are each provided with mutually orthogonal elliptical elongated holes for adjusting the horizontal error during column base installation. The thickness of the predetermined gap is adjusted and set by on-site injection of the high-strength grout 3 to adapt to different installation elevations and flatness requirements.

[0031] The force mechanism of this invention is as follows: Under compression-shear conditions: When the column base is subjected to vertical compression and horizontal shear force, the vertical compression is transmitted from the top steel plate 2 to the bottom steel plate 1 through the high-strength grout 3, and then from the bottom steel plate 1 to the foundation 6. The horizontal shear force is borne by the shear strength of the high-strength grout 3 itself and the friction between the grout and the contact surfaces of the top and bottom steel plates 1. Because the grout is under triaxial compression, its shear and friction resistance are fully utilized.

[0032] Tensile-shear conditions: When the column base is subjected to both vertical tensile force and horizontal shear force, the vertical tensile force is entirely borne by the high-strength bolts 4. The key design feature is that the preload applied by the high-strength bolts 4 must exceed the maximum tensile force design value that the column base may withstand. This ensures that even under tensile force, sufficient clamping force is maintained between the high-strength grout 3 and the steel plate contact surface, thereby continuously providing the frictional force required to resist horizontal shear force and ensuring that the shear force transmission path is uninterrupted. The grout itself also provides partial shear resistance under preload stress.

[0033] According to one embodiment of the present invention, a steel structure column base resistant to tensile-shear and compressive-shear interactions includes the following steps: The bottom steel plate 1 is fixedly installed on the foundation 6; The top steel plate 2 is fixedly installed at the lower end of the upper steel structure column 5, and the top steel plate 2 is placed parallel to the bottom steel plate 1 directly above it, forming a preset gap between the two. Grouting material fills and solidifies in the preset gap between the bottom steel plate 1 and the top steel plate 2, forming a contact surface with the upper surface of the bottom steel plate 1 and the lower surface of the top steel plate 2; At least one bolt, the shank of which passes through a first through hole in the top steel plate 2 and a corresponding second through hole in the bottom steel plate 1. The head of the bolt or a nut presses against the upper surface of the top steel plate 2 or the lower surface of the bottom steel plate 1, and the top steel plate 2, the grouting material and the bottom steel plate 1 are fastened together by applying a preload. Wherein, the design value of the preload applied to the bolt is greater than the design value of the maximum vertical tensile force that the bolt can withstand under the design load combination, so that when the vertical tensile force and the horizontal shear force work together, the contact surface between the grout and the bottom steel plate 1 and the top steel plate 2 always maintains a compressed state, thereby bearing all or part of the horizontal shear force through the static friction between the contact surfaces.

[0034] Specifically, the steel structure column base with tensile and compressive shear interaction provided in this embodiment includes a bottom steel plate 1, which is fixed to the concrete foundation 6 by pre-embedded anchor bolts. It also includes a top steel plate 2, which is welded to the lower end of the upper steel structure column 5 in the factory to form an integral component before being hoisted directly above the bottom steel plate 1. The top steel plate 2 and the bottom steel plate 1 are arranged parallel to each other, forming a pre-set gap between them. The thickness of this gap is determined based on the actual measured elevation on site, typically controlled within the range of 50 mm to 100 mm. The pre-set gap is completely filled with cured high-strength cement-based grout, which adheres tightly to the upper surface of the bottom steel plate 1 and the lower surface of the top steel plate 2, forming a contact surface with a stable coefficient of friction. Four high-strength bolts 4 are installed at the column base. The bolt shanks pass through the first through hole opened on the top steel plate 2 and the corresponding second through hole opened on the bottom steel plate 1. The bolt nuts are pressed against the upper surface of the top steel plate 2. The preload required by the design is applied by the torque method, thereby fastening the top steel plate 2, the grouting material and the bottom steel plate 1 into a whole load-bearing composite component.

[0035] The core design parameter of this embodiment lies in the value of the bolt preload. Based on the overall structural analysis, the maximum vertical tensile force design value that the column base may withstand during its service life is determined. The preload design value applied to each high-strength bolt 4 is set to 1.2 times this maximum vertical tensile force design value. This preload level ensures that under tensile-shear conditions where vertical tensile force and horizontal shear force act simultaneously, although the vertical tensile force tends to separate the contact surface between the top steel plate 2 and the grout, the continuous clamping effect provided by the bolt preload is sufficient to offset the tensile force, so that the contact surfaces between the grout and the top steel plate 2, and between the grout and the bottom steel plate 1, always remain in a clamped state and do not separate. At this time, the horizontal shear force is entirely borne by the static friction between the contact surfaces, without relying on the shear strength of the grout itself or the direct shearing of the bolts.

[0036] During installation, the bottom steel plate 1 is first placed on the foundation 6 and initially fixed and adjusted to a roughly horizontal position using pre-embedded anchor bolts. The steel structure column with the top steel plate 2 is hoisted above the bottom steel plate 1. The lower surface of the top steel plate 2 is supported by four temporary leveling jacks set around the bottom steel plate 1. The elevation and levelness of the top surface of the top steel plate 2 are measured using a precision level. The jacks are rotated to adjust the top steel plate 2 to the designed position. At this point, the cavity between the bottom steel plate 1 and the top steel plate 2 is the preset gap. Steel sleeves 8 coated with release agent 9 are inserted into the bolt holes of the top steel plate 2 and the bottom steel plate 1 to reserve bolt channels. A sealing template is set around the preset gap. High-strength, non-shrink cement-based grout is pressurized into the gap through the grouting holes reserved on the top steel plate 2. During the grouting process, the air in the gap is discharged through the vent holes reserved on the top steel plate 2 until the vent holes continuously overflow with full grout. After the grout has initially set, remove the steel sleeve 8 and continue curing until the grout reaches 28 days of age, at which point its compressive strength reaches the design requirement of 80 MPa. Finally, insert the high-strength bolts 4 and apply pre-tightening force in two stages from the center outwards. The final tightening torque is determined by converting the design pre-tightening force, thus completing the column base installation.

[0037] Existing technologies often employ conventional exposed rigid column bases. This column base consists of a base plate connected to the foundation 6 via four anchor bolts. A secondary grouting layer is installed beneath the base plate, and a cross-shaped shear key is welded to the center of the base plate, embedded in a pre-drilled groove on the top surface of the foundation 6. The upper steel column is connected to the base plate via a full-penetration bevel weld. During construction, the foundation 6 is first poured and anchor bolts are pre-embedded. After the concrete in the foundation 6 reaches its strength, the base plate is fitted with the anchor bolts. A group of steel pads is placed between the lower edge of the base plate and the top surface of the foundation 6 to adjust the elevation and level. The anchor bolts are then tightened, and fine aggregate concrete or grout is poured into the gap between the base plate and the foundation 6 to form a secondary grouting layer. The force transmission mechanism of this column base is as follows: vertical pressure is transmitted from the base plate to the foundation 6 through the secondary grouting layer; vertical tension is entirely borne by the anchor bolts; horizontal shear force is mainly borne by the shear key, with the friction between the anchor bolts, the base plate, and the grouting layer playing only an auxiliary role. Traditional column bases face inherent defects under tension-shear conditions. When vertical tension is applied, the base plate tends to pull upwards, the clamping force between the base plate and the secondary grouting layer disappears or even gaps appear, and the frictional force at the contact surface is lost. All horizontal shear force is forced to be borne solely by the shear key. There is compressive stress concentration between the shear key and the foundation concrete, which can easily lead to localized crushing. Simultaneously, the anchor bolts, while bearing tension, may also bear additional shear force due to base plate slippage, creating a combined tension-shear stress state, significantly reducing the anchor bolts' load-bearing capacity and ductility. After repeated tension-shear loading, the gap between the shear key and the concrete gradually widens, and the accumulation of plasticity in the anchor bolts leads to preload relaxation, resulting in a significant degradation of joint stiffness.

[0038] This embodiment ensures that the grout and steel plate contact surface remain tightly pressed together under tension-shear conditions by setting the bolt preload to be greater than the maximum vertical tensile force. Static friction remains effective, and horizontal shear force is uniformly transmitted through the contact surface. The grout is under triaxial compression, resulting in stable shear resistance. The bolts only bear tensile force and do not participate in direct shear resistance, leading to a clear force path without stress concentration. In this embodiment, the grout and steel plate contact surface remain tightly fitted under bolt preload, maintaining stable static friction under cyclic loads with no cumulative slippage. The joint's fatigue resistance and seismic performance are significantly superior to traditional structures.

[0039] This embodiment proposes a steel structure column base tensile-shear design method based on preload control, redefining the force transmission path of the column base under tensile-shear interactive conditions. It transforms the traditional indirect force transmission mode, relying on shear keys or anchor bolts, into a direct force transmission mode based on static friction at the contact surface. This scheme creatively achieves a continuous compression state between the grout and the steel plate contact surface under tensile force by forcibly setting the bolt preload design value to be greater than the maximum vertical tensile force. This unifies the compression-shear and tensile-shear conditions into a single friction-based shear resistance mechanism, greatly simplifying the design analysis model and making the stress behavior of the nodes highly predictable.

[0040] This embodiment completely solves the persistent problem of traditional column bases experiencing a sharp decline or even loss of shear resistance under tension and shear conditions, enabling the column base to maintain stable shear stiffness and bearing capacity under any ratio of vertical tension and horizontal shear force. Structurally, this embodiment eliminates complex shear keys, support plates, and other additional force-transmitting components, significantly simplifying the column base components, all of which can be prefabricated in a standardized factory. In terms of construction, this embodiment elevates the function of the grouting layer from passive filling to a dual role of active load-bearing and error absorption. On-site operations are simplified to three main processes: positioning, grouting, and fastening. This eliminates a large amount of on-site processing work such as hole enlargement, plate placement, and secondary alignment required in traditional column base installation, significantly shortening the construction cycle and greatly improving quality controllability. In terms of engineering adaptability, this structure exhibits extremely high tolerance for foundation construction errors, making it particularly suitable for complex projects with large-area, multi-column simultaneous installation requirements, such as large industrial plants, stadiums, and airport terminals, as well as high-rise buildings and bridge structures subjected to repeated wind, wave, or earthquake forces.

[0041] According to one embodiment of the present invention, a steel structure column base resisting tensile shear and compressive shear interaction is provided, wherein the grouting material is a high-strength grouting material 3 with a compressive strength of not less than 60 MPa, and the high-strength grouting material 3 is a cement-based or epoxy-based grouting material with micro-expansion characteristics. The at least one bolt is a high-strength bolt 4.

[0042] Specifically, this embodiment further specifies the selection and performance of grouting material and bolts based on the column base structure 6 defined in the previous embodiment. The grouting material filling the pre-defined gap between the bottom steel plate 1 and the top steel plate 2 in the column base is a high-strength cement-based grouting material with a 28-day compressive strength of not less than 60 MPa. The mixture exhibits micro-expansion characteristics, and the restricted expansion rate after 14 days of water curing is controlled within a reasonable range, effectively compensating for the chemical shrinkage and plastic settlement of the grout during the hydration and hardening process. Simultaneously, the bolts connecting the top steel plate 2 and the bottom steel plate 1 in the column base are high-strength large hexagonal head bolts or torque-shear type high-strength bolts, with a performance grade of 10.9 or 8.8. The design preload is determined according to current steel structure design specifications and is precisely applied using the torque method or by breaking the bolt's tail end.

[0043] During construction, the bottom steel plate 1 is fixed to the foundation 6, and the top steel plate 2 is hoisted into place after being connected to the upper steel column. The top steel plate 2 is then adjusted to the design elevation using a leveling device. A sealing template is erected around the pre-set gap, and the aforementioned high-strength micro-expansion grout is injected through the grouting holes using a pressure grouting process. The vent holes are sealed after grout overflows. Before the grout initially sets, it is properly cured to prevent water loss. Once the strength reaches the design requirements, high-strength bolts 4 are installed and pre-tightened. The micro-expansion effect of the grout generates slight self-stress during the hardening process, resulting in a tighter fit between the grout layer and the contact surfaces of the upper and lower steel plates, thus enhancing the initial contact pressure.

[0044] This embodiment utilizes high-strength grout 3 with a compressive strength of not less than 60 MPa, enabling the grout layer to possess higher compressive and shear bearing capacity reserves, allowing it to withstand greater vertical pressure and horizontal shear force without crushing or shear failure. The micro-expansion characteristic fundamentally solves the long-standing quality problem of contact surface voids caused by grout hardening shrinkage in column base construction. The expansion effect allows the grout layer to actively press against the steel plate, resulting in a significantly higher initial contact stress than ordinary grout, and a stable contact surface friction coefficient. The use of high-strength bolts 4 increases the preload level several times compared to ordinary anchors, and the preload application process is controlled and the values ​​are clearly defined, forming a complete technical chain with the design requirement of preload exceeding the maximum vertical tensile force. The relaxation rate of high-strength bolts 4 is far lower than that of ordinary bolts, and combined with the continuous pressing effect of the micro-expansion grout, the long-term maintenance of contact surface pressing force under tensile and shear conditions is fundamentally guaranteed.

[0045] This embodiment specifies the material and performance parameters of the grout and bolts, transforming the stress mechanism into an engineering-feasible and verifiable technical solution. The high-strength grout 3 provides a stable, high-friction coefficient contact surface for frictional force transmission. Its micro-expansion characteristics actively compensate for contraction and eliminate gaps, ensuring the contact surface is in a tightly compressed state from the initial stage. The high-strength bolt 4 provides sufficient and controllable preload, enabling designers to accurately calculate bolt specifications and quantity based on the maximum vertical tensile force, ensuring the contact surface remains tightly compressed under tension and shear conditions.

[0046] According to one embodiment of the present invention, a steel structure column base resistant to tensile shear and compressive shear interaction is provided, wherein at least three threaded through holes are provided around the periphery of the bottom steel plate 1, and a leveling load-bearing bolt 7 is inserted in the threaded through holes. The top end of the leveling load-bearing bolt 7 abuts against the lower surface of the top steel plate 2. The elevation and levelness of the top steel plate 2 are adjusted by rotating the leveling load-bearing bolt 7, and the thickness of the preset gap is set.

[0047] Specifically, this embodiment adds a structural device dedicated to adjusting the elevation and levelness of the top steel plate 2. Three or four threaded through holes are symmetrically positioned around the perimeter of the bottom steel plate 1. A fully threaded leveling bolt 7 is screwed into each hole, with the top end of the bolt machined into a spherical or flat shape for contact with the lower surface of the top steel plate 2. When hoisting the upper steel column with the top steel plate 2, the top steel plate 2 is first placed on top of each leveling bolt 7. Then, a precision level or laser leveling instrument is used to monitor the elevation and levelness of the characteristic points on the top surface of the top steel plate 2. The operator uses a regular wrench or a special torque wrench to rotate each leveling bolt 7, causing the bolt to screw into or out of the threaded hole in the bottom steel plate 1, thereby raising or lowering the corresponding corner points of the top steel plate 2 until the top steel plate 2 reaches the design elevation and the height difference between any two points is controlled within the installation accuracy requirements. At this point, the cavity height between the bottom steel plate 1 and the top steel plate 2 is uniform, which is the design thickness of the preset gap. Once the preset gap thickness is determined, this thickness will be completely filled and solidified by the grouting material during subsequent grouting operations. The leveling load-bearing bolt 7 does not need to be removed and can be permanently retained inside the column base or loosened according to design requirements.

[0048] This embodiment uses leveling load-bearing bolts 7 instead of traditional steel pads, upgrading the leveling device from discrete passive pads to a continuously adjustable active threaded mechanism. The leveling load-bearing bolts 7 form a helical pair with the threaded through holes on the bottom steel plate 1. Rotating the bolts allows for continuous and precise adjustment of the elevation of the top steel plate 2, with an adjustment resolution reaching millimeter or even sub-millimeter levels, far exceeding the discrete adjustment capability of the pad combination. Multiple leveling load-bearing bolts 7 are evenly arranged around the perimeter of the bottom steel plate 1, providing multi-point support for the top steel plate 2. The support points are clearly defined, ensuring balanced force distribution and stable horizontal posture of the top steel plate 2 during leveling, preventing tilting or torsion. The preset gap thickness is directly determined by the lifting height of the leveling bolts, ensuring thickness uniformity. The grout layer formed after grouting has a consistent thickness, resulting in uniform compressive stress distribution under load and eliminating localized stiffness zones caused by the pad method. After grouting, the leveling bolts can be retained or loosened according to the design. When retained, the bolts and the grout layer share the load, further improving the vertical load-bearing redundancy of the joint.

[0049] This embodiment introduces a leveling load-bearing bolt 7, enabling tool-based and precise adjustments to the elevation and levelness during column base installation. Its advantages include: completely eliminating the traditional trial-and-error leveling method using shims, reducing reliance on operator experience, and significantly shortening installation alignment time; the preset gap thickness can be precisely set and maintained constant, providing a geometric prerequisite for uniform force transmission in the grouting layer; the threaded connection between the leveling bolt and the bottom steel plate 1 forms a reliable self-locking mechanism, ensuring stable positioning after adjustment and preventing changes due to subsequent construction disturbances; this structure utilizes the column base's own components to achieve the leveling function without additional tooling or equipment, making it suitable for steel structure column bases of various sizes, especially for the installation of heavy steel columns with large tonnage and large cross-sections.

[0050] According to one embodiment of the present invention, a steel structure column base resistant to tensile shear and compressive shear interaction is provided, wherein the second through hole opened on the bottom steel plate 1 is an elliptical elongated hole, the first through hole opened on the top steel plate 2 is an elliptical elongated hole, and the major axis directions of the elliptical elongated holes on the bottom steel plate 1 and the top steel plate 2 are orthogonal to each other. Before injecting the high-strength grout 3, a pre-embedded sleeve is inserted into the first through hole and the second through hole. The outer wall of the pre-embedded sleeve 8 is coated with a release agent 9. The pre-embedded sleeve 8 is pulled out after the high-strength grout 3 has initially set. After the high-strength grout 3 has been cured to the design strength, the high-strength bolt 4 is installed.

[0051] This embodiment further defines the bolt hole form and forming process on the top steel plate 2 and bottom steel plate 1 within the defined column base structure 6. The first through hole on the top steel plate 2 is an elliptical elongated hole, with its major axis extending along a certain horizontal main axis of the structure. The second through hole on the bottom steel plate 1 is also an elliptical elongated hole, but its major axis is orthogonal to the major axis of the elongated hole on the top steel plate 2. That is, if the major axis of the elongated hole on the top steel plate 2 is east-west, then the major axis of the elongated hole on the bottom steel plate 1 is north-south. The allowance for the diameter of the elongated holes on both plates is determined based on the estimated installation deviation. Typically, an adjustment allowance of 20 mm to 40 mm is reserved in the major axis direction, and a clearance fit is formed between the minor axis direction and the bolt shank diameter to ensure that the bolt can be smoothly inserted.

[0052] The elliptical elongated hole is not directly machined, but precisely pre-reserved during the grouting stage using a pre-embedded sleeve method (8). After the top steel plate 2 and bottom steel plate 1 are in place and the preset gap thickness is adjusted, a steel sleeve 8 is inserted at the corresponding hole position. The outer wall of the sleeve 8 is evenly coated with a release agent 9, and both ends of the sleeve 8 extend a certain length beyond the upper surface of the top steel plate 2 and the lower surface of the bottom steel plate 1, respectively. High-strength grout 3 is then poured in. After the grout has initially set but before final setting, the sleeve 8 is rotated out, forming a complete and smooth elliptical channel in the not-yet-fully-hardened grout. After the grout continues to cure to the design strength, high-strength bolts 4 are inserted, washers and nuts are installed, and pre-tightening force is applied. The bolt shank does not directly contact the hole wall; the pre-reserved annular gap provides the structure with horizontal bidirectional free displacement capability under temperature changes, seismic action, or installation deviations.

[0053] This embodiment employs a bidirectional orthogonal elliptical elongated hole design, enabling the column base to simultaneously possess installation and adjustment capabilities in two main axial directions. It provides two-dimensional tolerance for spatial positional deviations of the foundation 6 embedded parts and the superstructure, significantly improving the success rate of on-site installation in a single attempt and completely eliminating destructive rework such as hole enlargement and anchor bolt relocation. The orthogonal elongated hole directions are independent of each other, and the adjustment functions do not interfere with each other. Designers can set the adjustment amount in each direction according to the actual deformation characteristics of the structure. The use of pre-embedded sleeves 8 to form the holes avoids the difficult work of secondary drilling on hardened grout. The hole position and diameter are precisely controllable, the hole wall is smooth and undamaged, and the tiny annular gap left after the sleeve 8 is pulled out further increases the radial displacement space of the bolts. More importantly, the grout completely covers the bolt hole area, and the hole wall is a solid grout layer, avoiding local weakening and stress concentration of the steel plate compared to directly drilling holes in the traditional steel plate.

[0054] This embodiment combines the orthogonal elliptical elongated holes with the pre-embedded sleeve 8 forming process to endow the steel structure column base with unprecedented installation tolerance and service adaptability. During the construction phase, the orthogonal elongated holes release bidirectional horizontal positioning errors, enabling flexible matching between the factory-prefabricated high-precision components and the foundation 6 with deviations on site, truly achieving prefabricated construction. During the service phase, the allowance of the elongated holes provides free travel for slow or reciprocating horizontal movements such as temperature deformation and seismic displacement, avoiding additional constraint stress in non-stress directions in the node area, significantly improving the seismic toughness and fatigue life of the structure. The pre-embedded sleeve 8 forming process allows the high-strength grouting material 3 to simultaneously serve as a force transmission medium and a channel forming agent, with high process integration, superior channel quality compared to mechanical drilling, and avoids weakening the steel plate cross-section.

[0055] According to one embodiment of the present invention, a steel structure column base resistant to tensile shear and compressive shear interaction has at least one grouting hole and at least one venting hole on the top steel plate 2 and / or the bottom steel plate 1. The grouting hole is used to inject the high-strength grout 3 into the preset gap, and the venting hole is used to discharge the air in the preset gap.

[0056] This embodiment further defines the structural conditions for the grouting operation. A grouting hole and a vent hole are pre-drilled on the upper surface of the top steel plate 2. Both the grouting hole and the vent hole have a diameter of 30 mm and are located on opposite sides of the edge of the top steel plate 2, with the grouting hole positioned slightly lower than the vent hole. Gravity and grouting pressure create an upward filling path. The bottom steel plate 1 has a through-hole corresponding to the grouting hole and vent hole of the top steel plate 2, or the bottom steel plate 1 itself has a separate grouting hole and vent hole, forming a vertically continuous grouting channel. After the top steel plate 2 is adjusted to the design elevation using the leveling bolts 7 and the preset gap thickness is determined, a sealing template is erected around the preset gap. The grouting hose is connected to the grouting hole connector, and the grouting pump is started to inject high-strength micro-expansion cement-based grout into the gap under pressure. During the grouting process, the air in the pre-set gaps is pushed towards the vent holes by the grout and continuously discharged through the vent holes until the grout overflowing from the vent holes has the same fluidity as the injected grout and no air bubbles are released. Then, the vent holes and grouting holes are sealed in sequence, and grouting is stopped. After grouting is completed, check the area around the vent holes and the edges of the formwork. There should be no leakage or voids, and the grout should be fully and densely filled.

[0057] This embodiment transforms grouting operations from experience-based judgment to a visible and controllable deterministic process by setting dedicated grouting holes and vents on the top steel plate 2 or bottom steel plate 1. The grouting holes and vents form a complete displacement channel, with the injected grout continuously displacing air from the gaps, ensuring that air can only escape through the vent, fundamentally eliminating the possibility of air stagnation. Grout overflow from the vent serves as a clear criterion for full grouting, allowing construction personnel to accurately determine the timing of grouting termination without relying on experience, making grouting quality inspection intuitive and reliable. The grouting holes and vents are pre-fabricated in the factory, eliminating the need for on-site drilling. The holes are precisely positioned with smooth walls, ensuring a good seal when connected to the grouting hose, preventing grout leakage and contamination. This structure utilizes the existing steel plate of the column base without adding any independent components, resulting in extremely low cost and significant effectiveness.

[0058] This embodiment provides a complete fluid channel and venting mechanism for the pressure grouting of high-strength grout 3 by setting grouting holes and venting holes on the top steel plate 2 or bottom steel plate 1. Its advantages are: ensuring 100% filling density of the grout within the preset gap, with no voids or missing grout on the contact surface, and all designed contact areas effectively participating in frictional force transmission; grout leakage from the venting holes serves as a clear signal of grouting completion, making grouting quality visible rather than hidden, with objective and unified inspection standards, significantly reducing reliance on the experience of construction personnel; the factory prefabrication of the grouting holes and venting holes ensures hole position accuracy and structural strength, requiring only pipe connection operations on-site, further reducing on-site process time. The complete and compacted contact surface state relied upon in this embodiment is fundamentally guaranteed at the construction level, and is a key quality control measure for translating the tensile and shear performance of column bases from design drawings to actual engineering.

[0059] According to one embodiment of the present invention, a steel structure column base resistant to tensile shear and compressive shear interaction, wherein the bottom steel plate 1 is fixedly connected to the foundation 6 by pre-embedded anchor bolts or welding; The top steel plate 2 is fixedly connected to the upper steel structure column 5 by welding or bolting.

[0060] This embodiment provides several standardized options for the connection between the column base and the foundation 6 and the superstructure. The connection between the bottom steel plate 1 and the concrete foundation 6 adopts one of the following two methods: Method 1, four anchor bolts are pre-embedded during the pouring of the foundation 6 concrete, and round holes are opened at the corresponding positions on the bottom steel plate 1. After the bottom steel plate 1 is in place, the anchor bolts are inserted, and the anchor bolt nuts are tightened to press the bottom steel plate 1 firmly against the top surface of the foundation 6; Method 2, a thick steel plate or a continuous angle steel is pre-embedded on the top surface of the foundation 6, and the edge of the bottom steel plate 1 is welded to the pre-embedded part with a continuous fillet weld, and the weld height is designed according to the equal strength. The connection between the top steel plate 2 and the upper steel structure column 5 adopts one of the following two methods: Method 1, a bevel is opened at the lower end of the upper steel column, and a full penetration butt weld is used to connect it to the top surface of the top steel plate 2. The weld is inspected and qualified by ultrasonic testing. Method 2, a flange connection plate is welded to the lower end of the upper steel column, and bolt holes are opened at the corresponding positions on the top steel plate 2. A high-strength bolt friction connection is used between the steel column flange and the top steel plate 2. The contact surface of the connection plate is sandblasted, and the anti-slip coefficient meets the design requirements. The above connection structures are mainly processed in the factory, and only anchor bolt tightening, welding or high-strength bolt 4 tightening operations are performed on site.

[0061] This embodiment provides two parallel optional technical solutions for the foundation 6 connection and column base connection: anchor bolt connection and welding connection, and welding connection and bolt connection. This allows the column base node to flexibly match different engineering conditions. For newly constructed concrete structures, anchor bolt connection is the mature and efficient preferred solution. For steel structure foundations 6 or the reinforcement and renovation of existing buildings, welding connection can avoid rebar installation or redoing foundation 6. For ordinary steel columns, the top plate welding connection provides direct force transmission and high rigidity. For parts that require frequent disassembly or assembly or where welding conditions are not available on site, the top plate bolt connection allows for fully prefabricated construction, and disassembly only requires loosening the nuts, allowing the column to be completely recovered. All connection structures follow the principle of factory prefabrication and on-site assembly, completing a large amount of high-precision processing in the factory, with only standardized fastening or welding procedures performed on-site, significantly improving quality control.

[0062] This embodiment allows the same column base design to be applied to both concrete foundation 6 and steel structure foundation 6, solving the inherent problem of traditional column bases relying solely on the form of foundation 6; when the top steel plate 2 and the steel column are connected by bolts, the column base node becomes a detachable node, providing technical possibilities for temporary structures, relocatable buildings, and rapid replacement after earthquakes; all connection structures are mature technologies covered by current steel structure codes, which designers can use without obstacles and without additional verification.

[0063] According to one embodiment of the present invention, a steel structure column base resistant to tensile shear and compressive shear interaction, wherein the thickness of the preset gap can be adjusted by the amount of high-strength grout 3 injected on site, so as to absorb the elevation error and flatness deviation of the foundation 6.

[0064] This embodiment provides active adjustment and error absorption capabilities for setting the thickness of the preset gap. Before construction, the actual elevation of multiple feature points on the top surface of foundation 6 is measured using a level or laser scanner to obtain the average actual elevation and local flatness deviation of the top surface of foundation 6. Based on the design elevation of the bottom of the upper steel structure column 5, the required theoretical gap thickness between the top surface of bottom steel plate 1 and the bottom surface of top steel plate 2 is calculated. The upper steel column with top steel plate 2 is hoisted above bottom steel plate 1, and top steel plate 2 is lifted by rotating the leveling load-bearing bolts 7 until the distance between the lower surface of top steel plate 2 and the upper surface of bottom steel plate 1 is equal to the above-mentioned theoretical gap thickness, and the thickness difference at each measuring point is controlled within 2 mm. At this point, the thickness of the preset gap is determined, and its value may be greater or less than the standard design value, but it completely corresponds to the actual geometry of foundation 6. Subsequently, high-strength grout 3 is injected into the preset gap, and the injection volume of the grout is the actual gap volume, without the need to add a shim or cut foundation 6. After the grout has cured, the thickness of the preset gap will be permanently fixed, the error of the foundation elevation 6 will be completely absorbed, and the column top elevation will reach the design expectation.

[0065] This embodiment transforms the preset gap thickness from a fixed design parameter into a variable construction parameter. The column base no longer passively accepts the existing foundation 6, but actively accommodates it. Any elevation deviation or local unevenness on the top surface of foundation 6 is converted into a corresponding adjustment of the preset gap thickness; the greater the deviation, the thicker the grout layer, but the force mechanism and transmission path of the column base remain unchanged. The high-strength grout 3 itself has high strength; appropriately increasing its thickness does not reduce its bearing capacity. On the contrary, the increased volume of the grout layer improves its tolerance to unevenness in foundation 6. This mechanism eliminates the need for finishing or secondary leveling of the top surface of foundation 6. The column base can be directly installed as long as the top surface of foundation 6 meets the basic strength requirements, significantly shortening the interval between civil engineering and steel structure installation. There is no need to stock various specifications of steel pads on site, nor to stack and adjust the pads, significantly improving installation efficiency.

[0066] This embodiment, by setting the preset gap thickness as an adjustable parameter on-site, endows the steel structure column base with adaptive absorption capability for civil construction errors. From a design perspective, it eliminates the stringent dependence of the column base on the precise elevation of foundation 6; the top surface of foundation 6 only needs to meet the general requirements of concrete flatness, significantly reducing civil construction costs and time. During on-site installation, there is no need for secondary chiseling or repair of foundation 6, avoiding wet work and dust pollution, achieving dry construction throughout the entire process. The grouting layer thickness can be individually determined according to actual deviations, and the preset gap thickness of each column base precisely matches the actual elevation of foundation 6 at that location, systematically eliminating the cumulative error in column top elevation.

[0067] According to one embodiment of the present invention, a steel structure column base resistant to tensile shear and compressive shear interaction is provided with a high-strength bolt 4 equipped with a long-term preload maintenance device. The device includes an elastic compensation element disposed below the bolt head or nut. The elastic compensation element automatically releases elastic potential energy to maintain the contact surface clamping force when the bolt preload decays.

[0068] Specifically, each high-strength bolt 4 is equipped with an elastic compensation element at its head or below the nut as a long-term preload maintenance device. This elastic compensation element consists of a set of disc spring washers, installed between the nut of the high-strength bolt 4 and the upper surface of the top steel plate 2 in a mating or overlapping configuration. When the high-strength bolt 4 is subjected to preload, the disc spring washer assembly is compressed to the design height, storing the corresponding elastic potential energy. When the bolt base is subjected to cyclic loads for a long time or when changes in ambient temperature cause creep, loosening, or indentation of the washer plate in the high-strength bolt 4, the bolt preload tends to decrease. At this time, the compressed disc spring washer assembly automatically releases part of the elastic potential energy using its axial rebound characteristics, pushing the nut upward to compensate for the recovery of bolt elongation, thereby maintaining the contact surface clamping force at the set level. The stiffness, number, and combination of the disc spring washers are calculated and determined based on the design preload of the high-strength bolt 4 and the estimated preload decay during the service life, ensuring that the contact surface clamping force is not lower than the minimum friction pressure required for shear resistance throughout the entire design service life. In another embodiment, the elastic compensation element may also be a ring wave spring or a Belleville spring washer, and an anti-loosening structure may be added to prevent the nut from rotating.

[0069] By installing elastic compensation elements under the bolt head or nut, preload decay can be compensated for in real time and automatically without manual intervention. The disc spring washer assembly automatically rebounds when the bolt preload decreases, maintaining the stability of the contact surface clamping force. This ensures that the contact surface remains clamped under tension and shear conditions, maintaining a stable static friction coefficient, and allowing horizontal shear force to be effectively transmitted continuously through friction. This device has a simple structure, is easy to install, does not alter the original force path of the column base, significantly extends the effective period of preload action, improves the fatigue resistance and seismic toughness of the column base under long-term cyclic loads, and reduces maintenance workload throughout its lifecycle. For large steel structure projects subjected to frequent horizontal cyclic loads such as wind, waves, and earthquakes, this technical solution has outstanding engineering practical value.

[0070] According to one embodiment of the present invention, a steel structure column base resisting tensile shear and compressive shear interaction has a radial clearance adjustment and progressive shear bearing structure between the high-strength bolt body and the wall of the elliptical elongated hole. This structure ensures that the bolt does not form shear bearing contact with the hole wall in the initial state, and establishes contact to share the shear force when the horizontal shear force exceeds the static friction force.

[0071] The bolt through holes on the bottom steel plate 1 and the top steel plate 2 are all elliptical elongated holes, and the major axes of the elliptical elongated holes on the two steel plates are orthogonal to each other. The first and second through holes are formed by pre-embedded sleeves 8 during the pouring of high-strength grout 3. The outer wall of the sleeve 8 is coated with a release agent 9. After the grout has initially set, it is pulled out and cured to the design strength before the high-strength bolt 4 is installed. Based on this, a radial clearance adjustment and progressive shear structure is provided between the bolt body and the wall of the elliptical elongated hole. In one embodiment, this structure is a precision-formed steel annular gasket. The gasket is tightly fitted onto the surface of the high-strength bolt 4 in the section of the elliptical elongated hole, and its outer diameter is slightly smaller than the minor axis of the elliptical elongated hole, forming a small and uniform radial clearance between them. The annular gasket is made of high-strength steel with high concentricity of the inner and outer circles, and the outer surface is hardened. After the high-strength bolt 4 is pre-tightened to secure the top steel plate 2, grout 3, and bottom steel plate 1 together, the bolt shank is positioned approximately centrally within the elliptical elongated hole, with no physical contact between the annular washer and the hole wall. Under normal use, the horizontal shear force of the column base is borne by the static friction of the contact surface, and the bolt is not subjected to shear. When encountering strong earthquakes or forces exceeding the design horizontal force, the static friction of the contact surface is overcome, and a relative slippage tendency occurs between the top steel plate 2 and the grout 3, and between the grout 3 and the bottom steel plate 1. The bolt shank moves with the top steel plate 2 or the bottom steel plate 1 in the direction of horizontal force, and the outer circle of the annular washer gradually contacts the hole wall of the elliptical elongated hole. Since the outer circle of the washer contacts the hole wall with an arc surface, and the initial contact is a line contact, as the slippage increases, the contact arc length gradually expands, the contact pressure steadily increases, and the shear force borne by the bolt gradually increases until it reaches the design value of the bolt's shear bearing capacity. The annular gasket serves multiple functions simultaneously: adjusting radial clearance, positioning the bolt, transmitting shear force, and preventing direct pressure feedback between the bolt shank and the grouting hole wall. In another embodiment, the progressive shear structure can also employ an elastic buffer layer with controllable thickness lined inside the elliptical elongated hole wall. This elastic buffer layer is made of high-damping rubber or polyurethane material, with an initial inner diameter larger than the bolt shank diameter, ensuring no contact between the bolt and the hole wall after installation. When the bolt shank displaces towards the hole wall, it first compresses the elastic buffer layer. As the compression increases, the bearing area and reaction force gradually increase, thus achieving progressive shear force transmission.

[0072] By incorporating radial clearance adjustment and progressive shear structure between the bolt shank and the wall of the elliptical elongated hole, the column base exhibits a distinct two-stage working characteristic throughout the entire stress process. In the first stage, the horizontal shear force is entirely borne by the static friction of the contact surface; the bolt does not participate in shear resistance, and the long axis allowance of the elliptical elongated hole is entirely used to absorb installation deviations and temperature deformation, placing the structure in an elastic working state. In the second stage, when the horizontal shear force exceeds the design value of the static friction force, slippage occurs at the contact surface. The bolt shank and the hole wall gradually establish contact through an annular washer or elastic buffer layer. The shear area and contact stress continuously increase with the amount of slippage, resulting in a smooth increase in bolt shear force, avoiding impact effects, and the joint exhibits good ductile failure characteristics. This structure transforms the bolt from passive shear resistance to progressively constrained shear resistance, ensuring frictional force transmission efficiency under normal service conditions and providing a stable second line of defense under extreme conditions such as earthquakes, significantly enhancing the seismic energy dissipation capacity and failure early warning capability of the steel structure column base. Meanwhile, the installation of annular gaskets or elastic buffer layers does not occupy additional space and is compatible with the orthogonal adjustment function of elliptical elongated holes, maintaining the advantage of high fault tolerance in column base installation. This technical solution is particularly suitable for high-intensity seismic fortification zones and important steel structure buildings subjected to cyclic loads.

[0073] A construction method for a steel structure column base subjected to tensile-shear and compressive-shear interaction as described in any one of the claims includes the following steps: The bottom steel plate 1 is fixedly installed on the foundation 6; The top steel plate 2 is fixedly installed at the lower end of the upper steel structure column 5; The upper steel structure column 5 with the top steel plate 2 is hoisted to the top of the bottom steel plate 1. The elevation and level of the top steel plate 2 are adjusted by screwing the leveling load-bearing bolts 7 set around the bottom steel plate 1, so as to set the thickness of the preset gap between the top steel plate 2 and the bottom steel plate 1. A sleeve 8 coated with release agent 9 is inserted into the first through hole opened on the top steel plate 2 and the corresponding second through hole opened on the bottom steel plate 1. High-strength grout 3 is injected into the preset gap under pressure until the high-strength grout 3 continuously overflows from the vent holes opened on the top steel plate 2 and / or the bottom steel plate 1. After the high-strength grout 3 has initially set, the sleeve 8 is pulled out to form a bolt hole; After the high-strength grout 3 has been cured to the design strength, high-strength bolts 4 are inserted into the bolt holes and a pre-tightening force is applied. The design value of the pre-tightening force is greater than the design value of the maximum vertical tensile force that the column base will bear during service.

[0074] During grouting, temporary sealing templates are installed around the bottom steel plate 1 and the top steel plate 2. The sealing templates are tightly fitted to the side edges of the bottom steel plate 1 and the top steel plate 2 to form a closed grouting cavity, preventing the high-strength grout 3 from overflowing while in a flowing state. The sealing templates are removed after the high-strength grout 3 has initially set.

[0075] According to one embodiment of the present invention, a steel structure column base resistant to tensile shear and compressive shear interactions includes: a bottom steel plate 1, a top steel plate 2, high-strength grout 3, and high-strength bolts 4; the high-strength grout 3 fills and solidifies in a preset gap between the bottom steel plate 1 and the top steel plate 2; the high-strength bolts 4 penetrate corresponding preset through holes on the top steel plate 2 and the bottom steel plate 1, and connect the two by pre-tightening force; the thickness of the preset gap is adjusted and set by injecting the high-strength grout 3 on site.

[0076] The high-strength grout 3 has a compressive strength of not less than 60 MPa, and it has sufficient adhesion and friction coefficient between its contact surfaces with the bottom steel plate 1 and the top steel plate 2.

[0077] The preload applied by the high-strength bolt 4 is designed to be greater than the maximum tensile force that the column base may withstand during service, so as to ensure that the high-strength grout 3 is always under pressure under tensile force.

[0078] The bottom steel plate 1 is fixed to the foundation 6 by anchor bolts or welding; the top steel plate 2 is connected to the upper steel structure column 5 by welding or bolts.

[0079] The bottom steel plate 1 and / or the top steel plate 2 are provided with grouting holes and venting holes for injecting the high-strength grouting material 3.

[0080] The bottom steel plate 1 and the top steel plate 2 are respectively provided with mutually orthogonal elliptical elongated holes, which are used to adjust the horizontal error when the column base is installed.

[0081] The adjustable range of the preset gap can accommodate the elevation error and flatness deviation during on-site installation.

[0082] At least three threaded holes are provided around the perimeter of the bottom steel plate 1 for setting leveling load-bearing bolts 7 to tighten the top steel plate 2 to adjust the elevation and flatness of the upper steel structure column 5.

[0083] The high-strength bolt 4 holes are first connected to the sleeve 8 with the release agent 9. The high-strength bolt 4 holes are reserved when the high-strength grout 3 is poured. After the high-strength grout 3 has initially set, the sleeve 8 is pulled out. After the high-strength grout 3 has reached the strength requirements, the high-strength bolt 4 is installed.

[0084] According to one embodiment of the present invention, such as Figure 1 , 2As shown, during construction, the bottom steel plate 1 is first fixed to the foundation 6 using pre-embedded anchors or welding. Then, the upper steel structure column 5 and the top steel plate 2 are welded (or bolted) together in the factory or on-site. Subsequently, the top steel plate 2 with the column body is hoisted above the bottom steel plate 1, and adjusted to the design elevation and horizontal position using the leveling load-bearing bolts 7, at which point a preset installation gap is formed between the bottom steel plate 1 and the top steel plate 2. Sleeves 8 with release agent 9 are inserted into the holes of the corresponding high-strength bolts 4 on the bottom steel plate 1 and the top steel plate 2. Sealing templates are set around the bottom steel plate 1 and the top steel plate 2. High-strength, non-shrinkage high-strength grout 3 (such as cement-based high-strength grout 3 or epoxy grout 3) is pressure-injected into the grouting holes 21 reserved on the bottom steel plate 1 and / or the top steel plate 2. The high-strength grout 3 fills the gap and overflows from the vent hole 22, ensuring compaction. After the high-strength grout 3 has initially set, pull out the sleeve 8. After the high-strength grout 3 has cured to the design strength, install the high-strength bolts 4 and apply pre-tightening force according to the design requirements to fasten the top steel plate 2, the high-strength grout 3 and the bottom steel plate 1 into one piece.

[0085] The preload of the high-strength bolt 4 needs to be determined by calculation, and its value should be greater than the maximum tensile force that may occur at the column base under various load combinations. This is the key to ensuring that the shear force can be transmitted through friction under tension and shear conditions. The high-strength grout 3 should be selected from materials with high strength, early strength, and micro-expansion characteristics to ensure its bonding performance with the steel plate and its own compressive and shear resistance.

[0086] By adjusting the thickness of grout 3, the cumulative errors during the structural installation process can be easily compensated, realizing the installation concept of "overcoming rigidity with flexibility".

[0087] Grout strength requirements: In addition to compensating for installation errors and leveling, the grout also serves as the force transmission medium between the upper steel column and the foundation 6. Its strength must meet the requirements for compressive and shear resistance. If the steel column pressure is N, the shear force is Q, and the grout area is A, then its compressive strength fc ≥ N / A, and its shear strength fv ≥ Q / A.

[0088] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A steel structure column base resistant to tensile-shear and compressive-shear interactions, characterized in that, include: The bottom steel plate is fixedly installed on the foundation. The top steel plate is fixedly installed at the lower end of the upper steel structure column, and the top steel plate is placed parallel to the bottom steel plate directly above it, forming a preset gap between the two. Grouting material, which fills and solidifies in the preset gap between the bottom steel plate and the top steel plate, and forms a contact surface with the upper surface of the bottom steel plate and the lower surface of the top steel plate; At least one bolt, the shank of which passes through a first through hole in the top steel plate and a corresponding second through hole in the bottom steel plate, the head of the bolt or nut pressing against the upper surface of the top steel plate or the lower surface of the bottom steel plate, and fastening the top steel plate, the grouting material and the bottom steel plate together by applying a preload; Wherein, the design value of the preload applied to the bolt is greater than the design value of the maximum vertical tensile force that the bolt can withstand under the design load combination, so that when the vertical tensile force and the horizontal shear force work together, the contact surface between the grout and the bottom steel plate and the top steel plate always remains in a compressed state, thereby bearing all or part of the horizontal shear force through the static friction between the contact surfaces.

2. The steel structure column base resisting tensile shear and compressive shear interaction as described in claim 1, characterized in that, The grouting material is a high-strength grouting material with a compressive strength of not less than 60 MPa, and the high-strength grouting material is a cement-based or epoxy-based grouting material with micro-expansion characteristics. At least one bolt is a high-strength bolt.

3. The steel structure column base resisting tensile shear and compressive shear interaction as described in claim 1, characterized in that, The bottom steel plate has at least three threaded through holes around its perimeter. A leveling and load-bearing bolt is inserted into each threaded through hole. The top of the leveling and load-bearing bolt abuts against the lower surface of the top steel plate. The elevation and levelness of the top steel plate are adjusted by rotating the leveling and load-bearing bolt, and the thickness of the preset gap is set.

4. The steel structure column base with tensile-shear and compressive-shear interaction as described in claim 2, characterized in that, The second through hole on the bottom steel plate is an elliptical elongated hole, and the first through hole on the top steel plate is an elliptical elongated hole, and the major axes of the elliptical elongated holes on the bottom steel plate and the top steel plate are orthogonal to each other. A pre-embedded sleeve is inserted into the first through hole and the second through hole. The outer wall of the pre-embedded sleeve is coated with a release agent. The pre-embedded sleeve is pulled out after the high-strength grout has initially set. The high-strength bolt is installed after the high-strength grout has been cured to the design strength.

5. The steel structure column base resisting tensile shear and compressive shear interaction as described in claim 1, characterized in that, At least one grouting hole and at least one venting hole are provided on the top steel plate and / or the bottom steel plate. The grouting hole is used to inject the high-strength grout into the preset gap, and the venting hole is used to discharge the air in the preset gap.

6. The steel structure column base resisting tensile shear and compressive shear interaction as described in claim 1, characterized in that, The bottom steel plate is fixedly connected to the foundation by pre-embedded anchor bolts or welding. The top steel plate is fixedly connected to the upper steel structure column by welding or bolting.

7. The steel structure column base with alternating tensile and compressive shear resistance as described in claim 2, characterized in that, The thickness of the preset gap can be adjusted by the amount of high-strength grout injected on site to absorb the elevation error and flatness deviation of the foundation.

8. The steel structure column base resisting tensile shear and compressive shear interaction as described in claim 2, characterized in that, The high-strength bolt is equipped with a long-term preload maintenance device, which includes an elastic compensation element located below the bolt head or nut. The elastic compensation element automatically releases elastic potential energy to maintain the contact surface clamping force when the bolt preload decays.

9. The steel structure column base resisting tensile shear and compressive shear interaction as described in claim 4, characterized in that, The high-strength bolt shank is equipped with a radial clearance adjustment and progressive shear structure between itself and the wall of the elliptical elongated hole. This structure ensures that the bolt does not form shear contact with the hole wall in the initial state, and gradually establishes contact to share the shear force when the horizontal shear force exceeds the static friction force.

10. A construction method for a steel structure column base resisting tensile shear and compressive shear interaction as described in any one of claims 1 to 9, characterized in that, Includes the following steps: The bottom steel plate is fixedly installed on the foundation; The top steel plate is fixedly installed at the lower end of the upper steel structure column; The upper steel structure column with the top steel plate is hoisted to the top of the bottom steel plate. The elevation and level of the top steel plate are adjusted by screwing the leveling load-bearing bolts set around the bottom steel plate, so as to set the thickness of the preset gap between the top steel plate and the bottom steel plate. A sleeve coated with a release agent is inserted into the first through hole opened on the top steel plate and the corresponding second through hole opened on the bottom steel plate; High-strength grout is injected into the preset gap under pressure until the high-strength grout continuously overflows from the vent holes opened on the top steel plate and / or bottom steel plate. After the high-strength grout has initially set, the sleeve is pulled out to form bolt holes; After the high-strength grout has cured to the design strength, high-strength bolts are inserted into the bolt holes and a pre-tightening force is applied. The design value of the pre-tightening force is greater than the design value of the maximum vertical tensile force that the column base will bear during service.

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