Connecting structure of newly-added steel beam and existing beam plate and reinforcing structure of existing beam plate

Abstract

The utility model discloses a connecting structure of a newly-added steel beam and an existing beam plate and a reinforcing structure of the existing beam plate, and relates to the technical field of building renovation, and the existing beam plate comprises an existing concrete beam and an existing concrete floor which are vertically connected. The reinforcing structure comprises a newly-added steel beam, a connecting assembly connected to the side wall of the existing concrete beam and a horizontal steel plate connected to the top end of the existing concrete beam. The newly-added steel beam is horizontally arranged below the existing concrete floor; an anchoring part and a connecting part which are vertically arranged are formed on the connecting assembly, a newly-added steel beam is connected to the connecting part, the anchoring part is arranged in the existing concrete floor in a penetrating mode, and a horizontal steel plate is connected to the end, extending out of the existing concrete floor, of the anchoring part. Thus, the horizontal steel plate is connected to the top end of the existing concrete beam, and the connecting assembly connected between the horizontal steel plate and the newly-added steel beam and connected with the side wall of the existing concrete beam in a fastened mode is arranged, so that the shear bearing capacity of the connecting joint of the newly-added steel beam and the existing concrete beam is increased.

Description

Technical Field

[0001] The utility model relates to the technical field of building reconstruction, in particular to a connection structure of a newly added steel beam and an existing beam plate and a reinforcement structure of the existing beam plate. Background Art

[0002] At present, a large number of projects in engineering construction need reinforcement and maintenance. At this stage, engineering construction has gradually developed from a large number of new construction stages to a stage where both new construction and maintenance are given equal importance. Buildings should meet the requirements of safety, applicability, and durability under specified conditions. Some of the main load-bearing components of building structures, such as reinforced concrete floor slabs, often increase their actual loads due to changes in use, resulting in insufficient structural bearing capacity and excessive deflection and deformation, which cannot meet the requirements of safety, applicability, and durability. Therefore, measures must be taken to repair and reinforce them.

[0003] Reinforced concrete floor slabs are important components in building structures. They not only need to bear vertical floor loads, but also meet structural bearing capacity requirements and functional use requirements. When the reinforced concrete floor slab has bearing capacity problems for some reason, the floor slab needs to be reinforced. At present, the main methods for reinforcing concrete floor slabs include reinforcement by gluing steel plates, reinforcement by gluing carbon fiber cloth on the bottom of the slab, reinforcement by adding steel beams to the bottom of the slab, etc. Among them, the most commonly used method is the reinforcement method by adding steel beams to the bottom of the slab, which is widely used in various reinforcement and renovation projects. The reinforcement method of adding steel beams to the bottom of the slab is to add a new steel beam under the original concrete floor slab, and use anchor bolts to connect the I-beam beam and the original concrete beam together.

[0004] Traditionally, newly added steel beams are used to reinforce nodes. After drilling holes in the original reinforced concrete beams, steel bars or chemical bolts are implanted to fix the steel anchor plates on the concrete structure surface, and then bolts or welding are used to reliably connect the newly added steel beams to the anchor steel plates. The anchor bolts bear all the shear force of the nodes. When the floor is heavily loaded, there is a large shear force at the connection between the newly added steel beams and the original concrete beams. Traditional newly added steel beam reinforcement nodes often cannot provide sufficient shear bearing capacity, and the anchor steel, concrete shear prying and concrete wedges will be damaged, resulting in the failure of the entire node. At the same time, the traditional newly added steel beam reinforcement nodes have poor seismic performance and do not meet the principle of strong shear and weak bending.

[0005] Therefore, how to improve the shear bearing capacity of the newly added steel beam reinforcement nodes is a technical problem faced by technical personnel in this field. Utility Model Content

[0006] The purpose of the utility model is to provide a connection structure between a newly added steel beam and an existing beam-slab and a reinforcement structure of the existing beam-slab, so as to solve the problems in the prior art that the actual load increases due to changes in building functions, resulting in insufficient structural bearing capacity, excessive deflection, and unsatisfactory safety and applicability.

[0007] The above-mentioned purpose of the utility model can be achieved by adopting the following technical solutions:

[0008] The utility model provides a connection structure of a newly added steel beam and an existing beam slab, comprising an existing concrete beam, an existing concrete slab vertically connected to the existing concrete beam, a newly added steel beam, a connection assembly connected to the side wall of the existing concrete beam, and a horizontal steel plate connected to the top end of the existing concrete beam;

[0009] The newly added steel beam is horizontally arranged below the existing concrete floor slab;

[0010] The connection assembly is formed with a vertically arranged anchoring portion and a connecting portion, the connecting portion is connected to the newly added steel beam, the anchoring portion is penetrated into the existing concrete floor slab, and the horizontal steel plate is connected to one end of the anchoring portion extending out of the existing concrete floor slab.

[0011] Specifically, the newly added steel beam is H-shaped, including a flange and a web that are vertically connected, and the thickness direction of the flange is parallel to the gravity direction.

[0012] Specifically, the connection assembly includes a vertically connected anchor plate and a steel beam extension plate. The connection assembly is connected to the side wall of the existing concrete beam through the anchor plate. The anchor plate is provided with the anchoring portion, and the steel beam extension plate is provided with the connecting portion. The flange of the steel beam extension plate is aligned and connected with the flange of the newly added steel beam, and the web of the steel beam extension plate is aligned and connected with the web of the newly added steel beam.

[0013] Specifically, the anchoring portion includes a plurality of anchoring plates spaced apart along the width direction of the existing concrete beam side wall, and the plurality of anchoring plates are formed by cutting inward at intervals from an edge of the anchoring plate, or the plurality of anchoring plates are spaced apart and connected on an edge of a rectangular steel plate by welding to form the anchoring plate.

[0014] Preferably, the width of the anchoring plate is not greater than 100 mm.

[0015] Preferably, the length of the anchoring portion extending out of the existing concrete floor is equal to the thickness of the horizontal steel plate.

[0016] Specifically, the anchor plate is connected to the side wall of the existing concrete beam through chemical anchor bolts.

[0017] Preferably, the flange of the steel beam extended plate is connected to the flange of the newly added steel beam by welding; the web of the steel beam extended plate is connected to the web of the newly added steel beam by a web connecting plate.

[0018] Furthermore, the web connecting plates are in two pieces, one section of the two web connecting plates is aligned and arranged on both sides of the connecting portion, the other section of the two web connecting plates is aligned and arranged on both sides of the web of the newly added steel beam, and the two web connecting plates are connected by high-strength bolts.

[0019] Preferably, the newly added steel beam is an I-beam formed by welding the flange and the web, or the newly added steel beam is a hot-rolled H-beam.

[0020] Preferably, the horizontal steel plate is connected to the top end of the existing concrete beam through a rebar anchor rod.

[0021] Another object of the utility model is to provide a reinforcement structure of an existing beam-slab, the existing beam-slab comprising an existing concrete beam and an existing concrete floor slab connected vertically, the reinforcement structure comprising: a newly added steel beam, a connection assembly connected to the side wall of the existing concrete beam, and a horizontal steel plate connected to the top end of the existing concrete beam;

[0022] The newly added steel beam is horizontally arranged below the existing concrete floor slab;

[0023] The connection assembly is formed with a vertically arranged anchoring portion and a connecting portion, the connecting portion is connected to the newly added steel beam, the anchoring portion is penetrated into the existing concrete floor slab, and the horizontal steel plate is connected to one end of the anchoring portion extending out of the existing concrete floor slab.

[0024] Specifically, the anchoring portion includes a plurality of small anchoring plates spaced apart along the width direction of the side wall of the existing concrete beam, and the width of each small anchoring plate is not greater than 100 mm.

[0025] Preferably, the length of the anchoring portion extending out of the existing concrete floor is equal to the thickness of the horizontal steel plate.

[0026] The characteristics and advantages of the utility model are as follows: the connection structure between the newly added steel beam and the existing beam-slab and the reinforcement structure of the existing beam-slab provided by the utility model increase the shear bearing capacity at the connection node between the newly added steel beam and the existing concrete beam by connecting a horizontal steel plate on the top end of the existing concrete beam and providing a connection component connected between the horizontal steel plate and the newly added steel beam and fastened to the side wall of the existing concrete beam, and convert the shear force borne by the chemical anchor bolts in the traditional design into a shear force borne jointly by the chemical anchor bolts, the embedded anchor rods, the connection component and the concrete beam, which can easily overcome the problem of insufficient shear bearing capacity at the connection node in the traditional design and meet the strength calculation and calculation assumptions of the node connection design. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 It is a schematic diagram of the connection structure between the newly added steel beam and the existing beam plate provided in the embodiment of the utility model;

[0029] Figure 2 It is an exploded schematic diagram of the connection between the newly added steel beam and the existing beam plate provided in the embodiment of the utility model;

[0030] Figure 3 for Figure 1 Section Ⅰ-Ⅰ of

[0031] Figure 4 for Figure 1 Section II-II of the

[0032] Figure 5 for Figure 2 The III-III section diagram;

[0033] Figure 6 It is a schematic structural diagram of the anchor plate in the reinforcement structure provided in the embodiment of the utility model.

[0034] Description of Figure Numbers:

[0035] 100. Existing concrete beams;

[0036] 200. Existing concrete floor slab;

[0037] 1. New steel beam; 11. Flange; 12. Web;

[0038] 2. Connecting assembly; 21. Anchor plate; 211. Anchor plate; 22. Steel beam extension plate;

[0039] 3. Horizontal steel plate;

[0040] 4. Anchor rods;

[0041] 5. Chemical anchor bolt;

[0042] 6. Web connecting plate;

[0043] 7. High strength bolts;

[0044] 8. Anchor plate. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0046] like Figures 1 to 5 As shown, the utility model provides a connection structure of a newly added steel beam 1 and an existing beam-slab, comprising an existing concrete beam 100, an existing concrete slab 200 vertically connected to the existing concrete beam 100, a newly added steel beam 1, a connection assembly 2 connected to the side wall of the existing concrete beam 100, and a horizontal steel plate 3 connected to the top of the existing concrete beam 100. The newly added steel beam 1 is horizontally arranged below the existing concrete slab 200; a vertically arranged anchoring portion and a connecting portion are formed on the connection assembly 2, the newly added steel beam 1 is connected to the connecting portion, the anchoring portion is passed through the existing concrete slab 200, and the horizontal steel plate 3 is connected to one end of the anchoring portion extending out of the existing concrete slab 200. Specifically, as Figure 1 As shown, the horizontal steel plate 3, the connection assembly 2, and the newly added steel beam 1 are in a "Z" shape as a whole. The newly added steel beam 1 is arranged below the existing concrete floor 200, and is tightly connected to the existing beam slab through the connection assembly 2 and the horizontal steel plate 3, so as to ensure the connection stability and safety between the newly added steel beam 1 and the existing beam slab, improve the bearing capacity of the existing beam slab, and solve the problem that the actual load of the existing beam slab increases due to the change of the building function, resulting in insufficient structural bearing capacity, excessive deflection, and safety and applicability that cannot meet the use requirements. In this embodiment, one end of the anchoring portion extending out of the existing concrete floor slab 200 is connected to the horizontal steel plate 3 by welding.

[0047] Specifically, the newly added steel beam 1 is H-shaped, including a flange 11 and a web 12 connected vertically, and the thickness direction of the flange 11 is parallel to the gravity direction. Figure 2 As shown, the newly added steel beam 1 includes two flanges 11 and a web 12. The two flanges 11 are vertically connected to both sides of the web 12, and the longitudinal extension direction of the two flanges 11 is the same as the longitudinal extension direction of the web 12. The newly added steel beam 1 formed by connecting the two flanges 11 and the web 12 is H-shaped. In order to better improve the bearing capacity of the existing beam and slab, when the newly added steel beam 1 is horizontally arranged below the existing concrete floor slab 200, the thickness direction of the flange 11 is kept parallel to the gravity direction.

[0048] Preferably, the newly added steel beam 1 is an I-beam formed by welding the flange 11 and the web 12, or the newly added steel beam 1 is a hot-rolled H-beam. Specifically, the newly added steel beam 1 can be an I-beam formed by welding two flanges 11 and a web 12, or a hot-rolled H-beam with suitable specifications can be directly selected as the newly added steel beam 1.

[0049] Preferably, if Figure 1 and Figure 3 As shown, the horizontal steel plate 3 is connected to the top of the existing concrete beam 100 through the anchor rod 4 to ensure the fastening connection between the horizontal steel plate 3 and the existing concrete beam 100. Of course, the horizontal steel plate 3 can also be fastened to the existing concrete beam 100 by other connection methods, and the utility model does not limit this.

[0050] Specifically, the connection assembly 2 includes a vertically connected anchor plate 21 and a steel beam extension plate 22. The connection assembly 2 is connected to the side wall of the existing concrete beam 100 through the anchor plate 21. The anchor plate 21 is provided with an anchoring portion, and the steel beam extension plate 22 is provided with a connecting portion. The flange of the steel beam extension plate 22 is aligned and connected with the flange 11 of the newly added steel beam 1, and the web of the steel beam extension plate 22 is aligned and connected with the web 12 of the newly added steel beam 1. Specifically, as Figure 1 , Figure 2 and Figure 5 As shown, the connection assembly 2 includes an anchor plate 21 and a steel beam extension plate 22. The steel beam extension plate 22 is also H-shaped, and the cross-section of the steel beam extension plate 22 along the longitudinal extension direction is consistent with the cross-section of the newly added steel beam 1 along the longitudinal extension direction. One end of the steel beam extension plate 22 is vertically connected to the anchor plate 21, and the other end of the steel beam extension plate 22 forms a connection portion and connects the newly added steel beam 1. Among them, the flange of the steel beam extension plate 22 is aligned and connected with the flange 11 of the newly added steel beam 1, and the web of the steel beam extension plate 22 is aligned and connected with the web 12 of the newly added steel beam 1, that is, along the longitudinal extension direction of the steel beam extension plate 22, the cross-sectional projection of the steel beam extension plate 22 coincides with the cross-sectional projection of the newly added steel beam 1. In actual construction, both ends of the newly added steel beam 1 are connected with the steel beam extension plates 22, that is, the newly added steel beam 1 is connected between two adjacent existing concrete beams 100 through the connection assembly 2 connected at both ends. Preferably, as Figure 3 and Figure 5 As shown, along the width direction of the side wall of the existing concrete beam 100, the steel beam extension plate 22 is vertically connected to the middle position of the anchor plate 21.

[0051] Specifically, the anchor plate 21 is connected to the side wall of the existing concrete beam 100 through the chemical anchor bolt 5. Figure 1 , Figure 3 and Figure 4As shown, the anchor plate 21 is fixedly connected to the side wall of the existing concrete beam 100 through multiple chemical anchor bolts 5. Among them, the anchor plate 21 is provided with multiple anchor bolt holes that match the multiple chemical anchor bolts 5. In this way, the good anchoring performance and shear resistance of the chemical anchor bolts 5 are utilized, which is convenient for construction and can provide strong bearing capacity. Preferably, as Figure 1 and Figure 4 As shown, in order to protect the anchor plate 21, an anchor pad 8 is provided at the connection between the anchor plate 21 and the chemical anchor bolt 5.

[0052] Preferably, the flange of the steel beam extension plate 22 is connected to the flange 11 of the newly added steel beam 1 by welding; the web of the steel beam extension plate 22 is connected to the web 12 of the newly added steel beam 1 by a web connecting plate 6.

[0053] Furthermore, the web connecting plates 6 are two pieces, one section of the two web connecting plates 6 is aligned and arranged on both sides of the connection portion, and the other section of the two web connecting plates 6 is aligned and arranged on both sides of the web 12 of the newly added steel beam 1, and the two web connecting plates 6 are connected by high-strength bolts 7. Specifically, as Figure 3 and Figure 4 As shown, there are two web connecting plates 6, which are arranged on both sides of the joint between the steel beam extension plate 22 and the newly added steel beam 1. A plurality of bolt holes are arranged at intervals on the web connecting plates 6, and a plurality of bolt through holes corresponding to the plurality of bolt holes are arranged on the connecting portion of the steel beam extension plate 22 and the newly added steel beam 1. The high-strength bolts 7 pass through the bolt holes, bolt through holes and bolt holes on one of the web connecting plates 6 and the other web connecting plates 6 in sequence, and realize the fastening connection between the web of the steel beam extension plate 22 and the web 12 of the newly added steel beam 1 through nuts. In actual construction, the web of the steel beam extension plate 22 and the web 12 of the newly added steel beam 1 are fastened first, and then the flange of the steel beam extension plate 22 and the flange 11 of the newly added steel beam 1 are welded and fixed.

[0054] Specifically, see Figure 6 As shown, the anchoring portion includes a plurality of anchoring plates 211 spaced apart along the width direction of the side wall of the existing concrete beam 100, and the plurality of anchoring plates 211 are formed by cutting inwardly from one edge of the anchoring plate 21, or the plurality of anchoring plates 211 are spaced apart and connected to one edge of a rectangular steel plate by welding to form the anchoring plate 21. Specifically, as Figure 3 , Figure 5 and Figure 6As shown, in order to facilitate the anchoring portion of the anchoring plate 21 to penetrate into the existing concrete floor 200 and ensure the structural strength of the existing concrete floor 200, the anchoring portion includes a plurality of anchoring small plates 211 arranged at intervals along the width direction of the side wall of the existing concrete beam 100. Among them, the plurality of anchoring small plates 211 can be formed by cutting inwardly from one edge of the anchoring plate 21, or the plurality of anchoring small plates 211 can also directly adopt small steel plates and be connected at intervals on one edge of the rectangular steel plate by welding to form the anchoring plate 21. Further, the specific number and width of the anchoring small plates 211 are matched and set according to the width of the flange 11 of the newly added steel beam 1 and the density of the steel bars in the existing concrete floor 200. Generally speaking, the wider the flange 11 of the newly added steel beam 1 is, and / or the denser the steel bars in the existing concrete floor 200 are, the smaller the width of the anchoring small plates 211 is, and the more the number of anchoring small plates 211 is.

[0055] Preferably, the width of the anchoring plate 211 is not greater than 100 mm. In this way, the structural strength of the existing concrete floor 200 can be better guaranteed. Specifically, the widths of the multiple anchoring plates 211 can be the same value not greater than 100 mm, or different values ​​not greater than 100 mm, and the utility model does not limit this. Preferably, the widths of the multiple anchoring plates 211 are the same.

[0056] Preferably, the length of the anchoring portion extending out of the existing concrete floor 200 is equal to the thickness of the horizontal steel plate 3. In this way, it is convenient to connect the anchoring plate 211 with the existing concrete floor 200 and to weld and fix the anchoring plate 211 with the horizontal steel plate 3.

[0057] Another object of the present invention is to provide a reinforcement structure of an existing beam-slab, the existing beam-slab comprising an existing concrete beam 100 and an existing concrete floor slab 200 connected vertically, the reinforcement structure comprising: a newly added steel beam 1, a connection assembly 2 connected to the side wall of the existing concrete beam 100, and a horizontal steel plate 3 connected to the top of the existing concrete beam 100; the newly added steel beam 1 is horizontally arranged below the existing concrete floor slab 200; the connection assembly 2 is formed with a vertically arranged anchoring portion and a connecting portion, the connecting portion is connected to the newly added steel beam 1, the anchoring portion is passed through the existing concrete floor slab 200, and the horizontal steel plate 3 is connected to one end of the anchoring portion extending out of the existing concrete floor slab 200. Specifically, Figure 1As shown, the horizontal steel plate 3, the connection assembly 2, and the newly added steel beam 1, which are integrally connected in a "Z" shape, constitute a reinforcement structure of the existing beam and slab. Among them, the horizontal steel plate 3 is fixedly connected to the top of the existing concrete beam 100 through the embedded anchor rod 4, and is connected to the end of the anchoring part of the connection assembly 2 that passes through the existing concrete floor slab 200 by welding. The connection assembly 2 is fixedly connected to the side wall of the existing concrete beam 100 through the chemical anchor bolt 5. The connection assembly 2 is fastened to the newly added steel beam 1 through the web connection plate 6 on both sides of the joint between the connection part and the newly added steel beam 1 and the high-strength bolts 7 that penetrate the web connection plate 6. Preferably, the connection component 2 includes a vertically connected anchor plate 21 and a steel beam extension plate 22. The connection component 2 is connected to the side wall of the existing concrete beam 100 through the anchor plate 21. An anchoring portion is provided on the anchor plate 21, and a connecting portion is provided on the steel beam extension plate 22. The flange of the steel beam extension plate 22 is aligned and connected with the flange 11 of the newly added steel beam 1, and the web 12 of the steel beam extension plate is aligned and connected with the web 12 of the newly added steel beam 1.

[0058] Specifically, the anchoring portion includes a plurality of anchoring plates 211 spaced apart along the width direction of the side wall of the existing concrete beam 100, and the width of each anchoring plate 211 is not greater than 100 mm. By arranging a plurality of anchoring plates 211 with a width not greater than 100 mm at intervals, it is convenient for the anchoring portion of the connection assembly 2 to be inserted into the existing concrete floor slab 200, and the structural strength of the existing concrete floor slab 200 can be better ensured.

[0059] Preferably, the length of the anchoring portion extending out of the existing concrete floor 200 is equal to the thickness of the horizontal steel plate 3. In this way, the length of the anchoring portion is adapted to the sum of the thickness of the existing concrete floor 200 and the thickness of the horizontal steel plate 3, which is convenient for the penetration connection of the anchoring plate 211 and the existing concrete floor 200, and the welding and fixing of the anchoring plate 211 and the horizontal steel plate 3.

[0060] Based on the above structural description, the connection structure between the newly added steel beam 1 and the existing beam plate and the reinforcement structure of the existing beam plate provided in the embodiment of the utility model have the following beneficial effects:

[0061] The connection structure between the newly added steel beam 1 and the existing beam-slab and the reinforcement structure of the existing beam-slab provided by the embodiment of the utility model increase the shear bearing capacity at the connection node between the newly added steel beam 1 and the existing concrete beam 100 by connecting the horizontal steel plate 3 to the top of the existing concrete beam 100, and providing a connection component 2 connected between the horizontal steel plate 3 and the newly added steel beam 1 and fastened to the side wall of the existing concrete beam 100, and converting the shear force borne by the chemical anchor 5 in the traditional design into the shear force borne by the chemical anchor 5, the embedded anchor rod 4, the connection component 2 and the concrete beam, which can easily overcome the problem of insufficient shear bearing capacity at the connection node in the traditional design and meet the strength calculation and calculation assumptions of the node connection design.

[0062] Specifically, the construction process of the connection structure of the newly added steel beam 1 and the existing beam slab and the reinforcement structure of the existing beam slab provided in the embodiment of the utility model includes:

[0063] Process S1: First, a hole is drilled in the existing concrete beam 100 by a drilling machine, and the anchor plate 21 and the steel beam extension plate 22 are pre-welded in the factory to form a connection assembly 2.

[0064] Process S2: drilling holes in the existing concrete floor slab 200 at the connection nodes, with the size of the holes being adapted to the size of the anchoring plates 211 forming the anchoring portions on the anchoring plates 21, while taking care to avoid cutting off the plate reinforcement.

[0065] Process S3: Insert the connection component 2 into the opening of the existing concrete floor 200 from the bottom, and implant the chemical anchor 5 to fasten it to the existing concrete beam 100, then connect the horizontal steel plate 3 to the top of the existing concrete beam 100 through the anchor rod 4, and weld it to the end of the anchor part extending out of the existing concrete floor 200.

[0066] Process S4: The newly added steel beam 1 is hoisted to the connection part of the connection assembly 2, and the web 12 of the newly added steel beam 1 is first connected with the web of the steel beam extension plate 22 through the web connection plate 6 and the high-strength bolts 7, and then the flange 11 of the newly added steel beam 1 is welded and fixed with the flange of the steel beam extension plate 22.

[0067] Furthermore, the design process of the connection structure between the newly added steel beam 1 and the existing beam slab and the reinforcement structure of the existing beam slab provided in the embodiment of the utility model includes:

[0068] Take a newly added steel beam 1 as a calculation unit, calculate the load on the upper part of the newly added steel beam 1 transferred from the existing concrete floor slab 200, including the self-weight of the existing concrete floor slab 200 and other loads on the slab, and apply it as a uniformly distributed load on the newly added steel beam 1. Calculate the internal force of the newly added steel beam 1 as a statically indeterminate beam with both ends fixed, and calculate the total bending moment M and total shear force V borne by the connection between the newly added steel beam 1 and the existing concrete beam 100.

[0069] Then, the bearing capacity of the connection node is verified based on the calculated total bending moment M and total shear force V. The node bearing capacity verification is as follows:

[0070] Firstly, the strength of the weld at the connection between the anchor plate 21 and the steel beam extension plate 22 is verified, and the calculation method refers to the Code for Design of Steel Structures (GB50017-2003).

[0071] Then, the bending, shear and tension-shear composite force bearing capacity of the anchor connection node between the anchor plate 21, the horizontal steel plate 3 and the existing concrete beam 100 is verified.

[0072] In the calculation of bending bearing capacity, the anchor plate 21 and the horizontal steel plate 3 are anchored together with the existing concrete beam 100 through the chemical anchor bolts 5 and the anchor rods 4 respectively. Under the action of the bending moment, the anchor bolts bear the tensile force. The calculation method of the tensile internal force of each chemical anchor bolt 5 and the anchor rods 4 in the anchor bolts and the calculation of the tensile bearing capacity refer to the "Technical Code for Post-Anchorage of Concrete Structures" (JGJ145-2013). The calculation method of the tensile internal force is as follows:

[0073]

[0074] Where: M is the total bending moment borne by the node;

[0075] y 1 —The distance of the anchor farthest from the centroid of the group anchor from the centroid. In the present invention, it is assumed that the centroid of the whole group anchor is located at the centroid of the chemical anchor 5 group on the anchor plate 21, and the anchor farthest from the centroid is the anchor rod 4 on the horizontal steel plate 3;

[0076] y i —The vertical distance between anchor bolt i and centroidal axis;

[0077] —The design value of the tension of the anchor bolt with the largest force in the anchor group, which in this application is the anchor rod 4 on the horizontal steel plate 3.

[0078] The tensile bearing capacity of anchor bolts shall comply with the following requirements:

[0079] Anchor steel damage:

[0080]

[0081] Concrete cone failure under tension:

[0082]

[0083] Concrete splitting damage:

[0084]

[0085] In the formula is the design value of the tension of the anchor with the largest tension in the anchor group, is the total tension design value of the tension zone of the anchor group, N Sd,s is the design value of the tensile bearing capacity of anchor steel, N Rd,c is the design value of the tensile bearing capacity of the concrete cone under failure, N Rd,sp It is the design value of tensile bearing capacity of concrete subject to splitting failure.

[0086] In the shear bearing capacity verification, it is assumed that the shear force borne by the connection node is borne by the chemical anchor bolts 5 on the anchor plate 21 and the anchor plates 211 forming the anchoring portion, and the force of the anchor rods 4 on the horizontal steel plate 3 is as follows:

[0087] V=V 1 +nV 2

[0088] Where V is the total shear force at the node, V 1 V is the shear force borne by all chemical anchors 5. 2 is the shear force borne by each anchoring plate 211 of the same specification, and n is the number of the anchoring plates 211.

[0089] The calculation of the internal shear force and the bearing capacity verification of the anchor bolts refer to the Technical Code for Post-Anchorage of Concrete Structures (JGJ 145-2013). The shear bearing capacity verification of the anchor plate 211 is as follows:

[0090]

[0091] Where: f is the design value of the tensile strength of the steel, b is the width of the steel plate, and t is the thickness of the steel plate.

[0092] In the calculation of the combined tensile-shear bearing capacity of anchor bolts, according to the Technical Code for Post-anchorage of Concrete Structures (JGJ 145-2013), the combined tensile-shear bearing capacity of a single anchor bolt should be calculated under the action of bending moment and shear force.

[0093] The bearing capacity of anchor bolt steel when it is destroyed under tension-shear combined force in elastic design is calculated as follows:

[0094]

[0095] The bearing capacity of concrete at the time of failure under tension-shear combined stress in elastic design is calculated as follows:

[0096]

[0097] In the above formula: N Sd is the design value of anchor bolt tension, N Sd,s is the design value of tensile bearing capacity when anchor steel fails, N Rd,c is the design value of the tensile bearing capacity of the concrete cone under failure, V Rd,s V is the design value of shear bearing capacity when the anchor steel fails. Rd,c It is the design value of shear bearing capacity when the anchor steel is destroyed.

[0098] Finally, the newly added steel beam 1 is rigidly connected to the existing concrete beam 100, and the node is subjected to negative bending moment, which causes the existing concrete beam 100 to be torsion. However, the existing concrete beam 100 and the existing concrete floor slab 200 are cast in place to form a T-shaped section, which improves the torsion resistance of the existing concrete beam 100. At the same time, the newly added steel beam 1 is modulated to appropriately reduce the negative bending moment at the beam end and reduce the torque on the existing concrete beam 100. In general, in actual design, it is generally not necessary to perform concrete torsion calculation on the existing concrete beam 100. If the newly added load on the floor is too large and the torque on the existing concrete beam 100 is too large, the torsion section bearing capacity of the existing concrete beam 100 can be verified by referring to the "Concrete Structure Design Code" (GB50010-2010).

[0099] The above are only several embodiments of the present invention. Those skilled in the art can make various changes or modifications to the embodiments of the present invention based on the contents disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims

1. A connection structure between a newly added steel beam and an existing beam-slab, characterized in that: It includes an existing concrete beam, an existing concrete floor slab vertically connected to the existing concrete beam, a newly added steel beam, a connection component connected to the side wall of the existing concrete beam, and a horizontal steel plate connected to the top of the existing concrete beam; The newly added steel beam is horizontally arranged below the existing concrete floor slab; The connection assembly is formed with a vertically arranged anchoring portion and a connecting portion, the connecting portion is connected to the newly added steel beam, the anchoring portion is penetrated into the existing concrete floor slab, and the horizontal steel plate is connected to one end of the anchoring portion extending out of the existing concrete floor slab.

2. The connection structure between the newly added steel beam and the existing beam-slab according to claim 1 is characterized in that: The newly added steel beam is H-shaped, including a flange and a web connected vertically, and the thickness direction of the flange is parallel to the gravity direction.

3. The connection structure between the newly added steel beam and the existing beam-slab according to claim 2 is characterized in that: The connection assembly includes a vertically connected anchor plate and a steel beam extension plate. The connection assembly is connected to the side wall of the existing concrete beam through the anchor plate. The anchor plate is provided with the anchoring portion, and the steel beam extension plate is provided with the connecting portion. The flange of the steel beam extension plate is aligned and connected with the flange of the newly added steel beam, and the web of the steel beam extension plate is aligned and connected with the web of the newly added steel beam.

4. The connection structure between the newly added steel beam and the existing beam-slab according to claim 3 is characterized in that: The anchoring portion includes a plurality of anchoring plates spaced apart along the width direction of the existing concrete beam side wall. The plurality of anchoring plates are formed by cutting inwardly at intervals from an edge of the anchoring plate, or the plurality of anchoring plates are spaced apart and connected on an edge of a rectangular steel plate by welding to form the anchoring plate.

5. The connection structure between the newly added steel beam and the existing beam-slab according to claim 4 is characterized in that: The width of the anchoring plate is not greater than 100 mm.

6. The connection structure between the newly added steel beam and the existing beam-slab according to claim 5 is characterized in that: The length of the anchoring portion extending out of the existing concrete floor is equal to the thickness of the horizontal steel plate.

7. The connection structure between the newly added steel beam and the existing beam-slab according to claim 6 is characterized in that: The anchor plate is connected to the side wall of the existing concrete beam through chemical anchor bolts.

8. The connection structure between the newly added steel beam and the existing beam-slab according to claim 3 is characterized in that: The flange of the steel beam extended plate is connected to the flange of the newly added steel beam by welding; the web of the steel beam extended plate is connected to the web of the newly added steel beam by a web connecting plate.

9. The connection structure between the newly added steel beam and the existing beam-slab according to claim 8 is characterized in that: There are two web connecting plates, one section of which is aligned and arranged on both sides of the connecting portion, and the other section of which is aligned and arranged on both sides of the web of the newly added steel beam, and the two web connecting plates are connected by high-strength bolts.

10. The connection structure between the newly added steel beam and the existing beam-slab according to claim 2 is characterized in that: The newly added steel beam is an I-beam formed by welding the flange and the web, or the newly added steel beam is a hot-rolled H-beam.

11. The connection structure between the newly added steel beam and the existing beam-slab according to claim 1 is characterized in that: The horizontal steel plate is connected to the top of the existing concrete beam through a reinforcing bar anchor rod.

12. A reinforcement structure of an existing beam-slab, the existing beam-slab comprising an existing concrete beam and an existing concrete floor slab connected vertically, characterized in that: The reinforcement structure includes: a newly added steel beam, a connection assembly connected to the side wall of the existing concrete beam, and a horizontal steel plate connected to the top end of the existing concrete beam; The newly added steel beam is horizontally arranged below the existing concrete floor slab; The connection assembly is formed with a vertically arranged anchoring portion and a connecting portion, the connecting portion is connected to the newly added steel beam, the anchoring portion is penetrated into the existing concrete floor slab, and the horizontal steel plate is connected to one end of the anchoring portion extending out of the existing concrete floor slab.

13. The reinforcement structure of an existing beam and slab according to claim 12, characterized in that: The anchoring portion includes a plurality of anchoring plates spaced apart along the width direction of the existing concrete beam side wall, and the width of each anchoring plate is no more than 100 mm.

14. The reinforcement structure of an existing beam and slab according to claim 13, characterized in that: The length of the anchoring portion extending out of the existing concrete floor is equal to the thickness of the horizontal steel plate.

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