A foundation pit beam string and concrete support structure

Abstract

The application relates to a foundation pit beam string and concrete support structure, which comprises a surrounding purlin, a support structure, a sealing plate, a beam string and a prestress applying structure; the surrounding purlin is arranged around the foundation pit; the support structure and the sealing plate are arranged at four corners in the surrounding purlin and are rigidly connected with the surrounding purlin, wherein the outer side of the support structure is provided with an outer main support; the prestress applying structure is connected with the support structure and the beam string; and the beam string is arranged at four sides in the surrounding purlin and is connected with the prestress applying structure. In the application, the prestress applying structure is arranged at the connecting position of the concrete main support and the beam string, the deformation of the key point at the position can be actively controlled, the foundation pit deformation at the connecting position of the concrete support and the beam string and the range of the beam string can be effectively controlled, and the safety of the foundation pit can be more effectively ensured.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and in particular to a tensioned beam and concrete support structure for a foundation pit. Background Technology

[0002] To ensure the safety of underground structure construction and the surrounding environment of the foundation pit, it is necessary to adopt support, reinforcement, and protection measures for the sidewalls and surrounding environment of the foundation pit. Whether it is a deep foundation pit project for high-rise buildings or subway construction, since most of the excavation is carried out in urban areas, there are usually various structures such as traffic arteries, existing buildings, or pipelines around the foundation pit. In order to ensure the safety of the surrounding environment of the foundation pit, increase the excavation space, save construction time, and save costs, the tensioned beam technology that can provide large spans is widely used.

[0003] In existing technologies, due to the complex surroundings and scarcity of land in foundation pits, there is often no suitable loading area for construction. Therefore, the first support must be used as a loading or vehicle access area. Steel supports are not suitable for loading, so the first support is often made into a tensioned beam with an additional concrete support. For example, Chinese invention patent CN111764405A proposes a combined foundation pit support tensioned beam, which includes: a concrete beam, wherein no steel walers are provided on the inner side of the concrete beam, and the end tie rods of the tensioned beam are pre-embedded and fixed in the concrete beam; a support prestressing device that acts directly or indirectly on the concrete beam corresponding to the end tie rods; the support prestressing device is not rigidly connected to the end tie rods; and a tensile device, which includes a metal part pre-embedded in the concrete beam within the foundation pit, a prestressing adjustment device connected to a prestressing connector, and the prestressing connector connected to the part of the metal part extending out of the concrete beam. However, since the main concrete support connected to the tensioned beam is subjected to large forces and cannot be prestressed, the deformation is passively controlled, which leads to larger deformation of the foundation pit at the connection point between the concrete support and the tensioned beam and within the range of the tensioned beam. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects of the prior art by providing a prestressing structure for a foundation pit tensioned beam and concrete support. A prestressing structure is added at the connection between the concrete support and the tensioned beam, so that the entire system can not only meet the load requirements, but also actively control the deformation of key locations in the foundation pit.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A tensioned beam and concrete support structure for a foundation pit includes a waler, a support structure, a sealing plate, a tensioned beam, and a prestressing application structure.

[0007] The walers are installed around the foundation pit;

[0008] The supporting structure and the sealing plate are set at the four corners inside the waler and are rigidly connected to the waler, wherein the outer side of the supporting structure is provided with an outer main support;

[0009] The prestressing application structure connects the supporting structure to the tensioned beam;

[0010] The tensioned beams are set on the four sides inside the walers and are rigidly connected to the prestressing structure. The use of tensioned beams can greatly increase the construction space of the foundation pit.

[0011] Furthermore, the prestressing structure includes a cantilever arm and a steel support. The cantilever arm is connected to the steel support and is used to bear the weight of the steel support. The steel support is connected to the outer main support.

[0012] Furthermore, the prestressing application structure also includes a prestressing application device, end connectors, embedded parts, and bolt connectors. One end of the steel support is equipped with a prestressing application device for applying prestress, and the other end is equipped with an end connector. The end connector is connected to the embedded parts through bolt connectors. The load of the tensioned beam will eventually be transferred to the concrete outer main support, which will cause large deformation at this position. Therefore, a prestressing application structure is set at the connection position between the concrete outer main support and the tensioned beam. Prestress can be applied at this position, and the deformation of the key point at this position can be actively controlled. This effectively controls the foundation pit deformation at the connection position between the concrete support and the tensioned beam and within the range of the tensioned beam, thus more effectively ensuring the safety of the foundation pit.

[0013] Furthermore, the bolted connector includes multiple screws and a base plate, which are welded together.

[0014] Furthermore, the base plate is welded and fixed to the embedded part.

[0015] Furthermore, the prestressing application structure also includes a secondary grouting zone, which is located at the front end of the prestressing application device and at the connection point between the end connector and the embedded part.

[0016] Furthermore, the walers, supporting structures, and sealing plates are all made of concrete.

[0017] Furthermore, the tensioned beam includes end tie rods and a prestress adjustment device.

[0018] Furthermore, the end tie rod is pre-embedded and fixed in the waler.

[0019] Furthermore, the prestressing adjustment device acts vertically on the waler, and a secondary grouting zone is set between it and the waler. The tie rods in the tensioned beam are connected to the concrete beam through struts to form a new type of combined tensioned beam system. This makes the entire steel support system have bidirectional stiffness in the pit support, both inward and outward, resulting in stronger integrity and higher safety.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] (1) The present invention adopts a combination of tensioned beam and concrete support, which can not only meet the requirements of surcharge and vehicle movement, but also provide a large space for foundation pit construction, making the truss support system and tensioned beam support system independent of each other. Thus, they can be installed and constructed separately during construction, and can also be dismantled separately, shortening the construction period and improving construction flexibility.

[0022] (2) In this invention, a prestressing structure is set at the connection between the concrete main support and the tension beam, which can actively control the deformation of the key point at this location, effectively control the foundation pit deformation at the connection between the concrete support and the tension beam and within the range of the tension beam, and more effectively ensure the safety of the foundation pit. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 This is a schematic diagram of the tensioned beam structure of the present invention;

[0025] Figure 3 This is a schematic diagram of the prestressing application structure of the present invention;

[0026] Figure 4 for Figure 3 Sectional view at point 1-1;

[0027] Figure 5 This is a schematic diagram of the bolted connector structure of the present invention.

[0028] In the diagram: 1. Waler; 2. Support structure; 21. External main brace; 3. Sealing plate; 4. Tensioned beam; 41. End tie rod; 42. Prestress adjustment device; 5. Prestress application structure; 51. Forward reach arm; 52. Steel support; 53. Prestress application device; 54. End connector; 55. Embedded part; 56. Bolt connector; 561. Screw; 562. Base plate; 57. Secondary grouting area. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0030] Example 1

[0031] like Figure 1As shown, a tensioned beam and concrete support structure for a foundation pit includes a waler 1, a support structure 2, a sealing plate 3, a tensioned beam 4, and a prestressing application structure 5. The waler 1 is arranged around the foundation pit, and the support structure 2 and the sealing plate 3 are located at the four inner corners of the waler 1 and rigidly connected to the waler 1. The concrete support and sealing plate are mainly used for supporting the foundation pit and for loading and transporting vehicles. The support structure 2 has an outer main brace 21 on its outer side. The prestressing application structure 5 connects the support structure 2 and the tensioned beam 4. The tensioned beam 4 is located on the four inner sides of the waler 1 and rigidly connected to the prestressing application structure 5. The use of the tensioned beam greatly increases the construction space of the foundation pit.

[0032] like Figure 3 and Figure 4 As shown, the prestressing application structure 5 includes a cantilever arm 51 and a steel support 52. The cantilever arm 51 is connected to the steel support 52 and rests on the concrete to bear the weight of the steel support 52. The steel support 52 is connected to the outer main support 21. The prestressing application structure 5 also includes a prestressing application device 53, an end connector 54, an embedded part 55, and a bolt connector 56. One end of the steel support 52 is equipped with a prestressing application device 53 for applying prestress, and the other end is equipped with an end connector 54. The end connector 54 is connected to the embedded part 55 through the bolt connector 56. The load of the tensioned beam will eventually be transferred to the concrete outer main support, which will cause large deformation at this location. Therefore, a prestressing application structure is set at the connection position between the concrete outer main support and the tensioned beam. Prestress can be applied at this location, which can actively control the deformation of key points at this location, effectively control the foundation pit deformation at the connection position between the concrete support and the tensioned beam and within the tensioned beam range, and more effectively ensure the safety of the foundation pit.

[0033] like Figure 5 As shown, the bolted connector 56 includes multiple screws 561 and a base plate 562, which are welded together. The base plate 562 is also welded together with the embedded part 55.

[0034] The prestressing application structure 5 also includes a secondary grouting zone 57, which is located at the front end of the prestressing application device 53 and at the connection point between the end connector 54 and the embedded part 55. The secondary grouting zone 57 is length-adjustable for length adjustment and leveling. Secondary grouting makes the equipment easier to adjust and install.

[0035] The waler 1, the supporting structure 2, and the sealing plate 3 are all made of concrete.

[0036] like Figure 2As shown, the tensioned beam 4 includes end tie rods 41 and a prestressing adjustment device 42. The end tie rods are pre-embedded and fixed in the waler 1. The prestressing adjustment device 42 acts vertically on the waler 1, and a secondary grouting zone 57 is provided between it and the waler 1. The tie rods in the tensioned beam are connected to the concrete beam by struts to form a new type of combined tensioned beam system, which makes the entire steel support system have bidirectional stiffness in both the inward and outward directions during foundation pit support, resulting in stronger integrity and higher safety.

[0037] In summary, this invention, by combining a tensioned beam with concrete support and setting a prestressing structure at the connection between the main concrete support and the tensioned beam, can actively control the deformation of this key point, effectively control the foundation pit deformation at the connection between the concrete support and the tensioned beam and within the range of the tensioned beam, and more effectively ensure the safety of the foundation pit.

[0038] It should be noted that in the description of this invention, the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0039] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

Claims

1. A tensioned beam and concrete support structure for a foundation pit, characterized in that, It includes walers (1), supporting structure (2), sealing plate (3), tensioned beam (4), and prestressing application structure (5); The walers (1) are set around the foundation pit; The support structure (2) and the sealing plate (3) are set at the four corners inside the waler (1) and are rigidly connected to the waler (1), wherein the support structure (2) is provided with an outer main support (21) on the outside. The prestressing structure (5) connects the support structure (2) and the tension beam (4); The tension beam (4) is set on the four sides inside the waler (1) and rigidly connected to the prestressing structure (5).

2. The tensioned beam and concrete support structure for a foundation pit according to claim 1, characterized in that, The prestressing structure (5) includes a forward extension arm (51) and a steel support (52). The forward extension arm (51) is connected to the steel support (52) and is used to bear the weight of the steel support (52). The steel support (52) is connected to the outer main support (21).

3. The foundation pit tensioned beam and concrete support structure according to claim 2, characterized in that, The prestressing structure (5) further includes a prestressing device (53), an end connector (54), an embedded part (55), and a bolt connector (56). One end of the steel support (52) is provided with a prestressing device (53) for applying prestress, and the other end is provided with an end connector (54). The end connector (54) is connected to the embedded part (55) through the bolt connector (56).

4. The tensioned beam and concrete support structure for a foundation pit according to claim 3, characterized in that, The bolted connector (56) includes a plurality of screws (561) and a base plate (562), which are welded together.

5. The tensioned beam and concrete support structure for a foundation pit according to claim 4, characterized in that, The base plate (562) is welded and fixed to the embedded part (55).

6. The tensioned beam and concrete support structure for a foundation pit according to claim 3, characterized in that, The prestressing structure (5) also includes a secondary grouting zone (57), which is located at the front end of the prestressing device (53) and at the connection between the end connector (54) and the embedded part (55).

7. The tensioned beam and concrete support structure for a foundation pit according to claim 1, characterized in that, The waler (1), the supporting structure (2), and the sealing plate (3) are all made of concrete.

8. The tensioned beam and concrete support structure for a foundation pit according to claim 1, characterized in that, The tensioned beam (4) includes end tie rods (41) and a prestress adjustment device (42).

9. The tensioned beam and concrete support structure for a foundation pit according to claim 8, characterized in that, The end tie rod is pre-embedded and fixed in the waler (1).

10. A tensioned beam and concrete support structure for a foundation pit according to claim 8, characterized in that, The prestress adjustment device (42) acts vertically on the waler (1), and a secondary grouting zone (57) is provided between it and the waler (1).

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