Rib-arch bridge based method for reinforcing arch-rib steel pipe concrete

Abstract

The present application relates to rib arch bridge technical field, specifically point to a kind of arch rib steel pipe concrete reinforcing method based on rib arch bridge, including S1, pours pile foundation concrete on arch support foundation;S2, symmetrically set rigid frame on both sides and closes;S3, pours steel pipe concrete in skeleton;S4, after the concrete in skeleton reaches design strength, pours arch ring concrete from symmetrically on both sides, until closes.This application is used for bearing arch support foundation and reinforcing part by pile foundation concrete;Steel pipe concrete is used for enhancing rigid frame and making rigid frame reach design strength;Arch ring concrete is used for reinforcing both sides and bottom of arch bridge.By pile foundation concrete bearing arch support foundation and reinforcing part, rigid frame bearing abutment, avoid the settlement or slip to main span side of abutment and arch support foundation caused by adverse geology, reinforce rib arch bridge, solve the problems, such as support string movement, completely empty or shear overrun, abutment, arch support, arch ring local cracking.

Description

Technical Field

[0001] This invention relates to the field of ribbed arch bridge technology, specifically to a method for reinforcing ribbed steel tube concrete in ribbed arch bridges. Background Technology

[0002] A ribbed arch bridge consists of two or more separate arch ribs. These ribs are connected by transverse tie beams (or diaphragms) to form a unified structure, allowing the ribs to share the load and increasing their lateral stability. This type of arch bridge is called a ribbed arch bridge. The main load-bearing structure of a ribbed arch bridge is the arch ring or arch ribs. Under vertical loads, the piers or abutments bear horizontal thrust. Simultaneously, this horizontal thrust significantly counteracts the bending moment caused by the load within the arch ring or arch ribs. Therefore, compared to beams of the same span, the bending moment and deformation of an arch are much smaller.

[0003] Regular inspections of bridges along the route have revealed settlement of abutment and arch foundations, as well as slippage of abutment and arch foundations towards the main span in some arch bridges. These phenomena can lead to issues such as bearing displacement, complete detachment, excessive shear, and localized cracking of abutments, arch foundations, and arch rings.

[0004] Based on the above situation, there is an urgent need for a method for reinforcing ribbed steel tube concrete for ribbed arch bridges, and to carry out reinforcement design work for the aforementioned bridge defects. Summary of the Invention

[0005] The purpose of this invention is to provide a method for reinforcing ribbed steel tube concrete for ribbed arch bridges, which solves the problems of bearing movement, complete voiding or excessive shear, and local cracking of abutments, arch seats, and arch rings.

[0006] This invention is achieved through the following technical solution:

[0007] A method for reinforcing ribbed steel-concrete composite arch bridges includes:

[0008] S1. Pour the pile foundation concrete on the arch base;

[0009] S2. Several rigid frameworks are symmetrically set up on both sides and joined together;

[0010] S3. Pour steel pipe concrete into the rigid frame;

[0011] S4. After the steel-concrete composite reaches its design strength, the arch ring concrete is poured symmetrically from both banks until the closure is completed.

[0012] Regular inspections of bridges along the route revealed settlement of abutment and arch foundation foundations in some arch bridges; and slippage of abutment and arch foundation foundations towards the main span. These phenomena can lead to bearing displacement, complete detachment, or excessive shear, as well as localized cracking in the abutments, arch foundations, and arch rings. This solution utilizes pile foundation concrete to support and reinforce the arch foundation. The reinforcement includes a stiffening frame, steel-concrete composite within the stiffening frame, and concrete in the arch ring outside the stiffening frame. The steel-concrete composite reinforces the stiffening frame and ensures it reaches its design strength; the concrete in the arch ring integrates the stiffening frame with the original arch ring. By using pile foundation concrete to support the arch foundation and reinforcement, and the stiffening frame to support the abutments, settlement or slippage of the abutment and arch foundation foundations towards the main span caused by adverse geological conditions is avoided, thus improving the load-bearing capacity of the ribbed arch bridge.

[0013] Furthermore, this solution does not exclusively limit the reinforcement steps of the pile foundation concrete. One feasible solution is: the aforementioned pouring of pile foundation concrete on the arch abutment foundation includes:

[0014] S11, Embedded arch foundation embedded parts, to make the rigid frame match the embedded parts;

[0015] S12, Pouring the remaining concrete for the pile foundation;

[0016] S13. A platform for reinforcing the main arch ring is erected under the bridge.

[0017] The reinforcement platform includes a full-span scaffold, temporary supports, and a protective shed. By setting up foundation embedded parts, it is easy to match the stiffening frame with the foundation embedded parts before pouring the remaining concrete of the arch seat. The connection between the stiffening frame and the embedded parts is reinforced by the pile foundation concrete, thereby ensuring the reliability of the connection between the stiffening frame and the arch seat foundation.

[0018] Furthermore, the aforementioned symmetrically arranged stiffening frame on both sides includes:

[0019] S21. The stiffening frame of each arch rib is assembled in several segments for each half span;

[0020] S22. Select a period of stable temperature to carry out instantaneous closure.

[0021] The rigid frame adopts a modular structure, which facilitates the transportation of several segments to the bridge. Due to the thermal expansion and contraction of the rigid frame material, a period of stable temperature is selected before the rigid frame is closed to avoid temperature changes causing changes in the dimensions of the rigid frame and affecting the construction.

[0022] Furthermore, to ensure the reliability of the rigid frame after closure, one feasible solution is: to perform instantaneous closure during a period of stable temperature, including:

[0023] S221. Measure the linearity and internal forces of each segment;

[0024] S222. If the internal force measurement value is within the preset range, the closure is officially completed. If the internal force measurement value exceeds the preset range, adjustments are made and then S221 is executed.

[0025] Because the alignment and internal forces of each segment are measured before the formal closure, the internal force data of the stiffening frame after closure can be obtained. By controlling the internal force, the stiffening frame can be made to withstand the preset load-bearing capacity, thereby ensuring the reliability of the stiffening frame after closure.

[0026] Furthermore, the rigid frame segment installation adopts a symmetrical cantilever splicing method on both banks. Each half-span of the rigid frame of each arch rib is divided into several hoisting segments and a closure segment. Before closure, during a period of relatively stable temperature, the gap length of each rigid frame is measured and the gaps between the rigid frames are filled. Specifically, a section of insert pipe with the same thickness as the rigid frame is processed according to the gap size, and some annular steel insert plates are prepared. During another period with the same temperature as the measurement period, closure is carried out. First, the gaps between the segments are tightly filled with insert pipes and insert plates. Then, two pre-processed semi-circular pipes are fitted into the closure gap and closed. They are connected and fixed with high-strength bolts, and the pipe openings are welded to the chord pipe walls, thus completing the closure process of the rigid frame. After closure, the linearity and internal forces are measured, and adjustments are made to complete the formal closure. By filling the gaps in the rigid frame, excessive internal stress after closure is avoided.

[0027] Furthermore, before pouring the arch ring concrete, several connecting bars are inserted into the arch bridge. When this method is adopted, the poured arch ring concrete and the connecting bars are integrally formed. The connecting bars are used to bear part of the weight of the arch ring concrete and the internal stress generated after solidification, which can prevent the arch ring concrete from falling off due to the aforementioned internal stress and increase the connection between the arch ring concrete and the arch bridge.

[0028] Furthermore, this plan does not exclusively limit the specific pouring steps of steel-concrete composite pipes; one feasible plan includes:

[0029] C80 self-compacting shrinkage-compensating concrete was used and pumped from the arch foot to the arch crown.

[0030] Ultrasonic geophysical testing was used to inspect the construction quality of concrete-filled steel pipes.

[0031] Self-compacting concrete is a type of concrete with high flowability, no segregation, no bleeding, and little or no vibration. It can automatically level itself and fill a rigid framework, preventing quality defects such as cracks and honeycombing. Using pumping for pouring not only significantly reduces construction noise and speeds up construction, ensuring and improving project quality, but also reduces high-altitude work, making construction operations more convenient and safer, resulting in significant overall benefits.

[0032] The specific methods for detecting the construction quality of steel-concrete composite structures using ultrasonic geophysical testing are as follows:

[0033] S1. Arrange the inspection vehicle on the bridge deck corresponding to the steel-concrete composite column;

[0034] S2. The testing vehicle uses its telescopic arm to place the testing component on the top outer wall of the steel-concrete composite column, and then activates the testing component to partially clamp it around the outer circumference of the steel-concrete composite column.

[0035] S3. The detection component moves along the axial direction of the steel-concrete composite column towards its bottom, and the density of the steel-concrete composite column is detected every 30cm after the detection component moves. After the density of the concrete within a vertical height of 30cm is completed, the detection component continues to move down and repeats its detection procedure.

[0036] S4. After the detection component moves to the bottom of the steel-concrete composite column, the detection component moves along the axial direction of the steel-concrete composite column towards its top. The detection component starts to detect the density of the steel-concrete composite column every 20cm. After the concrete density test within a vertical height of 20cm is completed, the detection component continues to move upward and repeats its detection procedure.

[0037] S5. After the detection component returns to the top of the steel-concrete composite column, the detection component releases its clamping on the steel-concrete composite column, and the telescopic arm retracts it, thus completing the detection process.

[0038] The detection component includes an upper support arm and a lower support arm, both of which are hollow and have a slight arc shape. A lifting ring is provided in the middle of the upper surface of the upper support arm, a first motor is provided in the middle of the lower surface of the upper support arm, and a third motor is provided upside down in the middle of the upper surface of the lower support arm.

[0039] It also includes a first support block and a second support block, both of which are hollow and have a slight arc shape. A first cylinder is provided on the upper surface of the first support block, and the output end of the first cylinder is connected to the first motor body. A second motor is provided in the middle of the lower surface of the first support block. A fourth motor is provided upside down in the middle of the upper surface of the second support block. A second cylinder is connected between the second motor body and the fourth motor body. The output end of the second cylinder is connected to the second motor body. A third cylinder is provided upside down on the lower surface of the second support block, and the output end of the third cylinder is connected to the third motor body.

[0040] From top to bottom, the forward projections of the upper support arm, the lower support arm, the first support block, and the second support block are located on the same circumference, and the forward projection of the upper support arm after rotating around its center by a specified angle can successively coincide with the forward projections of the lower support arm, the first support block, and the second support block.

[0041] Slightly curved movable arms are slidably installed at both ends of the upper and lower support arms, and slightly curved clamping plates are slidably installed at both ends of the first and second support blocks. Flexible rollers are spaced apart on the inner sidewall of each clamping plate, and openings for the flexible rollers to pass through are opened on the inner sidewall of the first and second support blocks. Each clamping plate is equipped with an ultrasonic transducer at its end, and multiple ultrasonic transducers are electrically connected to the first motor, second motor, third motor, fourth motor, first cylinder, second cylinder, and third cylinder through a controller.

[0042] Furthermore, on the opposite end faces of the two movable arms and two clamping plates located on the upper support arm, lower support arm, first support block, and second support block respectively, there are corresponding arc-shaped inner and outer guard plates. A gap is left between the outer and inner guard plates. Toothed belts are provided on the inner wall of the outer guard plate and the outer wall of the inner guard plate. A drive gear that meshes with the two toothed belts is provided in the gap. Among them, the drive gear in the upper support arm is connected to the output end of the first motor, the drive gear in the lower support arm is connected to the output end of the third motor, the drive gear in the first support block is connected to the output end of the second motor, and the drive gear in the second support block is connected to the output end of the fourth motor. Furthermore, when conducting density testing on steel-concrete composite columns, this technical solution abandons the traditional suspended basket-style manual testing. Instead, a testing vehicle is deployed on the bridge deck at the points corresponding to the steel-concrete composite columns. Its telescopic arm lowers the testing components to the top of the steel-concrete composite columns, and the testing is conducted by moving the components down and up along the axial direction of the steel-concrete composite columns. By testing the quality of different areas, it is possible to effectively determine whether there are defects such as non-density, voids, or debonding in the entire concrete column, so that construction personnel can take corresponding measures in a timely manner.

[0043] The quality inspection of the steel-concrete composite column is conducted in multiple stages, following the principle of testing one section before moving on to the next, until all sections are tested. Concrete testing inside the pipe is carried out after concrete pouring according to age, typically at 3, 7, 14, 28, and 56 days, and sometimes even long-term monitoring. The testing components in this technical solution can meet both short-term and long-term testing needs, allowing construction personnel to obtain sufficient testing data before the steel-concrete composite column is used. During vertical downward movement of the testing components, the telescopic arm of the testing vehicle lowers the components. During testing, once the upper support arm approaches the steel-concrete composite column, the first motor starts, driving the drive gear inside the upper support arm to engage with two toothed belts, causing the two movable arms to move along the concrete column. The outer wall undergoes circumferential movement. It is important to note that when the clamping plate moves outward to its limit position, the total arc length of the upper support arm and the two movable arms exceeds 180 degrees, which means that it can cover most of the outer wall of the steel-concrete composite column. The ultrasonic transducers on the two clamping plates are located at two bisectors of the circumference of the clamping plate. The ultrasonic waves will be reflected and refracted on the steel-concrete composite column, and the presence of corresponding defects in the concrete can be judged by parameters such as ultrasonic wave velocity and waveform. Furthermore, the structure of the lower support arm is the same as that of the upper support arm, the only difference being the location of its placement. Viewed from top to bottom, the frontal projections of the lower support arm and the upper support arm only partially overlap, and the movable arms in the upper support arm and the movable arms in the lower support arm extend outward one after the other.

[0044] Furthermore, the pile foundation concrete, steel pipe concrete, and arch ring concrete all include pure silicate cement and mineral admixtures as cementitious materials, which facilitates the control of the quality and quantity of mineral admixtures in the concrete. Specifically, the percentage of the mixed admixtures in the total cementitious materials is calculated by combining the type, quality, and dosage of mineral admixtures in the cement with the mineral admixtures added when preparing the concrete.

[0045] Furthermore, the mineral admixtures include fly ash plus silica fume or ground slag plus silica fume. Since the mineral admixtures can affect the porosity of the hardened cement paste, the strength of the cement after solidification can be ensured by controlling the porosity.

[0046] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0047] 1. The pile foundation concrete is used to support and reinforce the arch abutment foundation. The reinforcement includes the stiffening frame, the steel-concrete composite within the stiffening frame, and the arch ring concrete outside the stiffening frame. The steel-concrete composite reinforces the stiffening frame and ensures it reaches its design strength. The arch ring concrete integrates the stiffening frame with the original arch ring. By using the pile foundation concrete to support the arch abutment foundation and reinforcement, and the stiffening frame to support the abutment, the bridge avoids settlement or lateral slippage of the abutment and arch abutment foundation caused by adverse geological conditions, thus improving the load-bearing capacity of the ribbed arch bridge.

[0048] 2. The rigid frame segment installation adopts symmetrical cantilever splicing on both banks. Each half span of the rigid frame of each arch rib is divided into several hoisting segments and a closure segment. Before closure, the gap length of each rigid frame is measured during a period when the temperature is relatively stable and the gaps between the rigid frames are filled. By filling the gaps of the rigid frames, excessive internal stress is avoided after closure.

[0049] Third, the aforementioned pile foundation concrete, steel pipe concrete, and arch ring concrete all include pure silicate cement and mineral admixtures as cementing materials, which facilitates the control of the quality and quantity of mineral admixtures in the concrete. Specifically, the percentage of the mixed admixtures in the total cementing materials is calculated by combining the type, quality, and dosage of mineral admixtures in the cement with the mineral admixtures added during concrete preparation. The porosity of the hardened cement paste is changed by the mineral admixtures, thereby ensuring the strength of the cement after solidification. Attached Figure Description

[0050] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0051] Figure 1 This is a flowchart of the present invention;

[0052] Figure 2 This is a schematic diagram of the rib arch bridge structure of the present invention;

[0053] Figure 3 This is a cross-sectional view of the concrete arch ring of the present invention;

[0054] Figure 4 This is a schematic diagram of the connecting ribs of the present invention;

[0055] Figure 5 This is a structural diagram of the inspection vehicle;

[0056] Figure 6 This is a schematic diagram of the detection component.

[0057] Figure 7 This is a schematic diagram showing the fit between the outer and inner protective plates.

[0058] The attached diagram shows the markings and corresponding component names:

[0059] 1. Bridge deck; 2. Arch bridge; 3. Columns supporting the arch; 4. Rigid frame; 5. Concrete pile foundation; 6. Roadway;

[0060] 41. Concrete-filled steel tubing; 42. Concrete arch ring;

[0061] 7. Inspection vehicle; 8. Telescopic arm; 9. Ultrasonic transducer; 10. Upper support arm; 11. Lifting ring; 12. Movable arm; 13. First cylinder; 14. Flexible roller; 15. First support block; 16. Second motor; 17. Clamping plate; 18. Second support block; 19. Opening; 20. Lower support arm; 21. Outer protective plate; 22. Toothed belt; 23. Drive gear; 24. Inner protective plate; 25. First motor; 26. Second cylinder; 27. Third cylinder; 28. Third motor; 29. ​​Fourth motor. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are for illustrative purposes only and are not intended to limit the invention. It should be noted that this invention is already in the actual research and development stage.

[0063] First, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0064] Example 1:

[0065] As attached Figure 1 and Figure 2 As shown, this embodiment includes:

[0066] S1. Pour 5 pile foundation concrete on the arch abutment foundation;

[0067] S2, Several rigid frameworks are symmetrically set on both sides and joined together;

[0068] S3. Pour steel-concrete composite material into the rigid frame 41;

[0069] After the S4 and steel-concrete composite 41 reach their design strength, the arch ring concrete 42 is poured symmetrically from both banks until the closure is completed.

[0070] Regular inspections of bridges along the route revealed settlement of abutment and arch foundation foundations in some arch bridges; and slippage of abutment and arch foundation foundations towards the main span. These phenomena can lead to bearing displacement, complete detachment, or excessive shear, as well as localized cracking in the abutments, arch foundations, and arch rings. This solution utilizes pile foundation concrete 5 to support and reinforce the arch foundation. The reinforcement includes the stiffening frame 4, the steel-concrete composite 41 within the stiffening frame 4, and the arch ring concrete 42 outside the stiffening frame 4. The steel-concrete composite 41 strengthens the stiffening frame 4 and ensures it reaches its design strength; the arch ring concrete 42 integrates the stiffening frame 4 with the original arch ring. By using pile foundation concrete 5 to support the arch foundation and reinforcement, and the stiffening frame 4 to support the abutments, settlement or slippage of the abutment and arch foundation foundations towards the main span caused by adverse geological conditions is avoided, thus improving the load-bearing capacity of the ribbed arch bridge.

[0071] Preferably, since the bearing stresses of the pile foundation concrete 5, steel pipe concrete 41, and arch ring concrete 42 are different, in this embodiment, the steel pipe concrete 41 in the stiffening frame 4 is made of C80 self-compacting concrete; the arch ring concrete 42 is made of C50 self-compacting concrete (which can only be implemented after verification through on-site process tests); the arch seat is made of C50 and C30 concrete; the small box girder and T beam are made of C50 concrete; the cap beam, junction pier, approach bridge pier, foundation, and bridge deck pavement are made of C40 concrete; the pile foundation is made of C30 concrete; and the abutment approach slab is made of C30 concrete. By using concrete of different strengths for pouring, material costs are saved.

[0072] This scheme does not exclusively limit the reinforcement steps of the pile foundation concrete. One feasible scheme is: the aforementioned pouring of pile foundation concrete 5 on the arch abutment foundation includes:

[0073] S11, Embedded arch foundation embedded parts, to make the rigid frame match the embedded parts;

[0074] S12, Pouring the remaining concrete for the pile foundation;

[0075] S13. A platform for reinforcing the main arch ring is erected under the bridge.

[0076] The reinforcement platform includes a full-span support, temporary supports, and a protective shed. By setting up foundation embedded parts, it is easy to match the stiffening frame 5 with the foundation embedded parts before pouring the remaining concrete of the arch seat. The connection between the stiffening frame and the embedded parts is reinforced by the pile foundation concrete 5, thereby ensuring the reliability of the connection between the stiffening frame 4 and the arch seat foundation.

[0077] Preferably, in this embodiment, after the main arch reinforcement platform is set up, the speed limit for traffic on the underpass lane 6 is set up to ensure construction safety; after the arch concrete 42 reaches the design strength, the support platform is removed and the speed limit requirement for vehicles under the bridge is lifted.

[0078] The aforementioned symmetrically arranged stiffening frame on both sides includes:

[0079] S21, each arch rib stiffening frame 4, each half span is assembled in several segments;

[0080] S22. Select a period of stable temperature to carry out instantaneous closure.

[0081] The stiffening frame 4 adopts an assembly structure to facilitate the transportation of several segments to the bridge. Specifically, in this embodiment, the stiffening frame 4 includes Q345B steel plate, Q345C steel plate and / or Q235C steel plate. Due to the thermal expansion and contraction of the stiffening frame 4 material, a period of stable temperature is selected before the stiffening frame 4 is closed to avoid temperature changes causing changes in the size of the stiffening frame 4 and affecting the construction.

[0082] To ensure the reliability of the stiffening frame 4 after closure, one feasible solution is: to perform instantaneous closure during a period of stable temperature, including:

[0083] S221. Measure the linearity and internal forces of each segment;

[0084] S222. If the internal force measurement value is within the preset range, the closure is officially completed. If the internal force measurement value exceeds the preset range, adjustments are made and then S221 is executed.

[0085] Because the alignment and internal forces of each segment are measured before the formal closure, the internal force data of the stiffening frame 4 after closure can be obtained. By controlling the internal force, the stiffening frame can be made to withstand the preset load-bearing capacity, thereby ensuring the reliability of the stiffening frame 4 after closure.

[0086] The installation of the four-segment rigid frame adopts symmetrical cantilever splicing on both banks. Each half span of the rigid frame 4 of each arch rib is divided into several hoisting segments and a closure segment. Before closure, the gap length of each rigid frame 4 is measured during a period when the temperature is relatively stable, and the gaps between the rigid frames 4 are filled. By filling the gaps of the rigid frames 4, excessive internal stress after closure is avoided.

[0087] like Figure 4 As shown, before pouring the arch ring concrete 42, several connecting bars are inserted into the arch bridge 2. When this scheme is adopted, the poured arch ring concrete 42 and the connecting bars are integrally formed. The connecting bars are used to bear part of the weight of the arch ring concrete 42 and the internal stress generated after solidification. This can prevent the arch ring concrete 42 from falling off due to the internal stress and increase the connection between the arch ring concrete 42 and the arch bridge 2.

[0088] Preferably, in this embodiment, the connecting bar is L-shaped. The L-shaped structure can hook the arch ring concrete 42, further increasing the connection strength between the arch ring concrete 42 and the arch bridge 2.

[0089] This plan does not exclusively limit the specific pouring steps of steel-tube concrete. One feasible plan includes:

[0090] C80 self-compacting shrinkage-compensating concrete was used and pumped from the arch foot to the arch crown.

[0091] Ultrasonic geophysical testing was used to inspect the construction quality of concrete-filled steel pipes.

[0092] Self-compacting concrete is a type of concrete with high flowability, no segregation, no bleeding, and little or no vibration. It can automatically level itself and fill a rigid skeleton. It can prevent quality defects such as cracks and honeycombing. Using pumping for pouring can not only greatly reduce construction noise and speed up construction, and ensure and improve project quality, but also reduce high-altitude work, making construction operations more convenient and safe, resulting in significant overall benefits.

[0093] The pile foundation concrete 5, steel pipe concrete 41, and arch ring concrete 42 all include pure silicate cement and mineral admixtures as cementitious materials, which facilitates the control of the quality and quantity of mineral admixtures in the concrete. Specifically, the percentage of the mixed admixtures in the total cementitious materials is calculated by combining the type, quality, and dosage of mineral admixtures in the cement with the mineral admixtures added when preparing the concrete.

[0094] Preferably, the minimum amount of cementitious material in C30, C40, C50, and C80 concrete should be greater than 300 mg / L. 320 380 380 The maximum dosage shall not exceed 400. 450 500 500 The maximum water-to-binder ratios were 0.50, 0.45, 0.36, and 0.36, respectively.

[0095] The mineral admixtures include fly ash plus silica fume or ground slag plus silica fume. Since the mineral admixtures can affect the porosity of hardened cement paste, the strength of the cement after solidification can be guaranteed by controlling the porosity.

[0096] Preferably, the admixture has stable quality, uniform feed, and a fixed source, and does not contain radioactive substances, soluble toxic substances, or other substances that are harmful to the quality of concrete. Using this method can ensure the quality of concrete.

[0097] Example 2:

[0098] This embodiment only describes the parts that differ from Embodiment 1: This solution is not limited to the filling method of the stiffening frame gap. Specifically, in this embodiment, a section of inserting tube with the same thickness as the stiffening frame is processed according to the gap size. In addition, some annular steel inserting plates are prepared. The closure is carried out in another time period with the same temperature as the measurement period. First, the gap between the segments is tightly filled with the inserting tube and inserting plates. Then, the two pre-processed semi-circular tubes are put into the closure gap and closed. They are connected and fixed with high-strength bolts. The sleeve opening is welded to the chord tube wall, thus completing the closure process of the stiffening frame. After closure, the linearity and internal force are measured. After adjustment, the formal closure is completed.

[0099] Example 3:

[0100] This embodiment only describes the parts that differ from Embodiment 1: as shown in the appendix. Figure 3 As shown, several arch-supported columns 3 are provided between the bridge deck 1 and the arch bridge 2. The arch bridge 2 is used to bear the weight of the bridge deck system. In order to analyze the stress situation of the arch bridge 2, the arch bridge 2 is the compression member described below. One feasible solution includes:

[0101] From the formula Perform load-bearing capacity calculations for concrete-filled steel tubes.

[0102] Where n is the number of steel pipes;

[0103] k is the importance coefficient or seismic adjustment coefficient of the bridge structure, and its value is taken from the following table:

[0104] Component Name Main Arch Uprights and cross braces Node connection k 0.75 0.80 0.85

[0105] N is the axial force of the compression member formed by combining several steel pipes;

[0106] The slenderness ratio reduction factor for compression members is based on the converted slenderness ratio of the compression members. , Specifically, in this embodiment, a four-pipe combination is used, with each main pipe having the same cross-sectional area. , ,in The slenderness ratio of the main pipe of the compression member with respect to the y-axis is given. The slenderness ratio of the main pipe of the compression member with respect to the x-axis is given. The slenderness ratio of a node in a single-limb steel-concrete composite column;

[0107] This is the maximum initial stress reduction factor for a single-limb steel pipe;

[0108] The reduction factor for voids in single-limb steel-concrete composite tubes;

[0109] The axial compressive strength of a single-tube steel-concrete composite structure;

[0110] This represents the cross-sectional area of ​​a single-tube steel-concrete composite structure.

[0111] This scheme does not exclusively limit the calculation method of the axial force N of the compression member. One feasible scheme is: the axial force of the compression member is the resultant force of the various forces acting on the compression member, and is calculated using the formula... To calculate the axial force of the compression member,

[0112] in As a permanent force, it is calculated by summing the bridge structure's gravity, prestressing force, soil gravity, soil lateral pressure, concrete shrinkage force, and concrete creep force.

[0113] The variable forces are calculated by summing up the vehicle load, crowd load, fatigue load, and environmental load. The vehicle load includes: vehicle load, vehicle impact force, vehicle centrifugal force, earth pressure caused by the vehicle, and vehicle braking force. The environmental load includes: wind load, water pressure, ice pressure, wave force, and temperature-dependent forces.

[0114] It is an accidental force, calculated by summing the impact force of the ship, the impact force of the floating object, and the impact force of the car;

[0115] This refers to the seismic force.

[0116] The principle of this scheme is as follows:

[0117] The pile foundation concrete 5 is used to support the arch abutment foundation and the reinforcement part. The reinforcement part includes the stiffening frame 4, the steel pipe concrete 41 inside the stiffening frame 4, and the arch ring concrete 42 outside the stiffening frame 4. The steel pipe concrete 41 is used to strengthen the stiffening frame 4 and make the stiffening frame 4 reach the design strength. The arch ring concrete 42 is used to reinforce the sides and bottom of the arch bridge. The arch foundation and reinforcement are supported by the concrete pile foundation 5, while the rigid frame 4 supports the bridge deck. Before closure, during a period of relatively stable temperature, the gap length of each rigid frame 4 is measured and the gaps between the rigid frames 4 are filled. A section of insert pipe with the same thickness as the rigid frame 4 is processed according to the gap size. Some annular steel insert plates are also prepared. During another period with the same temperature as the measurement period, closure is carried out. First, the gaps between the segments are tightly filled with insert pipes and insert plates. Then, two pre-processed semi-circular pipes are fitted into the closure gaps and closed. They are connected and fixed with high-strength bolts, and the pipe openings are welded to the chord pipe walls, thus completing the closure process of the rigid frame. After closure, the linearity and internal forces are measured, and adjustments are made to complete the formal closure. By filling the gaps of the rigid frame 4, excessive internal stress after closure is avoided.

[0118] Example 4

[0119] like Figures 1 to 7 As shown, this embodiment, based on embodiment 1, specifically includes the following steps when using ultrasonic geophysical testing to inspect the construction quality of steel-concrete composite pipes:

[0120] S1. Arrange the inspection vehicle 7 on the bridge deck 1 corresponding to the steel-concrete composite column;

[0121] S2. The detection vehicle 7 places the detection component on the top outer wall of the steel-concrete composite column through its telescopic arm 8, and activates the detection component to partially clamp it around the outer circumference of the steel-concrete composite column.

[0122] S3. The detection component moves along the axial direction of the steel-concrete composite column towards its bottom, and the density of the steel-concrete composite column is detected every 30cm after the detection component moves. After the density of the concrete within a vertical height of 30cm is completed, the detection component continues to move down and repeats its detection procedure.

[0123] S4. After the detection component moves to the bottom of the steel-concrete composite column, the detection component moves along the axial direction of the steel-concrete composite column towards its top. The detection component starts to detect the density of the steel-concrete composite column every 20cm. After the concrete density test within a vertical height of 20cm is completed, the detection component continues to move upward and repeats its detection procedure.

[0124] S5. After the detection component returns to the top of the steel-concrete composite column, the detection component releases its clamping on the steel-concrete composite column, and the telescopic arm 8 retracts it, thus completing the detection process.

[0125] The detection component includes an upper support arm 10 and a lower support arm 20, both of which are hollow and have a slight arc shape. A lifting ring 11 is provided in the middle of the upper surface of the upper support arm 10, a first motor 25 is provided in the middle of the lower surface of the upper support arm 10, and a third motor 28 is provided upside down in the middle of the upper surface of the lower support arm 20.

[0126] It also includes a first support block 15 and a second support block 18, both of which are hollow and have a slight arc shape. A first cylinder 13 is provided on the upper surface of the first support block 15. The output end of the first cylinder 13 is connected to the body of the first motor 25. A second motor 16 is provided in the middle of the lower surface of the first support block 15. A fourth motor 29 is provided upside down in the middle of the upper surface of the second support block 18. A second cylinder 26 is connected between the body of the second motor 16 and the body of the fourth motor 29. The output end of the second cylinder 26 is connected to the body of the second motor 16. A third cylinder 27 is provided upside down on the lower surface of the second support block 18. The output end of the third cylinder 27 is connected to the body of the third motor 28.

[0127] From top to bottom, the forward projections of the upper support arm 10, the lower support arm 20, the first support block 15, and the second support block 18 are located on the same circumference, and the forward projection of the upper support arm 10 after rotating around its center by a specified angle can successively coincide with the forward projections of the lower support arm 20, the first support block 15, and the second support block 18.

[0128] At both ends of the upper support arm 10 and the lower support arm 20, there are movable arms 12 in the shape of a slight arc. At both ends of the first support block 15 and the second support block 18, there are clamping plates 17 in the shape of a slight arc. Flexible rollers 14 are spaced apart on the inner sidewall of each clamping plate 17. Openings 19 for the flexible rollers 14 to pass through are opened on the inner sidewall of the first support block 15 and the second support block 18. Each clamping plate 17 is provided with an ultrasonic transducer 9 at its end. Multiple ultrasonic transducers 9 are electrically connected to the first motor 25, the second motor 16, the third motor 28, the fourth motor 29, the first cylinder 13, the second cylinder 26 and the third cylinder 27 through a controller.

[0129] Furthermore, on the opposite end faces of the two movable arms 12 and the two clamping plates 17 located on the upper support arm 10, the lower support arm 20, the first support block 15, and the second support block 18 respectively, there are corresponding arc-shaped inner guard plate 24 and outer guard plate 21. There is a gap between the outer guard plate 21 and the inner guard plate 24. The inner wall of the outer guard plate 21 and the outer wall of the inner guard plate are both provided with toothed belts 22. In the gap, there are drive gears 23 that mesh with the two toothed belts 22 simultaneously. Among them, the drive gear 23 in the upper support arm 10 is connected to the output end of the first motor 25, the drive gear 23 in the lower support arm 20 is connected to the output end of the third motor 28, the drive gear 23 in the first support block 15 is connected to the output end of the second motor 16, and the drive gear 23 in the second support block 18 is connected to the output end of the fourth motor 29. Furthermore, when conducting density testing on steel-concrete composite columns, this technical solution abandons the traditional suspended basket-style manual testing. Instead, a testing vehicle 7 is deployed on the bridge deck 1 at the points corresponding to the steel-concrete composite columns. Its telescopic arm 8 lowers the testing components to the top of the steel-concrete composite columns. The testing is conducted by moving the vehicle down and up along the axial direction of the steel-concrete composite columns twice. By testing the quality of different areas, it is possible to effectively determine whether there are defects such as non-density, voids, or debonding in the entire concrete column, so that construction personnel can take corresponding measures in a timely manner.

[0130] The quality inspection of the steel-concrete composite column is carried out in multiple stages. The basic principle is to test one section before moving on to the next, until all sections are tested. The concrete inside the pipe is tested after the concrete is poured, according to the age of the concrete, generally at 3, 7, 14, 28, and 56 days, and even long-term monitoring is carried out. The testing component in this embodiment can meet the requirements of short-term or long-term testing operations, so that construction personnel can obtain sufficient test data before the steel-concrete composite column is used. When the testing component moves vertically downward for testing, the telescopic arm 8 of the testing vehicle 7 lowers the testing component. During testing, after the upper support arm 10 approaches the steel-concrete composite column, the first motor 25 starts, driving the drive gear 23 inside the upper support arm 10 to engage with the two toothed belts 22, so that the two movable arms 12 move circumferentially along the outer wall of the concrete column. It is important to note that when the clamping plate 17 moves outward to its limit position, the total arc length of the upper support arm 10 and the two movable arms 12 exceeds 180 degrees, which means that it can cover most of the outer wall of the steel-concrete composite column. The ultrasonic transducers 9 on the two clamping plates 17 are located at two bisecting points on the circumference of the clamping plate 17. The ultrasonic waves will be reflected and refracted on the steel-concrete composite column, and the presence of corresponding defects in the concrete can be judged by parameters such as ultrasonic wave velocity and waveform. Furthermore, the structure of the lower support arm 20 is the same as that of the upper support arm 10, the only difference being the location of its setting. From top to bottom, the frontal projections of the lower support arm 20 and the upper support arm 10 only partially overlap, and the movable arms 12 in the upper support arm 10 and the movable arms 12 in the lower support arm 20 extend outward one after the other.

[0131] After all the ultrasonic transducers 9 reach their preset positions, the second motor 16 and the fourth motor 29 begin to operate, driving the clamping plates 17 inside the first support block 15 and the second support block 18 to move outward simultaneously. This clamps the steel-concrete composite column at different heights and along different circumferential directions. Multiple flexible rollers 14 mounted on the inner walls of the clamping plates 17 reduce the impact between the clamping plates 17 and the outer walls of the steel-concrete composite column. The testing of the ultrasonic transducers 9 only begins after the movable arm 12 and the clamping plates 17 are in position. After the testing at that point is completed, the clamping plates 17 will adjust according to the corresponding drive equipment. The device is then reset. At this time, the lifting ring 11 on the upper support arm 10 is connected to the telescopic arm 8 of the testing vehicle 7 via a steel rope. When the steel rope is lowered by 30cm, the testing component moves down by the same amount. To increase the stability of the downward movement of the testing component, a counterweight can be set below the end of the movable arm 12 (at the point corresponding to the ultrasonic transducer 9), or ball bearings can be set on the inner walls of the upper support arm 10 and the lower support arm 20. After the testing component moves to the next testing point, the clamp 17 begins to extend outward rapidly to ensure the stability of the fixed-point testing. This process is repeated to complete the testing procedure from top to bottom.

[0132] After the detection component moves to the bottom of the steel-concrete composite column, the vertical upward detection process begins, and the corresponding length is retrieved by the steel rope, such as 20cm. The detection component then moves upward by the corresponding displacement of 20cm. The remaining actions are the same as when the detection component moves downward, until the detection component is reset to the top of the steel-concrete composite column 41.

[0133] Furthermore, the first cylinder 13, the second cylinder 26, and the third cylinder 27 not only enable the folding and unfolding of the detection components, but also change the distance between the upper support arm 10 and the lower support arm 20, thereby changing the detection coverage area of ​​the two sets of ultrasonic transducers 9.

[0134] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for reinforcing ribbed steel-concrete composite arch bridges, comprising: S1. Pour pile foundation concrete on the arch base (5). S2, Several rigid frames (4) are symmetrically set on both sides and then joined together; S3. Pour steel pipe concrete (41) inside the stiffening frame (4). S4. After the steel-concrete composite pipe (41) reaches the design strength, the arch ring concrete (42) is poured symmetrically from both sides until the closure is completed. The aforementioned symmetrical arrangement of several stiffening frames (4) on both sides includes: S21, the stiffening frame of each arch rib (4) is assembled in several segments for each half span; S22. Select a period of stable temperature to carry out instantaneous closure; The aforementioned selection of a stable temperature period for instantaneous closure includes: S221. Measure the linearity and internal forces of each segment; S222. If the internal force measurement value is within the preset range, the closure is officially completed. If the internal force measurement value exceeds the preset range, adjustments are made and then S221 is executed. The rigid frame (4) segment installation adopts symmetrical suspension splicing on both banks. Each half span of the rigid frame (4) of each arch rib is divided into several hoisting segments and a closure segment. Before closure, the gap length of each frame is measured and the gap between the frames is filled during a period when the temperature is relatively stable. The pile foundation concrete (5) is used to support the arch abutment foundation and for reinforcement. The reinforcement part includes the stiffening frame (4), the steel pipe concrete (41) inside the stiffening frame (4), and the arch ring concrete (42) outside the stiffening frame (4). The steel pipe concrete (41) is used to strengthen the stiffening frame (4) and make the stiffening frame (4) reach the design strength. The arch ring concrete (42) makes the stiffening frame (4) and the original arch ring form an integral whole.

2. The method for reinforcing ribbed steel-concrete composite arch bridges according to claim 1, wherein the concrete pile foundation (5) is poured on the arch abutment foundation, is characterized in that... include: S11, Embedded arch foundation embedded parts, so that the rigid frame (4) can be matched with the embedded parts; S12, Pouring the remaining concrete for the pile foundation; S13. A platform for reinforcing the main arch ring is erected under the bridge.

3. The method for reinforcing ribbed steel tube concrete arches based on ribbed arch bridges according to claim 1, wherein the symmetrical pouring of arch ring concrete from both banks (42) is characterized in that: Before pouring the concrete for the arch ring (42), several connecting bars are inserted into the arch bridge (2).

4. The method for reinforcing ribbed steel-concrete composite arch bridges according to claim 1, wherein the pouring of the steel-concrete composite (41) is characterized in that, include: C80 self-compacting concrete was used and pumped from the arch foot to the arch crown. The construction quality of steel-concrete composite (41) was inspected by ultrasonic geophysical testing.

5. The method for reinforcing ribbed steel-concrete composite arch bridges according to claim 4, wherein the pouring of the steel-concrete composite (41) is characterized in that, The specific methods for detecting the construction quality of steel-concrete composite (41) using ultrasonic geophysical testing are as follows: S1. Arrange the inspection vehicle (7) on the bridge deck (1) corresponding to the steel-concrete composite column. S2. The testing vehicle (7) places the testing component on the top outer wall of the steel pipe concrete column through its telescopic arm (8), and starts the testing component to locally clamp around the outer circumference of the steel pipe concrete column. S3. The detection component moves along the axial direction of the steel-concrete composite column towards its bottom, and the density of the steel-concrete composite column is detected every 30cm after the detection component moves. After the density of the concrete within a vertical height of 30cm is completed, the detection component continues to move down and repeats its detection procedure. S4. After the detection component moves to the bottom of the steel-concrete composite column, the detection component moves along the axial direction of the steel-concrete composite column towards its top. The detection component starts to detect the density of the steel-concrete composite column every 20cm. After the concrete density test within a vertical height of 20cm is completed, the detection component continues to move upward and repeats its detection procedure. S5. When the detection component returns to the top of the steel-concrete composite column, the detection component releases its clamp on the steel-concrete composite column and is retrieved by the telescopic arm (8), thus completing the detection process. The detection component includes an upper support arm (10) and a lower support arm (20) that are hollow inside and have a slight arc shape. A lifting ring (11) is provided in the middle of the upper surface of the upper support arm (10), a first motor (25) is provided in the middle of the lower surface of the upper support arm (10), and a third motor (28) is provided upside down in the middle of the upper surface of the lower support arm (20). It also includes a first support block (15) and a second support block (18) that are hollow inside and have a slight arc shape. A first cylinder (13) is provided on the upper surface of the first support block (15). The output end of the first cylinder (13) is connected to the body of the first motor (25). A second motor (16) is provided in the middle of the lower surface of the first support block (15). A fourth motor (29) is provided upside down in the middle of the upper surface of the second support block (18). A second cylinder (26) is connected between the body of the second motor (16) and the body of the fourth motor (29). The output end of the second cylinder (26) is connected to the body of the second motor (16). A third cylinder (27) is provided upside down on the lower surface of the second support block (18). The output end of the third cylinder (27) is connected to the body of the third motor (28). From top to bottom, the forward projections of the upper support arm (10), the lower support arm (20), the first support block (15), and the second support block (18) are located on the same circumference, and the forward projection of the upper support arm (10) after rotating around its center by a specified angle can successively coincide with the forward projections of the lower support arm (20), the first support block (15), and the second support block (18); At the ends of the upper support arm (10) and the lower support arm (20), movable arms (12) in the shape of a slight arc are slidably provided. At the ends of the first support block (15) and the second support block (18), clamping plates (17) in the shape of a slight arc are slidably provided. Flexible rollers (14) are provided at intervals on the inner sidewall of each clamping plate (17). Openings (19) for the flexible rollers (14) to pass through are opened on the inner sidewall of the first support block (15) and the second support block (18). Each clamping plate (17) is provided with an ultrasonic transducer (9) at its end. Multiple ultrasonic transducers (9) are electrically connected to the first motor (25), the second motor (16), the third motor (28), the fourth motor (29), the first cylinder (13), the second cylinder (26), and the third cylinder (27) through a controller. Furthermore, on the opposite end faces of the two movable arms (12) and two clamping plates (17) located on the upper support arm (10), lower support arm (20), first support block (15), and second support block (18) respectively, there are corresponding arc-shaped inner guard plate (24) and outer guard plate (21). A gap is left between the outer guard plate (21) and the inner guard plate (24). The inner wall of the outer guard plate (21) and the outer wall of the inner guard plate are both provided with toothed strips (22), and a toothed strip is provided in the gap that simultaneously interacts with the toothed strip. Two toothed belts (22) mesh with drive gears (23); wherein, the drive gear (23) in the upper support arm (10) is connected to the output end of the first motor (25), the drive gear (23) in the lower support arm (20) is connected to the output end of the third motor (28), the drive gear (23) in the first support block (15) is connected to the output end of the second motor (16), and the drive gear (23) in the second support block (18) is connected to the output end of the fourth motor (29).

6. The method for reinforcing ribbed steel-concrete composite arch bridges according to claim 1, characterized in that: The pile foundation concrete (5), steel pipe concrete (41) and arch ring concrete (42) all include pure silicate cement and mineral admixtures as cementing materials.

7. A method for reinforcing ribbed steel-concrete composite arch bridges according to claim 6, characterized in that: The mineral admixtures include fly ash plus silica fume or ground slag plus silica fume.

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