Vibration anti-floating structure of large-volume vertical shaft duct piece reinforcement cage and application method of vibration anti-floating structure

Abstract

The invention provides a vibration anti-floating structure for a large-volume vertical shaft segment reinforcement cage. The control end of a floating stopping mechanism abuts against the reinforcement cage, and anchoring steel bars are fixed to longitudinal main bars of the reinforcement cage. The invention further provides an application method of the vibration anti-floating structure of the large-volume vertical shaft duct piece reinforcement cage. The floating stopping mechanism on the outer side formwork of the pipe piece mold is matched with the anchoring steel bars at the longitudinal main bars of the steel reinforcement cage to lock the steel reinforcement cage, and the cooperative anti-floating effect is achieved; the pressure of the control end of the floating stopping mechanism on the reinforcement cage can be regulated and controlled in real time in the concrete pouring process, and the buoyancy generated by concrete pouring of the reinforcement cage and vibration is completely offset through the anchoring force between the anchoring steel bars and concrete and the pressure applied by the floating stopping mechanism on the reinforcement cage; the risk that the thickness of a concrete protection layer is not uniform due to upward floating of the reinforcement cage is greatly reduced, the reworking situation caused by the upward floating problem is greatly reduced, and waste of reinforcement and concrete materials is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of casting steel cages for vertical shaft segments, and in particular to a vibration-compacted anti-floating structure of a steel cage for vertical shaft segments with a large volume and an application method thereof. Background Art

[0002] During the shaft excavation construction process, the quality of large-volume shaft segments is of vital importance. During the casting process of large-volume shaft segments, the floating of the steel cage inside the mold has always been a key issue affecting the quality of the segments. Due to a series of uncertain factors such as buoyancy, recoil, vibration force, the weight of the steel cage itself, and unstable fixation generated during concrete pouring, the steel cage will float upward, which will cause the distribution of the steel cage inside the segment in the concrete to not meet the design requirements, seriously affecting the mechanical properties of the segment such as strength, crack resistance and impermeability, and affecting the safety of shaft construction and the service life of the segment.

[0003] At present, the technologies used to prevent the steel cage from floating mainly include: adding counterweights, placing heavy objects on the steel cage of the pipe segment to increase the deadweight of the steel cage to resist the buoyancy generated during concrete pouring. This method is relatively simple to operate, but it requires very accurate calculation of the weight of the counterweight. Insufficient or excessive counterweights will affect the construction efficiency. Improve the pouring process of concrete. On the one hand, control the pouring speed of concrete, use the layered pouring method to slowly pour concrete into the mold to reduce the impact and buoyancy of concrete on the steel cage. At the same time, according to the fluidity and slump of concrete, reasonably control the pouring speed. On the other hand, optimize the vibration process of concrete, select appropriate vibration methods and vibration frequencies, and reduce the vibration force on the steel cage. In addition, improve the mold design of the pipe segment, strengthen the steel cage fixing device, and set a more solid steel cage fixing device on the pipe segment mold to effectively limit the displacement of the steel cage. Improve the sealing of the mold, ensure the good sealing of the pipe segment mold, and prevent the leakage of concrete during the pouring process. At present, these existing measures still have problems in actual application, such as unsatisfactory anti-floating effect or complicated construction.

[0004] Therefore, in order to effectively control the floating problem of the steel cage during pouring, a large-volume shaft segment steel cage vibration anti-floating structure and application method are needed. Summary of the invention

[0005] In order to solve the above problems, the present invention aims to propose a large-volume vertical shaft segment steel cage vibration anti-floating structure and application method, which locks the steel cage through the floating stop mechanism on the outer template of the segment mold in conjunction with the anchor steel bars at the longitudinal main bars of the steel cage, thereby playing a synergistic anti-floating role.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows: A large-volume vertical shaft segment steel cage vibration anti-floating structure includes a floating stop mechanism installed on the outer template of the segment mold, anchor steel bars and a computer, the control end of the floating stop mechanism abuts the steel cage, and the anchor steel bars are fixed to the longitudinal main bars of the steel cage.

[0007] Furthermore, the floating stop mechanism includes a floating stop box, a driving mechanism is fixedly arranged inside the floating stop box, the driving mechanism is connected to a vertical threaded column, the vertical threaded column is threadedly connected to a lifting control plate, telescopic pressure rods are connected to both sides of the lifting control plate, and a circular channel corresponding to the telescopic pressure rod is arranged below the floating stop box, and the telescopic pressure rod is abutted against the steel cage through the circular channel.

[0008] Furthermore, a bearing is provided at the lower portion of the vertical threaded column, and a receiving opening corresponding to the bearing is provided at the lower portion of the floating stop box.

[0009] Furthermore, a linkage mechanism is connected to the vertical threaded column, and a circular cover plate is provided on the circular channel. When the telescopic pressure rod passes through the circular channel, the linkage mechanism drives the circular cover plate to open, and when the telescopic pressure rod exits the circular channel, the linkage mechanism drives the circular cover plate to close.

[0010] Furthermore, the linkage mechanism includes a first gear fixed to the lower part of the vertical threaded column, and the second gear and the third gear are respectively meshed on both sides of the first gear. The second gear and the third gear are connected to the top of the stepped shaft, and the steel wire rope is wrapped around the surface of the stepped shaft. The steel wire rope is connected to the circular cover plate on the corresponding side through a hook. The circular cover plate is hinged to the circular channel, and annular hanging rings are also provided on both sides of the circular cover plate. A hook is correspondingly installed on the bottom of the floating stop box, and a reset spring is connected between the annular hanging ring and the hook.

[0011] Furthermore, a telescopic arm, a pressure sensor and a pressure rod are provided inside the telescopic pressure rod, the pressure sensor is connected to the telescopic arm by bolts, the pressure sensor is connected to the pressure rod below by welding, the pressure sensor is connected to the computer, a triangular pressure claw corresponding to and abutting against the steel cage is installed at the bottom of the telescopic pressure rod, toothed pulleys are provided at both ends of the lifting control plate, and vertical toothed tracks corresponding to the toothed pulleys are provided on both sides of the floating stop box.

[0012] Furthermore, the driving mechanism includes a reversible motor, a universal coupling and a flange; the reversible motor is connected to the computer, a heat sink is provided on the outer shell of the reversible motor, and both ends of the universal coupling are respectively hinged to the vertical threaded column and the output shaft of the reversible motor through the flange.

[0013] Furthermore, the anchoring steel bar is connected to the steel cage by welding, and the welding position is located on the longitudinal main reinforcement of the steel cage close to the edge of the pipe segment. Two mounting holes are distributed on the outer template of the pipe segment mold, and the sizes of the two mounting holes are consistent with the sizes below the circular cover plate. The telescopic pressure rod is against the steel cage through the circular channel and the mounting hole.

[0014] In order to achieve the above object, the present invention also provides an application method of a large-volume shaft segment steel cage vibrating anti-floating structure, comprising the following steps: Step 1: Make a steel cage, weld a certain number of anchor steel bars after the steel cage is made, and place the steel cage into the segment mold; Step 2: Install the floating stop mechanism, install the floating stop box on both sides of the outer template of the segment mold, align it with the installation holes previously opened on the outer template of the segment mold, so that the circular cover can cover the installation holes, and connect the reversible motor and the pressure sensor to the computer; Step 3, turn on the reversible motor, the driving mechanism drives to open the circular channel, the telescopic pressure rod lowers the triangular pressure claw to press against the steel cage, and provides pressure for the first step of pouring concrete; Step 4: Initial pouring of concrete: slowly pour the concrete on the segment mold, stop pouring after the concrete is poured under the anchor steel bar, and then insert a vibrating rod to vibrate the poured part to make the concrete more dense and uniform; Step 5: Pour concrete again. Pour concrete again 2-3 hours after the initial pouring and vibration. Observe the pressure sensor reading at the same time. When the pressure is reduced to 0, retract the telescopic pressure rod upward, control the computer to turn on the reversible motor, and the reversible motor drives the lifting control panel upward. The reset spring pulls the circular cover plate downward to cover the installation hole. Insert the vibrating rod into the concrete in the mold again for vibration. After the vibration is completed, wait for the initial setting of the concrete. Open the segment mold before the initial setting of the concrete, and plaster the concrete surface to eliminate cracks and unevenness on the concrete surface. Step 6: Curing and demoulding the segments. When the segments reach demoulding strength, demoulding equipment is used to remove the segments from the mold.

[0015] Furthermore, in step 1, the anchor steel bar is welded to the steel cage, and after pouring concrete, the anti-floating force of the anchor steel bar is F 锚 , the calculation formula of the anti-buoyancy is as follows: Formula (1) In formula (1), n The number of anchor steel bars welded to the steel cage; l is the anchorage length of the anchor steel bar, m; A is the cross-sectional area of ​​the anchor steel bar, m2 ; f c is the compressive strength of the concrete cylinder, MPa; In step 4, when pouring concrete, the steel cage will be subjected to the vertical upward buoyancy of the concrete. F 1 Formula (2) In formula (2), ρ 液 is the density of the concrete liquid poured into the mold, kg / m 3 ; g is the acceleration due to gravity, which can be taken as 9.8m / s at this moment 2 ; v 排 is the volume of the steel cage immersed in the concrete liquid, m 3 ; The steel cage will be subjected to the upward impact force during concrete pouring. During the concrete pouring process, the concrete is poured from the bottom to the top. Under the action of the stamping, the concrete is continuously rebounded from the bottom to the top. During the upward movement of the concrete, the steel cage is subjected to the upward squeezing force. F 2. For the mixed fluid, combined with the law of conservation of momentum, the maximum impact force on the steel cage is: Formula (3) In formula (3), ρ 砼 is the density of poured concrete, kg / m 3 ; q v is the pouring speed of concrete, m 3 / s; D is the concrete conduit outlet diameter, m; The steel cage will be subjected to an upward friction force F 3. The upward friction force is related to the pouring speed and height of concrete. When the pouring speed is slow, the steel cage will not be subject to obvious friction. When the pouring speed is fast, the flow speed of concrete will also be faster, which will produce an upward friction force on the steel cage. When concrete is poured from a higher position and impacts the steel cage, it is possible to generate an upward friction force component in an instant. The steel cage is subject to upward friction force. F 3 is: Formula (4) In formula (4), f is the lateral pressure of the poured concrete on the steel cage, kN; h is the buried depth of the steel cage in the concrete, m; μ is the dynamic friction factor; Fn is the lateral pressure of poured concrete on any section of the steel cage, kN; Formulas (2), (3) and (4) are the buoyancy forces on the steel cage during pouring. The force provided by the floating stop mechanism is: F 压 ,satisfy: .

[0016] Beneficial effect: The present invention locks the steel cage through the floating stop mechanism on the outer template of the segment mold in cooperation with the anchor steel bars at the longitudinal main bars of the steel cage, thereby playing a synergistic anti-floating effect; the pressure of the control end of the floating stop mechanism on the steel cage can be adjusted in real time during the concrete pouring process, and the buoyancy caused by the concrete pouring steel cage and vibration is completely offset by the anchoring force between the anchor steel bars and the concrete and the pressure applied to the steel cage by the floating stop mechanism, which greatly reduces the risk of uneven thickness of the concrete protective layer due to the floating of the steel cage and the rework caused by the floating problem, avoids the waste of steel bars and concrete materials, and has significant benefits in terms of ensuring construction quality, improving construction efficiency and saving costs, and is of great significance to the field of vibration and anti-floating of steel cages for large-volume vertical shaft segments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings: Figure 1 A schematic diagram of the floating stop mechanism structure on the outer template of the segment mold of the large-volume vertical shaft segment steel cage vibrating anti-floating structure according to an embodiment of the present invention; Figure 2 A schematic diagram of the anchor steel bar structure on the steel cage of the large-volume vertical shaft segment steel cage vibrating anti-floating structure according to an embodiment of the present invention; Figure 3 It is a structural schematic diagram of a floating stop mechanism of a large-volume vertical shaft segment steel cage vibrating anti-floating structure according to an embodiment of the present invention; Figure 4 A schematic diagram of a driving mechanism for a large-volume vertical shaft segment steel cage vibrating anti-floating structure according to an embodiment of the present invention; Figure 5 It is a structural schematic diagram of a lifting control plate and a vertical threaded column of a large-volume vertical shaft segment steel cage vibrating anti-floating structure according to an embodiment of the present invention; Figure 6 A schematic diagram of a linkage mechanism for a large-volume vertical shaft segment steel cage vibrating anti-floating structure according to an embodiment of the present invention; Figure 7It is a schematic diagram of the coordination between the toothed pulley and the vertical toothed track of the large-volume vertical shaft segment steel cage vibrating anti-floating structure according to an embodiment of the present invention; Figure 8 It is a structural schematic diagram of the telescopic pressure rods of the large-volume vertical shaft segment steel cage vibrating anti-floating structure according to an embodiment of the present invention. DETAILED DESCRIPTION

[0018] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0019] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0020] Example 1 See also Figure 1-8 : A large-volume vertical shaft segment steel cage vibration anti-floating structure, including a floating stop mechanism 2 and anchor steel bars 3 installed on the outer template 1 of the segment mold, the control end of the floating stop mechanism 2 abuts the steel cage 4, and the anchor steel bars 3 are fixed to the longitudinal main bars of the steel cage 4.

[0021] In this embodiment, the floating stop mechanism on the outer template of the segment mold cooperates with the anchor steel bars at the longitudinal main bars of the steel cage to lock the steel cage, thereby playing a synergistic anti-floating role; the pressure of the control end of the floating stop mechanism on the steel cage can be adjusted in real time during the concrete pouring process, and the buoyancy caused by the concrete pouring steel cage and vibration is completely offset by the anchoring force between the anchor steel bars and the concrete and the pressure applied to the steel cage by the floating stop mechanism, which greatly reduces the risk of uneven thickness of the concrete protective layer due to the floating of the steel cage and the rework caused by the floating problem, avoids the waste of steel bars and concrete materials, and has significant benefits in ensuring construction quality, improving construction efficiency and saving costs, and is of great significance to the field of vibration and anti-floating of steel cages for large-volume vertical shaft segments.

[0022] In a specific example, the floating stop mechanism 2 includes a floating stop box 201, a driving mechanism 202 is fixedly arranged inside the floating stop box 201, the driving mechanism 202 is connected to a vertical threaded column 203, the vertical threaded column 203 is threadedly connected to a lifting control plate 204, telescopic pressure rods 205 are connected to both sides of the lifting control plate 204, and a circular channel 206 corresponding to the telescopic pressure rod 205 is arranged below the floating stop box 201, and the telescopic pressure rod 205 is abutted against the steel cage 4 through the circular channel 206.

[0023] In this embodiment, the driving mechanism can drive the vertical threaded column to rotate, thereby driving the lifting control plate to move up and down, thereby controlling the telescopic pressure rods on both sides to move up and down. The telescopic pressure rods can form abutment with the steel cage through the circular channel to complete the locking of the steel cage and prevent the steel cage from floating.

[0024] In a specific example, a bearing 2031 is disposed at the lower portion of the vertical threaded column 203 , and a receiving opening corresponding to the bearing 2031 is disposed at the lower portion of the floating stop box 201 .

[0025] The vertical threaded column of this embodiment completes the balance limit of the upper and lower positions through the bearing and the receiving opening below the floating stop box, so that the vertical threaded column can maintain the original position and rotate freely, thereby realizing the stable lifting and lowering of the lifting control plate.

[0026] In a specific example, a linkage mechanism 207 is also connected to the vertical threaded column 203, and a circular cover plate 208 is provided on the circular channel 206. When the telescopic pressure rod 205 passes through the circular channel 206, the linkage mechanism 207 drives the circular cover plate 208 to open, and when the telescopic pressure rod 205 exits the circular channel 206, the linkage mechanism 207 drives the circular cover plate 208 to close.

[0027] It should be noted that in this embodiment, the circular cover plate can be driven to open or close through the linkage mechanism, thereby realizing automatic linkage with the telescopic pressure rod entering and exiting the circular channel, and when the telescopic pressure rod passes through or exits the circular channel, the circular cover plate will avoid it and will not collide with the telescopic pressure rod and affect the movement trajectory of the telescopic pressure rod.

[0028] In a specific example, the linkage mechanism 207 includes a first gear 2071 fixed to the lower part of the vertical threaded column 203, and the second gear 2072 and the third gear 2073 are respectively meshed on both sides of the first gear 2071. The second gear 2072 and the third gear 2073 are connected to the top of each step shaft 2074. The surface of the step shaft 2074 is wrapped with a steel wire rope 2075, and the steel wire rope 2075 is connected to the circular cover plate 208 on the corresponding side through a hook 2076. The circular cover plate 208 is hinged on the circular channel 206. Annular hanging rings are also provided on both sides of the circular cover plate 208. A hook is correspondingly installed at the bottom of the floating stop box 201, and a reset spring 2077 is connected between the annular hanging ring and the hook.

[0029] In this embodiment, when the vertical threaded column rotates, it can drive the first gear to rotate, and the rotation of the first gear drives the second and third gears to rotate, and cooperates with the reset spring to drive the steel wire rope on the stepped shaft to be retracted and released, and control the opening and reset closing of the circular cover plate at the end of the steel wire rope, thereby realizing linkage with the telescopic pressure rod.

[0030] It should be noted that the second and third gears of this embodiment are both rotatably connected to the lower part of the floating stop box.

[0031] In a specific example, the floating stop mechanism 2 also includes a computer 209, and the telescopic pressure rod 205 is provided with a telescopic arm 2051, a pressure sensor 2052 and a pressure rod 2053 inside. The pressure sensor 2052 is connected to the telescopic arm 2051 by bolts, and the pressure sensor 2052 is connected to the pressure rod 2053 below by welding. The pressure sensor 2052 is connected to the computer 209, and a triangular pressure claw 20531 corresponding to the steel cage 4 is installed at the bottom of the pressure rod 2053. Toothed pulleys 2041 are provided at both ends of the lifting control plate 204, and vertical toothed rails 2011 corresponding to the toothed pulleys 2041 are provided on both sides of the floating stop box 201.

[0032] The telescopic arm of this embodiment has a certain independent stroke, and the triangular pressure claw can be controlled to have a constant F by a computer and a pressure sensor. 压 , thereby improving the stability of the abutment through the triangular pressure claw, and the lifting control plate rotates through the vertical threaded column to drive the toothed pulley to move up and down along the toothed slide rail, thereby realizing the stable up and down lifting and moving of the lifting control plate.

[0033] In a specific example, the driving mechanism 202 includes a reversible motor 2021, a universal coupling 2022 and a flange 2023; the reversible motor 2021 is connected to the computer 209, and a heat sink 20211 is provided on the outer shell of the reversible motor 2021. The two ends of the universal coupling 2022 are respectively hinged to the vertical threaded column 203 and the output shaft of the reversible motor 2021 through the flange 2023.

[0034] The reversible motor of this embodiment is controlled by a computer, and the drive mechanism adopts a reversible motor and a universal joint is hinged by a flange, so that the power output adaptability of the drive mechanism is stronger, providing buffering and shock absorption, and improving the dynamic performance of shaft power transmission.

[0035] In a specific example, the anchor steel bar 3 is connected to the steel cage 4 by welding, and the welding position is located on the longitudinal main reinforcement of the steel cage 4 close to the edge of the pipe segment. The outer template 1 of the pipe segment mold has two mounting holes, and the sizes of the two mounting holes are consistent with the sizes below the circular cover plate 208. The telescopic pressure rod 205 is against the steel cage 4 through the circular channel 206 and the mounting hole.

[0036] The working principle of the large-volume vertical shaft segment steel cage vibration anti-floating structure of this embodiment is as follows: install a reversible motor, connect the motor, universal coupling and vertical threaded column together to form a power device of the floating stop mechanism; turn on the reversible motor, the motor provides clockwise power, drives the vertical threaded column to rotate through the universal coupling, the vertical threaded column drives the first gear to rotate, the first gear drives the second and third gears to rotate, and drives the stepped shaft above the two gears to rotate counterclockwise, the wire rope is tightened and wrapped around the stepped shaft, and the circular cover plate is pulled upward to open the circular channel. Before the cover plate is fully opened, the triangular pressure claw cannot contact the upward trajectory of the cover plate; at the same time , the vertical threaded column rotates to drive the lifting control plate to slide downward along the vertical slide rail, driving the triangular pressure claw downward through the circular channel and the outer arc side template installation hole to press against the steel cage until the reversible motor produces a decrease in speed, and then the reversible motor is turned off; when the work of pressing the steel cage is completed, the reversible motor is turned on again, and the motor provides counterclockwise power. First, the triangular pressure claw is subjected to an upward pulling force, which releases the pressing effect on the steel cage and moves upward with the vertical track. During the upward movement, the triangular pressure claw cannot contact the downward trajectory of the cover plate. When the circular cover plate goes down and completely covers the circular channel, the floating stop device is completed and the motor stops running.

[0037] Example 2 In order to achieve the above-mentioned purpose, the present embodiment further provides an application method of a large-volume shaft segment steel cage vibrating anti-floating structure, comprising the following steps: Step 1, making a steel cage 4, welding a certain number of anchoring steel bars 3 after the steel cage 4 is made, and placing the steel cage 4 into a segment mold; Step 2, install the floating stop mechanism 2, install the floating stop box 201 on both sides of the outer template 1 of the segment mold, align with the installation holes previously opened on the outer template 1 of the segment mold, so that the circular cover plate 208 can cover the installation holes, and connect the reversible motor 2021 and the pressure sensor 2052 to the computer 209; Step 3, turn on the reversible motor 2021, the driving mechanism 202 drives to open the circular channel 206, and the telescopic pressure rod 205 lowers the triangular pressure claw 20531 to press against the steel cage 4, providing pressure for the first step of pouring concrete; Step 4: pour concrete for the first time. Slowly pour concrete on the segment mold. Stop pouring after the concrete is poured under the anchor steel bar 3. Insert a vibrating rod to vibrate the poured part to make the concrete more dense and uniform. Step 5, pouring concrete again. Pour concrete again 2-3 hours after the initial pouring and vibration. Observe the reading of the pressure sensor 2052 at the same time. When the pressure is reduced to 0, retract the telescopic pressure rod 205 upward, control the computer 209 to turn on the reversible motor 2021, and the reversible motor 2021 drives the lifting control board 204 upward. The return spring 2077 pulls the circular cover plate 208 downward to cover the installation hole. Insert the vibrating rod into the concrete in the mold again for vibration. After the vibration is completed, wait for the initial setting of the concrete. Open the segment mold before the initial setting of the concrete, and plaster the concrete surface to eliminate cracks and unevenness on the concrete surface. Step 6: Curing and demoulding the segments. When the segments reach demoulding strength, demoulding equipment is used to remove the segments from the mold.

[0038] It should be noted that during the demoulding process, care should be taken to avoid damaging the segments, check the appearance quality of the segments, and ensure that the segments do not have defects such as cracks and deformation due to problems such as floating of the steel cage.

[0039] In a specific example, in step 1, the anchor steel bar is welded to the steel cage. After pouring concrete, the anti-floating force of the anchor steel bar is F 锚 , the calculation formula of the anti-buoyancy is as follows: Formula (1) In formula (1), n ​​is the number of anchor steel bars welded to the steel cage; l is the anchor length of the anchor steel bar, m; A is the cross-sectional area of ​​the anchor steel bar, m 2 ;f c is the compressive strength of the concrete cylinder, MPa; In step 4, when pouring concrete, the steel cage will be immersed in the concrete and receive the vertical buoyancy F1. Formula (2) In formula (2), ρ 液 is the density of the concrete liquid poured into the mold, kg / m 3 ; g is the acceleration due to gravity, which can be taken as 9.8m / s at this moment 2 ;v 排 is the volume of the steel cage immersed in the concrete liquid, m 3 ; The steel cage will be subjected to the upward impact force during the concrete pouring. During the concrete pouring process, the concrete is poured from the bottom to the top. Under the action of the stamping, the concrete is continuously rebounded from the bottom to the top. As the concrete moves upward, it exerts an upward squeezing force F2 on the steel cage. For the mixed fluid, combined with the law of conservation of momentum, the maximum impact force on the steel cage is: Formula (3) In formula (3), ρ 砼 is the density of poured concrete, kg / m 3 ;q v is the pouring speed of concrete, m 3 / s; D is the concrete conduit outlet diameter, m; The steel cage will be subjected to an upward friction force F3, which is related to the concrete pouring speed and the height of the concrete pouring. When the pouring speed is slow, the steel cage will not be subjected to obvious friction. When the pouring speed is fast, the flow speed of the concrete will also be correspondingly fast, which will produce an upward friction force on the steel cage. When the concrete is poured from a higher position and impacts the steel cage, an upward friction force component may be generated in an instant. The upward friction force F3 on the steel cage is: Formula (4) In formula (4), f is the lateral pressure of the steel cage under the poured concrete, kN; h is the buried depth of the steel cage in the concrete, m; μ is the dynamic friction coefficient; F n is the lateral pressure of poured concrete on any section of the steel cage, kN; Formulas (2), (3) and (4) are the buoyancy forces on the steel cage during pouring. The force provided by the floating stop mechanism is F 压 ,satisfy: .

[0040] The anti-buoyancy formula of this embodiment plays a key role in theoretical support and quantitative design in this embodiment, which is specifically reflected in the following aspects: 1. Quantify the dynamic balance between anti-buoyancy and buoyancy ‌Anchor force calculation (Formula 1)‌: Accurately calculate the anti-buoyancy force F provided by the anchor system through the number and length of anchored steel bars and concrete strength 锚 , ensure that the anchor design meets the minimum resistance requirements and avoid the deficiencies of empirical design.

[0041] ‌Buoyancy decomposition (Formula 2-4): The buoyancy of the steel cage is decomposed into buoyancy F1, impact force F2 and friction force F3, which comprehensively covers the influence of concrete fluid behavior, impact momentum and friction effect during the pouring process, and provides a theoretical basis for dynamic control.

[0042] 2. Guide the precise control of the floating stop device ‌Pressure threshold determination‌: Through the formula , clarify the real-time F 压, ensuring the stability of the steel cage during vibration; the pressure sensor monitoring data is linked with the formula calculation results to trigger the lifting and lowering of the telescopic pressure rod to achieve automatic anti-floating.

[0043] 3. Optimize construction parameters and material usage Dynamically adjust the pouring strategy: Parameters in the formula (such as pouring speed q v , conduit diameter D) is directly related to construction operations, guiding engineers to adjust the pouring speed or conduit size to avoid excessive pouring that causes a surge in impact force.

[0044] ‌Material Economic Design‌: By calculating the number of anchor bars n and the cross-sectional area A, over-design can be avoided, material costs can be saved, and structural safety can be ensured at the same time.

[0045] 4. Improve segment quality and process reliability ‌Prevent quality defects‌: By precisely controlling the buoyancy, the risk of cage displacement is reduced, cracks or deformation of the segments after demoulding are prevented, and the appearance and structural integrity are ensured.

[0046] Optimization of vibration process: Based on the calculation results of the formula, pour and vibrate in stages (such as pouring again 2-3 hours after the initial vibration) to avoid sudden changes in buoyancy caused by changes in concrete fluidity and improve density.

[0047] 5. Theoretical support for technological innovation Momentum-friction coupling model: Formulas 3 and 4 combine fluid mechanics and friction theory, innovatively incorporating concrete impact and flow friction into anti-floating analysis, providing a new method for similar projects.

[0048] ‌Computer linkage control‌: formula parameters (such as q v , D) and sensor data are input into the computer to achieve real-time feedback control, reflecting the innovation of intelligent construction.

[0049] 6. Risk avoidance and standardized construction ‌Risk warning‌: Through the preset formula threshold, if the pressure is close to the critical value (F 压 →0), the system automatically adjusts to avoid human judgment errors.

[0050] ‌Basis for standardization‌: The formula provides a unified calculation standard for similar projects, reduces reliance on experience, and promotes process standardization.

[0051] In a specific implementation, in the large-volume vertical shaft segment steel cage vibrating anti-floating structure of the present application: 压 It is the key force provided by the floating stop device to resist the floating of the steel cage. 压The result directly determines the design parameters and operating status of the floating stop mechanism. 压 The size of the reversible motor in the drive mechanism can be reasonably selected to ensure that it has sufficient power to drive the telescopic pressure rod so that the triangular pressure claw can provide stable and required pressure. 压 The results also provide a reference for adjusting the relevant parameters of the anchoring steel bars (such as quantity, length, and cross-sectional area) to achieve the best balance between the anchoring force of the anchoring steel bars and the F of the floating stop mechanism. 压 Collaboratively and accurately offset the buoyancy, upward impact force and upward friction force exerted on the steel cage during concrete pouring and vibration, ensuring that the steel cage remains stable during the pouring process and prevents it from floating.

[0052] Taking a certain caisson type shaft prefabricated pipe segment casting project as an example, the prefabricated pipe segment includes a multi-ring structure, each ring of the prefabricated pipe segment is composed of 6 completely identical prefabricated pipe segment blocks, the center angle of each prefabricated pipe segment block is α=60°, the ring width H of the prefabricated pipe segment block is 1000~1500mm, the ring surface is not set with a wedge, the lining ring is staggered, the staggered angle is 20°, and the prefabricated pipe segments are bolted and connected from bottom to top. In the caisson type shaft prefabricated pipe segment casting project, the known relevant parameters are as follows: Density of poured concrete ρ 液 =ρ 砼 =2400kg / m 3 ; Concrete pouring speed q v =0.03m 3 / s; concrete conduit outlet diameter D = 0.25m; the volume of the steel cage immersed in the concrete liquid v 排 =0.1933m 3 ; The steel cage is subjected to the lateral pressure F of the poured concrete n =25kN / m 2 ; The depth of the steel cage in the concrete is h = 0.45m; The dynamic friction coefficient is μ = 0.25; The acceleration of gravity is g = 9.8m / s 2 .

[0053] Based on the requirements of the tube segment reinforcement ratio and the internal test system layout, the anchor steel bars are not installed, and the various forces on the steel cage are calculated using formula 2-4: Calculating buoyancy

[0054] Calculate the upward impact force

[0055] Calculate the upward friction force F3

[0056] 4) Calculate the force F that the floating stop device needs to provide压 , because F 压 It should be able to offset the buoyancy of the steel cage, that is, , so calculate F 压 =5223.253N.

[0057] Therefore, in this embodiment, the force F provided by the floating stop device is 压 It should be at least 5223.253N to ensure that the steel cage does not float during the pouring process. In actual engineering applications, according to the specific conditions of the project (such as the size of the steel cage, concrete pouring process, etc.), F is accurately calculated. 压 And reasonably design the floating stop mechanism, such as selecting a reversible motor with appropriate power to ensure that the floating stop mechanism can provide sufficient pressure F 压 To balance the buoyancy of the steel cage, so as to ensure the construction quality. Or when vibrating and tamping the steel cage of a large-volume shaft segment to prevent buoyancy, based on the displacement control method adopted in this application (i.e., constant steel cage displacement = 0), the actual F is measured by the pressure sensor of the compression rod. 压 Perform a verification calibration.

[0058] in conclusion: The anti-buoyancy formula is not only a theoretical tool, but also a bridge connecting design, construction and control. It ensures the stability of the steel cage through quantitative analysis, drives the intelligent response of the floating stop device, and finally achieves high-quality production of the pipe segment, which reflects the scientificity and practicality of this method in engineering practice. The introduction of such formulas in the patent application has significantly improved the rigor and innovative value of the technical solution.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A large-volume vertical shaft segment steel cage vibration anti-floating structure, characterized in that: It comprises a floating stop mechanism (2) and anchoring steel bars (3) installed on the outer template (1) of the pipe segment mold, wherein the control end of the floating stop mechanism (2) abuts against the steel cage (4), and the anchoring steel bars (3) are fixed to the longitudinal main bars of the steel cage (4).

2. The large-volume vertical shaft segment steel cage vibrating anti-floating structure according to claim 1 is characterized in that: The floating stop mechanism (2) comprises a floating stop box (201), a driving mechanism (202) is fixedly arranged inside the floating stop box (201), the driving mechanism (202) is connected to a vertical threaded column (203), the vertical threaded column (203) is threadedly connected to a lifting control plate (204), telescopic pressure rods (205) are connected to both sides of the lifting control plate (204), and a circular channel (206) corresponding to the telescopic pressure rod (205) is arranged below the floating stop box (201), and the telescopic pressure rod (205) is abutted against the steel cage (4) through the circular channel (206).

3. The large-volume vertical shaft segment steel cage vibrating anti-floating structure according to claim 2 is characterized in that: A bearing (2031) is provided at the lower portion of the vertical threaded column (203), and a receiving opening corresponding to the bearing (2031) is provided at the lower portion of the floating stop box (201).

4. The large-volume vertical shaft segment steel cage vibrating anti-floating structure according to claim 2 is characterized in that: The vertical threaded column (203) is also connected to a linkage mechanism (207), and a circular cover plate (208) is provided on the circular channel (206). When the telescopic pressure rod (205) passes through the circular channel (206), the linkage mechanism (207) drives the circular cover plate (208) to open; when the telescopic pressure rod (205) exits the circular channel (206), the linkage mechanism (207) drives the circular cover plate (208) to close.

5. The large-volume vertical shaft segment steel cage vibrating anti-floating structure according to claim 4 is characterized in that: The linkage mechanism (207) comprises a first gear (2071) fixed to the lower part of the vertical threaded column (203), the first gear (2071) is meshed with a second gear (2072) and a third gear (2073) on both sides, the second gear (2072) and the third gear (2073) are connected to a stepped shaft (2074) above, a steel wire rope (2075) is wound around the surface of the stepped shaft (2074), the steel wire rope (2075) is connected to the circular cover plate (208) on the corresponding side through a hook (2076), the circular cover plate (208) is hinged on the circular channel (206), and annular hanging rings are also provided on both sides of the circular cover plate (208), a hook is correspondingly installed at the bottom of the floating stop box (201), and a reset spring (2077) is connected between the annular hanging ring and the hook.

6. The large-volume vertical shaft segment steel cage vibrating anti-floating structure according to claim 2 is characterized in that: The floating stop mechanism (2) further comprises a computer (209); a telescopic arm (2051), a pressure sensor (2052) and a pressure rod (2053) are provided inside the telescopic pressure rod (205); the pressure sensor (2052) is connected to the telescopic arm (2051) by bolts; the pressure sensor (2052) is connected to the pressure rod (2053) below by welding; the pressure sensor (2052) is connected to the computer (209); a triangular pressure claw (20531) corresponding to and abutting against the steel cage (4) is installed at the bottom of the pressure rod (2053); toothed pulleys (2041) are provided at both ends of the lifting control plate (204); and vertical toothed tracks (2011) corresponding to and abutting against the toothed pulleys (2041) are provided on both sides of the floating stop box (201).

7. The large-volume vertical shaft segment steel cage vibrating anti-floating structure according to claim 6 is characterized in that: The driving mechanism (202) comprises a reversible motor (2021), a universal coupling (2022) and a flange (2023); the reversible motor (2021) is connected to the computer (209), a heat sink (20211) is provided on the outer shell of the reversible motor (2021), and two ends of the universal coupling (2022) are respectively hinged to the vertical threaded column (203) and the output shaft of the reversible motor (2021) through the flange (223).

8. The large-volume vertical shaft segment steel cage vibrating anti-floating structure according to claim 4 is characterized in that: The anchoring steel bar (3) is connected to the steel cage (4) by welding, and the welding position is located on the longitudinal main reinforcement of the steel cage (4) close to the edge of the pipe segment. The outer template (1) of the pipe segment mold is provided with two mounting holes, and the sizes of the two mounting holes match the sizes of the bottom of the circular cover plate (208). The telescopic pressure rod (205) is pressed against the steel cage (4) through the circular channel (206) and the mounting hole.

9. An application method of a large-volume vertical shaft segment steel cage vibrating anti-floating structure, characterized in that: The following steps are involved: Step 1, manufacturing a steel cage (4), welding a certain number of anchoring steel bars (3) after the steel cage (4) is manufactured, and placing the steel cage (4) into a segment mold; Step 2, installing the floating stop mechanism (2), installing the floating stop box (201) on both sides of the outer template (1) of the segment mold, aligning with the mounting holes previously opened on the outer template (1) of the segment mold, so that the circular cover plate (208) can cover the mounting holes, and connecting the reversible motor (2021) and the pressure sensor (2052) to the computer (209); Step 3, turning on the reversible motor (221), the driving mechanism (202) drives the circular channel (206) to open, and the telescopic pressure rod (205) lowers the triangular pressure claw (20531) to press against the steel cage (4), thereby providing pressure for the first step of pouring concrete; Step 4: pouring concrete for the first time. Slowly pour concrete on the segment mold. Stop pouring after the concrete is poured under the anchor steel bar (3). Insert a vibrating rod to vibrate the poured part to make the concrete more dense and uniform. Step 5, pouring concrete again. Pour concrete again 2-3 hours after the initial pouring and vibration. Observe the reading of the pressure sensor (2052) at the same time. When the pressure is reduced to almost 0, retract the telescopic pressure rod (205) upward, control the computer (209) to turn on the reversible motor (2021), and the reversible motor (2021) drives the lifting control board (204) upward. The return spring (2077) pulls the circular cover plate (208) downward to cover the installation hole. Insert the vibrating rod into the concrete in the mold again to vibrate. After the vibration is completed, wait for the concrete to initially set. Open the segment mold before the concrete initially sets, and plaster the concrete surface to eliminate cracks and unevenness on the concrete surface. Step 6: Curing and demoulding the segments. When the segments reach demoulding strength, demoulding equipment is used to remove the segments from the mold.

10. The application method of the large-volume vertical shaft segment steel cage vibrating anti-floating structure according to claim 9 is characterized in that: In step 1, the anchor steel bar is welded to the steel cage. After pouring concrete, the anti-floating force of the anchor steel bar is F 锚 , the calculation formula of the anti-buoyancy is as follows: Formula (1) In formula (1), n The number of anchor steel bars welded to the steel cage; l is the anchorage length of the anchor steel bar, m; A is the cross-sectional area of ​​the anchor steel bar, m 2 ; f c is the compressive strength of the concrete cylinder, MPa; In step 4, when pouring concrete, the steel cage will be subjected to the vertical upward buoyancy of the concrete. F 1 Formula (2) In formula (2), ρ 液 is the density of the concrete liquid poured into the mold, kg / m 3 ; g is the acceleration due to gravity, which can be taken as 9.8m / s at this moment 2 ; v 排 is the volume of the steel cage immersed in the concrete liquid, m 3 ; The steel cage will be subjected to the upward impact force during concrete pouring. During the concrete pouring process, the concrete is poured from the bottom to the top. Under the action of the stamping, the concrete is continuously rebounded from the bottom to the top. During the upward movement of the concrete, the steel cage is subjected to the upward squeezing force. F 2. For the mixed fluid, combined with the law of conservation of momentum, the maximum impact force on the steel cage is: Formula (3) In formula (3), ρ 砼 is the density of poured concrete, kg / m 3 ; q v is the pouring speed of concrete, m 3 / s; D is the concrete conduit outlet diameter, m; The steel cage will be subjected to an upward friction force F 3. The upward friction force is related to the pouring speed and height of concrete. When the pouring speed is slow, the steel cage will not be subject to obvious friction. When the pouring speed is fast, the flow speed of concrete will also be faster, which will produce an upward friction force on the steel cage. When concrete is poured from a higher position and impacts the steel cage, it is possible to generate an upward friction force component in an instant. The steel cage is subject to upward friction force. F 3 is: Formula (4) In formula (4), f is the lateral pressure of the poured concrete on the steel cage, kN; h is the buried depth of the steel cage in the concrete, m; μ is the dynamic friction factor; F n is the lateral pressure of poured concrete on any section of the steel cage, kN; Formulas (2), (3) and (4) are the buoyancy forces on the steel cage during pouring. The force provided by the floating stop mechanism is: F 压 ,satisfy: .

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