Method and system for synchronous construction of pylon lower beam without support integral hoisting and tower beam

Abstract

The application discloses a kind of tower beam synchronous construction method and system of whole hoisting of support-free lower cross beam of cable tower, and the method comprises the following steps: establishing lower cross beam finite element model, calculating self-weight reverse displacement and generating reverse geometric model, guiding factory prefabrication and pre-arch, to ensure that hoisting is restored design linear after in place.Tower column construction, pose is collected by measurement robot and interface coordinates are predicted, virtual pre-assembly is carried out, and steel bar avoidance instruction is output.Tower beam is regarded as coupling system, stress balance model is established, and overturning moment is actively balanced by setting counterweight or applying prestressed cable on the opposite side of tower column through calculating eccentric load moment.Concrete stiffness change is monitored in real time, and pumping speed difference is dynamically adjusted using synchronous pouring rate planning method, to ensure that tower column and lower cross beam settlement deformation are coordinated.

Description

Technical Field

[0001] This invention belongs to the field of bridge construction technology, and more specifically, relates to a method and system for the scaffold-free integral hoisting of the lower crossbeam of a cable tower and the synchronous construction of the tower and beam. Background Technology

[0002] In the construction of modern long-span bridges, the pylon, as the core load-bearing and force-transmitting component of cable-stayed or suspension bridges, directly determines the safety and durability of the entire bridge through its structural form and construction quality. With the continuous breakthroughs in bridge spans and the increasing demands for architectural aesthetics, the structural forms of pylons are becoming increasingly complex, especially portal or A-shaped pylon structures with large-volume, long-span lower crossbeams, which are widely used. The lower crossbeam not only connects the two tower columns and provides lateral restraint to ensure the out-of-plane stability of the tower columns, but also bears enormous self-weight and the loads transferred from the subsequent bridge deck system, making it a crucial load-bearing component in the pylon structure. Traditionally, the construction of the lower crossbeam of pylons often employs the full-span scaffolding method or bracket method. This involves erecting a massive support system or installing complex corbel brackets on-site after the tower columns have reached the required height, followed by rebar tying, formwork installation, and concrete pouring.

[0003] However, this traditional construction method reveals numerous insurmountable drawbacks when facing towering cable towers or complex environments. Firstly, because the lower crossbeam is typically located at high altitude, the erection and dismantling of supports or brackets are extremely risky, require huge material inputs, and have long construction cycles, severely restricting the overall construction efficiency of the cable tower. Secondly, high-altitude cast-in-place operations are significantly affected by wind loads, temperature changes, and eccentric construction loads. During the pouring of the lower crossbeam on one side of the tower column, asymmetrical deformation or even overturning risks can easily occur, posing a significant challenge to controlling the verticality of the tower column. Furthermore, traditional methods struggle to accurately predict and control the asynchronous settlement and creep of the tower column and crossbeam due to age differences and uneven stress during concrete hardening, easily generating additional stress within the structure and affecting its structural performance and aesthetic appearance. Especially in today's pursuit of high-quality construction, how to achieve high-precision installation of the lower crossbeam and stress coordination between the tower and beam structures while ensuring construction safety has become a critical problem urgently needing to be solved in the field of cable tower construction technology. Therefore, developing a new synchronous construction method that can break free from dependence on external support and achieve coordinated control of tower and beam deformation is of great practical significance for improving the level of bridge construction. Summary of the Invention

[0004] This invention aims to solve the problems of high risk in scaffolding erection, easy instability of tower columns due to eccentric loading, and difficulty in coordinating tower-beam deformation during the construction of the lower crossbeam of a cable tower. By employing a scaffold-free, integral hoisting and synchronous construction method, it achieves high-precision installation of the lower crossbeam and coordinated control of structural stress throughout the entire process, thereby improving construction safety and efficiency.

[0005] To address the aforementioned deficiencies or improvement needs of existing technologies, as a first aspect of this invention, the present invention provides a method for the integral hoisting of the lower crossbeam of a cable tower without supports and the synchronous construction of the tower and beam, comprising: S1. Establish a finite element model of the lower crossbeam as a whole hoisting segment, and simulate its stress distribution and deformation curve under the state of suspension without support; run the pre-deformation compensation method to calculate the reverse displacement vector field of the lower crossbeam under its own weight, and generate the reverse geometric model accordingly; based on the reverse geometric model, perform pre-arching processing on the steel frame and template of the lower crossbeam in the factory prefabrication stage, so that after the lower crossbeam is hoisted into place and the hook is released, its structure recovers to the design theoretical shape under the action of gravity; S2. Before the tower column is constructed to the height of the lower crossbeam connection, the actual spatial posture and environmental parameters of the tower column are collected by a measurement robot and input into the dynamic matching method to predict the tower column interface coordinates at the time of lower crossbeam installation; based on the predicted coordinates, the tower beam is virtually pre-assembled, and when there is interference, the steel bar avoidance and adjustment command is output to guide the fine adjustment of the reserved steel bars of the tower column on site; S3. Treat the lower crossbeam hoisting segment and the tower column as a coupled system and establish a synchronous force balance model of the tower and beam; after the lower crossbeam is hoisted and locked and before the concrete is poured, calculate the counterbalance moment required to offset the eccentric load moment of the lower crossbeam using the balance decoupling method; based on the calculation results, set an adjustable temporary counterweight on the opposite side of the tower column or apply prestressed cables inside the tower column to actively balance the overturning moment generated by the lower crossbeam, and ensure that the tower column always maintains its verticality within the safety threshold when all external supports are removed; S4. Monitor the strength and stiffness changes of the concrete of the tower column and the lower crossbeam in real time, and use the synchronous pouring rate planning method to dynamically adjust the difference in concrete pouring speed according to the stiffness ratio of the two, and control the pumping equipment to ensure that the settlement deformation of the tower column and the lower crossbeam remains coordinated.

[0006] Furthermore, the pre-deformation compensation method in S1 specifically includes: The nonlinear finite element analysis method is used to discretize the overall hoisting segment of the lower crossbeam into several beam elements; the initial design alignment is set as the target state, and the gravity load is used as the variable. The vertical displacement components of each node under the action of self-weight are solved by iterative calculation; the vertical displacement components are inverted as the pre-camber value and superimposed on the initial design coordinates of the lower crossbeam to generate a reverse geometric model containing pre-camber information.

[0007] Furthermore, the specific method for constructing the inverse geometric model in S1 is as follows: First, a time-varying finite element model incorporating the construction environment parameter field is established, wherein the environment parameter field includes at least the real-time wind speed field. and non-uniform temperature field of solar radiation Calculate the lower crossbeam hoisting segment at the closure moment. Instantaneous theoretical deformation tensor ; Secondly, regarding the instantaneous theoretical deformation tensor By decoupling the error components, the elastic deformation component caused by the structure's own weight is separated. Residual shrinkage caused by welding process and random disturbance components caused by environmental effects ; Next, construct the inverse compensation function. Its expression is: in, The target coordinates of the inverse geometry model. To design coordinates, This is the weld shrinkage coefficient. The stiffness transfer matrix for the tower-beam connection interface. This is the real-time offset vector of the tower in cantilever mode; Finally, based on the aforementioned inverse compensation function A reverse geometry model containing pre-twisting and pre-deflection features is generated, enabling the lower crossbeam to counteract nonlinear disturbances in complex environments and precisely conform to the design line after hoisting into place and releasing constraints.

[0008] Furthermore, the specific process of the dynamic matching method in S2 is as follows: Before the tower column is constructed to the height of the lower crossbeam connection, a surveying robot is used to collect the actual spatial attitude and environmental parameters of the tower column. These parameters are then input into a dynamic matching method to predict the tower column interface coordinates at the moment of lower crossbeam installation. Specific steps include: First, based on the 3D point cloud data of the tower column acquired by the measurement robot at the current moment, the measured center point coordinates of the surface to be connected to the tower column are extracted by fitting. and normal vector ; Secondly, combined with real-time wind speed data collected by the weather station ,wind direction and ambient temperature Using a pre-established time-varying deformation prediction model for the tower column, the time difference from the current moment to the installation moment of the lower crossbeam is calculated. The deformation increment of the tower column; the deformation increment includes the elastic displacement vector caused by wind load. and the thermal deformation vector caused by temperature gradient change ; Finally, the measured center point coordinates are... By vector superposition with the deformation increment, the predicted coordinates of the tower column interface at the moment of lower beam installation are obtained. and the predicted coordinates Used as the target control coordinates for the lower crossbeam hoisting and positioning system to guide hoisting and assembly accuracy.

[0009] Furthermore, the specific process in S3 of calculating the required counterbalance moment to offset the eccentric load moment of the lower crossbeam using the balance decoupling method is as follows: First, based on the finite element model of the coupled system of the tower column and the lower crossbeam, the structural stiffness matrix after the lower crossbeam is hoisted and locked is extracted. And combined with the self-weight of the lower crossbeam and hoisting eccentricity Calculate the initial eccentric load moment generated by the lower crossbeam on the tower column. ; Secondly, by using tilt sensors and strain gauges installed at the top of the tower column, the tower top displacement is monitored in real time when the lower crossbeam is locked. The stress distribution at the tower base was analyzed, and the actual thrust stiffness of the tower column was calculated using an inverse iterative algorithm. And correct the finite element model to eliminate the deviation between the theoretical value and the measured value; Next, based on the revised model, the counter-side equilibrium torque is set. Under the loading condition, the opposing balancing moment is applied through temporary prestressed tendons or a counterweight system on the opposite side of the tensioning tower column; a moment balance equation is constructed. ,in The frictional constraint moment at the tower-beam joint. This is the safety reserve factor; Finally, the torque balance equation is solved to obtain the required theoretical opposing equilibrium torque value. This information is then converted into specific tension force values ​​or counterweight mass, and output to the construction control system to guide the precise loading of the lateral balancing system, ensuring that the verticality deviation of the tower column is controlled within the allowable range.

[0010] Furthermore, the adjustable temporary counterweight set on the opposite side of the tower column in S3 specifically involves installing a water tank or sand box on the corbel or embedded part on the opposite side of the tower column as a counterweight; the opposite side balance torque calculated by the balance decoupling method is directly converted into the mass parameters of the counterweight; during construction, water or sand is injected into the water tank or sand box in real time according to the progress of the lower crossbeam concrete pouring to maintain the dynamic balance of the torque.

[0011] Furthermore, the application of prestressed cables inside the tower column in S3 specifically involves: Temporary steel strands are threaded through prestressed ducts inside the tower column. The upper anchor point of the temporary steel strands is located at the top of the tower column, and the lower anchor point is located in the tower column segment below the bottom of the lower crossbeam. The temporary steel strands are tensioned to generate a reverse bending moment to counteract the eccentric load moment generated by the self-weight of the lower crossbeam.

[0012] Furthermore, the specific process of dynamically adjusting the difference in concrete pouring speed based on the stiffness ratio of the two in S4 is as follows: First, set a dead zone threshold for stiffness deviation. ,when When the stiffness matching is considered to meet the requirements, the current pouring speed is maintained; when When this occurs, it indicates that the tower column stiffness is too large relative to the lower crossbeam, and the tower column settlement rate may lag behind that of the lower crossbeam. In this case, the system will adjust according to the formula... Calculate the speed correction amount, where This is the proportionality coefficient. The integral coefficient is... This is the stiffness compatibility deviation coefficient. The difference in concrete pouring speed is the target; the calculated This represents the relative increase in pouring rate required; Combined with the cross-sectional area of ​​the tower column casting and the cross-sectional area of ​​the lower crossbeam The system generates specific pumping instructions: increase the discharge capacity of the concrete pump for the lower crossbeam. Or reduce the displacement of the concrete pump for the tower column. , making This accelerates the load increase of the lower crossbeam to match the stiffness state of the tower column; conversely, when If the situation is reversed, the opposite adjustment logic will be executed, either increasing the pouring speed of the tower column or slowing down the speed of the lower crossbeam.

[0013] As a second aspect of the present invention, a system for the integral hoisting of the lower crossbeam of a cable tower without supports and the synchronous construction of the tower and beam is also provided, comprising: The lower crossbeam pre-deformation compensation unit is used to establish a finite element model of the overall hoisting segment of the lower crossbeam, and to simulate its stress distribution and deformation curve under the state of suspension without support. The pre-deformation compensation method is used to calculate the reverse displacement vector field of the lower crossbeam under its own weight, and a reverse geometric model is generated accordingly. Based on the reverse geometric model, the steel frame and template of the lower crossbeam are pre-arched during the factory prefabrication stage, so that after the lower crossbeam is hoisted into place and the hook is released, its structure recovers to the design theoretical shape under the action of gravity. The tower-beam dynamic matching pre-assembly unit is used to collect the actual spatial posture and environmental parameters of the tower column using a measuring robot before the tower column is constructed to the lower crossbeam connection height. These parameters are then input into the dynamic matching method to predict the tower column interface coordinates at the time of lower crossbeam installation. Based on the predicted coordinates, the tower-beam is virtually pre-assembled. When interference occurs, a rebar avoidance and adjustment command is output to guide the fine-tuning of the reserved rebars in the tower column on site. The tower-beam synchronous force balance unit is used to treat the lower crossbeam hoisting segment and the tower column as a coupled system and establish a tower-beam synchronous force balance model. After the lower crossbeam is hoisted and locked and before the concrete is poured, the counterbalance moment required to offset the eccentric load moment of the lower crossbeam is calculated by the balance decoupling method. According to the calculation results, an adjustable temporary counterweight is set on the opposite side of the tower column or prestressed cables are applied inside the tower column to actively balance the overturning moment generated by the lower crossbeam and ensure that the tower column always maintains its verticality within the safety threshold when all external supports are removed. The dynamic control unit for pouring rate is used to monitor the changes in strength and stiffness of the concrete of the tower column and the lower crossbeam in real time. It uses a synchronous pouring rate planning method to dynamically adjust the difference in concrete pouring speed according to the stiffness ratio of the two, and controls the pumping equipment to ensure that the settlement deformation of the tower column and the lower crossbeam remains coordinated.

[0014] As a third aspect of the invention, a computer-readable storage medium is also provided, on which a computer program is stored, which is executed by a processor, according to any one of the methods for the integral hoisting of the lower crossbeam of a cable tower without support and the synchronous construction of the tower and beam.

[0015] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: 1. The present invention provides a method for the seamless hoisting of the lower crossbeam of a cable tower, synchronized with tower-beam construction. This method establishes a finite element model of the lower crossbeam to calculate its self-weight reverse displacement vector field. Based on this, a reverse geometric model is generated to guide the pre-arching of the steel frame and formwork during the factory prefabrication stage. This ensures that after the lower crossbeam is hoisted into place and the hook is released, it returns to its theoretical design alignment under gravity. Simultaneously, before the tower column reaches its connection height, a measuring robot collects actual spatial posture and environmental parameters. A dynamic matching method is used to predict the tower column interface coordinates at the installation moment. Based on these predicted coordinates, virtual pre-assembly of the tower-beam is performed, and reinforcement avoidance adjustment commands are output to guide on-site fine-tuning. This technical solution effectively solves the problem of accurately controlling the deformation of the lower crossbeam due to its own weight in traditional construction, ensuring that the alignment accuracy after hoisting meets design requirements. It avoids delays and increased costs caused by secondary on-site adjustments. Furthermore, virtual pre-assembly allows for the early detection and resolution of tower-beam interface interference problems, improving installation accuracy and construction efficiency.

[0016] 2. The present invention provides a method for the integrated hoisting of the lower crossbeam without supports and the synchronous construction of the tower and beam. By treating the hoisted lower crossbeam segment and the tower column as a coupled system and establishing a synchronous force balance model for the tower and beam, after the lower crossbeam is hoisted and locked but before concrete pouring, the method of balance decoupling is used to calculate the counterbalancing moment required to offset the eccentric load moment of the lower crossbeam. Based on the calculation results, an adjustable temporary counterweight is installed on the opposite side of the tower column or prestressed cables are applied inside the tower column to actively balance the overturning moment generated by the lower crossbeam. This ensures that the tower column maintains its verticality within a safe threshold even after all external supports are removed. This technical solution overcomes the limitations of traditional construction methods that rely on external supports, enabling synchronous construction of the tower and beam without supports. It significantly reduces the construction risks and costs associated with support erection and dismantling, and effectively controls the verticality of the tower column by actively balancing the overturning moment, ensuring the safety and stability of the structure during construction.

[0017] 3. The method for the scaffold-free integral hoisting of the lower crossbeam of the cable tower and the synchronous construction of the tower beam in this invention monitors the strength and stiffness changes of the concrete of the tower column and the lower crossbeam in real time. It utilizes a synchronous pouring rate planning method to dynamically adjust the difference in concrete pouring speed based on the stiffness ratio of the two, controlling the pumping equipment to ensure coordinated settlement deformation of the tower column and the lower crossbeam. This technical solution effectively solves the problem of deformation incoordination caused by stiffness differences during concrete hardening, avoids structural cracks and stress concentration caused by settlement differences, improves the integrity and durability of the structure, and achieves refined control of the construction process through dynamic adjustment of the pouring speed, ensuring the quality of concrete pouring and providing a reliable guarantee for the safety and long-term performance of the cable tower structure. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating a method for the integrated hoisting of the lower crossbeam of a cable tower without supports and the synchronous construction of the tower and beam, according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the overall hoisting of the lower crossbeam of the cable tower without a support frame, according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the hoisting model of the lower crossbeam component according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the system units according to an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0020] Example 1 Please refer to Figure 1 This embodiment 1 provides a method for the integral hoisting of the lower crossbeam of the cable tower without support and the synchronous construction of the tower and beam, including: S1. Establish a finite element model of the lower crossbeam as a whole hoisting segment, and simulate its stress distribution and deformation curve under the state of suspension without support; run the pre-deformation compensation method to calculate the reverse displacement vector field of the lower crossbeam under its own weight, and generate the reverse geometric model accordingly; based on the reverse geometric model, perform pre-arching processing on the steel frame and template of the lower crossbeam in the factory prefabrication stage, so that after the lower crossbeam is hoisted into place and the hook is released, its structure recovers to the design theoretical shape under the action of gravity; S2. Before the tower column is constructed to the height of the lower crossbeam connection, the actual spatial posture and environmental parameters of the tower column are collected by a measurement robot and input into the dynamic matching method to predict the tower column interface coordinates at the time of lower crossbeam installation; based on the predicted coordinates, the tower beam is virtually pre-assembled, and when there is interference, the steel bar avoidance and adjustment command is output to guide the fine adjustment of the reserved steel bars of the tower column on site; S3. Treat the lower crossbeam hoisting segment and the tower column as a coupled system and establish a synchronous force balance model of the tower and beam; after the lower crossbeam is hoisted and locked and before the concrete is poured, calculate the counterbalance moment required to offset the eccentric load moment of the lower crossbeam using the balance decoupling method; based on the calculation results, set an adjustable temporary counterweight on the opposite side of the tower column or apply prestressed cables inside the tower column to actively balance the overturning moment generated by the lower crossbeam, and ensure that the tower column always maintains its verticality within the safety threshold when all external supports are removed; S4. Monitor the strength and stiffness changes of the concrete of the tower column and the lower crossbeam in real time, and use the synchronous pouring rate planning method to dynamically adjust the difference in concrete pouring speed according to the stiffness ratio of the two, and control the pumping equipment to ensure that the settlement deformation of the tower column and the lower crossbeam remains coordinated.

[0021] This embodiment 1 further elaborates on the above steps.

[0022] (1) Pre-deformation compensation of the lower crossbeam In the construction of the lower crossbeam of a bridge pylon, traditional methods rely on scaffolding systems, which are susceptible to the risks of high-altitude operations and structural deformation. To address this issue, this invention establishes a finite element model to simulate the stress distribution and deformation patterns of the lower crossbeam under unsupported suspension. The entire lower crossbeam hoisting segment is discretized into several beam elements; the initial design alignment is set as the target state, and gravity load is used as the variable. The vertical displacement components of each node under its own weight are calculated iteratively; the vertical displacement components are inverted as the pre-camber value and superimposed on the initial design coordinates of the lower crossbeam to generate a reverse geometric model containing pre-camber information. This model guides the pre-cambering of the steel frame and formwork during the factory prefabrication stage, ensuring that the structure naturally returns to the design alignment after hoisting.

[0023] Building upon this foundation, an environmental parameter field is further introduced to construct a time-varying finite element model, comprehensively considering the influence of real-time wind speed and solar radiation temperature difference on structural deformation. Through fluid-structure interaction and thermo-structure interaction analysis, elastic deformation caused by self-weight, residual shrinkage due to welding processes, and random disturbances caused by environmental factors are separated, achieving quantitative isolation of complex disturbances. For welding deformation, an equivalent negative temperature field model is established based on process parameters to simulate the weld cooling process, extracting transverse and longitudinal shrinkage amounts and converting them into deterministic compensation quantities to improve prefabrication accuracy.

[0024] In practical implementation, the lower crossbeam hoisting segment is discretized into a form containing... The mesh of the nth node is defined. The design theoretical coordinates of each node are: In the finite element model, not only the self-weight load must be applied. Real-time wind speed field also needs to be introduced. and non-uniform temperature field of solar radiation As boundary conditions; the nodes at the closure moment are calculated using a nonlinear solver. Total displacement vector To separate deformations caused by different physical mechanisms, the superposition principle is used to decompose the total displacement into elastic deformation components. Random disturbance components caused by self-weight and prestressing and environmental effects (Caused by wind load and temperature difference); among which, The calculation needs to be based on the fluid-structure interaction formula. Calculate wind load and thermal deformation caused by temperature gradient based on heat conduction equation, thereby achieving quantitative isolation of interference from complex environments; Secondly, to address the irreversible deformation caused by the welding process, it is necessary to construct a weld shrinkage model and calculate the residual shrinkage component. During implementation, technicians, based on the welding procedure qualification report, extract the transverse shrinkage amount under specific plate thickness and bevel type. and longitudinal shrinkage The weld region is defined as a solid element with an equivalent negative temperature field in the finite element model, and the weld cooling process is simulated through thermo-structural coupling analysis; at this time, the weld shrinkage coefficient is... This is defined as a correction term for the ratio of the actual weld volume to the theoretical design volume, typically ranging from 0.8 to 1.1; then, the calculated nodal-level shrinkage deformation vectors are superimposed to form the residual shrinkage component of the entire structure. This transforms process errors from random errors into deterministic compensation quantities.

[0025] Next comes the core step of this embodiment: quantifying and obtaining the stiffness transfer matrix of the cable tower-beam connection interface. This matrix is ​​used to address the coupled influence of the pylon's flexible deformation on the crossbeam installation accuracy. The specific calculation method is as follows: a refined finite element sub-model is established at the connection between the pylon and the lower crossbeam, and unit virtual force vectors are applied at the connection interface nodes. , and The longitudinal, lateral, and vertical force states are simulated respectively; the solver is used to calculate the response displacement vector of the tower under a unit force. Stiffness transfer matrix This is the inverse matrix relationship between unit force and response deviation, i.e. The matrix is A square array, whose elements Indicates the first When a unit force is applied in the direction at the first The displacement stiffness coefficient generated by the direction accurately describes the flexibility characteristics of the cable tower at the current cantilever height.

[0026] Then, the real-time offset vector of the cable tower needs to be introduced. Spatiotemporal coordinate mapping is performed. In actual construction, the dynamic displacement of the tower under wind load and sunlight is monitored in real time using a high-precision GPS or total station installed on the top of the tower to obtain... The offset data in three directions constitute a vector. The stiffness transfer matrix obtained from the above calculation Multiply by the real-time offset vector, i.e. This allows for the calculation of the forced displacement transmitted from the tower offset to the lower crossbeam connection end face; this step solves the problem of closure difficulties caused by the traditional method neglecting the "dynamic base" effect of the tower.

[0027] Finally, based on the above quantization parameters, the final inverse compensation function is constructed. And generate a machining model. Reverse coordinates The calculation formula must be strictly followed: ;in, To design coordinates, This refers to the reverse target coordinates used for factory prefabrication. Technicians reverse the coordinates of all nodes. Importing CAD software, a reverse geometric surface is fitted and generated, incorporating features of pre-twisting (resisting elastic deformation), pre-shrinkage (resisting welding deformation), and pre-deflection (resisting cable tower misalignment). This surface is directly used to generate CNC machining code, guiding the production of the steel frame and formwork. This ensures that after the lower crossbeam is hoisted into place in complex environments, it can automatically counteract various nonlinear interferences, achieving high-precision stress-free closure.

[0028] (2) Dynamic matching and pre-assembly of tower and beam Please refer to Figure 2 as well as Figure 3Before the tower column is constructed to the height required for the lower crossbeam connection, traditional methods often result in misalignment of the interface or interference of the reinforcing bars during the hoisting of the lower crossbeam due to deviations in the actual posture of the tower column and time-varying environmental conditions. To address this issue, before the tower column is constructed to the height required for the lower crossbeam connection, a measuring robot is used to collect the actual spatial posture and environmental parameters of the tower column. These parameters are then input into a dynamic matching method to predict the tower column interface coordinates at the moment of lower crossbeam installation. Specific steps include: First, based on the 3D point cloud data of the tower column acquired by the measurement robot at the current moment, the measured center point coordinates of the surface to be connected to the tower column are extracted by fitting. and normal vector ; Secondly, combined with real-time wind speed data collected by the weather station ,wind direction and ambient temperature Using a pre-established time-varying deformation prediction model for the tower column, the time difference from the current moment to the installation moment of the lower crossbeam is calculated. The deformation increment of the tower column; the deformation increment includes the elastic displacement vector caused by wind load. and the thermal deformation vector caused by temperature gradient change ; Finally, the measured center point coordinates are... By vector superposition with the deformation increment, the predicted coordinates of the tower column interface at the moment of lower beam installation are obtained. and the predicted coordinates Used as the target control coordinates for the lower crossbeam hoisting and positioning system to guide hoisting and assembly accuracy.

[0029] Based on this, virtual pre-assembly of the tower beam is carried out using predicted coordinates, and the actual assembly state of the interface between the lower crossbeam and the tower column is simulated through a digital model. When it is found that the net spacing of the reinforcing bars is less than the preset threshold during virtual pre-assembly, the offset vector of the reinforcing bars is automatically calculated, and adjustment parameters containing the offset direction and offset distance are generated to form a reinforcing bar avoidance adjustment command, which guides the fine-tuning of the reserved reinforcing bars of the tower column on site.

[0030] This process, through a closed-loop control of "actual measurement-prediction-virtual pre-assembly-adjustment," mitigates the risks of dynamic deformation of the tower column and interference with the reinforcing bars in advance. It avoids the delays and accuracy losses caused by temporary on-site adjustments in traditional methods, and achieves high-precision matching of the tower-beam interface and orderly avoidance of the reinforcing bars, providing a reliable spatial positioning guarantee for the overall hoisting of the lower crossbeam without supports.

[0031] (3) Dynamic matching and pre-assembly of tower and beam In the unsupported hoisting construction of the lower crossbeam of the tower, the self-weight of the lower crossbeam can easily cause the tower column to overturn due to its eccentric load. The traditional method of relying on external supports for balancing poses hidden dangers for high-altitude operations. To solve this problem, this embodiment treats the entire hoisting segment of the lower crossbeam and the tower column as a coupled system and establishes a synchronous force balance model of the tower and beam. After the lower crossbeam is hoisted and locked but before concrete pouring, the counter-side balancing moment required to offset the eccentric load moment is calculated using a balance decoupling method, guiding the implementation of active balancing measures.

[0032] First, based on the finite element model of the coupled system of the tower column and the lower crossbeam, the structural stiffness matrix after the lower crossbeam is hoisted and locked is extracted. And combined with the self-weight of the lower crossbeam and hoisting eccentricity Calculate the initial eccentric load moment generated by the lower crossbeam on the tower column. ; Secondly, by using tilt sensors and strain gauges installed at the top of the tower column, the tower top displacement is monitored in real time when the lower crossbeam is locked. The stress distribution at the tower base was analyzed, and the actual thrust stiffness of the tower column was calculated using an inverse iterative algorithm. And correct the finite element model to eliminate the deviation between the theoretical value and the measured value; Next, based on the revised model, the counter-side equilibrium torque is set. Under the loading condition, the opposing balancing moment is applied through temporary prestressed tendons or a counterweight system on the opposite side of the tensioning tower column; a moment balance equation is constructed. ,in The frictional constraint moment at the tower-beam joint. This is the safety reserve factor; Finally, the torque balance equation is solved to obtain the required theoretical opposing equilibrium torque value. This information is then converted into specific tension force values ​​or counterweight mass, and output to the construction control system to guide the precise loading of the lateral balancing system, ensuring that the verticality deviation of the tower column is controlled within the allowable range.

[0033] The solution process employs a numerical trial-and-error method: firstly, an initial assumed torque is applied to the opposite side of the model. Calculate the residual offset at the top of the tower column. ;like Exceeding the permitted range (e.g.) If the direction is towards the off-center load side, then follow the step size. Increase And recalculate; until a solution is found that satisfies the equation constraints and minimizes the verticality deviation of the tower column. The value is determined as the required counter-side balancing torque. Based on this, output the tension force of the side cable or the mass command of the counterweight block.

[0034] The counterbalance measures on the opposite side can be achieved by using adjustable temporary counterweights or prestressed cables. Adjustable temporary counterweights are achieved by installing water tanks or sand boxes on the corbels or embedded parts on the opposite side of the tower column, directly converting the calculated balancing torque into the mass parameters of the counterweight body; during construction, water or sand is injected into the water tanks or sand boxes in real time according to the progress of the concrete pouring of the lower crossbeam to maintain dynamic torque balance.

[0035] The prestressed cables utilize prestressed ducts inside the tower column to thread temporary steel strands. The upper anchor point is located at the top of the tower column, and the lower anchor point is located in the tower column segment below the bottom of the lower crossbeam. By tensioning the temporary steel strands, a reverse bending moment is generated to counteract the eccentric load moment generated by the self-weight of the lower crossbeam, ensuring that the tower column always maintains its verticality within the safety threshold when there is no external support.

[0036] By employing adjustable temporary counterweights or prestressed cables to actively balance the overturning moment generated by the lower crossbeam, the tower column is ensured to remain vertical within a safe threshold even after all external supports are removed. (4) Dynamic control of pouring rate In the simultaneous construction of the tower and beam during the unsupported hoisting of the lower crossbeam, the changes in the strength and stiffness of the concrete in the tower column and lower crossbeam are key factors affecting the coordination of structural settlement. Traditional construction methods often result in asynchronous settlement deformation due to the mismatch in stiffness between the two, leading to structural cracking or installation accuracy deviations. To solve this problem, this invention monitors the changes in the strength and stiffness of the concrete in the tower column and lower crossbeam in real time and dynamically adjusts the difference in concrete pouring speed using a synchronous pouring rate planning method to ensure coordinated settlement deformation between the two.

[0037] First, fiber optic grating sensors or resistance strain gauges pre-embedded in key sections of the tower column and lower crossbeam are used to collect strain data of the concrete in real time during the hardening process. Combined with the compressive strength test results of specimens cured under the same conditions, the real-time flexural stiffness of the tower column concrete is calculated using a dynamic stiffness inversion algorithm. Real-time flexural stiffness of the lower crossbeam concrete .in, and These are the real-time elastic moduli of the concrete for the tower columns and crossbeams, respectively. and These are the moments of inertia of the cross sections for both.

[0038] Secondly, based on the aforementioned real-time data, the stiffness ratio between the tower column and the lower crossbeam is calculated. and coordinate it with the preset target ratio. By comparison, the stiffness compatibility deviation coefficient is obtained. This deviation coefficient reflects the degree of mismatch between the deformation capabilities of the two.

[0039] Next, the stiffness compatibility deviation coefficient is calculated using the control function in the synchronous casting rate planning method. This is converted into a pouring speed difference adjustment command, specifically by establishing a proportional-integral closed-loop feedback adjustment model in the control system; firstly, setting a "dead zone" threshold for stiffness deviation. ,when When the stiffness matching is considered to meet the requirements, the current pouring speed is maintained; when When this occurs, it indicates that the tower column stiffness is too large relative to the lower crossbeam, and the tower column settlement rate may lag behind that of the lower crossbeam. In this case, the system will adjust according to the formula... Calculate the speed correction amount, where This is the proportionality coefficient. The integral coefficient is... The difference in concrete pouring speed is the target. (Calculated) This represents the relative pouring rate that needs to be increased.

[0040] Combined with the cross-sectional area of ​​the tower column casting and the cross-sectional area of ​​the lower crossbeam The system generates specific pumping instructions: increase the discharge capacity of the concrete pump for the lower crossbeam. Or reduce the displacement of the concrete pump for the tower column. , making This accelerates the load increase of the lower crossbeam to match the stiffness state of the tower column; conversely, when If the situation is reversed, the opposite adjustment logic will be executed, either increasing the pouring speed of the tower column or slowing down the speed of the lower crossbeam.

[0041] Finally, the calculated target pouring speed difference The data is automatically transmitted to the central control system of the concrete pumping equipment. This system automatically adjusts the discharge rate of the concrete pumps distributed to the tower column and the lower crossbeam. By controlling the inflow of concrete per unit time, it ensures that the settlement and deformation rates of the two remain coordinated during the subsequent hardening process until the concrete is poured and reaches its final setting state.

[0042] This process, through closed-loop management of "real-time monitoring - data inversion - deviation calculation - rate adjustment - pumping control", achieves stiffness coordination and settlement synchronization during the concrete pouring process of the tower column and lower crossbeam, effectively avoiding the risk of structural deformation caused by stiffness mismatch and improving construction accuracy and structural safety.

[0043] Example 2 Please refer to Figure 4 This embodiment 2 provides a system for the scaffold-free integral hoisting of the lower crossbeam of a cable tower and the synchronous construction of the tower and beam, including: The lower crossbeam pre-deformation compensation unit is used to establish a finite element model of the overall hoisting segment of the lower crossbeam, and to simulate its stress distribution and deformation curve under the state of suspension without support. The pre-deformation compensation method is used to calculate the reverse displacement vector field of the lower crossbeam under its own weight, and a reverse geometric model is generated accordingly. Based on the reverse geometric model, the steel frame and template of the lower crossbeam are pre-arched during the factory prefabrication stage, so that after the lower crossbeam is hoisted into place and the hook is released, its structure recovers to the design theoretical shape under the action of gravity. The tower-beam dynamic matching pre-assembly unit is used to collect the actual spatial posture and environmental parameters of the tower column using a measuring robot before the tower column is constructed to the lower crossbeam connection height. These parameters are then input into the dynamic matching method to predict the tower column interface coordinates at the time of lower crossbeam installation. Based on the predicted coordinates, the tower-beam is virtually pre-assembled. When interference occurs, a rebar avoidance and adjustment command is output to guide the fine-tuning of the reserved rebars in the tower column on site. The tower-beam synchronous force balance unit is used to treat the lower crossbeam hoisting segment and the tower column as a coupled system and establish a tower-beam synchronous force balance model. After the lower crossbeam is hoisted and locked and before the concrete is poured, the counterbalance moment required to offset the eccentric load moment of the lower crossbeam is calculated by the balance decoupling method. According to the calculation results, an adjustable temporary counterweight is set on the opposite side of the tower column or prestressed cables are applied inside the tower column to actively balance the overturning moment generated by the lower crossbeam and ensure that the tower column always maintains its verticality within the safety threshold when all external supports are removed. The dynamic control unit for pouring rate is used to monitor the changes in strength and stiffness of the concrete of the tower column and the lower crossbeam in real time. It uses a synchronous pouring rate planning method to dynamically adjust the difference in concrete pouring speed according to the stiffness ratio of the two, and controls the pumping equipment to ensure that the settlement deformation of the tower column and the lower crossbeam remains coordinated.

[0044] Example 3 This embodiment 3 also provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it can realize any step of a method for the overall hoisting of the lower beam of a cable tower without supports and the synchronous construction of the tower and beam.

[0045] The computer-readable storage medium may include various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0046] For a description of the computer-readable storage medium provided in this application, please refer to the above method embodiments; further details will not be repeated here.

[0047] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements 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 the integral hoisting of the lower crossbeam of a cable tower without supports and the synchronous construction of the tower and beam, characterized in that, include: S1. Establish a finite element model of the lower crossbeam integral hoisting segment to simulate its stress distribution and deformation curve under the state of suspension without support; The reverse displacement vector field of the lower crossbeam under its own weight is calculated by running the pre-deformation compensation method, and a reverse geometric model is generated accordingly. Based on the reverse geometric model, the steel frame and template of the lower crossbeam are pre-arched during the factory prefabrication stage, so that after the lower crossbeam is hoisted into place and the hook is released, its structure recovers to the design theoretical shape under the action of gravity. S2. Before the tower column is constructed to the height of the lower crossbeam connection, the actual spatial posture and environmental parameters of the tower column are collected by a measurement robot and input into the dynamic matching method to predict the tower column interface coordinates at the time of lower crossbeam installation; based on the predicted coordinates, the tower beam is virtually pre-assembled, and when there is interference, the steel bar avoidance and adjustment command is output to guide the fine adjustment of the reserved steel bars of the tower column on site; S3. Treat the lower crossbeam hoisting segment and the tower column as a coupled system and establish a synchronous force balance model of the tower and beam; after the lower crossbeam is hoisted and locked and before the concrete is poured, calculate the counterbalance moment required to offset the eccentric load moment of the lower crossbeam using the balance decoupling method; based on the calculation results, set an adjustable temporary counterweight on the opposite side of the tower column or apply prestressed cables inside the tower column to actively balance the overturning moment generated by the lower crossbeam, and ensure that the tower column always maintains its verticality within the safety threshold when all external supports are removed; S4. Monitor the strength and stiffness changes of the concrete of the tower column and the lower crossbeam in real time, and use the synchronous pouring rate planning method to dynamically adjust the difference in concrete pouring speed according to the stiffness ratio of the two, and control the pumping equipment to ensure that the settlement deformation of the tower column and the lower crossbeam remains coordinated.

2. The method for the integral hoisting of the lower crossbeam of a cable tower without support and the synchronous construction of the tower and beam according to claim 1, characterized in that, The pre-deformation compensation method in S1 specifically includes: The nonlinear finite element analysis method is used to discretize the overall hoisting segment of the lower crossbeam into several beam elements; the initial design alignment is set as the target state, and the gravity load is used as the variable. The vertical displacement components of each node under the action of self-weight are solved by iterative calculation; the vertical displacement components are inverted as the pre-camber value and superimposed on the initial design coordinates of the lower crossbeam to generate a reverse geometric model containing pre-camber information.

3. The method for the integral hoisting of the lower crossbeam of a cable tower without support and the synchronous construction of the tower and beam according to claim 1, characterized in that, The specific method for constructing the inverse geometric model in S1 is as follows: First, a time-varying finite element model incorporating the construction environment parameter field is established, wherein the environment parameter field includes at least the real-time wind speed field. and non-uniform temperature field of solar radiation Calculate the lower crossbeam hoisting segment at the closure moment. Instantaneous theoretical deformation tensor ; Secondly, regarding the instantaneous theoretical deformation tensor By decoupling the error components, the elastic deformation component caused by the structure's own weight is separated. Residual shrinkage caused by welding process and random disturbance components caused by environmental effects ; Next, construct the inverse compensation function. Its expression is: in, The target coordinates of the inverse geometry model. To design coordinates, This is the weld shrinkage coefficient. The stiffness transfer matrix for the tower-beam connection interface. This is the real-time offset vector of the tower in cantilever mode; Finally, based on the aforementioned inverse compensation function A reverse geometry model containing pre-twisting and pre-deflection features is generated, enabling the lower crossbeam to counteract nonlinear disturbances in complex environments and precisely conform to the design line after hoisting into place and releasing constraints.

4. The method for the integral hoisting of the lower crossbeam of a cable tower without support and the synchronous construction of the tower and beam according to claim 1, characterized in that, The specific process of the dynamic matching method in S2 is as follows: Before the tower column is constructed to the height of the lower crossbeam connection, a surveying robot is used to collect the actual spatial posture and environmental parameters of the tower column. These parameters are then input into a dynamic matching method to predict the tower column interface coordinates at the moment of lower crossbeam installation. Specific steps include: First, based on the 3D point cloud data of the tower column acquired by the measurement robot at the current moment, the measured center point coordinates of the surface to be connected to the tower column are extracted by fitting. and normal vector ; Secondly, combined with real-time wind speed data collected by the weather station ,wind direction and ambient temperature Using a pre-established time-varying deformation prediction model for the tower column, the time difference from the current moment to the installation moment of the lower crossbeam is calculated. The deformation increment of the tower column; the deformation increment includes the elastic displacement vector caused by wind load. and the thermal deformation vector caused by temperature gradient change ; Finally, the measured center point coordinates are... By vector superposition with the deformation increment, the predicted coordinates of the tower column interface at the moment of lower beam installation are obtained. and the predicted coordinates Used as the target control coordinates for the lower crossbeam hoisting and positioning system to guide hoisting and assembly accuracy.

5. The method for the integral hoisting of the lower crossbeam of a cable tower without support and the synchronous construction of the tower and beam according to claim 1, characterized in that, The specific process in S3 for calculating the required counterbalance moment to offset the eccentric load moment of the lower crossbeam using the balance decoupling method is as follows: First, based on the finite element model of the coupled system of the tower column and the lower crossbeam, the structural stiffness matrix after the lower crossbeam is hoisted and locked is extracted. And combined with the self-weight of the lower crossbeam and hoisting eccentricity Calculate the initial eccentric load moment generated by the lower crossbeam on the tower column. ; Secondly, by using tilt sensors and strain gauges installed at the top of the tower column, the tower top displacement is monitored in real time when the lower crossbeam is locked. The stress distribution at the tower base was analyzed, and the actual thrust stiffness of the tower column was calculated using an inverse iterative algorithm. And correct the finite element model to eliminate the deviation between the theoretical value and the measured value; Next, based on the revised model, the counter-side equilibrium torque is set. Under the loading condition, the opposing balancing moment is applied through temporary prestressed tendons or a counterweight system on the opposite side of the tensioning tower column; a moment balance equation is constructed. ,in The frictional constraint moment at the tower-beam joint. This is the safety reserve factor; Finally, the torque balance equation is solved to obtain the required theoretical opposing equilibrium torque value. This information is then converted into specific tension force values ​​or counterweight mass, and output to the construction control system to guide the precise loading of the lateral balancing system, ensuring that the verticality deviation of the tower column is controlled within the allowable range.

6. The method for the integral hoisting of the lower crossbeam of a cable tower without support and the synchronous construction of the tower and beam according to claim 1, characterized in that, The adjustable temporary counterweight set on the opposite side of the tower column in S3 specifically involves installing a water tank or sand box on the corbel or embedded part on the opposite side of the tower column as a counterweight; the opposite side balance torque calculated by the balance decoupling method is directly converted into the mass parameters of the counterweight; during construction, water or sand is injected into the water tank or sand box in real time according to the progress of the lower crossbeam concrete pouring to maintain the dynamic balance of the torque.

7. The method for the integral hoisting of the lower crossbeam of a cable tower without support and the synchronous construction of the tower and beam according to claim 1, characterized in that, The application of prestressed cables inside the tower column in S3 specifically involves: Temporary steel strands are threaded through prestressed ducts inside the tower column. The upper anchor point of the temporary steel strands is located at the top of the tower column, and the lower anchor point is located in the tower column segment below the bottom of the lower crossbeam. The temporary steel strands are tensioned to generate a reverse bending moment to counteract the eccentric load moment generated by the self-weight of the lower crossbeam.

8. The method for the integral hoisting of the lower crossbeam of a cable tower without support and the synchronous construction of the tower and beam according to claim 1, characterized in that, The specific process of dynamically adjusting the difference in concrete pouring speed based on the stiffness ratio of the two components in S4 is as follows: First, set a dead zone threshold for stiffness deviation. ,when When the stiffness matching is considered to meet the requirements, the current pouring speed is maintained; when When this occurs, it indicates that the tower column stiffness is too large relative to the lower crossbeam, and the tower column settlement rate may lag behind that of the lower crossbeam. In this case, the system will adjust according to the formula... Calculate the speed correction amount, where This is the proportionality coefficient. The integral coefficient is... This is the stiffness compatibility deviation coefficient. The difference in concrete pouring speed is the target; the calculated This represents the relative increase in pouring rate required; Combined with the cross-sectional area of ​​the tower column casting and the cross-sectional area of ​​the lower crossbeam The system generates specific pumping instructions: increase the discharge capacity of the concrete pump for the lower crossbeam. Or reduce the displacement of the concrete pump for the tower column. , making This accelerates the load increase of the lower crossbeam to match the stiffness state of the tower column; conversely, when If the situation is reversed, the opposite adjustment logic will be executed, either increasing the pouring speed of the tower column or slowing down the speed of the lower crossbeam.

9. A system for the integrated hoisting of the lower crossbeam of a cable tower without supports and the synchronous construction of the tower and beam, characterized in that, include: The lower crossbeam pre-deformation compensation unit is used to establish a finite element model of the overall hoisting segment of the lower crossbeam and simulate its stress distribution and deformation curve under the state of suspension without support. The reverse displacement vector field of the lower crossbeam under its own weight is calculated by running the pre-deformation compensation method, and a reverse geometric model is generated accordingly. Based on the reverse geometric model, the steel frame and template of the lower crossbeam are pre-arched during the factory prefabrication stage, so that after the lower crossbeam is hoisted into place and the hook is released, its structure recovers to the design theoretical shape under the action of gravity. The tower-beam dynamic matching pre-assembly unit is used to collect the actual spatial posture and environmental parameters of the tower column using a measuring robot before the tower column is constructed to the lower crossbeam connection height. These parameters are then input into the dynamic matching method to predict the tower column interface coordinates at the time of lower crossbeam installation. Based on the predicted coordinates, the tower-beam is virtually pre-assembled. When interference occurs, a rebar avoidance and adjustment command is output to guide the fine-tuning of the reserved rebars in the tower column on site. The tower-beam synchronous force balance unit is used to treat the lower crossbeam hoisting segment and the tower column as a coupled system and establish a tower-beam synchronous force balance model. After the lower crossbeam is hoisted and locked and before the concrete is poured, the counterbalance moment required to offset the eccentric load moment of the lower crossbeam is calculated by the balance decoupling method. According to the calculation results, an adjustable temporary counterweight is set on the opposite side of the tower column or prestressed cables are applied inside the tower column to actively balance the overturning moment generated by the lower crossbeam and ensure that the tower column always maintains its verticality within the safety threshold when all external supports are removed. The dynamic control unit for pouring rate is used to monitor the changes in strength and stiffness of the concrete of the tower column and the lower crossbeam in real time. It uses a synchronous pouring rate planning method to dynamically adjust the difference in concrete pouring speed according to the stiffness ratio of the two, and controls the pumping equipment to ensure that the settlement deformation of the tower column and the lower crossbeam remains coordinated.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, The computer program is executed by the processor as described in any one of claims 1-8: a method for the integral hoisting of the lower crossbeam of a cable tower without supports and the synchronous construction of the tower and beam.

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