Double-walled steel cofferdam without bottom cover and construction method for deep-water rock capping platform rotary excavation trench

Abstract

The present invention relates to a double-walled steel cofferdam with no bottom and a construction method for deep-water rock capping platform rotary excavation. The BIM three-dimensional simulation technology is used to accurately design the size of the cofferdam module and the position of the preset holes, which greatly improves the accuracy and efficiency of the construction. By solving the problems of module size and layout in the design stage, the installation and commissioning work on site can be significantly reduced, thereby speeding up the construction progress and ensuring the quality of the project. The quick connection method of prestressed tendons and extruded waterproof strips is adopted between the cofferdam modules, which saves a lot of welding work, not only improves the construction efficiency but also reduces the construction difficulty. The guide device used for the lowering of the cofferdam is used for horizontal and vertical displacement and inclination monitoring, which can help the cofferdam lowering process more accurately, and greatly improve the construction efficiency and safety. The comprehensive slotting method of impact drill, rotary drilling drill and grab bucket greatly improves the slotting efficiency and reduces the slotting difficulty.

Description

Technical Field

[0001] The invention belongs to the technical field of cofferdam construction, and in particular relates to a double-wall steel cofferdam with no bottom sealed and a construction method thereof, which is formed by rotary excavation of a deep-water rock cap. Background Art

[0002] In the construction of bridges across water, in order to build a working space without water interference and ensure the safety and efficiency of construction, cofferdam technology has become an indispensable means. As a temporary waterproof barrier, the main function of the cofferdam is to block the water flow during construction and provide dry ground conditions for the project. After the project is completed, these cofferdams will be dismantled and the original water state will be restored.

[0003] Among them, double-walled steel cofferdams are highly favored due to their excellent performance. They can not only effectively resist high-intensity water pressure and external impacts, ensuring stability during construction, but also have good reusability, greatly improving resource utilization and reducing project costs. Therefore, in various water-related projects, especially those that require long-term or multiple constructions, double-walled steel cofferdams are widely used and have become a key technology in modern water conservancy project construction.

[0004] At present, cofferdam construction faces a series of challenges, the most prominent of which is the lengthy construction period. Traditional cofferdam construction methods often rely on a large amount of manual operations, especially on key processes such as welding, which consumes too much time. This not only slows down the pace of construction, but also increases the cost burden of the project. In addition, the efficiency of the grooving technology in deep-water rock entry needs to be improved. In addition, frequent manual welding is not only inefficient, but may also introduce errors due to human factors, affecting the accuracy and quality of construction. Therefore, it is very important to explore and implement an efficient, fast and accurate cofferdam construction method. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a double-walled steel cofferdam and a construction method for a deep-water rock cap rotary excavation trench without a bottom seal.

[0006] The construction method of the deep-water rock cap rotary excavation trench without bottom sealing double-wall steel cofferdam comprises the following steps:

[0007] Step 1: Use computer-aided technology to produce modular cofferdams;

[0008] Step 2: Comprehensively use impact drill, rotary drill and grab bucket to dig the riverbed and groove;

[0009] Step 3: Install the auxiliary guide device and assemble the corbel on the steel casing;

[0010] Step 4: Connect the high steel casing, install the hanging device and auxiliary guide device to splice the cofferdam segments on the assembled corbels;

[0011] Step 5: Remove the assembled corbels, lower the first section of the cofferdam, and pour the blade foot concrete when it reaches the self-floating state. After the pouring is completed, connect the contact hanging device and the cofferdam;

[0012] Step 6: Continue to assemble cofferdam segments, pour concrete, and complete the cofferdam construction.

[0013] Preferably, the cofferdam has an inner and outer double-layer structure, both of which include a cofferdam straight section module and a cofferdam corner section module. The ends of the cofferdam corner section modules of the inner layer of the cofferdam are fixedly connected to the cofferdam straight section modules of the outer layer of the cofferdam by prestressed tendons.

[0014] Preferably, the interface between the cofferdam straight section module and the cofferdam corner section module is a hypotenuse, and when the cofferdam straight section module and the cofferdam corner section module are connected by prestressed reinforcement, an extruded waterproof strip is arranged at the interface.

[0015] Preferably, the auxiliary guide device includes a casing connecting plate, and a reserved hole is opened on the steel casing; the auxiliary guide device is arranged above the assembled corbel, and in step three, the auxiliary guide device is connected to the casing connecting plate through the reserved hole on the steel casing by high-strength bolts; the casing connecting plate is an arc surface at the surface connected to the steel casing.

[0016] Preferably, in step four, the steel casing is connected, a shoulder beam and a hanging device are installed on the top of the steel casing, the bottom end of the hanging device is fixedly connected to the cofferdam, and a hanging monitoring device is installed at the connection between the hanging device and the cofferdam; the auxiliary guide device lowers the first section of the cofferdam onto the assembly corbel to splice the cofferdam, and in steps four and six, displacement monitoring is performed during the splicing process through the hanging monitoring device on the hanging device.

[0017] Preferably, the auxiliary guide device includes a telescopic rod and an auxiliary guide steel plate; the telescopic rod includes a telescopic rod fixed section and a telescopic rod movable section, the front end of the telescopic rod movable section is connected to a ball sleeve connecting device through a spherical connecting device, and the ball sleeve connecting device is connected to the back side of the auxiliary guide steel plate; the ball sleeve connecting device is used to fix the spherical connecting device, and the spherical connecting device rotates freely in the ball sleeve connecting device, and the two telescopic rods are respectively connected to the auxiliary guide steel plate at different heights, and the auxiliary guide steel plate is adjusted to rotate through the action of the telescopic rod to control the inclination of the cofferdam.

[0018] Preferably, in step six, the remaining cofferdam segments are assembled above the first cofferdam segment by means of an auxiliary guiding device. After the assembly of each cofferdam segment is completed, a permeability test and a watertight test are carried out, and then underwater concrete is poured. After the overall assembly of the cofferdam is completed, the water jetting method is used to sink the cofferdam to the specified position, and the cabin is filled with water; the bottom plate concrete is poured, the water is pumped out, and the steel supports are installed layer by layer to finally complete the cofferdam construction.

[0019] Preferably, a guide monitoring device is installed on the auxiliary guide steel plate, and in step four and step six, the guide monitoring device is used to monitor the inclination of the auxiliary guide steel plate.

[0020] Preferably, in step two, the riverbed is excavated by using an impact drill and a rotary drill. The impact drill excavates the bare rock area, and the rotary drill excavates the pebble area. A grab bucket is used for excavation and transportation. The specific steps of excavation include drilling the main hole, drilling the auxiliary hole, repairing the hole with a square hammer, forming a slot and clearing the bottom.

[0021] The beneficial effects of the present invention are:

[0022] 1) The use of BIM 3D simulation technology can accurately design the size of the cofferdam module and the location of the preset holes, which greatly improves the accuracy and efficiency of the construction. By solving the problems of module size and layout in the design stage, the installation and commissioning work on site can be significantly reduced, thereby speeding up the construction progress and ensuring the quality of the project.

[0023] 2) The cofferdam wall is a double-layer structure with inner and outer layers. Prestressed tendons are used to reinforce the modules between the inner and outer layers. The connection between the modules on the same layer is set as an inclined surface and an extruded waterproof strip is installed to achieve quick connection, which saves a lot of welding work, not only improving the construction efficiency but also reducing the construction difficulty.

[0024] 3) The auxiliary guide device used in the cofferdam lowering adjusts the inclination angle through the telescopic rod, and cooperates with the hanging device to realize horizontal and vertical displacement and inclination monitoring, which can help the cofferdam lowering process more accurately and greatly improve construction efficiency and safety.

[0025] 4) The comprehensive grooving method of impact drill, rotary drill and grab bucket greatly improves the grooving efficiency and reduces the difficulty of grooving, greatly reducing the construction period and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A three-dimensional diagram of the cofferdam of the present invention;

[0027] Figure 2 It is a front view of the cofferdam of the present invention;

[0028] Figure 3 A three-dimensional diagram of the auxiliary guide device of the present invention;

[0029] Figure 4 It is a side view of the auxiliary guide device of the present invention;

[0030] Figure 5 This is a front view of the cofferdam installation of the present invention;

[0031] Figure 6 This is a diagram of the construction steps of deep-water rock cap rotary excavation trenching of the present invention;

[0032] Figure 7 This is a schematic diagram of the construction of deep-water rock cap rotary excavation and grooving drilling using an impact drill according to the present invention;

[0033] Figure 8 This is a schematic diagram of the present invention using a rotary drill to perform deep-water rock cap rotary drilling and grooving construction;

[0034] Fig. 9 It is a construction flow chart of the present invention.

[0035] Among them: 1-straight section module of cofferdam; 2-corner section module of cofferdam; 3-prestressed tendon reserved channel of cofferdam; 4-prestressed tendon; 5-anchor; 6-extruded waterproof strip; 7-steel casing; 8-casing connecting plate; 9-high-strength bolt; 10-fixed section of telescopic rod; 11-movable section of telescopic rod; 12-spherical connecting device; 13-ball sleeve connecting device; 14-auxiliary guide steel plate; 15-guide monitoring device; 16-cofferdam; 17-auxiliary guide device; 18-assembled corbel; 19-hanging device; 20-hanging monitoring device; 21-impact drill; 22-rotary drill. DETAILED DESCRIPTION

[0036] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for ordinary persons in the art, without departing from the principle of the present invention, the present invention can also be modified in some ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0037] Embodiment 1

[0038] As an embodiment, the construction method of this deep-water rock cap rotary excavation trench without bottom sealing double-wall steel cofferdam is as follows: Fig. 9 As shown, specifically:

[0039] Step 1: Use computer-aided technology (BIM) to accurately design the cofferdam straight section module 1, the cofferdam corner section module 2, and the cofferdam reserved prestressed reinforcement channel 3, accurately arrange the holes, and perform BIM-based parametric modular design of the cofferdam. By inputting the cofferdam parameters, the cofferdam processing drawings can be quickly generated, and the processing parameters can be extracted with one click to carry out modular production of the cofferdam;

[0040] Step 2: The cofferdam modules, other components and construction machinery and equipment are brought to the site and the construction machinery and equipment are ready;

[0041] Step 3: Figure 7 and Figure 8 As shown, the impact drill 21, rotary drilling drill 22, and grab bucket are used to excavate the riverbed groove. The impact drill 21 excavates the bare rock area, the rotary drilling drill 22 excavates the pebble area, and the grab bucket is used for excavation and transportation. The excavation sequence is as follows: Figure 6As shown, the main hole, auxiliary hole, square hammer repair hole and slot hole are cleaned to the designed elevation.

[0042] Step 4: Install the auxiliary guide device 17 on the steel casing 7, and connect the auxiliary guide device 17 through the reserved holes on the steel casing through the high-strength bolts 9 and the casing connecting plate 8. Install the assembled corbel 18;

[0043] Step 5, connect the high steel casing 7, install the shoulder beam, and use the hanging device 19 and the auxiliary guide device 17 to connect the cofferdam straight section module 1 and the cofferdam corner section module 2 of the first cofferdam through the cofferdam reserved prestressed tendon channel 3, prestressed tendon 4, anchor 5, and extruded waterproof strip 6 on the assembled corbel 18 to perform cofferdam splicing. During the splicing process, the hanging monitoring device 20 on the hanging device 19 and the guide monitoring device 15 on the auxiliary guide device 17 are used to monitor the displacement and inclination;

[0044] Step 6: Remove the assembled corbel 18, lower the first section of the cofferdam, and pour the blade foot concrete when it reaches a self-floating state. After the pouring is completed, remove the hanging device 19;

[0045] Step 7: Assemble the remaining segmental cofferdams through the auxiliary guide device 17. During the splicing process, the suspension monitoring device 20 on the suspension device 19 and the guide monitoring device 15 on the auxiliary guide device 17 are used to monitor the displacement and inclination. After each segmental cofferdam is assembled, a penetration test and a watertight test should be carried out, and then the underwater concrete is poured.

[0046] Step 8: Use the water jetting mud suction method to sink the cofferdam 16 to the designated position and fill the cabin with water;

[0047] Step nine: pour the bottom slab concrete, pump out water and install steel supports layer by layer, and finally complete the construction of the cofferdam 16.

[0048] Embodiment 2

[0049] As another embodiment, this embodiment 3 proposes, based on the embodiment 1, a more specific construction method of deep-water rock cap rotary excavation trench without bottom-sealed double-wall steel cofferdam:

[0050] like Figures 3 to 5 As shown, the auxiliary guide device 17 includes a casing connecting plate 8, and a reserved hole is opened on the steel casing; the auxiliary guide device 17 is arranged above the assembled corbel 18, and in step three, the auxiliary guide device 17 is connected to the casing connecting plate 8 through the reserved hole on the steel casing by high-strength bolts 9; the surface of the casing connecting plate 8 connected to the steel casing 7 is an arc surface.

[0051] In step four, the steel casing 7 is connected, a shoulder beam and a hanging device 19 are installed on the top of the steel casing 7, the bottom end of the hanging device 19 is fixedly connected to the cofferdam 16, and a hanging monitoring device 20 is installed at the connection between the hanging device 19 and the cofferdam 16; the auxiliary guide device 17 lowers the first section of the cofferdam 16 onto the assembly corbel 18 to splice the cofferdam 16. In steps four and six, displacement monitoring is performed during the splicing process through the hanging monitoring device 20 on the hanging device 19.

[0052] The auxiliary guide device 17 includes a telescopic rod and an auxiliary guide steel plate 14; the telescopic rod includes a telescopic rod fixed section 10 and a telescopic rod movable section 11, the front end of the telescopic rod movable section 11 is connected to a ball sleeve connecting device 13 through a spherical connecting device 12, and the ball sleeve connecting device 13 is connected to the back of the auxiliary guide steel plate 14; the ball sleeve connecting device 13 is used to fix the spherical connecting device 12, and the spherical connecting device 12 rotates freely in the ball sleeve connecting device 13, and the two telescopic rods are respectively connected to the auxiliary guide steel plate 14 at different heights, and the auxiliary guide steel plate 14 is adjusted to rotate through the action of the telescopic rod to control the inclination of the cofferdam 16.

[0053] In step six, the remaining sections of the cofferdam 16 are assembled above the first section of the cofferdam 16 through the auxiliary guide device 17. After the assembly of each section of the cofferdam is completed, a permeability test and a watertight test are carried out, and then underwater concrete is poured. After the overall assembly of the cofferdam 16 is completed, the water jetting method is used to sink the cofferdam 16 to the specified position, and the cabin is filled with water; the bottom plate concrete is poured, the water is pumped out, and the steel supports are installed layer by layer, and finally the construction of the cofferdam 16 is completed.

[0054] A guide monitoring device 15 is installed on the auxiliary guide steel plate 14 . In step 4 and step 6, the guide monitoring device 15 is used to monitor contents including the inclination of the auxiliary guide steel plate 14 .

[0055] It should be noted that the parts in this embodiment that are the same or similar to those in the first embodiment can be referenced to each other and will not be described in detail in this application.

[0056] Embodiment 3

[0057] As another embodiment, this embodiment 3 is proposed on the basis of embodiments 1 and 2, and the deep-water rock cap rotary excavation trench without bottom sealing double-wall steel cofferdam obtained by this method is:

[0058] like Figure 1 and Figure 2 As shown, the cofferdam 16 includes a cofferdam straight section module 1, a cofferdam corner section module 2, a cofferdam reserved prestressed tendon channel 3, prestressed tendons 4, an anchor 5, an extruded waterproof strip 6, and the auxiliary guide device 17 includes a steel casing 7, a casing connecting plate 8, high-strength bolts 9, a telescopic rod fixed section 10, a telescopic rod movable section 11, a spherical connecting device 12, a ball sleeve connecting device 13, an auxiliary guide steel plate 14 and a guide monitoring device 15.

[0059] The cofferdam 16 is a double-layer structure, both of which include a cofferdam straight section module 1 and a cofferdam corner section module 2. The end of the cofferdam corner section module 2 of the inner layer of the cofferdam 16 is fixedly connected to the cofferdam straight section module 1 of the outer layer of the cofferdam 16 by prestressed tendons 4.

[0060] The interface between the cofferdam straight section module 1 and the cofferdam corner section module 2 is a hypotenuse. When the cofferdam straight section module 1 and the cofferdam corner section module 2 are connected by prestressed tendons 4, an extruded waterproof strip 6 is arranged at the interface.

[0061] It should be noted that the parts in this embodiment that are the same or similar to those in the first embodiment can be referenced to each other and will not be described in detail in this application.

[0062] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

Claims

1. A construction method for deep-water rock capping rotary excavation trenching without bottom sealing double-wall steel cofferdam, characterized in that: The following steps are involved: Step 1: Use computer-aided technology to produce modular cofferdams; Step 2: Comprehensively use impact drill, rotary drill and grab bucket to dig the riverbed and groove; Step 3: Install the auxiliary guide device and assemble the corbel on the steel casing; Step 4: connect the high steel casing, install the hanging device and the auxiliary guide device to splice the cofferdam segments on the assembled corbels; the auxiliary guide device includes a telescopic rod and an auxiliary guide steel plate; the telescopic rod includes a fixed section of the telescopic rod and a movable section of the telescopic rod, the front end of the movable section of the telescopic rod is connected to a ball sleeve connecting device through a spherical connecting device, and the ball sleeve connecting device is connected to the back of the auxiliary guide steel plate; the ball sleeve connecting device is used to fix the spherical connecting device, and the spherical connecting device rotates freely in the ball sleeve connecting device, and the two telescopic rods are respectively connected to different heights of the auxiliary guide steel plate, and the auxiliary guide steel plate is adjusted to rotate through the action of the telescopic rod to control the inclination of the cofferdam; Step 5: Remove the assembled corbels, lower the first section of the cofferdam, and pour the blade foot concrete when it reaches the self-floating state. After the pouring is completed, connect the contact hanging device and the cofferdam; Step six, continue to assemble the cofferdam segments, pour concrete, and complete the cofferdam construction; a guide monitoring device is installed on the auxiliary guide steel plate. In steps four and six, the guide monitoring device is used to monitor the inclination of the auxiliary guide steel plate.

2. The construction method of deep-water rock cap rotary excavation trench without bottom sealing double-wall steel cofferdam according to claim 1 is characterized in that: The cofferdam has an inner and outer double-layer structure. Both the inner and outer layers of the cofferdam include a cofferdam straight section module and a cofferdam corner section module. The ends of the cofferdam corner section modules of the inner layer of the cofferdam are fixedly connected to the cofferdam straight section modules of the outer layer of the cofferdam by prestressed tendons.

3. The construction method of deep-water rock cap rotary excavation trench without bottom sealing double-wall steel cofferdam according to claim 2 is characterized in that: The interface between the cofferdam straight section module and the cofferdam corner section module is a bevel. When the cofferdam straight section module and the cofferdam corner section module are connected by prestressed reinforcement, an extruded waterproof strip is arranged at the interface.

4. The construction method of deep-water rock cap rotary excavation trench without bottom sealing double-wall steel cofferdam according to claim 1, characterized in that: The auxiliary guide device includes a casing connecting plate, and a reserved hole is opened on the steel casing; the auxiliary guide device is arranged above the assembled corbel, and in step three, the auxiliary guide device is connected to the casing connecting plate through the reserved hole on the steel casing by high-strength bolts; the casing connecting plate is an arc surface at the surface connected to the steel casing.

5. The construction method of deep-water rock cap rotary excavation trench without bottom sealing double-wall steel cofferdam according to claim 1, characterized in that: In step four, the steel casing is connected, a shoulder beam and a hanging device are installed on the top of the steel casing, the bottom end of the hanging device is fixedly connected to the cofferdam, and a hanging monitoring device is installed at the connection between the hanging device and the cofferdam; the auxiliary guide device lowers the first section of the cofferdam onto the assembly corbel to splice the cofferdam, and in steps four and six, displacement monitoring is performed during the splicing process through the hanging monitoring device on the hanging device.

6. The construction method of deep-water rock cap rotary excavation trench without bottom sealing double-wall steel cofferdam according to claim 1, characterized in that: In step six, the remaining cofferdam segments are assembled above the first cofferdam section through auxiliary guiding devices. After the assembly of each cofferdam segment is completed, permeability test and watertight test are carried out, and then underwater concrete is poured. After the overall assembly of the cofferdam is completed, the water jetting method is used to sink the cofferdam to the designated position and fill the cabin with water; the bottom plate concrete is poured, the water is pumped out and the steel supports are installed layer by layer to finally complete the cofferdam construction.

7. The construction method of deep-water rock cap rotary excavation trench without bottom sealing double-wall steel cofferdam according to claim 1, characterized in that: In step two, the riverbed is excavated by using an impact drill and a rotary drill. The impact drill excavates the bare rock area, and the rotary drill excavates the pebble area. A grab bucket is used for excavation and transportation. The specific steps of excavation include drilling the main hole, drilling the auxiliary hole, repairing the hole with a square hammer, forming a slot and clearing the bottom.

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