Cast-in-place beam construction support structure for deep soft soil area

Abstract

The invention relates to the field of bridge engineering, and discloses a cast-in-place beam construction support structure for a deep and thick soft soil area, which comprises a permanent structure pier column for supporting an integral device, a bailey beam is mounted on the upper surface of the permanent structure pier column, a supporting piece is mounted on the lower surface of the bailey beam, and a bottom end supporting mechanism is mounted on the lower surface of the supporting piece; a distribution beam is installed on the upper surface of the bailey beam, a full framing is installed on the upper surface of the distribution beam, and an upper formwork system is installed on the upper surface of the full framing. And the long spiral cast-in-place pile foundation is used for supporting the bailey beam, and a bearing platform is installed on the upper surface of the long spiral cast-in-place pile foundation. A rigid foundation is formed by a long spiral cast-in-place pile foundation and a bottom end supporting mechanism, the compression bearing capacity of a single pile is larger than the maximum supporting reaction force, the unfavorable geological characteristics of deep soft soil can be effectively dealt with, the bearing platform is anchored to the cast-in-place piles through reserved steel bars, and the top elevation is strictly controlled.

Description

Technical Field

[0001] This invention relates to the field of bridge engineering technology, specifically to a support structure for the construction of cast-in-place beams in deep soft soil areas. Background Technology

[0002] In bridge construction, cast-in-place beam construction is a common form of superstructure construction, and full-span scaffolding is currently the most widely used scaffolding method. The quality of the foundation treatment before scaffolding erection directly affects construction safety and efficiency. For foundations with good geological conditions, ground hardening is a simple and efficient conventional treatment method.

[0003] However, in areas with poor geological conditions, especially in deep soft soil areas, foundation treatment faces many challenges. Commonly used methods include dredging and replacement, enlarged concrete foundations, cement mixing piles, and pipe pile foundations, but these methods have significant limitations: dredging and replacement are prone to uneven settlement due to uneven replacement materials or insufficient compaction; while enlarged concrete foundations can distribute loads, their overall stability is poor in deep soft soil, and the large amount of material used leads to high costs; cement mixing piles are significantly affected by geological uniformity, and differences in pile strength can easily occur, leading to uneven settlement; pipe pile foundations have high construction costs and limited applicability in areas with deep open water or where equipment access is difficult.

[0004] These problems not only affect construction efficiency and the quality of cast-in-place beams, but may also increase safety risks due to foundation instability. Therefore, a cast-in-place beam construction support structure suitable for deep soft soil areas is needed to solve problems such as settlement control, cost control and adaptability to complex working conditions in foundation treatment. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a support structure for cast-in-place beam construction in deep soft soil areas, solving the problem that "existing technologies face many challenges in foundation treatment in areas with poor geological conditions, and a support structure suitable for cast-in-place beam construction in deep soft soil areas is needed."

[0006] To achieve the above objectives, the present invention provides the following technical solution: a support structure for cast-in-place beam construction in deep soft soil areas, comprising: A permanent structural pier is used to support the overall device. A Bailey beam is installed on the upper surface of the permanent structural pier. A support member is installed on the lower surface of the Bailey beam. A bottom support mechanism is installed on the lower surface of the support member. A distribution beam is installed on the upper surface of the Bailey beam. A full-span scaffold is installed on the upper surface of the distribution beam. An upper formwork system is installed on the upper surface of the full-span scaffold. A long spiral cast-in-place pile foundation is used to support a Bailey beam. A pile cap is installed on the upper surface of the long spiral cast-in-place pile foundation, and the pile cap is installed on the lower surface of the Bailey beam.

[0007] Preferably, the support member includes, but is not limited to, I-beams.

[0008] Preferably, the outer wall of the permanent structural pier is equipped with a climbing cone bracket, the upper surface of the climbing cone bracket is equipped with a main beam, and the main beam is installed on the lower surface of the Bailey beam.

[0009] Preferably, the long spiral cast-in-place pile foundation and the bottom support mechanism are evenly arranged along the longitudinal direction of the bridge, and the number of piles arranged in the transverse direction is determined according to the width of the support and the load.

[0010] Preferably, the unsupported portion of the top cantilever of the pier is filled with high-strength grout, and the Bailey beam and the distribution beam are connected by U-bolts.

[0011] Preferably, the bottom support mechanism further includes an inner support rod, which is fixedly connected to the lower surface of the support member. A displacement sensor is installed on the inner wall of the inner support rod, and the displacement sensor can measure parameters including but not limited to tilt angle.

[0012] Preferably, the lower part of the full-span support frame is provided with an adjustable base and a support, and the contact position between the adjustable base and the support and the distribution beam is centered.

[0013] Preferably, the inner wall of the inner support rod is slidably connected with protrusions, and multiple sets of protrusions are arranged in a rotating array with the center line of the inner support rod as the rotation axis.

[0014] Preferably, an adjusting sleeve is slidably connected through the outer wall of the inner support rod, a pressing rod is fixedly connected to the inner wall of the adjusting sleeve, a protective sleeve is fixedly connected to the inner wall of the inner support rod, the pressing rod is slidably connected to the inner wall of the protective sleeve, and the lower surface of the pressing rod is connected to the protrusion via a hinge rod.

[0015] Preferably, a sliding plate is sleeved on the outer wall of the inner support rod, a pressing block is fixedly connected to the upper surface of the sliding plate, a support plate is fixedly connected to the outer wall of the adjusting sleeve near the bottom end, and a locking block is slidably connected to the inner wall of the support plate.

[0016] This invention provides a support structure for cast-in-place beam construction in deep soft soil areas. It has the following beneficial effects: 1. This invention uses a long spiral cast-in-place pile foundation and a bottom support mechanism to form a rigid foundation. The compressive bearing capacity of a single pile is greater than the maximum support reaction force, which can effectively cope with the adverse geological characteristics of deep soft soil. The pile cap is anchored to the cast-in-place pile through reserved steel bars, and the top elevation is strictly controlled, which can evenly transfer the upper load to the pile foundation, greatly reduce uneven settlement of the foundation, and ensure the stability of the overall structure.

[0017] 2. This invention eliminates the need for complex pre-treatment procedures when constructing long spiral cast-in-place piles. The equipment is easy and flexible to operate, and is less affected by the conditions after the initial site preparation. Each machine can stably construct 8 to 10 piles per day, enabling large-area foundation construction to be completed in a short time. It is also less susceptible to severe weather, can operate continuously, and can effectively cope with complex construction environments such as water accumulation and mud in deep soft soil areas. This can significantly shorten the overall construction cycle and ensure that the project progresses as planned.

[0018] 3. By moving the support plate, the adjusting sleeve can be moved downwards, which in turn causes the squeezing rod inside the adjusting sleeve to push the hinge rod to rotate. The rotation of the hinge rod pushes the protrusion to move outwards, thus causing the protrusion to insert into the soft soil area. This further increases the contact area between the inner support rod and the soft soil area, thereby further improving the stability.

[0019] 4. By making the inner support rod hollow, when the protrusion extends outward, the through groove below the protrusion will also be exposed, so that filler can be injected into the inner support rod. The filler will flow directly out from the bottom of the inner support rod through the through groove, so that the gap between the inner support rod and the soft soil area can be filled directly from below. The whole device is more convenient to fill. Attached Figure Description

[0020] Figure 1 This is a front view of the present invention; Figure 2 This is a side view of the long spiral cast-in-place pile foundation support of the present invention; Figure 3 This is a side view of the bottom support mechanism bracket of the present invention; Figure 4 This is an elevation view of the long spiral cast-in-place pile and the pile cap of the present invention; Figure 5 The following are elevation and side views of the 6-hole bracket of the present invention; Figure 6 The following are elevation and side views of the four-hole bracket of the present invention; Figure 7 The above views are of the 6-hole bracket and the 4-hole bracket of the present invention. Figure 8 This is a three-dimensional structural diagram of the bottom support mechanism of the present invention; Figure 9 This is a three-dimensional cross-sectional view of the bottom support mechanism of the present invention.

[0021] The components include: 1. Long spiral cast-in-place pile foundation; 2. Bottom support mechanism; 21. Inner support rod; 22. Adjusting sleeve; 23. Support plate; 24. Locking block; 25. Slide plate; 26. Protrusion; 27. Extrusion block; 28. Extrusion rod; 29. ​​Protective sleeve; 210. Hinge rod; 211. Through slot; 3. Pier; 4. Climbing cone bracket; 5. Main beam; 6. Support component; 7. Bailey beam; 8. Distribution beam; 9. Full-span scaffold; 10. Upper formwork system; 11. Permanent structural pier; 12. High-strength grouting material. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1:

[0023] Please see the appendix Figure 1 - Appendix Figure 9 This invention provides a support structure for cast-in-place beam construction in deep soft soil areas, comprising: The permanent structural pier 11, as the core load-bearing structure of the bridge, has its strength rigorously calculated to bear all the loads of the superstructure and supports the overall structure. A Bailey bridge 7 is installed on the upper surface of the permanent structural pier 11, and the Bailey bridge 7 is firmly fixed to the permanent structural pier 11 by bolts and other connectors. A support member 6 is installed on the lower surface of the Bailey bridge 7, which acts as a bridge connecting the Bailey bridge 7 and the bottom support mechanism 2. The bottom support mechanism 2 is installed on the lower surface of the support member 6, and it extends into the soft soil layer to provide vertical support for the superstructure. A distribution beam 8 is installed on the upper surface of the Bailey bridge 7, distributing the load borne by the Bailey bridge 7 to the full-span scaffold 9. The full-span scaffold 9 is installed on the upper surface of the distribution beam 8, and it further distributes the load through dense uprights. An upper formwork system 10 is installed on the upper surface of the full-span scaffold 9; the upper formwork system 10 directly determines the forming dimensions and appearance quality of the cast-in-place beam. The long spiral cast-in-place pile foundation 1 is formed by long spiral drilling technology, which can penetrate into the soft soil layer to provide stable support and is used to support Bailey beam 7. A pile cap 3 is installed on the upper surface of the long spiral cast-in-place pile foundation 1. The pile cap 3 and the long spiral cast-in-place pile foundation 1 are anchored with steel bars to form an integral load-bearing structure. The pile cap 3 is installed on the lower surface of Bailey beam 7 and the pile cap 3 evenly transfers the load of Bailey beam 7 to the long spiral cast-in-place pile foundation 1.

[0024] Reference Figure 1 - Figure 3The connection between the support member 6 and the bottom support mechanism 2 includes, but is not limited to, direct fixing with bolts. Bolt connection is convenient to install and easy to adjust. The support member 6 includes, but is not limited to, I-beams, crossbeams, and slide rails. Crossbeams are more suitable for fixed load-bearing scenarios, while slide rails are more convenient for fine-tuning the installation position. The outer wall of the permanent structural pier 11 is equipped with a climbing cone bracket 4. The climbing cone bracket 4 is connected to the permanent structural pier 11 through pre-embedded climbing cones to ensure strength. The upper surface of the climbing cone bracket 4 is equipped with a main beam 5. The connection surface between the main beam 5 and the climbing cone bracket 4 is leveled to ensure uniform stress. The main beam 5 is installed on the lower surface of the Bailey beam 7. The main beam 5 provides additional support points for the Bailey beam 7 to enhance the overall rigidity. The long spiral cast-in-place pile foundation 1 and the bottom support mechanism 2 are evenly arranged along the longitudinal direction of the bridge. The even arrangement in the longitudinal direction can make the load evenly distributed along the length of the bridge. The number of piles arranged in the transverse direction is determined according to the width of the support and the load. The number of piles in the transverse direction is determined by mechanical calculation to meet the stress requirements.

[0025] Reference Figure 1 - Figure 3 The unsupported portion of the top cantilever of the foundation 3 is filled with high-strength grout 12. High-strength grout 12 has the characteristics of high strength and no shrinkage, which can ensure dense filling. Bailey beam 7 and distribution beam 8 are connected by saddle bolts. Saddle bolts can enhance the integrity of the two and prevent relative slippage. The lower part of the full-span support 9 is equipped with an adjustable base and support. The adjustable base and support can flexibly adjust the height to adapt to foundation settlement. The contact position of the adjustable base and support of the full-span support 9 with the distribution beam 8 is centered. The centered contact can avoid uneven load distribution and ensure uniform load transfer.

[0026] Reference Figure 3 , Figure 8 and Figure 9The bottom support mechanism 2 also includes an inner support rod 21. As the core load-bearing component of the bottom support mechanism, the inner support rod 21 is made of high-strength steel to ensure its load-bearing capacity. The inner support rod 21 is fixedly connected to the lower surface of the support member 6, and the fixed connection between the two is achieved through welding or bolts. This effectively transfers the load borne by the support member 6 to the inner support rod 21. A displacement sensor is installed on the inner wall of the inner support rod 21. The displacement sensor can monitor the dynamic changes of the inner support rod 21 in real time. The displacement sensor can measure parameters including but not limited to tilt angle. By measuring the tilt angle, it can promptly detect whether the inner support rod 21 is tilted, providing data reference for structural stability. The inner wall of the inner support rod 21 is slidably connected with protrusions 26. Multiple sets of protrusions 26 are provided, and multiple sets of protrusions 26 can reinforce the inner support from multiple directions. The interlocking force between the support rod 21 and the soft soil is achieved by multiple sets of protrusions 26 arranged in a rotating array around the center line of the inner support rod 21. This array arrangement ensures that the protrusions 26 are evenly stressed, preventing structural damage due to excessive local stress. An adjusting sleeve 22 is slidably connected to the outer wall of the inner support rod 21. The inner wall of the adjusting sleeve 22 is polished to reduce frictional resistance with the outer wall of the inner support rod 21. A pressing rod 28 is fixedly connected to the inner wall of the adjusting sleeve 22. The connection between the pressing rod 28 and the adjusting sleeve 22 is achieved by welding. A protective sleeve 29 is fixedly connected to the inner wall of the inner support rod 21. The protective sleeve 29 is made of wear-resistant material and protects the sliding of the pressing rod 28. The pressing rod 28 is slidably connected to the inner wall of the protective sleeve 29. This sliding fit ensures that the pressing rod 28 maintains a stable trajectory during movement.

[0027] Reference Figure 3 , Figure 8 and Figure 9 The lower surface of the extrusion rod 28 is connected to the protrusion 26 via a hinge rod 210. A sliding plate 25 is sleeved on the outer wall of the inner support rod 21. An extrusion block 27 is fixedly connected to the upper surface of the sliding plate 25. The upper surface of the extrusion block 27 is designed to be arc-shaped. A support plate 23 is fixedly connected to the outer wall of the adjusting sleeve 22 near the bottom. When the adjusting sleeve 22 moves downward, the support plate 23 also moves downward synchronously. A locking block 24 is slidably connected to the inner wall of the support plate 23. The locking block 24 near the inner support rod 21 has anti-slip texture to enhance its locking effect. When the support plate 23 moves downward, it will drive the locking block 24 to move downward synchronously. When the locking block 24 contacts the extrusion block 27, the locking block 24 will be forced to move inward to extrude the inner support rod 21. In this way, the locking block 24 will be unable to continue to move downward. At the same time, the support plate 23 and the adjusting sleeve 22 will also be forced to stop moving. The position of the adjusting sleeve 22 can be fixed by sliding the locking block 24.

[0028] Construction Method: Before installing the overall device, foundation construction is required. For the long spiral cast-in-place pile foundation 1, the site needs to be cleared and leveled with an excavator before construction, and materials such as slag and slag of appropriate thickness should be filled to meet the construction requirements of the long spiral pile driver. During construction, the drilling deviation needs to be controlled to be no greater than the allowable value specified in the specification. The reinforcing cage is inserted into the pile foundation concrete to a predetermined depth by vibrating the vibrating rod using the rear insertion method to ensure that the grade of the pile foundation concrete meets the vertical force strength requirements of a single pile. For the bottom support mechanism 2, the pile position coordinates and center deviation are checked before construction. After adjusting the plane position and verticality, the pile is driven into the soil by the weight of the bottom support mechanism 2 and the vibrating hammer. After the pile body is driven into the soil to a certain depth and confirmed to be stable, and the pile position and inclination are retested and found to be qualified, the vibrating hammer is started to carry out vibration sinking construction. The pile driving operation is completed in one go. The extension welding adopts equal-length ring welding, the weld reinforcement height is not less than 2mm, the misalignment dimension is not greater than 3mm, and the perimeter fillet weld is reinforced by welding with an outer reinforcing steel plate. When working outdoors, impurities within the weld area need to be removed in time to ensure welding quality.

[0029] When fixing the bottom support mechanism 2, the inner support rod 21 needs to be fixed in the support position first. Then, the adjusting sleeve 22 can be moved downward to drive the pressing rod 28 to move downward. The downward movement of the pressing rod 28 will press the hinge rod 210, forcing it to rotate outward. This will drive the protrusion 26 to move outward and unfold. In this way, the protrusion 26 can be used to further increase the stability of the connection between the inner support rod 21 and the ground. Then, the grout can be injected into the inner support rod 21. The grout can flow into the connection between the inner support rod 21 and the ground through the through groove 211, thus achieving permanent fixation of the inner support rod 21.

[0030] After the foundation construction is completed, a pile cap 3 is constructed on top of the long spiral cast-in-place pile foundation 1. The pre-reserved steel bars of the long spiral cast-in-place pile foundation 1 are anchored into the pile cap 3. The top elevation of each row of pile cap 3 is strictly controlled. Anchoring steel bars are added to the top of the pile cap 3, and steel bars are arranged inside. For any unsupported sections, high-strength grout 12 is used to fill them until they are dense. At the same time, climbing cone brackets 4 are pre-embedded during the construction of the permanent structural pier 11. The number and type of climbing cone brackets are determined according to the load. After the concrete strength of the permanent structural pier 11 reaches the requirements, the climbing cone brackets 4 are installed to ensure that the top surface is level and the bolt tightening force meets the design specifications.

[0031] Next, the load-bearing structure is installed. Double-jointed main beams 5 are installed on top of the climbing corbel 4, the foundation 3, and the bottom support mechanism 2. The length of the main beam 5 is determined according to the width of the box girder. The material must be free of cracks, dents, and rust. If extension is required, the joints must be set according to equal strength. The steel web and upper and lower flanges are connected by bevel butt welds. After completion, splice plates are welded around both sides of the web to ensure weld quality. Before installation, the plane position and elevation of the climbing corbel 4, the foundation 3, and the bottom support mechanism 2 are re-measured to ensure that the main beam 5 fits tightly with the top surface of the platform. After positioning, the anchoring steel bars are welded to the top surface of the concrete platform for limit positioning. Then, Bailey beams 7 are installed. The connection between Bailey beam 7 and the distribution beam 8 is reinforced with U-bolts. Full-span supports 9 are installed on the distribution beam 8, ensuring that the adjustable base and supports of the full-span supports 9 are centered with the distribution beam 8. Any gaps in the supports caused by the beam's transverse slope are filled with wedges.

[0032] Next, the upper formwork system 10 is installed, using a splicing method to ensure that the upper formwork system 10 is horizontally and vertically straight. Finally, the cast-in-place support is preloaded. Before preloading, the support is inspected and accepted according to the design drawings and specifications. During preloading, the load is applied symmetrically and evenly, and local overloading or overall uneven loading is strictly prohibited. The load weight and stacking condition are checked and verified to ensure that the load weight of each level meets the requirements. The loading time of each stage is strictly controlled according to the stage loading stability standard, and the unloading time is controlled according to the preloading qualification judgment standard. It is ensured that the settlement observation point marks are firm and do not slip, and the observation point marks are not damaged during the loading process. After preloading, the pre-camber is set according to the elastic deformation value to ensure that the beam meets the design alignment requirements after the concrete is poured.

[0033] Although embodiments of the 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 invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A support structure for cast-in-place beam construction in deep soft soil areas, characterized in that, include: A permanent structural pier (11) is used to support the overall device. A Bailey beam (7) is installed on the upper surface of the permanent structural pier (11). A support member (6) is installed on the lower surface of the Bailey beam (7). A bottom support mechanism (2) is installed on the lower surface of the support member (6). A distribution beam (8) is installed on the upper surface of the Bailey beam (7). A full-span scaffold (9) is installed on the upper surface of the distribution beam (8). An upper formwork system (10) is installed on the upper surface of the full-span scaffold (9). A long spiral cast-in-place pile foundation (1) is used to support a Bailey beam (7). A pile cap (3) is installed on the upper surface of the long spiral cast-in-place pile foundation (1), and the pile cap (3) is installed on the lower surface of the Bailey beam (7).

2. The support structure for cast-in-place beam construction in deep soft soil areas according to claim 1, characterized in that, The support member (6) includes, but is not limited to, I-beams.

3. The support structure for cast-in-place beam construction in deep soft soil areas according to claim 1, characterized in that, The outer wall of the permanent structural pier (11) is fitted with a climbing cone bracket (4), and the upper surface of the climbing cone bracket (4) is fitted with a main beam (5), which is installed on the lower surface of the Bailey beam (7).

4. A support structure for cast-in-place beam construction in deep soft soil areas according to claim 1, characterized in that, The long spiral cast-in-place pile foundation (1) and the bottom support mechanism (2) are evenly arranged along the longitudinal direction of the bridge, and the number of piles arranged in the transverse direction is determined according to the width of the support and the load.

5. A support structure for cast-in-place beam construction in deep soft soil areas according to claim 1, characterized in that, The unsupported portion of the top of the pier (3) is filled with high-strength grout (12), and the Bailey beam (7) and the distribution beam (8) are connected by saddle bolts.

6. A support structure for cast-in-place beam construction in deep soft soil areas according to claim 4, characterized in that, The bottom support mechanism (2) also includes an inner support rod (21), which is fixedly connected to the lower surface of the support member (6). A displacement sensor is installed on the inner wall of the inner support rod (21), and the displacement sensor can measure parameters including but not limited to tilt angle.

7. A support structure for cast-in-place beam construction in deep soft soil areas according to claim 1, characterized in that, The lower part of the full-span support (9) is provided with an adjustable base and a support, and the adjustable base and support of the full-span support (9) are centered in contact with the distribution beam (8).

8. A support structure for cast-in-place beam construction in deep soft soil areas according to claim 6, characterized in that, The inner wall of the inner support rod (21) is slidably connected with a protrusion (26). Multiple sets of the protrusion (26) are arranged in a rotating array with the center line of the inner support rod (21) as the rotation axis.

9. A support structure for cast-in-place beam construction in deep soft soil areas according to claim 8, characterized in that, An adjusting sleeve (22) is slidably connected to the outer wall of the inner support rod (21). An extrusion rod (28) is fixedly connected to the inner wall of the adjusting sleeve (22). A protective sleeve (29) is fixedly connected to the inner wall of the inner support rod (21). The extrusion rod (28) is slidably connected to the inner wall of the protective sleeve (29). The lower surface of the extrusion rod (28) is connected to the protrusion (26) via a hinge rod (210).

10. A support structure for cast-in-place beam construction in deep soft soil areas according to claim 9, characterized in that, The outer wall of the inner support rod (21) is fitted with a sliding plate (25), and the upper surface of the sliding plate (25) is fixedly connected with a pressing block (27). The outer wall of the adjusting sleeve (22) is fixedly connected with a support plate (23) near the bottom end, and the inner wall of the support plate (23) is slidably connected with a locking block (24).

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