A construction device and process for a large beam sinking well

Abstract

This invention discloses a caisson construction device and process using a large beam-driven sinking method, comprising: a ground anchor box, an anchor box pre-embedded seat, a sinking beam assembly, a support pre-embedded part, a support, and sinking-specific through-hole jacks. Through the steel components of the support pre-embedded part, the support, and the sinking beam, the downward pressure provided by four sinking-specific through-hole jacks is transmitted to the caisson, while the ground anchor box provides the reaction force required for the through-hole jacks to operate. The sinking beam has high overall structural rigidity and can be arranged in other ways according to actual working conditions. The advantages of this invention are: the steel components such as the sinking beam are easy to process and install, have strong versatility and can be adapted to various specifications of caissons; it significantly optimizes the caisson sinking construction process, eliminating the need for any structural components to be installed on the outer wall of the caisson, thus improving construction efficiency and avoiding precision problems caused by the production and installation of external structural components.

Description

Technical Field

[0001] This invention relates to the field of caisson construction technology, and in particular to a beam-pressed caisson construction device and process. Background Technology

[0002] Caissons, as the core foundation structure of underground engineering, foundation pit engineering, and water supply and drainage engineering, are widely used in the construction of municipal bridges, water conservancy pumping stations, underground parking garages, and shield tunneling shafts due to their strong structural stability, wide applicability to various geological formations, and high construction reliability. Caisson sinking is a crucial step in the entire project, directly determining the construction quality, progress, and safety.

[0003] Currently, the traditional caisson sinking construction process generally adopts a force-transmitting structure with external structural components installed on the outer wall of the caisson. These external structural components bear the load of the sinking equipment, thus achieving the sinking of the caisson. This construction method has several inherent drawbacks: First, it requires precise pre-installation of welding plates for the external structural components on the outer wall of the caisson, a cumbersome prefabrication process with extremely high requirements for template positioning and rebar placement. Any deviation in the pre-installed position will directly affect subsequent construction. Second, on-site welding of the external structural components is required during construction, resulting in a large amount of welding work, long construction time, and welding quality being greatly affected by the site environment and manual operation, easily leading to problems such as incomplete welds and missing welds, posing a safety hazard. Third, the external structural components are separate welded structures, resulting in concentrated stress and poor overall load-bearing capacity. During the sinking process, the external structural components are prone to deformation, cracking, or even detachment, leading to caisson tilting and significant construction safety hazards. Finally, after construction, the external structural components need to be cut and removed, adding extra dismantling procedures and time. Cutting can also easily damage the external structural components, rendering them unusable.

[0004] Among existing related patent technologies, such as the pressurized sinking device for caisson construction disclosed in patent document (CN208604615U), the core idea is to apply downward pressure to the top of the caisson through a reaction support fixed to the ground and an inverted hydraulic cylinder. Although this patent attempts to alleviate local stress by "having an elastic pad at the end of the cylinder piston rod," in actual heavy caisson construction conditions, this solution still has the following inherent technical defects that are difficult to overcome: under concentrated loads of hundreds of tons, the "elastic pad" described in the patent alone cannot effectively disperse stress, and the top of the concrete caisson is very prone to crushing or cracking. Therefore, in actual construction, it is necessary to precisely pre-embed / weld high-strength steel pads or force-transmitting brackets (i.e., external structural components) on the outer wall or top of the caisson to disperse the load. This requires that the pre-embedded positions of the external structural components be positioned with extremely high precision during the prefabrication of the caisson, and complex avoidance of the main reinforcing steel bars is required. Even a millimeter-level deviation in the reserved position will cause eccentric force during hydraulic jacking, directly leading to loss of control of the caisson's attitude or structural damage. The patent explicitly states that "the reaction support is composed of welded steel components such as columns, bottom beams, diagonal braces, upper brackets, and middle brackets," and must be coordinated with the caisson's force transmission components. Caisson construction sites are typically in harsh environments (damp, muddy, and confined spaces). To meet the force transmission requirements of a 100t thrust, extensive welding of external structural components is required on-site. Welding quality is highly dependent on manual operation skills and the site environment, making defects such as incomplete welds, missed welds, undercut, or weld porosity highly likely. Under alternating loads and vibrations during the caisson's sinking process, these weak weld points are highly susceptible to fatigue fracture, posing significant structural safety hazards. The patent mentions that "eccentricity can be corrected by adjusting the output pressure of the hydraulic cylinders separately," implying that the device must withstand complex eccentric moments. External force transmission components are often split cantilever or locally reinforced structures welded later, and their connection rigidity with the main caisson structure is often insufficient. Under continuous pressure, especially during "correction" operations that generate huge eccentric moments, stress will be highly concentrated at the weld and connection root. This type of split welded structure has poor overall load-bearing capacity and is extremely prone to plastic deformation, weld cracking, or even the complete detachment of external structural components. Once detached, it will not only lead to pressure failure but also cause serious construction safety accidents such as severe well tilting and well jamming.

[0005] Therefore, in view of the problems existing in the existing technology, there is an urgent need for a caisson sinking construction device and process that does not require the addition of external structural components, has wide adaptability, is highly efficient in installation, and is stable under stress. Summary of the Invention

[0006] The purpose of this invention is to address the reliance on external structural components in existing caisson sinking processes by providing a beam-based caisson construction device and process that eliminates the traditional force transmission mode of external structural components. Through easily installable and dismantled multi-specification sinking beams, combined with a force transmission system of anchor boxes, supports, and other structural components, caisson sinking construction can be achieved without external structural components, resulting in a construction process that is universal in structural components, highly efficient in construction, and stable in stress distribution.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A beam-driven caisson construction device includes an anchor box pre-embedded seat, a ground anchor box, a through-hole jack, a support pre-embedded part, a high support, a low support, and a sinking beam. The anchor box pre-embedded seat is pre-embedded in the ground for welding and fixing to the ground anchor box; the ground anchor box is welded and fixed to the ground anchor box pre-embedded seat on the construction ground; the through-hole jack is installed and fixed on the sinking beam; the support pre-embedded part is pre-embedded on the top end face of the caisson concrete structure; the high support and the low support are respectively connected to the support pre-embedded part by precision-rolled threaded steel bars and matching nuts, and their tops are welded and fixed to the sinking beam; the sinking beam has reserved round holes according to one or more caisson specifications for steel strands to pass through, so as to adapt to the operation requirements of various caissons of different specifications.

[0009] Furthermore, the ground anchor box and the anchor box pre-embedded seat are welded and fixed to the ground of the construction site, and the torque is transmitted through the steel strand to provide the reaction force required when the through-hole jack is working.

[0010] Furthermore, four through-hole jacks are deployed and fixedly installed on the sinking beam structure to provide vertical downward driving force for the caisson sinking operation.

[0011] Furthermore, the pre-embedded parts of the support, along with the matching precision-rolled threaded steel and nuts, are pre-embedded on the top surface of the caisson concrete for installing and connecting the high and low supports.

[0012] Furthermore, the sinking beam is composed of two identical straight beams arranged at different heights, and the arrangement is selected according to the actual working conditions.

[0013] A construction process for a beam-supported caisson, using the aforementioned construction device, includes the following steps: (1) When the well location is laid out at the construction site and the ground concrete is poured, the anchor box pre-embedded seat is placed in the concrete at the corresponding planned location; (2) When the caisson is being made and the concrete is being poured, the pre-embedded support parts, including the matching precision rolled threaded steel bars and nuts, are placed in the concrete at the corresponding planned position on the top end face of the caisson. (3) The ground anchor box and the anchor box pre-embedded seat are welded and fixed; (4) The high and low supports and the embedded parts of the supports are positioned and installed by precision rolled threaded steel bars, and the matching nuts are tightened to fix them; (5) Based on the position of the internal support beams of the caisson, the sinking beams are arranged to coincide and match so as to facilitate the soil removal operation when the caisson sinks; the sinking beams are level and without deviation by adding steel plates; the pre-set round holes of the sinking beams must be arranged concentrically with the ground anchor boxes so that the steel strands can pass through; the bottom of the sinking beams is welded and fixed to the top of the high and low supports, and the height difference of the high and low supports is used to adapt the staggered arrangement of the sinking beams. (6) Installation of through-hole jacks and steel strands: Install through-hole jacks at the preset installation points of the sinking beam; the through-hole jacks must be arranged concentrically with the preset round holes of the sinking beam and the ground anchor box, and be supplemented with spot welding for limiting; the steel strands of each through-hole jack pass through the sinking beam and are connected to the ground anchor box. Adjust the pre-tension of the steel strands to ensure that all steel strands are evenly stressed, without slack or deviation; (7) Synchronous sinking operation: Adjust all through-hole jacks to ensure synchronous start-up and shutdown, synchronous pressurization, and apply downward pressure slowly in stages. The downward pressure is transmitted to the top of the caisson through the sinking beam, high and low supports, and support embedded parts. In conjunction with soil removal in the caisson, the sinking construction can be realized. During the sinking process, the caisson attitude and sinking rate can be monitored and calculated through the jack stroke data. The cylinder pressure can be adjusted according to the monitoring data to ensure that the caisson sinks vertically. (8) Subsequent dismantling operations: After the caisson sinks to the design elevation, is statically stable and the settlement data meets the standards, loosen the anchor ends of the steel strands in sequence and remove all the through-core jacks; then remove the nuts on the high and low supports so that the sinking beam can be removed from the caisson; cut off the ground anchor box and the anchor box pre-embedded seat; at this point, the dismantling operation of the entire sinking system components is completed, and the caisson bottom sealing construction will be carried out subsequently.

[0014] Compared with the prior art, the present invention has the following significant advantages: This invention provides a construction process for a beam-driven caisson, abandoning the traditional external structural component force transmission mode. It utilizes a through-hole jack to apply downward pressure to the caisson via a pressure beam, eliminating the need for pre-installed welding plates on the caisson wall and on-site welding of external structural components, effectively avoiding potential welding quality issues. The structural design of the split high and low supports combined with the adjustable pressure beam can adapt to the operational needs of caissons of various sizes and specifications, significantly improving the reusability of structural components and reducing construction costs for different projects. Furthermore, most components of the entire system adopt a detachable connection form, allowing for direct disassembly and reuse after construction without cutting, reducing subsequent cleaning procedures and avoiding damage to structural components. This process optimizes force transmission path, adaptability, construction efficiency, and structural protection from multiple dimensions, effectively solving many inherent defects of traditional caisson sinking processes and possessing high engineering application and promotion potential.

[0015] The process of this invention is only applicable to caissons that do not require secondary heightening (not applicable if there is steel reinforcement at the top). It cannot be used when steel reinforcement is arranged at the top of the caisson. It is particularly suitable for steel shell caissons with relatively thin walls and has high value for engineering promotion and application. Attached Figure Description

[0016] Fig. 1 This is a schematic diagram of the construction cross-section of the present invention; Fig. 2 This is a top view of the construction process of the present invention; Fig. 3 This is a cross-sectional view of the sinking beam in this invention; Fig. 4 This refers to the pre-embedded precision-rolled threaded steel in this invention. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0018] like Figs. 1 to 4 As shown in the figure, an embodiment of the present invention provides a beam-type caisson construction device, including an anchor box pre-embedded seat 1, a ground anchor box 2, a through-hole jack 3, a support pre-embedded part 4, a high support 5, a low support 6, and a sinking beam 7. Wherein: Anchor box pre-embedded seat 1: Pre-embedded in the ground for welding connection and fixation with the ground anchor box.

[0019] Ground anchor box 2: Welded and fixed to the construction ground with ground anchor box pre-embedded seat 1.

[0020] Through-hole jack 3: Installed and fixed on the sinking beam 7.

[0021] Support embedded part 4: Pre-installed on the top end face of the concrete structure of caisson 9.

[0022] High support 5: It is connected to the support embedded part 4 by precision rolled threaded steel and matching nuts, and the top is welded and fixed to the sinking beam 7.

[0023] Low support 6: It is connected to the support embedded part 4 by precision rolled threaded steel and matching nuts, and the top is welded and fixed to the sinking beam 7.

[0024] Sinking Beam 7: Consists of two identical straight beams arranged at different heights, and their arrangement can be selected according to the actual working conditions. Sinking Beam 7 has pre-drilled round holes according to the specifications of one or more caissons 9 for the steel strands 8 to pass through, in order to adapt to the needs of various caisson operations.

[0025] Furthermore, the ground anchor box 2 and the anchor box pre-embedded seat 1 are welded and fixed to the ground of the construction site, and the torque is transmitted through the steel strand 8 to provide the reaction force required when the through-hole jack 3 is working.

[0026] Furthermore, four through-hole jacks 3 are deployed and fixedly installed on the sinking beam structure to provide vertical downward driving force for the sinking operation of caisson 9.

[0027] Furthermore, the pre-embedded parts 4 of the support, along with the matching precision-rolled threaded steel bars and nuts, are pre-embedded on the top surface of the caisson concrete for the installation and connection of the high and low supports.

[0028] This invention also provides a construction process for a beam-supported caisson, using the aforementioned construction device, the steps of which include: (1) When the well location is laid out at the construction site and the ground concrete is poured, the anchor box pre-embedded seat is placed in the concrete at the corresponding planned location; (2) When the caisson is being made and the concrete is being poured, the pre-embedded parts of the support shall be placed in the concrete at the corresponding planned position on the top end face of the caisson (including the matching precision rolled threaded steel and nuts). (3) The ground anchor box and the anchor box pre-embedded seat are welded and fixed; (4) The high and low supports and the embedded parts of the supports are positioned and installed by precision rolled threaded steel bars, and the matching nuts are tightened to fix them.

[0029] (5) Based on the position of the internal support beams of the caisson, the sinking beams are arranged to coincide and match, so as to facilitate the soil removal operation when the caisson sinks; the sinking beams can be leveled and free from tilt by appropriately adding steel plates; the pre-set round holes of the sinking beams must be arranged concentrically with the ground anchor boxes so that the steel strands can pass through; the bottom of the sinking beams is welded and fixed to the top of the high and low supports, and the height difference of the high and low supports is used to adapt to the staggered arrangement of the sinking beams (if the sinking beams are arranged in a non-intersecting manner, the supports do not need to be made in different heights).

[0030] (6) Installation of through-hole jacks and steel strands: Install through-hole jacks at the preset installation points (round holes) of the sinking beam; the jacks must be arranged concentrically with the preset round holes of the sinking beam and the ground anchor box, and be supplemented with spot welding for limiting; the steel strands of each through-hole jack pass through the sinking beam and are connected to the ground anchor box. Adjust the pre-tension of the steel strands to ensure that all steel strands are evenly stressed, without slack or deviation.

[0031] (7) Synchronous sinking operation: Adjust all through-hole jacks to ensure synchronous start-up and shutdown, synchronous pressurization, and apply downward pressure slowly in stages. The downward pressure is transmitted to the top of the caisson through the sinking beam, high and low supports, and support embedded parts, in conjunction with soil removal in the caisson to achieve caisson sinking construction; during the sinking process, the caisson attitude and sinking rate can be monitored and calculated through jack stroke data, and the cylinder pressure can be adjusted according to the monitoring data to ensure that the caisson sinks vertically.

[0032] (8) Subsequent dismantling operations: After the caisson sinks to the design elevation, is statically stable and the settlement data meets the standards, loosen the anchor ends of the steel strands in sequence and remove all the through-core jacks; then remove the nuts on the high and low supports so that the sinking beam can be removed from the caisson; cut off the ground anchor box and the anchor box pre-embedded seat; at this point, the dismantling operation of the entire sinking system components is completed, and the caisson bottom sealing construction will be carried out subsequently.

[0033] The advantages of this invention are: steel components such as sinking beams are easy to process and install, and have strong versatility, making them suitable for various specifications of caissons; the caisson sinking construction process is greatly optimized, and no structural components need to be installed on the outer wall of the caisson, which improves construction efficiency and avoids the accuracy problems caused by the production and installation of external structural components.

[0034] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the invention. Those skilled in the art can make various changes and modifications without departing from the concept and scope of the present invention. Therefore, all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A beam-pressing caisson construction device, characterized in that: The system includes anchor box pre-embedded seats, ground anchor boxes, through-hole jacks, support pre-embedded parts, high supports, low supports, and sinking beams. The anchor box pre-embedded seats are pre-embedded in the ground for welding and fixing to the ground anchor boxes. The ground anchor boxes are welded and fixed to the ground anchor box pre-embedded seats on the construction ground. The through-hole jacks are installed and fixed on the sinking beams. The support pre-embedded parts are pre-embedded on the top end face of the caisson concrete structure. The high supports and low supports are connected to the support pre-embedded parts by precision-rolled threaded steel bars and matching nuts, and their tops are welded and fixed to the sinking beams. The sinking beams have reserved round holes according to one or more caisson specifications for steel strands to pass through, so as to adapt to the operation requirements of various caisson specifications.

2. The beam-pressing caisson construction device according to claim 1, characterized in that: The ground anchor box and the anchor box pre-embedded seat are welded and fixed to the ground of the construction site. The torque is transmitted through the steel strand to provide the reaction force required when the through-hole jack is working.

3. The beam-pressing caisson construction device according to claim 1, characterized in that: Four through-hole jacks are deployed and fixedly installed on the sinking beam structure to provide vertical downward driving force for the caisson sinking operation.

4. The beam-pressing caisson construction device according to claim 1, characterized in that: The pre-embedded parts of the support, along with the matching precision-rolled threaded steel and nuts, are pre-embedded on the top surface of the caisson concrete for the installation and connection of high and low supports.

5. The beam-pressing caisson construction device according to claim 1, characterized in that: The sinking beam consists of two identical straight beams arranged at different heights, with the arrangement selected according to the actual working conditions.

6. A construction process for a beam-supported caisson, employing the construction device described in any one of claims 1-5, characterized in that, Includes the following steps: (1) When the well location is laid out at the construction site and the ground concrete is poured, the anchor box pre-embedded seat is placed in the concrete at the corresponding planned location; (2) When the caisson is being made and the concrete is being poured, the pre-embedded support parts, including the matching precision rolled threaded steel bars and nuts, are placed in the concrete at the corresponding planned position on the top end face of the caisson. (3) The ground anchor box and the anchor box pre-embedded seat are welded and fixed; (4) The high and low supports and the embedded parts of the supports are positioned and installed by precision rolled threaded steel bars, and the matching nuts are tightened to fix them; (5) Based on the position of the internal support beams of the caisson, the sinking beams are arranged to coincide and match so as to facilitate the soil removal operation when the caisson sinks; the sinking beams are level and without deviation by adding steel plates; the pre-set round holes of the sinking beams must be arranged concentrically with the ground anchor boxes so that the steel strands can pass through; the bottom of the sinking beams is welded and fixed to the top of the high and low supports, and the height difference of the high and low supports is used to adapt the staggered arrangement of the sinking beams. (6) Installation of through-hole jacks and steel strands: Install through-hole jacks at the preset installation points of the sinking beam; the through-hole jacks must be arranged concentrically with the preset round holes of the sinking beam and the ground anchor box, and be supplemented with spot welding for limiting; the steel strands of each through-hole jack pass through the sinking beam and are connected to the ground anchor box. Adjust the pre-tension of the steel strands to ensure that all steel strands are evenly stressed, without slack or deviation; (7) Synchronous sinking operation: Adjust all through-hole jacks to ensure synchronous start-up and shutdown, synchronous pressurization, and apply downward pressure slowly in stages. The downward pressure is transmitted to the top of the caisson through the sinking beam, high and low supports, and support embedded parts. In conjunction with soil removal in the caisson, the sinking construction can be realized. During the sinking process, the caisson attitude and sinking rate can be monitored and calculated through the jack stroke data. The cylinder pressure can be adjusted according to the monitoring data to ensure that the caisson sinks vertically. (8) Subsequent dismantling operations: After the caisson sinks to the design elevation, is statically stable and the settlement data meets the standards, loosen the anchor ends of the steel strands in sequence and remove all the through-core jacks; then remove the nuts on the high and low supports so that the sinking beam can be removed from the caisson; cut off the ground anchor box and the anchor box pre-embedded seat; at this point, the dismantling operation of the entire sinking system components is completed, and the caisson bottom sealing construction will be carried out subsequently.

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