Active cross brace control device for inclined bridge tower construction

Abstract

The utility model discloses an active cross brace control device for inclined bridge tower construction, which comprises a steel wedge block, a servo component, a cross brace steel pipe and a steel connecting piece, one end of the transverse supporting steel pipe is connected with the inner side of one tower column of the inclined bridge tower through a steel connecting piece, the other end of the transverse supporting steel pipe abuts against the inner side of the other tower column of the inclined bridge tower through a servo assembly and a steel wedge block, and the servo assembly comprises a front end plate, a rear end plate, a steel frame, a servo jack, a locking mechanism and a base. The bottom side of the steel frame is installed on the base, the rear end plate is connected with the rear side of the steel frame and the base, a base of the servo jack is installed in the steel frame and connected with the steel frame and the rear end plate, the hydraulic rod extends out of the steel frame and is connected with the front end plate, and the two locking mechanisms are arranged on the two sides of the servo jack respectively. The locking mechanism comprises a locking screw and a locking nut. The utility model has the advantage that the safety and the stability of the bridge tower structure are ensured.

Description

Technical Field

[0001] This utility model relates to the technical field of inclined bridge towers, and in particular to an active cross bracing control device for the construction of inclined bridge towers. Background Technology

[0002] Cable-stayed bridges, as a long-span bridge structural system, are challenging to construct and require stringent monitoring during construction. The bridge towers are a crucial component of cable-stayed bridges, and their construction quality and stress state have a decisive impact on the bridge's safety. Especially for cable-stayed bridges employing multi-limbed symmetrical inclined towers (such as A-type towers or tripod towers), the towers, during segment-by-segment construction, experience inward tilting forces due to their own weight and construction loads. This leads to significant bending moments at the tower base, which in turn generate substantial tensile stress on the outer side of the tower base, increasing the risk of cracking and overturning.

[0003] To effectively balance these horizontal forces, eliminate adverse stress states in the inclined tower column concrete, control lateral displacement at the top of the tower column, and improve construction stability, horizontal transverse bracing is typically installed between the tower segments. Traditional active transverse bracing construction methods involve pre-embedding connectors during tower segment construction. After segment construction is completed, connecting steel plates are installed and the transverse bracing is fixed. The active force of the transverse bracing is applied via an external hydraulic jack at one end. After loading, steel wedges are used to tighten the transverse bracing and the connecting steel plate of the tower column, and after welding and fixing, the jacks are unloaded.

[0004] However, traditional active cross bracing methods have limitations. First, due to factors such as welding deformation and tightness of local gaps in the cross bracing connections, the active force of the cross bracing often decays rapidly and is damaged after installation, causing the main force of the cross bracing to deviate from the design value. Furthermore, the active force of traditional active cross bracing is unadjustable after installation. This not only affects the stability of the bridge tower but also jeopardizes the safety of bridge tower construction.

[0005] Secondly, as construction progresses, the self-weight of the post-cast tower segments, construction loads, and additional loads such as weld deformation, wind loads, annual temperature differences, and solar radiation temperature differences cause the active force of the cross braces to be excessively large, insufficient, or asymmetrical compared to the design value for this construction stage. Therefore, an active cross brace control device is needed for inclined bridge tower construction to ensure that the active force of the cross braces remains within the design requirements and to address the stress and deformation problems in the bridge tower caused by the asymmetry of the active forces of the two cross braces. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of the prior art by providing an active cross bracing control device for the construction of inclined bridge towers. This active cross bracing control device consists of a steel wedge, a servo component, a cross bracing steel pipe, and a steel connector. One end of the cross bracing steel pipe is connected to the inner side of one tower column of the inclined bridge tower via the steel connector, and the other end is pressed against the inner side of another tower column of the inclined bridge tower via the servo component and the steel wedge. The active force of the active cross bracing control device is adjusted in real time to ensure that it always meets the design value requirements, and it can effectively adjust the problem of asymmetry in the active forces of the two active cross bracing control devices.

[0007] The objective of this utility model is achieved through the following technical solution:

[0008] An active cross bracing control device for the construction of tilted bridge towers includes a steel wedge, a servo component, a cross bracing steel pipe, and a steel connector. One end of the cross bracing steel pipe is connected to the inner side of one tower column of the tilted bridge tower via the steel connector, and the other end is pressed against the inner side of another tower column of the tilted bridge tower via the servo component and the steel wedge. The servo component includes a front end plate, a rear end plate, a steel frame, a servo jack, a locking mechanism, and a base. The steel frame is a box-shaped structure with openings on the bottom and rear sides. The bottom side of the steel frame is mounted on the base, and the rear end plate is connected to the steel frame. The servo jack is connected to the rear side and the base. The base of the servo jack is installed inside the steel frame and connected to the steel frame and the rear end plate. The hydraulic rod extends to the outside of the steel frame and is connected to the front end plate. There are two locking mechanisms, which are respectively located on both sides of the servo jack. Each locking mechanism includes a locking screw and a locking nut. One end of the locking screw is connected to the front end plate, and the other end extends into the steel frame. The locking nut is installed on the locking screw and located outside the steel frame. The locking screw is locked to the steel frame by the locking nut.

[0009] A working platform is provided below each end of the cross bracing steel pipe. The base of the servo component and the steel wedge are placed on the placement platform. The steel connector, the placement platform and the working platform are all connected to the embedded parts respectively.

[0010] The embedded parts include anchor rods and anchor plates. One end of the anchor rod extends into the tower column of the inclined bridge tower, and the other end is connected and fixed to the anchor plate.

[0011] The steel connector, the placement platform, and the working platform are all connected to the anchor plate, and the placement platform and the anchor plate are connected by steel supports.

[0012] A temperature detector is installed on the cross bracing steel pipe.

[0013] The servo jack is driven by a wireless servo oil pump, which is installed on the tower column of the tilted bridge tower.

[0014] Both the temperature detector and the wireless servo oil pump are connected to the monitoring system.

[0015] The front-end board and the servo jack are connected by a frustum.

[0016] The rear end plate and the cross brace steel pipe are connected by a flange.

[0017] The advantages of this utility model are:

[0018] (1) By introducing a monitoring system, the active force of the cross bracing can be monitored and dynamically adjusted in real time, thus upgrading the traditional active cross bracing to an adjustable active cross bracing. This greatly improves the functionality of the active cross bracing, effectively avoids the problem of main force attenuation or over-limit due to external factors, and ensures the safety and stability of the bridge tower structure.

[0019] (2) By adopting the symmetry ratio and continuous 24-hour statistical analysis method, and taking into account the real-time temperature effect correction, the over-limit and asymmetry of the active force of the double cross bracing can be accurately identified and adjusted, which can effectively improve the safety, construction efficiency and the accuracy of the final bridge alignment during the bridge tower construction stage, and has practical engineering application value. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the installation of the active cross brace control device of this utility model;

[0021] Figure 2 This is a frontal view of the servo component of this utility model;

[0022] Figure 3 This is a plan view of the servo component of this utility model;

[0023] Figure 4 This is a schematic diagram of the installation of the active cross brace control device of this utility model with a servo component end.

[0024] Figure 5 This is a schematic diagram of the installation of the active cross brace control device of this utility model without servo components.

[0025] Figure 6 This is a flowchart illustrating the overall control and adjustment method of the active cross brace control device of this utility model.

[0026] like Figures 1-6 As shown in the figure, the markings represent:

[0027] 10 steel wedge, 20 servo component, 201 front end plate, 202 rear end plate, 203 steel frame, 204 servo jack, 205 locking mechanism, 2051 locking screw, 2052 locking nut, 206 base, 30 cross brace steel pipe, 40 steel connector, 50 temperature detector, 60 wireless servo oil pump, 70 tilted bridge tower, 701 tower column, 80 embedded part, 801 anchor bolt, 802 anchor plate, 90 placement platform, 100 working platform, 110 steel support, 120 lower crossbeam. Detailed Implementation

[0028] The features and other related features of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments, so as to facilitate the understanding of those skilled in the art:

[0029] Example: Figures 1-5As shown, this embodiment relates to an active cross bracing control device for the construction of inclined bridge towers. A lower crossbeam 120 is provided on the inner side of the bottom of the tower column 701 of the inclined bridge tower 70. Two active cross bracing control devices are located on the inner side of the middle of the tower column 701 of the inclined bridge tower 70, on the horizontal plane. The active cross bracing control device mainly includes a steel wedge 10, a servo component 20, a cross bracing steel pipe 30, a steel connector 40, a temperature detector 50, a wireless servo oil pump 60, and a monitoring system. One end of the cross bracing steel pipe 30 is connected to the inner side of one tower column 701 of the inclined bridge tower 70 via the steel connector 40, and the other end is pressed against the inner side of another tower column 701 of the inclined bridge tower 70 via the servo component 20 and the steel wedge 10. The cross bracing steel pipe 30 is connected to the steel wedge 10 via the servo component 20, and the steel wedge 10 is pressed against the inner side of the tower column 701. The servo assembly 20 includes a front-end plate 201, a rear-end plate 202, a steel frame 203, a servo jack 204, a locking mechanism 205, and a base 206. The steel frame 203 is a box-shaped structure with openings on the bottom and rear sides. The bottom side of the steel frame 203 is mounted on the base 206. The rear-end plate 202 is connected to the rear side of the steel frame 203 and the base 206. The rear-end plate 202 is connected to the cross brace steel pipe 30 via a flange. The base of the servo jack 204 is installed inside the steel frame 203 and is connected to the steel frame 203 and the rear-end plate 202. The hydraulic rod extends to the outside of the steel frame 203 and is connected to the front-end plate 201, used to transmit the pushing force of the servo jack 204 to the cross brace steel pipe 30. Two locking mechanisms 205 are provided, and the two locking mechanisms 205 are respectively located on both sides of the servo jack 204. The locking mechanism 205 includes a locking screw 2051 and a locking nut 2052. One end of the locking screw 2051 is connected to the front end plate 201, and the other end extends into the steel frame 203. The steel frame 203 has a through hole that allows the locking screw 2051 to pass through. The locking nut 2052 is installed on the locking screw 2051 and located outside the steel frame 203. The locking screw 2051 is locked to the steel frame 203 by the locking nut 2052. The locking mechanism 205 is used as a protective measure in case of sudden pressure relief or sudden increase in displacement of the servo jack 204. The front end plate 201 is connected to the servo jack 204 through a frustum, which is used to transmit the jacking force of the servo jack 204 to the steel wedge block 10 and can adapt to a certain degree of angular deformation. Temperature detector 50 is attached to the cross brace steel pipe 30 to measure its temperature for practical correction. Servo jack 204 is driven by wireless servo oil pump 60, which is mounted on the tower column 701 of the inclined bridge tower 70. Both temperature detector 50 and wireless servo oil pump 60 are connected to a monitoring system to monitor the temperature of the cross brace steel pipe 30, as well as its main force and displacement.

[0030] like Figures 1-5As shown, a working platform 100 is provided below each end of the cross bracing steel pipe 30. The base 206 of the servo component 20 and the steel wedge block 10 are placed on the placement platform 90. The steel connector 40, the placement platform 90, and the working platform 100 are all connected to the embedded part 80. The embedded part 80 includes an anchor rod 801 and an anchor plate 802. One end of the anchor rod 801 extends into the tower column 71 of the inclined bridge tower 70, and the other end is connected and fixed to the anchor plate 802. The steel connector 40, the placement platform 90, and the working platform 100 are all connected to the anchor plate 802. The placement platform 90 and the anchor plate 802, as well as the working platform 100 and the anchor plate 802, are connected by steel supports 110.

[0031] like Figures 1-6 As shown, this embodiment also includes an active cross bracing control and adjustment method for inclined bridge tower construction, comprising the following steps:

[0032] S1: Install an active cross brace control device (active cross brace) on the inclined bridge tower 70 and load the active force of the active cross brace control device to the design value.

[0033] The installation method of the active cross brace control device is as follows:

[0034] S1.1: Embedded part arrangement: During the construction of tower column 701, embedded part 80 is installed, working platform 100 and placement platform 90 are set up, and steel connector 40 is installed on embedded part 80.

[0035] S1.2: Component connection: Connect the rear end plate 202 of the servo component 20 to one side of the cross brace steel pipe 30 on the ground to ensure that the axes of the servo component 20 and the cross brace steel pipe 30 are aligned.

[0036] S1.3: Lifting and positioning: Lift the cross bracing steel pipe 30 and the servo component 20 as a whole to the installation position of the active cross bracing control device. After adjusting the position, weld the steel wedge block 10 and the front end plate 201, and tighten the locking nut 2052 to complete the connection. At this time, the steel wedge block 10 is attached to the inside of the tower column 701.

[0037] S1.4: Temperature detector installation: Install temperature detector 50 on the surface of cross brace steel pipe 30.

[0038] S1.5: Apply initial active force: Apply the active force to the design value through the servo jack 204.

[0039] S2: Monitor the active force of the active cross brace control device.

[0040] S2.1: Real-time data acquisition:

[0041] The monitoring system continuously monitors the active force, displacement, and temperature of the active cross brace control device and stores hourly data as a statistical basis.

[0042] S2.2: Dynamically correct the design value of the active force of the active cross brace control device.

[0043] The dynamic correction method for the active force design value of the active cross brace control device is as follows:

[0044] During the construction of cable-stayed bridges, the design value of the active force of the active cross brace control device needs to be dynamically adjusted to adapt to load changes, environmental temperature effects, and other additional loads during the construction phase. The hourly active force and temperature of the active cross brace control device over a 24-hour period are used as the basis for calibrating and judging the active force of the active cross brace control device. The corrected design value of the active force F of the active cross brace control device is then determined. d,t,i It can be calculated using the following formula:

[0045] F d,t,i =f(t,S,L)+ΔF T,i +ΔF L ;

[0046] In the formula, f(t,S,L) is the design value of the active force foundation of the active cross brace control device during the construction stage without considering temperature load. It is mainly used to describe the influence of the construction stage on the active force of the active cross brace control device. This function is determined based on finite element analysis (FEA) and actual construction load; t is the construction stage, representing the construction progress; i is the i-th hour in a continuous 24 hours; S is the construction load, including the self-weight of subsequent tower segments and construction load; L is the change of constraint conditions, considering the effect of the tower, the installed active cross brace control device, and the support constraint.

[0047] ΔF T,i The temperature effect correction value is given by the following formula:

[0048] ΔF T,i =f(t,S,L=EAα) T ΔT i );

[0049] In the formula, E is the elastic modulus of the cross bracing steel pipe; A is the cross-sectional area of ​​the cross bracing steel pipe; α T ΔT is the coefficient of linear expansion of the cross bracing steel pipe. i The difference between the monitored temperature in the i-th hour and the initial installation temperature;

[0050] ΔF L Other additional load correction values, including wind load, solar radiation difference, and tower settlement, can be obtained by combining engineering experience or measured data with the construction load and support conditions in f(t,S,L).

[0051] S2.3: Determine if the resultant force of the active forces of the two active cross brace control devices exceeds the limit.

[0052] The method for determining the over-limit of the resultant force of the two active cross brace control devices is as follows:

[0053] The formula for calculating the resultant force of the active forces of the two active cross brace control devices is:

[0054]

[0055] In the formula, and These are the monitoring values ​​of the two active cross brace control devices in the i-th hour during a continuous 24-hour monitoring cycle;

[0056] The criteria for determining whether the resultant force of the main driving force exceeds the limit during a continuous 24-hour monitoring period are as follows:

[0057] a. F ​​per hour A,i Does it meet the following conditions:

[0058] F A,i >(1+K U )F d,t,i or F A,i <(1-K D )F d,t,i ;

[0059] In the formula, K U The overload coefficient of the active cross brace control device can be taken as 0.4; K D The load factor of the active cross brace control device can be taken as 0.2; the overload factor and load factor take into account the allowable error requirements of the construction specifications; in addition, the adjustment method of the monitoring system in case of overload is unloading, so the risk of unloading is reduced, and the safety factor index of overload is increased accordingly.

[0060] b. Count the number of hours j within 24 hours that meet the exceeding condition; if the following formula is met, then the resultant force is determined to exceed the limit:

[0061]

[0062] S2.4: Determine the symmetry of the active forces of the two active cross brace control devices.

[0063] The method for determining the symmetry of the active forces of the two active cross brace control devices is as follows:

[0064] Symmetry calibration is performed by calculating the symmetry ratio R using hourly data over a continuous 24-hour period.

[0065]

[0066] The design target value for R is 1.0 to 1.2; if R i >1.4 indicates that there is a significant asymmetry in the active force of the two active cross brace control devices;

[0067] If the following conditions are met when statistically analyzing data over a continuous 24-hour period, a symmetry problem is considered to exist;

[0068]

[0069] In the formula, 1(R) i >1.4) is an indicator function, when R i The value is 1 when it is greater than 1.4, and 0 otherwise.

[0070] S3: Adjust the active force of the active cross brace control device.

[0071] If it is determined that the combined force of the two active cross bracing control devices exceeds the limit or that there is a symmetry problem in the active forces of the two active cross bracing control devices, dynamic adjustments will be made through the monitoring system.

[0072] The method for adjusting the active force of the active cross brace control device is as follows:

[0073] A staged loading method (number of stages: n) is adopted to gradually adjust the main force to the design value, with each stage loading value ΔF. g The following formula can be used to calculate the value, which should then be rounded to a multiple of 5t:

[0074]

[0075] During the adjustment process, real-time data needs to be monitored and the monitoring data of the monitoring system needs to be analyzed. When the active force of the active cross brace control device approaches the design value, the pressure level difference should be appropriately reduced to gradually approach the target value.

[0076] The adjustment can only be terminated after the following conditions are met:

[0077] 1. The main power is close to the design value:

[0078] |F d,t,i -F A,i |<0.1F d,t,i ;

[0079] 2. Symmetry satisfies the target value:

[0080] R i ≤1.2;

[0081] 3. Monitor the active cross bracing control device's active force or the stress state of the tilted bridge tower to determine the adjustment effect.

[0082] The beneficial technical effects of this embodiment are as follows:

[0083] (1) Solved the problem of active cross bracing loss:

[0084] In traditional active cross bracing construction, the active force relies on hydraulic jacks for application and fixation. Affected by factors such as welding deformation, gap tightening error and steel component relaxation effect, the active force of the cross bracing decays rapidly in a short period of time, making it impossible to maintain the design value. This loss of active force not only affects the overall stiffness of the bridge tower, but may also lead to the risk of cracking or uncontrolled deformation of the tower column due to insufficient balance of inclination force.

[0085] (2) Solved the problem of the inability to adjust the main power in real time:

[0086] Once the traditional cross bracing system is installed, if the active force changes, it cannot be compensated or corrected by the adjustment device. During construction, due to the dynamic changes in external factors such as the self-weight of the tower column, construction load, and ambient temperature, the active force of the cross bracing will continuously deviate from the design value. There may also be asymmetry in the active force of the cross bracing on the left and right sides, which will lead to uneven pressure on the tower column, abnormal stress distribution, and affect the stability and vertical alignment control during the construction of the bridge tower.

[0087] (3) Solved the problem of insufficient remote monitoring and adjustment:

[0088] Currently, most cross bracing systems are passively designed and lack intelligent monitoring and remote adjustment functions. Construction units cannot keep track of the main force status of the cross bracing in real time or adjust the main force that does not meet the design requirements in a timely manner, which increases construction risks and on-site management complexity.

[0089] Although the above embodiments have described the concept and embodiments of the present invention in detail with reference to the accompanying drawings, those skilled in the art will recognize that various improvements and modifications can still be made to the present invention without departing from the scope of the claims, and therefore will not be elaborated here.

Claims

1. An active cross brace control device for construction of inclined bridge towers, characterized in that: The active cross bracing control device includes a steel wedge, a servo component, a cross bracing steel pipe, and a steel connector. One end of the cross bracing steel pipe is connected to the inner side of one tower column of the inclined bridge tower via the steel connector, and the other end is pressed against the inner side of another tower column of the inclined bridge tower via the servo component and the steel wedge. The servo component includes a front end plate, a rear end plate, a steel frame, a servo jack, a locking mechanism, and a base. The steel frame is a box-shaped structure with openings on the bottom and rear sides. The bottom side of the steel frame is mounted on the base, and the rear end plate is connected to the rear side of the steel frame and the base. Next, the base of the servo jack is installed inside the steel frame and connected to the steel frame and the rear end plate. The hydraulic rod extends to the outside of the steel frame and is connected to the front end plate. There are two locking mechanisms, which are respectively located on both sides of the servo jack. Each locking mechanism includes a locking screw and a locking nut. One end of the locking screw is connected to the front end plate, and the other end extends into the steel frame. The locking nut is installed on the locking screw and located outside the steel frame. The locking screw is locked to the steel frame by the locking nut.

2. The active cross bracing control device for construction of inclined bridge towers as described in claim 1, characterized in that: A working platform is provided below each end of the cross bracing steel pipe. The base of the servo component and the steel wedge are placed on the placement platform. The steel connector, the placement platform and the working platform are all connected to the embedded parts respectively.

3. The active cross bracing control device for construction of inclined bridge towers as described in claim 2, characterized in that: The embedded parts include anchor rods and anchor plates. One end of the anchor rod extends into the tower column of the inclined bridge tower, and the other end is connected and fixed to the anchor plate.

4. The active cross bracing control device for construction of inclined bridge towers as described in claim 3, characterized in that: The steel connector, the placement platform, and the working platform are all connected to the anchor plate, and the placement platform and the anchor plate are connected by steel supports.

5. The active cross bracing control device for construction of inclined bridge towers as described in claim 1, characterized in that: A temperature detector is installed on the cross bracing steel pipe.

6. The active cross bracing control device for construction of inclined bridge towers as described in claim 5, characterized in that: The servo jack is driven by a wireless servo oil pump, which is installed on the tower column of the tilted bridge tower.

7. The active cross bracing control device for construction of inclined bridge towers as described in claim 6, characterized in that: Both the temperature detector and the wireless servo oil pump are connected to the monitoring system.

8. The active cross bracing control device for construction of inclined bridge towers as described in claim 1, characterized in that: The front-end board and the servo jack are connected by a frustum.

9. The active cross bracing control device for construction of inclined bridge towers as described in claim 1, characterized in that: The rear end plate and the cross brace steel pipe are connected by a flange.

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