Active cross brace control and adjustment method for inclined bridge tower construction

Abstract

The invention discloses an active cross brace control and adjustment method for inclined bridge tower construction, and the method comprises the steps: S1, installing an active cross brace control device on an inclined bridge tower, and loading the active force of the active cross brace control device to a design value; s2, monitoring the active force of the active cross arm control device; s3, adjusting the active force of the active cross arm control device; wherein if it is judged that the resultant force of the main power of the two active cross arm control devices exceeds the limit or the main power of the two active cross arm control devices has the symmetry problem, dynamic adjustment is conducted through the monitoring system. The method has the advantages that real-time monitoring and dynamic adjustment of the active force of the cross arm are achieved by introducing the monitoring system, a traditional active cross arm is upgraded to be an adjustable active cross arm, the functionality of the active cross arm is greatly improved, the problem of active force attenuation or over-limit caused by external factors is effectively avoided, and the safety and stability of a bridge tower structure are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of inclined bridge towers, and in particular to an active cross brace control and adjustment method for the construction of inclined bridge towers. Background Art

[0002] As a large-span bridge structure system, the cable-stayed bridge has great construction difficulty and strict monitoring requirements during the construction process. The bridge tower is a key component of the cable-stayed bridge, and its construction quality and stress state have a decisive impact on the safety of the bridge. Especially for cable-stayed bridges with multi-limb symmetrically inclined tower columns (such as A-type bridge towers or tripod-type bridge towers), when the tower columns are constructed upward section by section, due to the action of self-weight and construction loads, an inward force will be generated, resulting in a large bending moment at the root of the tower column, and then a large tensile stress will be generated on the outer side of the root of the tower column, increasing the risk of cracking and overturning.

[0003] In order to effectively balance these horizontal component forces, eliminate the adverse stress state of the concrete of the inclined tower column, control the lateral displacement at the top of the tower column, and improve the construction stability, horizontal transverse supports are usually provided between the tower limbs. The traditional active cross brace construction method pre-buries connecting parts during the construction of the tower column section. After the section construction is completed, a connecting steel plate is installed and the cross brace is fixed. The active force of the cross brace is applied by an external hydraulic jack at one end. After loading, a steel wedge block is used to tightly wedge the cross brace and the tower column connecting steel plate, and after welding and fixing, the jack is unloaded.

[0004] However, the traditional active cross brace method has limitations. First, due to factors such as the welding deformation of the cross brace connection and the local clearance wedging, the active force of the cross brace often rapidly decays and is damaged after installation, resulting in a deviation between the active force of the cross brace and the design value. And the active force of the traditional active cross brace is not adjustable after installation. This not only affects the stability of the bridge tower, but also endangers the construction safety of the bridge tower.

[0005] Secondly, with the progress of the construction, affected by the self-weight and construction loads of the post-cast sections of the tower column, as well as additional loads such as weld deformation, wind load, annual temperature difference, and solar radiation temperature difference, problems such as being too large, too small, or the asymmetry of the active forces of the double cross braces occur when comparing the active force of the cross brace with the design value of this construction stage. Therefore, an active cross brace control and adjustment method for the construction of inclined bridge towers is needed to ensure that the active force of the cross brace is always within the design requirements and solve the problems of bridge tower stress and deformation caused by the asymmetry of the active forces of the double cross braces. Summary of the Invention

[0006] The object of the present invention is to provide an active cross brace control and adjustment method for the construction of an inclined bridge tower according to the deficiencies of the above-mentioned prior art. This method utilizes an active cross brace control device, which is composed of a steel wedge block, a servo assembly, a cross brace steel pipe, and a steel connector. One end of the cross brace steel pipe is connected to the inner side of one tower column of the inclined bridge tower through the steel connector, and the other end is tightly abutted against the inner side of the other tower column of the inclined bridge tower through the servo assembly and the steel wedge block. The active force of the active cross brace control device is adjusted in real time to always meet the design value requirements, and the problem of asymmetry of the active forces of the two active cross brace control devices can be effectively adjusted.

[0007] The object of the present invention is achieved by the following technical solutions:

[0008] An active cross brace control and adjustment method for the construction of an inclined bridge tower, the method comprising:

[0009] S1: Install an active cross brace control device on the inclined bridge tower and load the active force of the active cross brace control device to the design value;

[0010] Wherein, the active cross brace control device is arranged on the tower column of the inclined bridge tower and there are two on the horizontal plane. The active cross brace control device includes a steel wedge block, a servo assembly, a cross brace steel pipe, and a steel connector. One end of the cross brace steel pipe is connected to the inner side of one tower column of the inclined bridge tower through the steel connector, and the other end is tightly abutted against the inner side of the other tower column of the inclined bridge tower through the servo assembly and the steel wedge block. The servo assembly 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 an open bottom side and a rear side. The bottom side of the steel frame is installed on the base. The rear end plate is connected to the rear side of the steel frame and the base. The base of the servo jack is installed inside the steel frame and is connected to the steel frame and the rear end plate. The hydraulic rod extends outside the steel frame and is connected to the front end plate. There are two locking mechanisms, and the two locking mechanisms are respectively arranged on both sides of the servo jack. The 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 is arranged outside the steel frame. The locking screw is locked to the steel frame through the locking nut. A working platform is provided below each end of the cross brace steel pipe. The base of the servo assembly and the steel wedge block are both placed on the placement platform. The steel connector, the placement platform, and the working platform are all respectively connected to the embedded parts. A temperature detector is installed on the cross brace steel pipe. The servo jack is driven by a wireless servo oil pump, and the wireless servo oil pump is installed on the tower column of the inclined bridge tower. The temperature detector and the wireless servo oil pump are both respectively connected to the monitoring system;

[0011] S2: Monitor the active force of the active cross brace control device;

[0012] S2.1: Continuously monitor the active force, displacement, and temperature of the active cross brace control device through the monitoring system, and store the hourly data as a statistical basis;

[0013] S2.2: Dynamically correct the design value of the active force of the active cross brace control device;

[0014] S2.3: Determine whether the resultant force of the active forces of the two active cross brace control devices exceeds the limit;

[0015] S2.4: Determine the symmetry of the active forces of the two active cross brace control devices;

[0016] S3: Adjust the active force of the active cross brace control device;

[0017] Among them, if it is determined that the resultant force of the active forces of the two active cross brace control devices exceeds the limit or there is a symmetry problem with the active forces of the two active cross brace control devices, dynamic adjustment is performed through the monitoring system.

[0018] The embedded part includes an anchor rod and an anchor plate. One end of the anchor rod extends into the tower column of the inclined bridge tower, and the other end is fixedly connected to the anchor plate.

[0019] The steel connector, the placement platform, and the working platform are respectively connected to the anchor plate, and the placement platform and the anchor plate as well as the working platform and the anchor plate are connected by steel supports.

[0020] The front end plate and the servo jack are connected by a frustum.

[0021] The rear end plate and the cross brace steel pipe are flange-connected.

[0022] In step S1, the installation method of the active cross brace control device is as follows:

[0023] S1.1: During the construction of the tower column, install the embedded part, set up the working platform and the placement platform, and install the steel connector on the embedded part;

[0024] S1.2: Connect the rear end plate of the servo component and one side of the cross brace steel pipe on the ground to ensure that the axes of the servo component and the cross brace steel pipe are aligned;

[0025] S1.3: Hoist the cross-bracing steel pipe and the servo assembly as a whole to the installation position of the active cross-bracing control device. After adjusting the position, weld the steel wedge block and the front end plate, and tighten the locking nut to complete the connection. At this time, the steel wedge block is attached to the inner side of the tower column;

[0026] S1.4: Install the temperature detector on the surface of the cross-bracing steel pipe;

[0027] S1.5: Apply the active force through the servo jack to the design value.

[0028] In step S2.2, the dynamic correction method for the design value of the active force of the active cross-bracing control device is as follows:

[0029] Take the active force and temperature of the active cross-bracing control device per hour within 24 hours as the basis for calibrating and determining the active force of the active cross-bracing control device. The corrected design value F of the active force of the active cross-bracing control device d,t,i can be calculated according to the following formula:

[0030] F d,t,i = f(t, S, L)+ΔF T,i +ΔF L ;

[0031] In the formula, f(t, S, L) is the basic design value of the active force of the active cross-bracing control device in the construction stage without considering the temperature load; t is the construction stage, indicating the construction progress; i is the i-th hour in 24 consecutive hours; S is the construction load, including the self-weight of the subsequent tower column segments and the construction load; L is the change in the constraint conditions;

[0032] ΔF T,i is the temperature effect correction value, which is given by the following formula:

[0033] ΔF T,i = f(t, S, L = EAα T ΔT i );

[0034] 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 is the linear expansion coefficient of the cross-bracing steel pipe; ΔT i is the difference between the monitored temperature in the i-th hour and the initial installation temperature;

[0035] ΔF L is the correction value for other additional loads, including wind load, sunshine difference, and tower column settlement, which can be obtained by combining engineering experience or measured data into the construction load and support conditions in f(t, S, L).

[0036] In step S2.3, the method for determining whether the resultant force of the driving forces of the two active cross bracing control devices exceeds the limit is as follows:

[0037] The formula for calculating the resultant force of the driving forces of the two active cross bracing control devices is:

[0038]

[0039] In the formula, and are the monitoring values of the two active cross bracing control devices at the i-th hour within a continuous 24-hour monitoring period, respectively;

[0040] Within a continuous 24-hour monitoring period, the criteria for determining that the resultant driving force exceeds the limit are:

[0041] a. Whether F per hour A,i meets the following conditions:

[0042] F A,i >(1 + K U )F d,t,i or F A,i <(1 - K D )F d,t,i ;

[0043] In the formula, K U is the overload coefficient of the driving force of the active cross bracing control device, which can be taken as 0.4; K D is the load coefficient of the driving force of the active cross bracing control device, which can be taken as 0.2;

[0044] b. Count the number of hours j that meet the over-limit conditions within 24 hours; if the following formula is satisfied, it is determined that the resultant force exceeds the limit:

[0045]

[0046] In step S2.4, the method for determining the symmetry of the driving forces of the two active cross bracing control devices is as follows:

[0047] Symmetry calibration is determined by calculating the symmetry ratio R based on the data for each hour within 24 hours:

[0048]

[0049] The designed target value of R is from 1.0 to 1.2; if R i > 1.4, it indicates that there is a significant asymmetry in the driving forces of the two active cross bracing control devices;

[0050] For the statistics of the data within 24 hours, if the following conditions are met, it is determined that there is a symmetry problem;

[0051]

[0052] In the formula, 1(R i >1.4) is an indicator function, which takes the value of 1 when R i >1.4, and 0 otherwise.

[0053] In step S3, the active force adjustment method of the active cross brace control device is as follows:

[0054] Adopt a hierarchical loading method to gradually adjust the active force to the design value. Each level of loading value ΔF g can be calculated according to the following formula, and the calculated value is rounded to a multiple of 5t to obtain:

[0055]

[0056] During the adjustment process, real-time data needs to be monitored, and the monitoring data of the monitoring system is analyzed. When the active force of the active cross brace control device is close to the design value, the pressure step difference should be appropriately reduced to gradually approach the target value;

[0057] After the adjustment is completed, the following conditions need to be met to terminate:

[0058] 1. The active force is close to the design value:

[0059] |F d,t,i -F A,i |<0.1F d,t,i ;

[0060] 2. The symmetry meets the target value:

[0061] R i ≤1.2;

[0062] 3. Monitor the active force of the active cross brace control device or the stress state of the inclined pylon to judge the adjustment effect.

[0063] The advantages of the present invention are:

[0064] (1) By introducing a monitoring system, the real-time monitoring and dynamic adjustment of the active force of the cross brace are realized, upgrading the traditional active cross brace to an adjustable active cross brace, greatly improving the functionality of the active cross brace, effectively avoiding the problems of active force attenuation or overlimit caused by external factors, and ensuring the safety and stability of the pylon structure;

[0065] (2) Adopting the symmetry ratio and continuous 24-hour statistical analysis method, and considering the real-time temperature effect correction at the same time, accurately identifying and adjusting the overlimit and asymmetry of the active forces of the double cross braces, which can effectively improve the safety, construction efficiency and the accuracy of the final bridge alignment during the pylon construction stage, and has practical engineering application value. Description of the Drawings

[0066] Figure 1 Installation schematic diagram of the active cross-brace control device of the present invention;

[0067] Figure 2 Elevation schematic diagram of the servo component of the present invention;

[0068] Figure 3 Planar schematic diagram of the servo component of the present invention;

[0069] Figure 4 Installation schematic diagram of the end of the active cross-brace control device of the present invention with a servo component;

[0070] Figure 5 Installation schematic diagram of the end of the active cross-brace control device of the present invention without a servo component;

[0071] Figure 6 General flowchart of the control and adjustment method of the active cross-brace control device of the present invention;

[0072] As Figures 1 to 6 shown, the marks in the figure are respectively represented as:

[0073] Steel wedge block 10, servo component 20, front end plate 201, rear end plate 202, steel frame 203, servo jack 204, locking mechanism 205, locking screw 2051, locking nut 2052, base 206, cross-brace steel pipe 30, steel connector 40, temperature detector 50, wireless servo oil pump 60, inclined bridge tower 70, tower column 701, embedded part 80, anchor rod 801, anchor plate 802, placement platform 90, working platform 100, steel support 110, lower cross beam 120. Specific embodiments

[0074] The following further details the features of the present invention and other related features through embodiments in conjunction with the drawings, so as to facilitate the understanding of those skilled in the same industry:

[0075] Embodiment: As Figures 1 to 6 shown, this embodiment relates to a method for controlling and adjusting the active cross-brace for the construction of an inclined bridge tower, and this method mainly includes the following steps:

[0076] S1: Install the 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.

[0077] Among them, as Figures 1 to 5As shown in the figure, a lower cross beam 120 is provided inside the bottom of the tower column 701 of the inclined bridge tower 70, and the active cross brace control device is arranged inside the middle part of the tower column 701 of the inclined bridge tower 70. There are two active cross brace control devices arranged on the horizontal plane. The active cross brace control device mainly includes a steel wedge block 10, a servo assembly 20, a cross brace steel pipe 30, a steel connecting piece 40, a temperature detector 50, a wireless servo oil pump 60 and a monitoring system. One end of the cross brace steel pipe 30 is connected to the inside of one tower column 701 of the inclined bridge tower 70 through the steel connecting piece 40, and the other end is tightened against the inside of the other tower column 701 of the inclined bridge tower 70 through the servo assembly 20 and the steel wedge block 10. The cross brace steel pipe 30 is connected to the steel wedge block 10 through the servo assembly 20, and the steel wedge block 10 is tightened against the inside 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 at the bottom side and the rear side. The bottom side of the steel frame 203 is installed on the base 206, and 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 flange-connected to the cross brace steel pipe 30. 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 outside the steel frame 203 and is connected to the front end plate 201, and is used to transfer the jacking force of the servo jack 204 to the cross brace steel pipe 30. There are two locking mechanisms 205, and the two locking mechanisms 205 are respectively arranged 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 is provided with a through hole allowing the locking screw 2051 to pass through. The locking nut 2052 is installed on the locking screw 2051 and is arranged outside the steel frame 203. The locking screw 2051 is locked to the steel frame 203 through the locking nut 2052. The locking mechanism 205 is used for protective measures in case of sudden pressure relief or sudden increase in displacement of the servo jack 204. The front end plate 201 and the servo jack 204 are connected through a frustum of a cone, which is used to transfer the jacking force of the servo jack 204 to the steel wedge block 10 and can adapt to a certain angular deformation. The temperature detector 50 is attached to the cross brace steel pipe 30 and is used to measure the temperature of the cross brace steel pipe 30 for actual measurement and correction. The servo jack 204 is driven by the wireless servo oil pump 60, and the wireless servo oil pump 60 is installed on the tower column 701 of the inclined bridge tower 70. The temperature detector 50 and the wireless servo oil pump 60 are respectively connected to the monitoring system, and are used to monitor the temperature of the cross brace steel pipe 30 and the active force and displacement of the cross brace steel pipe 30.

[0078] A working platform 100 is provided below each end of the cross bracing steel pipe 30. The base 206 of the servo assembly 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 respectively 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 fixedly connected to the anchor plate 802. The steel connector 40, the placement platform 90, and the working platform 100 are respectively connected to the anchor plate 802, and 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.

[0079] The installation method of the active cross bracing control device is as follows:

[0080] S1.1: Embedded part layout: During the construction of the tower column 701, install the embedded part 80, set up the working platform 100 and the placement platform 90, and install the steel connector 40 on the embedded part 80.

[0081] S1.2: Component connection: Connect the rear end plate 202 of the servo assembly 20 and one side of the cross bracing steel pipe 30 on the ground to ensure that the axes of the servo assembly 20 and the cross bracing steel pipe 30 are aligned.

[0082] S1.3: Hoisting and positioning: Hoist the cross bracing steel pipe 30 and the servo assembly 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 inner side of the tower column 701.

[0083] S1.4: Installation of temperature detector: Install the temperature detector 50 on the surface of the cross bracing steel pipe 30.

[0084] S1.5: Apply initial active force: Apply an active force to the design value through the servo jack 204.

[0085] S2: Monitor the active force of the active cross bracing control device.

[0086] S2.1: Real-time data acquisition:

[0087] Continuously monitor the active force, displacement, and temperature of the active cross bracing control device through the monitoring system, and store the data per hour as the statistical basis.

[0088] S2.2: Dynamically correct the design value of the active force of the active cross bracing control device.

[0089] Among them, the dynamic correction method of the design value of the active force of the active cross bracing control device is as follows:

[0090] During the construction process of the cable-stayed bridge, the design value of the active force of the active cross-brace control device needs to be dynamically adjusted to adapt to the load changes during the construction stage, the environmental temperature effect, and other additional loads. Take the active force and temperature of the active cross-brace control device per hour within 24 hours as the basis for calibrating and judging the active force of the active cross-brace control device. The design value of the active force F of the corrected active cross-brace control device d,t,i can be calculated according to the following formula:

[0091] F d,t,i = f(t, S, L) + ΔF T,i + ΔF L ;

[0092] In the formula, f(t, S, L) is the basic design value of the active force of the active cross-brace control device during the construction stage without considering the temperature load, which 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 loads; t is the construction stage, indicating the construction progress; i is the i-th hour within 24 consecutive hours; S is the construction load, including the self-weight of the subsequent tower column segments and the construction load; L is the change in the constraint conditions, considering the effects of the tower column, the installed active cross-brace control device, and the support constraints;

[0093] ΔF T,i is the temperature effect correction value, which is given by the following formula:

[0094] ΔF T,i = f(t, S, L = EAα T ΔT i );

[0095] In the formula, E is the elastic modulus of the cross-brace steel pipe; A is the cross-sectional area of the cross-brace steel pipe; α T is the linear expansion coefficient of the cross-brace steel pipe; ΔT i is the difference between the monitored temperature at the i-th hour and the initial installation temperature;

[0096] ΔF L is the other additional load correction value, including wind load, sunshine difference, and tower column settlement, which can be obtained by combining engineering experience or measured data into the construction load and support conditions in f(t, S, L).

[0097] S2.3: Carry out over-limit discrimination on the resultant force of the active forces of the two active cross-brace control devices.

[0098] Among them, the over-limit discrimination method for the resultant force of the active forces of the two active cross-brace control devices is as follows:

[0099] The resultant force calculation formula for the active forces of the two active cross-brace control devices is:

[0100]

[0101] In the formula, and are respectively the monitoring values of the two active cross bracing control devices at the i-th hour within a continuous 24-hour monitoring period;

[0102] Within a continuous 24-hour monitoring period, the criteria for determining that the resultant active force exceeds the limit are as follows:

[0103] a. Whether F per hour A,i meets the following conditions:

[0104] F A,i >(1 + K U )F d,t,i or F A,i <(1 - K D )F d,t,i ;

[0105] In the formula, K U is the overload coefficient of the active force of the active cross bracing control device, and can take 0.4; K D is the load coefficient of the active force of the active cross bracing control device, and can take 0.2; the overload coefficient and the load coefficient take into account the allowable error requirements of the construction specifications; in addition, the adjustment method of the monitoring system during overload is unloading, so as to reduce the unloading risk, and accordingly the safety factor index for overload exceeding the limit is increased;

[0106] b. Count the number of hours j that meet the over-limit conditions within 24 hours; if the following formula is satisfied, it is determined that the resultant force exceeds the limit:

[0107]

[0108] S2.4: Discriminate the symmetry of the active forces of the two active cross bracing control devices.

[0109] Among them, the discrimination method for the symmetry of the active forces of the two active cross bracing control devices is as follows:

[0110] The symmetry calibration is discriminated by calculating the symmetry ratio R based on the data per hour within 24 hours continuously:

[0111]

[0112] The design target value of R is 1.0 to 1.2; if R i > 1.4, it indicates that there is a significant asymmetry in the active forces of the two active cross bracing control devices;

[0113] For the statistics of the data within 24 hours continuously, if the following conditions are satisfied, it is determined that there is a symmetry problem;

[0114]

[0115] wherein, 1(R i >1.4) is an indicator function, which takes the value of 1 when R i >1.4, and 0 otherwise.

[0116] S3: Adjust the active force of the active cross strut control device.

[0117] Among them, if it is determined that the resultant force of the active forces of the two active cross strut control devices exceeds the limit or there is a symmetry problem with the active forces of the two active cross strut control devices, dynamic adjustment is performed through the monitoring system.

[0118] The method for adjusting the active force of the active cross strut control device is as follows:

[0119] Adopt a hierarchical loading method (number of levels: n) to gradually adjust the active force to the design value. Each level of loading value ΔF g can be calculated according to the following formula and the calculated value is rounded to a multiple of 5t:

[0120]

[0121] During the adjustment process, real-time data needs to be monitored, and the monitoring data of the monitoring system is analyzed. When the active force of the active cross strut control device is close to the design value, the pressure step difference should be appropriately reduced to gradually approach the target value;

[0122] After the adjustment is completed, the following conditions need to be met before termination:

[0123] 1. The active force is close to the design value:

[0124] |F d,t,i -F A,i |<0.1F d,t,i ;

[0125] 2. The symmetry meets the target value:

[0126] R i ≤1.2;

[0127] 3. Monitor the active force of the active cross strut control device or the stress state of the inclined pylon to judge the adjustment effect.

[0128] The beneficial technical effects of this embodiment are:

[0129] 1. Solve the problem of active force loss of the active cross strut:

[0130] In traditional active bracing construction, the active force relies on being applied and fixed by hydraulic jacks. Affected by factors such as welding deformation, gap tightening error, and relaxation effect of steel members, the active force of the bracing rapidly decays within a short period, resulting in the inability to maintain the design value. This loss of active force not only affects the overall stiffness of the bridge tower but also may lead to the risk of cracking or out-of-control deformation of the tower column due to insufficient balance of the internal inclination force.

[0131] 2. Solved the problem that the active force cannot be adjusted in real time:

[0132] Once the active force changes after the installation of the traditional bracing system, it cannot be compensated or corrected through the adjusting device. During the construction process, due to the dynamic changes of external factors such as the self-weight of the tower column, construction load, and environmental temperature, the active force of the bracing will continuously deviate from the design value; there may also be an asymmetric phenomenon of the active forces on the left and right sides of the bracing, which may further cause tower column eccentric compression and abnormal stress distribution, affecting the stability and vertical alignment control during the construction of the bridge tower.

[0133] 3. Solved the problem of insufficient remote monitoring and adjustment:

[0134] The current bracing systems are mostly passive designs, lacking intelligent monitoring and remote adjustment functions. Construction units cannot timely grasp the state of the active force of the bracing or promptly adjust the active force that does not meet the design requirements, increasing the construction risk and the complexity of on-site management.

[0135] Although the above embodiments have elaborated on the concept and embodiments of the present invention with reference to the accompanying drawings, those of ordinary skill in the art can recognize that various improvements and transformations can still be made to the present invention without departing from the scope defined by the claims. Therefore, they are not elaborated one by one here.

Claims

1. An active cross-brace control and adjustment method for the construction of inclined bridge towers, characterized in that The method includes: S1: Install an active cross-brace control device on the inclined bridge tower and load the active force of the active cross-brace control device to the design value; Wherein, the active cross-brace control device is arranged on the tower column of the inclined bridge tower and there are two on the horizontal plane. The active cross-brace control device includes a steel wedge block, a servo assembly, a cross-brace steel pipe and a steel connecting piece. One end of the cross-brace steel pipe is connected to the inner side of one tower column of the inclined bridge tower through the steel connecting piece, and the other end is tightened against the inner side of the other tower column of the inclined bridge tower through the servo assembly and the steel wedge block. The servo assembly 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 an open bottom side and a rear side. The bottom side of the steel frame is installed on the base. The rear end plate is connected to the rear side of the steel frame and the base. The base of the servo jack is installed inside the steel frame and is connected to the steel frame and the rear end plate. The hydraulic rod extends outside the steel frame and is connected to the front end plate. There are two locking mechanisms and the two locking mechanisms are respectively arranged on both sides of the servo jack. The 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 is arranged outside the steel frame. The locking screw is locked to the steel frame through the locking nut. A working platform is arranged below each end of the cross-brace steel pipe. The base of the servo assembly and the steel wedge block are both placed on the placement platform. The steel connecting piece, the placement platform and the working platform are all respectively connected to the embedded parts. A temperature detector is installed on the cross-brace steel pipe. The servo jack is driven by a wireless servo oil pump. The wireless servo oil pump is installed on the tower column of the inclined bridge tower. The temperature detector and the wireless servo oil pump are both respectively connected to the monitoring system; S2: Monitor the active force of the active cross-brace control device; S2.1: Continuously monitor the active force, displacement and temperature of the active cross-brace control device through the monitoring system and store the data per hour as the statistical basis; S2.2: Dynamically correct the design value of the active force of the active cross-brace control device; S2.3: Determine whether the resultant force of the active forces of the two active cross-brace control devices exceeds the limit; S2.4: Determine the symmetry of the active forces of the two active cross-brace control devices; S3: Adjust the active force of the active cross-brace control device; Wherein, if it is determined that the resultant force of the active forces of the two active cross-brace control devices exceeds the limit or there is a symmetry problem with the active forces of the two active cross-brace control devices, dynamic adjustment is performed through the monitoring system.

2. The active cross-brace control and adjustment method for the construction of an inclined pylon according to claim 1, characterized in that The embedded part includes an anchor rod and an anchor plate. One end of the anchor rod extends into the tower column of the inclined bridge tower and the other end is fixedly connected to the anchor plate.

3. The active cross-brace control and adjustment method for the construction of an inclined pylon according to claim 2, characterized in that The steel connector, the placement platform, and the working platform are all connected to the anchor plate respectively. The placement platform and the anchor plate, as well as the working platform and the anchor plate, are connected by steel supports.

4. The active cross brace control and adjustment method for the construction of an inclined pylon according to claim 1, wherein The front end plate and the servo jack are connected by a frustum.

5. The active cross-brace control and adjustment method for inclined pylon construction according to claim 1, wherein The rear end plate and the cross bracing steel pipe are flange-connected.

6. The active cross brace control and adjustment method for inclined pylon construction according to claim 1, characterized in that In step S1, the installation method of the active cross bracing control device is as follows: S1.1: During the construction of the tower column, install the embedded parts, set the working platform and the placement platform, and install the steel connector on the embedded parts; S1.2: Connect the rear end plate of the servo assembly and one side of the cross bracing steel pipe on the ground to ensure that the axes of the servo assembly and the cross bracing steel pipe are aligned; S1.3: Hoist the cross bracing steel pipe and the servo assembly as a whole to the installation position of the active cross bracing control device. After adjusting the position, weld the steel wedge block and the front end plate, and tighten the locking nut to complete the connection. At this time, the steel wedge block is attached to the inner side of the tower column; S1.4: Install the temperature detector on the surface of the cross bracing steel pipe; S1.5: Apply the active force to the design value through the servo jack.

7. The active cross brace control and adjustment method for inclined pylon construction according to claim 6, wherein In step S2.2, the dynamic correction method of the design value of the active force of the active cross bracing control device is as follows: Take the active force and temperature of the active cross bracing control device per hour within 24 hours as the basis for calibrating and determining the active force of the active cross bracing control device, and the designed value F of the active force of the active cross bracing control device after correction d,t,i can be calculated according to the following formula: F d,t,i = f(t, S, L) + ΔF T,i + ΔF L ; In the formula, f(t,S,L) is the basic design value of the active force of the active cross bracing control device in the construction stage without considering the temperature load; t is the construction stage, indicating the construction progress; i is the i-th hour in 24 consecutive hours; S is the construction load, including the self-weight of the subsequent tower column segments and the construction load; L is the change of the constraint conditions; ΔF T,i is the temperature effect correction value, which is given by the following formula: ΔF T,i = f(t, S, L = EAα T ΔT i ); Wherein, 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 is the linear expansion coefficient of the cross-bracing steel pipe; ΔT i is the difference between the monitored temperature at the i-th hour and the initial installation temperature; ΔF L It is the correction value for other additional loads, including wind load, solar radiation difference, and tower column settlement, which can be obtained by incorporating engineering experience or measured data into the construction load and support conditions in f(t, S, L).

8. The active cross brace control and adjustment method for inclined pylon construction according to claim 7, characterized in that In step S2.3, the overrun discrimination method for the resultant force of the active forces of the two active cross bracing control devices is as follows: The formula for calculating the resultant force of the active forces of the two active cross bracing control devices is: In the formula, and are respectively the monitoring values of the i-th hour of the two active cross bracing control devices within a continuous 24-hour monitoring period; During the 24-hour monitoring period, the criterion for determining that the resultant force of the active forces is overrun is: a. F per hour A,i Does it meet the following conditions: F A,i (1 + K U )F d,t,i or F A,i <(1 - K D )F d,t,i ; Where K U is the overload coefficient of the active force of the active cross brace control device, which can be taken as 0.4; K D is the load coefficient of the active force of the active cross brace control device, which can be taken as 0.2; b. Count the number of hours j that meet the overrun condition within 24 hours; if the following formula is satisfied, it is determined that the resultant force is overrun:

9. A method for controlling and adjusting an active cross brace for the construction of an inclined pylon, as described in claim 8, characterized in that In step S2.4, the discrimination method for the symmetry of the active forces of the two active cross bracing control devices is as follows: Symmetry calibration is determined by calculating the symmetry ratio R from the data of each hour within 24 consecutive hours: The design target value of R is 1.0 to 1.2; if R i > 1.4, it indicates that there is a significant asymmetry in the driving forces of the two active cross bracing control devices; For the statistical data of 24 consecutive hours, if the following conditions are met, it is determined that there is a symmetry problem; where 1(R i > 1.4) is an indicator function that takes the value of 1 when R i > 1.4 and 0 otherwise.

10. A method for controlling and adjusting an active cross brace for the construction of an inclined bridge tower according to claim 9, characterized in that In step S3, the active force adjustment method of the active cross bracing control device is as follows: Adopt a step-by-step loading method to gradually adjust the driving force to the design value, with the loading value per step being ΔF g After calculation according to the following formula, round the calculated value to the nearest multiple of 5t to obtain: 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 bracing control device is close to the design value, the pressure differential should be appropriately reduced to gradually approach the target value; After the adjustment is completed, the following conditions need to be met to terminate:

1. The active force is close to the design value: |F d,t,i -F A,i |<0.1F d,t,i ; 2. The symmetry meets the target value: R i ≤1.2； 3. Monitor the active force of the active cross bracing control device or the stress state of the inclined bridge tower to judge the adjustment effect.

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