Emergency lifting compensation structure for shield crossing overhead

Abstract

The utility model relates to emergency lifting compensation structure technical field discloses a kind of shield crossing viaduct emergency lifting compensation structure, including bridge pier, deck component.Using modularization, prefabricated steel support, improve construction efficiency, and steel support component is handled installation by small hoisting equipment, reduce the occupation of site, steel support is directly fixed by deck component Ground, without drilling, reinforcing bar and the like operation to elevated pile, avoid destroying original structure integrity.Assembly process is mainly mechanical splicing, without piling operation (additional pile foundation) high-frequency vibration, reduce disturbance to elevated structure and surrounding environment;And steel component after detection repair after dismantling can be used in other engineering again, reduce material waste and engineering cost;And after lifting is completed, by loosening bolt, unloading jack can be quickly disassembled, without crushing operation, reduce dust, noise pollution, meet green construction requirement.

Description

Technical Field

[0001] This utility model relates to the field of emergency lifting and compensation structure technology, specifically an emergency lifting and compensation structure for shield tunneling through elevated structures. Background Technology

[0002] An emergency support and compensation structure is a set of active or passive temporary support and control systems installed in advance between the bottom of the bridge pier (or abutment) and the foundation to cope with possible uneven or sudden settlement of the bridge piers and abutments that exceeds the preset limits during the shield tunnel crossing the foundation of an existing viaduct.

[0003] In emergency situations where shield tunneling causes disturbance to the foundation soil and excessive bridge settlement, the bridge foundation can be quickly and effectively "supported," and the pier elevation can be restored or maintained through an adjustable "compensation" mechanism to ensure the structural and operational safety of the viaduct.

[0004] Shield tunneling is the mainstream construction method for underground engineering. Elevated bridges (urban expressways and main road bridges), due to their deep pile foundations and wide spans, are among the structures most frequently subject to spatial conflicts with shield tunnels. The disturbance to the ground caused by shield construction is easily transmitted to the pile foundations, leading to settlement risks and becoming an unavoidable engineering problem in urban renewal. The main causes of elevated bridge settlement are ground loss and stress redistribution; failure to fill the shield tail gap in a timely manner, insufficient / fluctuating slurry pressure, and improper propulsion parameters can amplify settlement.

[0005] Traditional construction methods include: 1. Dynamic grouting and intelligent control: An automated grouting system is based on real-time linkage between surface / bridge pile deformation and grouting pressure. If the pressure exceeds the limit, the grouting volume and pressure are automatically increased, achieving a "deformation-parameter" closed loop. These technologies are often implemented in areas with high speeds and minimal traffic disruption. For urban bridges, ground excavation for grouting is often not feasible, and the impact on existing traffic must be fully considered.

[0006] 2. Supplementary pile foundation method: Construct Φ800-1200mm bored cast-in-place piles next to the original pile (1.5-2.0m away from the original pile), embed them in the same bearing layer as the original pile, and rigidly connect them to the original pile cap through reinforced concrete connecting beams to form a composite pile foundation of "original pile + new pile".

[0007] 3. PLC active lifting of the cap beam corbel: The steel corbel is a temporary component, and its connection with the cap beam relies on bolts or welding. Long-term stress (especially the continuous disturbance during the tunnel boring machine's passage) may cause the connection to loosen, reducing the overall support stability.

[0008] The above technologies have a significant impact on elevated road traffic. How to achieve bridge deck displacement compensation during shield tunneling crossings of existing bridges without disrupting traffic, ensuring the operational safety of the elevated bridges, and maintaining the bridge deck elevation is a pressing technical challenge that needs to be addressed. Therefore, we need to propose an emergency support and compensation structure for shield tunneling crossings of elevated roads. Utility Model Content

[0009] The purpose of this utility model is to provide an emergency support and compensation structure for shield tunneling through elevated structures. It adopts modular and prefabricated steel supports, which improves construction efficiency. The steel support components are transported and installed by small hoisting equipment, reducing the occupation of the site. The steel supports are directly fixed to the ground through the pier components, eliminating the need for drilling and rebar installation on the elevated piles, thus avoiding damage to the integrity of the original structure and solving the problems mentioned in the background art.

[0010] To achieve the above objectives, this utility model provides the following technical solution: an emergency lifting and compensation structure for shield tunneling through elevated structures, comprising a pier and a support platform for supporting the pier. A hollow slab for vehicle passage is installed on the pier. Two sets of steel supports are installed on both sides of the pier on the support platform. A steel crossbeam is installed on the top of the steel support, and a steel longitudinal beam is installed on the steel crossbeam. Multiple height-adjusting steel cylinders are installed at equal intervals on the steel longitudinal beams. Jacks for lifting the hollow slab are installed on the height-adjusting steel cylinders, and a gap is left between the top of the jack and the bottom of the hollow slab.

[0011] Preferably, the bottom of the pier is truncated pyramidal, and the pier cap component includes an original pier cap with the same dimensions as the bottom of the pier and an additional pier cap disposed around the original pier cap. The original pier cap and the additional pier cap are connected by pier cap reinforcement.

[0012] Preferably, the steel supports are installed on the newly added pier, and each group of steel supports consists of four in a matrix, with the center position of two adjacent steel supports being 1.2m apart.

[0013] Preferably, in each group of steel supports, a reinforcing rib connects two longitudinally adjacent steel supports.

[0014] Preferably, the support structure is connected to the steel beam by multiple diagonal braces.

[0015] Preferably, the lifting force of the jack is 200-300T, the height of the jack itself is 10-15cm, and the stroke is 4-6cm.

[0016] Preferably, the steel support is made of steel pipe with an inner diameter of 600-650mm and a wall thickness of 10-16mm.

[0017] Compared with the prior art, the beneficial effects of this utility model are: 1. This utility model adopts modular and prefabricated steel supports, which improves construction efficiency. The steel support components are transported and installed by small hoisting equipment, which reduces the occupation of the site. The steel supports are directly fixed to the ground through the pier components, eliminating the need for drilling, rebar installation and other operations on the elevated piles, thus avoiding damage to the integrity of the original structure.

[0018] 2. The assembly process of this utility model is mainly mechanical splicing, without the high-frequency vibration of pile driving (adding pile foundation), reducing the disturbance to the elevated structure and the surrounding environment; and the steel components after dismantling can be reused in other projects after inspection and repair, reducing material waste and project costs; and after the lifting is completed, it can be quickly dismantled by loosening the bolts and unloading the jacks, without the need for crushing operations (the dismantling of concrete supports requires blasting or mechanical crushing), reducing dust and noise pollution, and meeting the requirements of green construction. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is the front view of the present invention; Figure 3 This is a side view of the present invention; Figure 4 This is a top view of the present invention.

[0020] In the diagram: 1. Pier component; 11. Original pier; 12. Newly added pier; 13. Pier reinforcement; 2. Pier; 3. Steel support; 4. Connecting reinforcement; 5. Steel crossbeam; 6. Steel longitudinal beam; 7. Height adjustment steel cylinder; 8. Jack; 9. Diagonal brace; 10. Elevated hollow slab. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Please see Figure 1-4 This utility model provides a technical solution: an emergency support and compensation structure for shield tunneling through elevated structures. It adopts an integral support structure, does not require traffic closure, can achieve active compensation of pile foundation bearing capacity, and can serve as an emergency support system for the original structure.

[0023] The structure includes a pier 2 and a support structure 1 for supporting the pier 2. The top area of ​​the support structure 1 is larger than the bottom area of ​​the pier 2 to reserve space for installing other structures. The pier 2 is equipped with an elevated hollow slab 10 for vehicles to pass through. Multiple elevated hollow slabs 10 are provided, and adjacent elevated hollow slabs 10 are connected by a hinge joint, that is, a hinged structure is formed by setting transverse steel bars (N-shaped steel bars) on both sides of the elevated hollow slab 10.

[0024] The pier component 1 is equipped with two sets of steel supports 3 located on both sides of the pier 2. The steel supports 3 are the bottom foundation supports of the overall support structure. The top of the steel supports 3 is equipped with steel crossbeams 5. In this embodiment, four steel crossbeams 5 are arranged in parallel. Steel longitudinal beams 6 are installed on the steel crossbeams 5. In this embodiment, two steel longitudinal beams 6 are arranged in parallel. Obviously, the steel crossbeams 5 and the steel longitudinal beams 6 are arranged perpendicularly. Both the steel crossbeam 5 and the steel longitudinal beam 6 are made of H-beams (such as H700×300×13×24), with a flange width not less than 1 / 3 of the thickness of the elevated hollow slab 10 and ≥200mm, a web thickness ≥12mm, and a cantilever length not exceeding 1.5m.

[0025] Multiple height-adjustable steel cylinders 7 are installed at equal intervals on the steel longitudinal beam 6. The height-adjustable steel cylinders 7 are used to extend the compensation stroke to achieve large displacement compensation and act as pad blocks. Since the piston stroke of the jack 8 is limited, in extreme cases, the settlement that the pier 2 needs to compensate for will exceed the stroke of the jack 8. Therefore, the height of the overall support structure can be increased by adjusting the height of the steel cylinders 7.

[0026] The height-adjusting steel cylinder 7 is equipped with jacks 8 for lifting the hollow slab, and a gap is left between the top of the jacks 8 and the bottom of the hollow slab.

[0027] When the jack 8 is working, it applies preload to the steel support 3 to actively offset part of the settlement and monitors the settlement data of the elevated structure in real time. By adjusting the support force (such as increasing the preload value), it controls the deformation and achieves "dynamic lifting" to avoid settlement exceeding the limit.

[0028] Before the tunnel boring machine (TBM) passes through, the bridge load is gradually transferred to the steel support 3-distribution beam (steel crossbeam 5 and steel longitudinal beam 6) system to ensure that the pier 2 is completely separated from the original support (gap ≤ 5mm).

[0029] After the tunnel boring machine passes through, the jack 8 is lowered according to the principle of graded unloading to restore the original support stress.

[0030] The lifting force of the jack 8 is 200-300T, the height of the jack 8 is 10-15cm, and the stroke is 4-6cm. The design value of the lifting force of the jack 8 is 1.2 to 1.5 times the calculated load, and the bearing capacity of a single steel support 3 is reserved with a redundancy of more than 20%.

[0031] The rated load of a single jack 8 shall not be less than twice the calculated lifting force. Furthermore, multiple jacks 8 shall be synchronously controlled using a PLC hydraulic synchronization system, with displacement synchronization deviation ≤ ±2mm and pressure deviation ≤ ±5%.

[0032] The bottom of the pier 2 is set in a frustum shape. The pier component 1 includes an original pier 11 with the same size as the bottom of the pier 2 and a new pier 12 set around the original pier 11. The original pier 11 and the new pier 12 are connected by pier reinforcement 13. The setting of the new pier 12 facilitates the installation of steel supports 3 on the new pier 12.

[0033] The steel supports 3 are installed on the newly added pier 12. Each group of steel supports 3 consists of four in a matrix, and the distance between the center positions of two adjacent steel supports 3 is 1.2m.

[0034] Ideally, the bridge (elevated hollow slab 10) support achieves real-time compensation, and the support structure can monitor the displacement of the superstructure in real time. After the shield tunneling excavation, the bridge deck elevation is typically pre-lifted based on the estimated settlement of 5-10mm.

[0035] In each group of steel supports 3, there are reinforcing ribs connecting two longitudinally adjacent steel supports 3.

[0036] Multiple diagonal braces 9 are connected between the support structure 1 and the steel beam 5. These braces are used to reduce the deformation of the steel beam 5. The top of the diagonal braces 9 is connected to the cantilever section of the steel beam 5. The diagonal braces 9 are also made of H-beams (such as H700×300×13×24).

[0037] The steel support 3 is made of steel pipe with an inner diameter of 600-650mm and a wall thickness of 10-16mm. The top of the steel support 3 adopts a cantilever structure. The steel support 3 is made of Q345B or higher strength steel (such as Q390), with a yield strength ≥345MPa and a tensile strength ≥470MPa, which conforms to GB / T1591 standard.

[0038] The connection node between steel support 3 and steel beam 5 adopts a bevel full penetration weld, the weld grade is not lower than level 2, the flaw detection ratio is 100% (UT or MT), and the weld leg size is ≥8mm.

[0039] In use, a new foundation 12 of equal height is laid around the original foundation 11, and two sets of steel supports 3 are installed on the new foundation 12. Each set of steel supports 3 has four in a matrix, and two connecting ribs 4 are connected between the four steel supports 3 in each set to enhance the stability of the steel supports 3. Then, steel crossbeams 5 are welded on the top of the steel supports 3, and steel longitudinal beams 6 are welded on the top of the steel crossbeams 5. Diagonal braces 9 are welded between the new foundation 12 and the steel crossbeams 5 to reduce the deformation of the steel crossbeams 5. Finally, the height adjustment steel cylinder 7 and jack 8 are installed on the steel longitudinal beam 6. Before the shield tunnel passes through, the piston end of the jack 8 is controlled by the PLC control system (this is existing technology, and the control principle is common knowledge to the relevant technical personnel, so it will not be described here). The elevated hollow slab 10 (elevated bridge deck cover beam) is lifted upward and completely separated from the original support (bridge pier 2). The gap between the elevated hollow slab 10 and the bridge pier 2 is ≤5mm. After the tunnel boring machine passes through, the jack 8 is lowered according to the principle of graded unloading to restore the load on the elevated hollow slab 10 of the bridge pier 2.

[0040] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An emergency lifting and compensation structure for shield tunneling through elevated structures, characterized in that: The system includes a pier (2) and a support structure (1) for supporting the pier (2). The pier (2) is equipped with an elevated hollow slab (10) for vehicles to pass through. The support structure (1) is equipped with two sets of steel supports (3) located on both sides of the pier (2). A steel crossbeam (5) is installed on the top of the steel support (3). A steel longitudinal beam (6) is installed on the steel crossbeam (5). Multiple height-adjusting steel cylinders (7) are installed at equal intervals on the steel longitudinal beam (6). A jack (8) for lifting the hollow slab is installed on the height-adjusting steel cylinder (7). A gap is left between the top of the jack (8) and the bottom of the hollow slab.

2. The emergency lifting and compensation structure for shield tunneling through elevated structures according to claim 1, characterized in that: The bottom of the pier (2) is set in a frustum shape. The pier component (1) includes an original pier (11) with the same size as the bottom of the pier (2) and a new pier (12) set around the original pier (11). The original pier (11) and the new pier (12) are connected by pier reinforcement (13).

3. The shield tunneling emergency support and compensation structure for tunneling through elevated structures according to claim 2, characterized in that: The steel supports (3) are installed on the newly added pier (12). Each group of steel supports (3) consists of four in a matrix, and the distance between the center positions of two adjacent steel supports (3) is 1.2m.

4. The emergency lifting and compensation structure for shield tunneling through elevated structures according to claim 1, characterized in that: Each set of steel supports (3) has a reinforcing rib connecting two longitudinally adjacent steel supports (3).

5. The emergency lifting and compensation structure for shield tunneling through elevated structures according to claim 1, characterized in that: Multiple diagonal braces (9) connect the pier component (1) to the steel beam (5).

6. The emergency lifting and compensation structure for shield tunneling through elevated structures according to claim 1, characterized in that: The lifting force of the jack (8) is 200-300T, and the height of the jack (8) itself is 10-15cm and the stroke is 4-6cm.

7. The emergency lifting and compensation structure for shield tunneling through elevated structures according to claim 1, characterized in that: The steel support (3) is made of steel pipe with an inner diameter of 600-650mm and a wall thickness of 10-16mm.

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