A fish-belly beam steel support and concrete support connection structure and connection method

Abstract

This invention proposes a connection structure and method for a fish-belly beam steel support and a concrete support. The connection structure includes a pre-embedded connection unit, a fish-belly beam steel support connection end, a fish-belly beam steel support body, connecting bolts, a prestressing adjustment component, a support crossbar, and a shear locking structure. The connection method involves pre-embedding the pre-embedded connection unit within the concrete support structure. Then, when the concrete support strength reaches at least 75% of its design strength, the fish-belly beam steel support connection end, located at one end of the fish-belly beam steel support body, is installed onto the pre-embedded connection unit using connecting bolts. A shear locking structure is installed on the outside of the fish-belly beam steel support connection end. Finally, a support crossbar and a prestressing adjustment component are installed on the fish-belly beam steel support body. This connection structure and method effectively solve the problems of unreliable connection between the two support structures, complex construction, and inability to fully utilize their respective advantages in existing technologies, thereby improving the overall performance of foundation pit support.

Description

Technical Field

[0001] This invention relates to the field of foundation pit support technology in building engineering, specifically to a fish-belly beam steel support and concrete support connection structure and connection method. Background Technology

[0002] In foundation pit support for building construction, the selection and connection method of the support structure are crucial to the stability of the foundation pit, construction efficiency, and cost control. Although traditional reinforced concrete supports have good overall integrity, are suitable for complex foundation pits, and have strong load-bearing capacity, they also have problems such as high cost, long construction period, time-consuming formwork and pouring processes, difficulty in excavation, easy shrinkage of concrete, and difficulty in dismantling supports later. Moreover, the construction is not environmentally friendly, generating too much construction waste that cannot be consumed or disposed of. With the application and promotion of prefabricated prestressed fish-belly beam steel support technology, the advantages of prefabricated prestressed fish-belly beam steel supports, such as less steel consumption, recyclability, large construction area, and flexible replacement, have been recognized. However, in practical engineering applications, due to the complexity of foundation pit conditions, some foundation pits still require the use of concrete support structures. Therefore, there are situations where some foundation pits use both concrete support structures and prefabricated prestressed fish-belly beam steel supports. When using the two in combination, the existing connection structure suffers from poor reliability, complex construction, and difficulty in leveraging the advantages of both. To address this, the applicant has developed a fish-belly beam steel support and concrete support connection structure and method based on the needs of foundation pit support. This method can effectively solve the problems of unreliable connection, complex construction, and inability to fully leverage the advantages of each support in existing technologies, thereby improving the overall performance of foundation pit support, reducing construction costs, shortening the construction period, and achieving green and environmentally friendly construction. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention proposes a connection structure and method for fish-belly beam steel support and concrete support. By pre-embedding a connection unit within the concrete support structure, and then, when the concrete support strength reaches at least 75% of its design strength, the fish-belly beam steel support connection end, located at one end of the main body, is installed onto the pre-embedded connection unit using connecting bolts. Simultaneously, a shear locking structure is installed. Then, support crossbars and prestressing adjustment components are installed on the main body of the fish-belly beam steel support, and prestress is applied to the support structure. This connection structure and method effectively solve the problems of unreliable connection between the two support structures, complex construction, and the inability to fully utilize their respective advantages in existing technologies, thereby improving the overall performance of the foundation pit support.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A connection structure and method for connecting a fish-belly beam steel support and a concrete support includes a pre-embedded connection unit, a fish-belly beam steel support connection end, a fish-belly beam steel support body, connecting bolts, a prestressing adjustment component, a support crossbar, and a shear locking structure. The fish-belly beam steel support and concrete support connection structure is characterized by: the pre-embedded connection unit being embedded at the connection point between the fish-belly beam steel support and the concrete support; the fish-belly beam steel support connection end being installed on the pre-embedded connection unit; the fish-belly beam steel support connection end being located at one end of the fish-belly beam steel support body; and the other end of the fish-belly beam steel support body having mounting bolt holes and prestressing tension holes; the fish-belly beam steel support connection end of the fish-belly beam steel support body being installed on the pre-embedded connection unit via connecting bolts; and the support crossbar and prestressing adjustment component being installed on the fish-belly beam steel support body; and a shear locking structure being provided between the fish-belly beam steel support connection end and the pre-embedded connection unit.

[0005] Furthermore, the connection structure between the fish-belly beam steel support and the concrete support is provided with a pre-embedded connection unit. The pre-embedded connection unit structure is provided with a pre-embedded steel plate, four sets of anchoring steel bars are provided on the rear side of the pre-embedded steel plate, six sets of connecting sleeves are provided on the pre-embedded steel plate, and an annular boss is provided in the middle of the front side of the pre-embedded steel plate.

[0006] Furthermore, the connection structure between the fish-belly beam steel support and the concrete support is provided with a fish-belly beam steel support connection end. The fish-belly beam steel support connection end structure is provided with a connecting ear plate, and the connecting ear plate is provided with stiffening ribs. The stiffening ribs are triangular structures, numbering 4 to 6, and are evenly distributed around the connecting ear plate. The thickness of the stiffening ribs is 16 to 20 mm, and the height is not less than twice the thickness of the connecting ear plate. A support transition section is provided between the fish-belly beam steel support connection end and the fish-belly beam steel support body. The inner side of the connecting ear plate is provided with a concave arc groove, and the connecting ear plate is provided with ten sets of mounting screw holes.

[0007] Furthermore, the connection structure between the fish-belly beam steel support and the concrete support is equipped with a prestressing adjustment component, which includes prestressed steel strands, wedge-type anchors, and prestressed connectors. The prestressed steel strands are located on the upper part of the fish-belly beam steel support body.

[0008] Furthermore, the connection structure between the fish-belly beam steel support and the concrete support is equipped with a shear locking structure. The shear locking structure is equipped with anti-slip pads and wedge-shaped shear keys. The anti-slip pads are made of 304 or 316 stainless steel with a thickness of 3-5mm and a sandblasted surface, with a friction coefficient of not less than 0.4. The wedge-shaped shear keys are forged from 40CrNiMoA alloy structural steel, with an upper base width of 30-50mm, a lower base width of 50-70mm, and a height of 40-60mm.

[0009] Furthermore, the connection method steps for the fish-belly beam steel support and the concrete support connection structure are as follows: Step 1: Select the appropriate pre-embedded connection unit, fish belly beam steel support connection end, fish belly beam steel support body, connecting bolts, prestressing adjustment components and shear locking structure according to the actual site conditions; Step 2: After the reinforcement binding of the concrete support structure and the formwork installation are completed, install and bind the pre-embedded connection units onto the reinforcement cage. Use a total station to calibrate the position of the pre-embedded connection units, ensuring that the flatness, verticality, and fixed position are within the allowable error range. Also, verify the position and orientation of the connecting sleeves. After verification, pour the concrete. Step 3: After the concrete is poured and cured to more than 75% of its design strength, install the main body of the fish belly beam steel support onto the pre-embedded connection unit using connecting bolts, and simultaneously install the shear locking structure. Step 4: Install the support crossbars and prestressing adjustment components on the fish-belly beam steel support body. Anchor one end of the prestressed steel strand to the connector of the fish-belly beam steel support body on one side using a wedge-type anchor. Pass the other end through the fish-belly beam steel support body to the other end and anchor it to the connector on the other side using a wedge-type anchor. Install jacks on the prestressed steel strands on the wedge-type anchors and connect a pressure sensor in series between the jacks and the wedge-type anchors. Connect a digital display instrument and apply prestress using a graded loading method. Each loading level is 20% to 30% of the design prestress value. Stabilize the pressure for 3 to 5 minutes after each loading level until the design prestress value is reached. After stabilizing the pressure for 10 minutes, lock the prestressed steel strands.

[0010] The benefits of this application are: 1. The connection structure and method between the steel support and concrete support of the fish belly beam can effectively transfer vertical and horizontal loads through the synergistic effect of the pre-embedded connection components, prestressing application device and shear key, prevent relative displacement or rotation of the two supports, and ensure the safety and stability of the foundation pit support structure. 2. The increase in manufacturing cost for the connection structure and method between the steel support and concrete support of the fish belly beam is small and controllable; 3. The connection structure and method between the fish-belly beam steel support and the concrete support have the advantage of low power consumption, making them suitable for passive wireless sensors and increasing battery life. 4. The connection structure and method between the steel support and concrete support of the fish belly beam utilizes a miniature fan, which effectively accelerates gas diffusion, reduces measurement time, and improves measurement efficiency. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a partial structural diagram of the present invention. Figure 1 ; Figure 3 This is a partial structural diagram of the present invention. Figure 2 ; Figure 4 This is a partial structural diagram of the present invention. Figure 3 ; Figure 5 This is a partial structural diagram of the present invention. Figure 4 ; Figure 6 This is a partial structural diagram of the present invention. Figure 5 ; Figure 7 This is a partial structural diagram of the present invention. Figure 6 ; Figure 8 This is a partial structural diagram of the present invention. Figure 7 .

[0012] The markings in the diagram are as follows: 1. Embedded connection unit; 1-2. Embedded steel plate; 1-2. Anchoring steel bar; 1-3. Connecting sleeve; 1-4. Annular boss; 2. Fish belly beam steel support connection end; 2-1. Connecting ear plate; 2-2. Stiffening rib; 2-3. Support transition section; 2-4. Concave arc groove; 2-5. Mounting bolt hole; 3. Fish belly beam steel support body; 4. Connecting bolt; 5. Prestressing adjustment component; 5-1. Prestressed steel strand; 5-2. Wedge-type anchor; 5-3. Prestressed connector; 6. Support crossbar; 7. Shear locking structure; 7-1. Anti-slip pad; 7-2. Wedge-shaped shear key. Detailed Implementation

[0013] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments: like Figure 1-8 As shown, this is a connection structure and method for a fish-belly beam steel support and a concrete support, including a pre-embedded connection unit 1, a fish-belly beam steel support connection end 2, a fish-belly beam steel support body 3, connecting bolts 4, a prestressing adjustment component 5, a support crossbar 6, and a shear locking structure 7. Figure 1 As shown, the fish-belly beam steel support and concrete support connection structure is provided with a pre-embedded connection unit 1. The pre-embedded connection unit 1 is installed at the connection between the fish-belly beam steel support and the concrete support. The fish-belly beam steel support connection end 2 is installed on the pre-embedded connection unit 1. The fish-belly beam steel support connection end 2 is located at one end of the fish-belly beam steel support body 3. The other end of the fish-belly beam steel support body 3 is provided with mounting bolt holes and prestressing tension holes. The fish-belly beam steel support connection end 2 of the fish-belly beam steel support body 3 is installed on the pre-embedded connection unit 1 by connecting bolts 4. The fish-belly beam steel support body 3 is equipped with a support crossbar 6 and a prestressing adjustment component 5. The fish-belly beam steel support connection end 2 and the pre-embedded connection unit 1 are provided with an anti-shear locking structure 7.

[0014] like Figure 2-3 As shown, the pre-embedded connection unit 1 of the connection structure between the steel support and concrete support of the fish belly beam consists of a pre-embedded steel plate 1-1. The pre-embedded steel plate 1-1 is cut from a whole plate according to the actual needs of the site. Four sets of anchoring steel bars 1-2 are set on the rear side of the pre-embedded steel plate 1-1. The tail end of the anchoring steel bars 1-2 is set with a hook. Six sets of connecting sleeves 1-3 are set on the pre-embedded steel plate 1-1. The connecting sleeves 1-3 have an open front end and a closed tail end. The connecting sleeves 1-3 have threads inside. An annular boss 1-4 is set in the middle of the front side of the pre-embedded steel plate 1-1. The anchoring steel bars 1-2, connecting sleeves 1-3 and annular boss 1-4 are connected to the pre-embedded steel plate 1-1 by welding.

[0015] like Figure 4-6 As shown, the fish-belly beam steel support and concrete support connection structure is provided with a fish-belly beam steel support connection end 2. The fish-belly beam steel support connection end 2 is provided with a connecting ear plate 2-1. The connecting ear plate 2-1 is provided with stiffening ribs 2-2. The stiffening ribs 2-2 are triangular structures, numbering 4 to 6, and are evenly distributed around the connecting ear plate 2-1. The thickness of the stiffening ribs 2-2 is 16 to 20 mm, and the height is not less than twice the thickness of the connecting ear plate 2-1. A support transition section 2-3 is provided between the fish-belly beam steel support connection end 2 and the fish-belly beam steel support body 3. The inner side of the connecting ear plate 2-1 is provided with a concave arc groove 2-4. The connecting ear plate 2-1 is provided with ten sets of mounting screw holes 2-5. The fish-belly beam steel support body 3 and the transition section 23 are factory integrated welded. After welding, 100% ultrasonic flaw detection is performed to ensure that the weld quality meets the first-class standard.

[0016] like Figure 7 As shown, the fish-belly beam steel support and concrete support connection structure is equipped with a prestressing adjustment component 5. The prestressing adjustment component 5 is equipped with a prestressed steel strand 5-1, a wedge-type anchor 5-2 and a prestressed connector 5-3. The prestressed steel strand 5-1 is located on the upper part of the fish-belly beam steel support body 3.

[0017] like Figure 5 , Figure 8 The fish-belly beam steel support and concrete support connection structure shown are equipped with a shear locking structure 7. The shear locking structure 7 is equipped with an anti-slip pad 7-1 and a wedge-shaped shear key 7-2. The anti-slip pad 7-1 is made of 304 or 316 stainless steel with a thickness of 3-5mm and a sandblasted surface. The friction coefficient is not less than 0.4. The wedge-shaped shear key 7-2 is forged from 40CrNiMoA alloy structural steel with an upper base width of 30-50mm, a lower base width of 50-70mm, and a height of 40-60mm.

[0018] The connection method steps for the fish-belly beam steel support and concrete support connection structure shown are as follows: Step 1: Select the appropriate pre-embedded connection unit according to the actual site conditions: 1. Fish belly beam steel support connection end; 2. Fish belly beam steel support body; 3. Connecting bolts; 4. Prestress adjustment component; 5. Support crossbar; 6. Shear locking structure; 7. Step 2: After the reinforcement binding of the concrete support structure and the formwork installation are completed, install and bind the pre-embedded connection unit 1 to the reinforcement cage. Use a total station to calibrate the position of the pre-embedded connection unit 1 to ensure that the flatness, verticality and fixed position are within the allowable error range. The flatness error is ≤2mm / m and the verticality error is ≤0.5°. Use wooden supports to reinforce the unit and prevent displacement during concrete pouring. Check the position and orientation of the connecting sleeves 1-3. After verification, pour the concrete. Step 3: After the concrete is poured and cured to more than 75% of its design strength, install the fish-belly beam steel support body 3 onto the pre-embedded connection unit 1 using connecting bolts 4, and simultaneously install the shear locking structure 7; tie the concrete support reinforcement, with the main reinforcement diameter 32mm and spacing 150mm; pour C40 impermeable concrete with an impermeability grade of P8; use an immersion vibrator to vibrate in layers, with a vibration radius ≤500mm, to ensure the concrete around the pre-embedded steel plate 1-1 is dense; the concrete pouring is complete. After covering and curing, the curing time is ≥14 days. After the strength reaches 75% of the design strength, it is tested by test blocks under the same conditions before proceeding to the next process. During construction, a 25t truck crane is used to lift the fish belly beam steel support body 3 to the docking position. Manual adjustment is used to make the concave arc groove 2-4 of the connecting ear plate 2-1 precisely fit with the annular boss 1-4 on the pre-embedded steel plate 1-1. M30 high-strength bolts 4 are inserted and tightened in three times in a diagonal sequence. The final torque value is 480 N·m, which is controlled by a torque wrench. Step 4: Install the support crossbar 6 and prestressing adjustment component 5 on the fish-belly beam steel support body 3. Anchor one end of the prestressed steel strand 5-1 to the connector 5-3 on one side of the fish-belly beam steel support body 3 through the clamp-type anchor 5-2. The other end passes through the fish-belly beam steel support body 3 to the other end and is anchored to the connector 5-3 on the other side through the clamp-type anchor 5-2. Install a jack on the prestressed steel strand 5-1 on the clamp-type anchor 5-2, and connect a pressure sensor in series between the jack and the clamp-type anchor 5-2. Connect a digital display instrument and apply prestress using a graded loading method. Each loading level is 20% to 30% of the design prestress value. Stabilize the pressure for 3 to 5 minutes after each loading level until the design prestress value is reached. After stabilizing the pressure for 10 minutes, lock the prestressed steel strand 5-1.

[0019] The working principle of the connection structure and method between the fish-belly beam steel support and the concrete support is as follows: the pre-embedded connection unit 1 is fixed synchronously during the concrete support pouring; the anchoring steel bar 1-2 combines with the concrete to form a rigid base; the concave arc groove 2-4 of the connecting ear plate 2-1 fits into the annular boss 1-4 of the pre-embedded steel plate 1-1, directly aligning with the bolt holes to prevent on-site alignment errors; the horizontal earth pressure borne by the fish-belly beam steel support is distributed through the transition section 2-3 and then transferred to the connecting ear plate 2-1, and then transferred to the pre-embedded steel plate 1-1 and the concrete support through the dual paths of the connecting bolt 4 and the wedge shear key 7-2. Soil support prevents weak single force transmission; jacks apply prestress to prestressed steel strands 5-1, eliminating connection gaps, increasing the friction coefficient of anti-slip pads 7-1, and simultaneously allowing connecting bolts 4 and wedge-shaped shear keys 7-2 to be stressed in advance to cope with load impact; pressure sensors can monitor in real time and provide additional tension when necessary to ensure stable force transmission; stiffening ribs 2-2, connecting ear plates 2-1, and the transition section 2-3 of the support body form a triangular support to resist deformation of connecting ear plates 2-1; the rigidity of concrete support and the flexibility of fish-belly beam steel support are combined to achieve "rigid-flexible synergy," control the displacement of the foundation pit, and improve overall stability.

[0020] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any modifications or equivalent changes made based on the technical essence of the present invention shall still fall within the scope of protection claimed by the present invention.

Claims

1. A fish-belly beam steel support and concrete support connection structure, comprising a pre-embedded connection unit (1), a fish-belly beam steel support connection end (2), a fish-belly beam steel support body (3), connecting bolts (4), a prestressing adjustment component (5), a support crossbar (6), and a shear locking structure (7), characterized in that: The connection structure between the fish belly beam steel support and the concrete support is provided with a pre-embedded connection unit (1). The pre-embedded connection unit (1) is installed at the connection between the fish belly beam steel support and the concrete support. The fish belly beam steel support connection end (2) is installed on the pre-embedded connection unit (1). The fish belly beam steel support connection end (2) is located at one end of the fish belly beam steel support body (3). The other end of the fish belly beam steel support body (3) is provided with mounting bolt holes and prestressing tension holes. The fish belly beam steel support connection end (2) of the fish belly beam steel support body (3) is installed on the pre-embedded connection unit (1) by connecting bolts (4). The support crossbar (6) and the prestressing adjustment component (5) are installed on the fish belly beam steel support body (3). The fish belly beam steel support connection end (2) and the pre-embedded connection unit (1) are provided with a shear locking structure (7). The shear locking structure (7) is provided with anti-slip pads (7-1) and wedge-shaped shear keys (7-2). The pre-embedded connection unit (1) is provided with a pre-embedded steel plate (1-1). Six sets of connecting sleeves (1-3) are provided on the pre-embedded steel plate (1-1). An annular boss (1-4) is provided in the middle of the front side of the pre-embedded steel plate (1-1). The fish belly beam steel support connection end (2) is provided with a connecting ear plate (2-1). An inwardly concave arc groove (2-4) is provided on the inner side of the connecting ear plate (2-1). The anti-slip pads (7-1) are provided between the annular boss (1-4) and the concave arc groove (2-4). Wedge-shaped shear keys (7-2) are provided on the left and right sides of the connecting ear plate (2-1). The key (7-2) is installed on both sides of the connecting ear plate (2-1) by bolts. The horizontal earth pressure borne by the fish belly beam steel support is transferred to the connecting ear plate (2-1) after the stress is dispersed by the transition section (2-3). Then, the load is transferred to the embedded steel plate (1-1) and the concrete support through the dual paths of the connecting bolt (4) and the wedge shear key (7-2). The anti-slip pad (7-1) is made of 304 or 316 stainless steel with a thickness of 3-5mm and a sandblasted surface. The friction coefficient is not less than 0.

4. The wedge shear key (7-2) is forged from 40CrNiMoA alloy structural steel with an upper bottom width of 30-50mm, a lower bottom width of 50-70mm, and a height of 40-60mm.

2. The fish-belly beam steel support and concrete support connection structure according to claim 1, characterized in that: The connection structure between the steel support and the concrete support of the fish belly beam is provided with a pre-embedded connection unit (1), and four sets of anchoring steel bars (1-2) are provided on the rear side of the pre-embedded steel plate (1-1).

3. The fish-belly beam steel support and concrete support connection structure according to claim 1, characterized in that: The fish-belly beam steel support and concrete support connection structure is provided with a fish-belly beam steel support connection end (2), and a stiffening rib (2-2) is provided on the connecting ear plate (2-1); the stiffening rib (2-2) is a triangular structure, with 4 to 6 pieces, evenly distributed around the connecting ear plate (2-1), the stiffening rib (2-2) is 16 to 20 mm thick, and the height is not less than twice the thickness of the connecting ear plate (2-1); a support transition section (2-3) is provided between the fish-belly beam steel support connection end (2) and the fish-belly beam steel support body (3).

4. The fish-belly beam steel support and concrete support connection structure according to claim 1, characterized in that: The connection structure between the fish belly beam steel support and the concrete support is provided with a prestress adjustment component (5). The prestress adjustment component (5) is provided with a prestressed steel strand (5-1), a wedge-type anchor (5-2), and a prestressed connector (5-3). The prestressed steel strand (5-1) is located on the upper part of the fish belly beam steel support body (3).

5. The connection method of the fish-belly beam steel support and concrete support connection structure according to claim 1, characterized in that: The connection method for the fish-belly beam steel support and concrete support connection structure is as follows: Step 1: Select the appropriate pre-embedded connection unit (1), fish belly beam steel support connection end (2), fish belly beam steel support body (3), connecting bolt (4), prestress adjustment component (5), support crossbar (6), and shear locking structure (7) according to the actual site conditions. Step 2: After the reinforcement binding of the concrete support structure is completed and the formwork is installed, the pre-embedded connection unit (1) is installed and bound to the reinforcement cage. The position of the pre-embedded connection unit (1) is calibrated by a total station to ensure that the flatness, verticality and fixed position are within the allowable error range. The position and direction of the connecting sleeve (1-3) are checked. After the check is completed, the concrete is poured. Step 3: After the concrete is poured and cured to more than 75% of the design strength, the fish belly beam steel support body (3) is installed on the pre-embedded connection unit (1) through connecting bolts (4), and the shear locking structure (7) is installed at the same time. Step 4: Install the support crossbar (6) and prestress adjustment component (5) on the fish belly beam steel support body (3). Anchor one end of the prestressed steel strand (5-1) through the wedge anchor (5-2) in the connector (5-3) of the fish belly beam steel support body (3) on one side. The other end passes through the fish belly beam steel support body (3) to the other end and is anchored through the wedge anchor (5-2) in the connector (5-3) on the other side. Install a jack on the prestressed steel strand (5-1) on the wedge anchor (5-2) and connect a pressure sensor in series between the jack and the wedge anchor (5-2). Connect a digital display instrument and apply prestress using a graded loading method. Each loading level is 20% to 30% of the design prestress value. Stabilize the pressure for 3 to 5 minutes after each loading level until the design prestress value is reached. After stabilizing the pressure for 10 minutes, lock the prestressed steel strand (5-1).

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