A method for reverse tensioning construction of cable-supported grid roof based on sensitivity feedback

Abstract

The application discloses a method for reverse tensioning construction of a cable-supported grid roof based on sensitivity feedback, and comprises the following steps: obtaining a theoretical sensitivity parameter through finite element analysis, obtaining a measured sensitivity parameter in previous construction, comprehensively combining the theoretical sensitivity parameter and the measured sensitivity parameter to obtain a corrected sensitivity parameter, and using the corrected sensitivity parameter to calculate a reverse tensioning adjustment amount in the next construction, so as to accurately control the response of the cable net, enable the cable net to be reverse tensioned to a design configuration, ensure accurate control in the whole construction process, and enable the cable net to be reverse tensioned to the design configuration as much as possible.

Description

Technical Field

[0001] This invention relates to the field of cable-supported grid roof construction technology, specifically to a method for reverse tensioning construction of cable-supported grid roofs based on sensitivity feedback. Background Technology

[0002] Cable-supported grid roof structures are commonly used for the roofs of large-span buildings such as stadiums and convention centers. These structures typically include a ring truss, circumferential cables, radial cables, cable clamps, struts, support nodes, and the upper roof steel structure. For spoke-type cable-supported grid roofs, the circumferential and radial cables form the main load-bearing cable net, with the ring truss serving as the boundary. The configuration and cable stress state of the cable net during construction directly affect the installation accuracy of the subsequent roof steel structure and its final form.

[0003] Traditional cable-stayed roof construction typically relies on scaffolding, support frames, or temporary support systems for installation. While this method offers relatively straightforward construction control, it presents challenges for large stadium roofs. It involves a large number of temporary measures, long erection and dismantling cycles, significant site occupation, and can easily disrupt cross-construction work involving stands, curtain walls, and electromechanical systems. To reduce the need for temporary supports, various scaffolding-free or minimal-scaffolding construction methods have been proposed in existing technologies. These include first laying circumferential and radial cables to form a cable net structure, then lifting the cable net using lifting tools; or using temporary components such as pull-down cables, counterweight cables, vertical construction cables, and reaction frame devices to pull down or counter-tension the cable net nodes; and other technical solutions employ zoned construction, phased tensioning, finite element simulation analysis, or utilizing the self-weight of the upper steel structure to gradually bring the cable net nodes closer to the design elevation.

[0004] Existing methods can reduce the amount of scaffolding required, lower construction costs, and address issues related to cable net lifting, superstructure installation, or temporary support replacement to some extent. However, for the precision control of reverse tensioning during the cable-before-steel construction process, existing methods primarily focus on construction sequence, the arrangement of temporary cables or reaction devices, structural lifting methods, theoretical tension force calculations, and ensuring control nodes reach predetermined elevations. They typically lack a closed-loop control method based on actual field measurements. Especially when the cable net is pre-tensioned before the roof steel structure installation, its stress state during construction is not entirely consistent with its final formed state. If control is based solely on theoretical tension force, single cable force indicators, or a few control node elevations, it can easily lead to mismatches in node elevations, height differences, or spatial positions during subsequent roof steel structure installation, thus affecting component placement, connection accuracy, and construction safety.

[0005] In actual construction, the control of reverse tensioning and forming of cable-supported grid roofs involves the following issues: 1. The elevation of cable clamps and the elevation difference between cable clamps need to be coordinately controlled. During construction, it is not only necessary to control the elevation of a single circumferential cable clamp or radial cable clamp, but also to control the elevation difference between adjacent circumferential cable clamps, the elevation difference between cable clamps on the same radial cable, and the elevation difference between a radial cable clamp and an adjacent circumferential cable clamp. The above-mentioned elevation differences are directly related to whether the steel structure of the roof can be smoothly installed in place, and it is difficult to ensure the overall installation matching only by controlling the elevation of a single point or the force of a single cable.

[0006] 2. The on-site measurement points are not completely consistent with the model control points. On site, the points on the surface of components are usually measured, while the actual finite element model controls the center points. If the coordinates of on-site measurement points are directly used as model control points, or only simple coordinate comparison is performed, there may be correspondence errors between the measured data and the theoretical control values, which will further affect the judgment of forming deviation and the calculation of reverse tension adjustment amount.

[0007] 3. The structural responses in different construction stages differ significantly. During the reverse tension forming process of the cable net, when a single down-draw cable is adjusted, the elevation of cable clamps, the displacement of supporting nodes and the cable force will change in a linked manner. In the stages of graded reverse tension of circumferential cables, graded reverse tension of radial cables and installation of the roof steel structure, the assembly state of the cable net, structural stiffness and boundary constraints will all change. In the past, construction often adopted fixed parameters or mainly relied on on-site experience, which made it difficult to ensure the adjustment accuracy.

[0008] 4. Although the prior art can determine the tension sequence, theoretical tension force or target elevation of control nodes through finite element analysis or construction experience, it usually does not establish the stage sensitivity relationship between the reverse tension control amount and the elevation of cable clamps, the elevation difference between cable clamps, the cable force and the displacement of supporting nodes, nor does it use the measured response after each stage of on-site reverse tension to dynamically correct the sensitivity relationship. Therefore, when there is a difference between the on-site structural response and the theoretical model, construction adjustment often lacks a quantifiable feedback basis, which is prone to the situation that the adjustment should be completed in theory but the on-site response is insufficient or excessive.

[0009] 5. There is a lack of a model correction trigger mechanism based on measured deviations in key construction stages. When the on-site measured cable force, displacement of supporting nodes or elevation of cable clamps differ greatly from the finite element analysis results, the model parameters should be corrected in time and form-finding should be re-performed. Although the existing construction methods may use finite element simulation for pre-construction analysis, they usually lack a clear process that combines on-site re-measurement data, stage sensitivity parameters and model correction conditions, resulting in the subsequent construction control benchmark may continuously deviate from the real structural response.

[0010] Therefore, on the basis of the existing technologies such as frameless construction, cable net lifting, temporary down-draw cable reverse tension, batch tension and finite element construction simulation, it is still necessary to propose a reverse tension forming precision control method with the sensitivity parameters of construction stages as the calculation core to achieve precise control. Contents of the Invention

[0011] This invention provides a method for reverse tensioning construction of cable-supported mesh roofs based on sensitivity feedback. It solves the problem that there is no quantifiable sensitivity relationship between the reverse tensioning control quantity and the cable mesh forming response during the construction of cable-supported mesh roofs with cables first and steel later, and that this sensitivity relationship cannot be dynamically corrected with the actual measured response on site. This transforms the reverse tensioning forming control of the cable mesh from theoretical calculation value or empirical control to closed-loop control based on actual measured on site sensitivity parameters.

[0012] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: A method for reverse tensioning construction of a cable-supported grid roof based on sensitivity feedback includes the following steps: S1, Construct a control table: Construct a control table based on construction stage k, response control node i, anti-tension control group j, control quantity ΔQ, control response ΔR, sensitivity parameter S, and deviation parameter e; S2, Obtaining Initial Sensitivity: Obtain the theoretical sensitivity parameter S of the control node in stage k through finite element analysis. 理论 , S 理论 =ΔR 理论 / ΔQ 理论 , S3, Obtain the measured deviation: Perform actual measurements on the construction structure and calculate the deviation parameter e for stage k; S4, Calculate the counter-tensioning adjustment amount: using the theoretical sensitivity parameter S 理论 The counter-tension adjustment ΔQ for stage k is calculated using the deviation parameter e. min‖W·[S 理论 (k)·ΔQ(k)+e(k)]‖², in, W represents the weight matrix of the control parameters in the control response ΔR. S 理论 (k) represents the theoretical sensitivity parameter matrix for stage k. e(k) is the deviation parameter vector for stage k; S5, Anti-tensioning construction: Perform anti-tensioning construction in stage k; S6, Sensitivity Correction: Collect the actual control quantity ΔQ during the K-stage anti-tensioning construction. 实际 and actual control response ΔR 实际 And calculate the measured sensitivity parameter S for stage k. 实测 Based on the measured sensitivity parameter S 实测 and theoretical sensitivity parameter S 理论 Calculate the correction sensitivity parameter S 修正 ; S 修正 =αS 理论+(1-α)S 实测 , In the formula, α is the fusion weight of the theoretical sensitivity parameter and the measured sensitivity parameter; S7, Parameter Correction: Use the correction sensitivity parameter S in the control table. 修正 Alternative theoretical sensitivity parameter S 理论 , used for anti-tensioning construction in stage k+1; S8, Repeated Construction: Obtain the deviation parameter e of stage k+1, and adjust the sensitivity parameter S according to the correction. 修正 The counter-tensioning adjustment amount ΔQ for stage k+1 is calculated from the deviation parameter e of stage k+1, and counter-tensioning construction for this stage is carried out according to the counter-tensioning adjustment amount ΔQ. Repeat construction steps S6-S8 until the current area is tensioned.

[0013] Further, in step S1, the anti-tension control group j is the pull cable, the response control node i is the cable clamp, the response control node i and the anti-tension control group j correspond one-to-one, the control quantity ΔQ is the change in the anti-tension length of the pull cable, and the control indicators of the control response ΔR include the change in cable clamp elevation, the change in the height difference between cable clamps, the change in the displacement of the support node, the change in the cable net tension, and the change in the slippage of the support node. The control response ΔR takes the change in cable clamp elevation and the change in the height difference between cable clamps as the main control indicators, and the change in the displacement of the support node, the change in the cable net tension, and the change in the slippage of the support node as the secondary control indicators.

[0014] Furthermore, the sensitivity parameter S of a single control indicator is, S ＿ ij(k, p, q) = ΔR ＿ i, p(k) / ΔQ ＿ j, q(k), in, K stands for: Construction phase p represents the region where the response control point is located. q represents the area where the anti-tensioning control group is located. i represents the response control point number. j represents the anti-tensioning control group number; When the cable is reverse-tensioned, it simultaneously affects this region and other regions. The impact on the control response ΔR of different regions is as follows: ΔR ＿ i, p(k) = ΣS ＿ ij(k, p, q)·ΔQ ＿ j, q(k), in, ΔR ＿i, p(k) represents the change in structural response at the i-th response point in region p during the k-th stage. ΔQ ＿ j,q(k) represents the change in control quantity for the j-th control group in region q during stage k. S ＿ ij(k, p, q) represents the sensitivity parameter of the j-th control group in region q during the k-th stage to the i-th response point in region p. When p=q, it represents the effect of the anti-tensioning operation on the control response of this region; when p≠q, it represents the effect of the anti-tensioning operation on the control response of other regions.

[0015] Furthermore, in step S2, the reverse tensioning operation of the cable is simulated in the finite element analysis to obtain the theoretical control quantity ΔQ. 理论 and theoretical control response ΔR 理论 And calculate the theoretical sensitivity parameter S. 理论 .

[0016] Further, in step S3, the deviation parameter e includes the cable clamp elevation deviation, the elevation difference between cable clamps deviation, the support node displacement deviation, the cable net tension deviation, and the support node slippage deviation, which correspond to the changes in cable clamp elevation, the elevation difference between cable clamps, the displacement of support nodes, the cable net tension, and the slippage of support nodes, respectively.

[0017] Furthermore, in step S4, the weight W is determined based on the allowable deviation of the control index in the control response ΔR. W ＿ i=1 / δ ＿ i², in, W ＿ i represents the weight of the i-th control indicator. δ ＿ i² represents the allowable deviation of the i-th control index.

[0018] Furthermore, in step S7, the sensitivity parameter S is corrected. 修正 When the threshold is exceeded, the finite element model is corrected, and the theoretical sensitivity parameter S is re-acquired. 理论 .

[0019] The beneficial effects of this invention are as follows: First, the initial sensitivity parameters between the anti-tension control quantity and the structural response are established through finite element analysis. Then, the sensitivity parameters are corrected through on-site measured data. The corrected sensitivity parameters are used to back-calculate the next anti-tension control quantity to ensure the accuracy of anti-tension control. Through continuous correction, the precise control of the entire construction process is ensured, and the cable net can be anti-tensioned to the design position as much as possible, thereby ensuring the accuracy of the roof structure installation. By employing overall coordinated control of multiple control parameters, the accuracy and matching of the overall cable net construction are ensured. Furthermore, different weights are set for control at different stages to address the defect of large differences in control response at different construction stages and ensure that the control response is more in line with construction requirements. By taking into account the forming deviation and using it together with the sensitivity parameter in the calculation of the anti-tension control quantity, the accuracy of anti-tension control is further improved. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall process of the present invention; Figure 2 This is a schematic diagram of the forming deviation calculation process of the present invention; Figure 3 This is a schematic diagram of the sensitivity calculation process of the present invention; Figure 4 This is a schematic diagram of the sensitivity correction process of the present invention; Figure 5 This is a schematic diagram of the actual application structure of the present invention.

[0021] Reference numerals: 1. Compression ring truss; 2. Circumferential cable; 3. Radial cable; 4. Circumferential cable clamp; 5. Radial cable clamp; 6. Support node; 7. Circumferential down-stayed cable; 8. Radial down-stayed cable. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] like Figure 5 As shown, the application of this invention is the construction of a cable-supported grid roof using pull-down cables for counter-tensioning. The cable-supported grid roof includes a pressure ring truss 1, circumferential cables 2, radial cables 3, circumferential cable clamps 4, radial cable clamps 5, support nodes 6, and pull-down cables for counter-tensioning. The pull-down cables include circumferential pull-down cables 7 and radial pull-down cables 8. The circumferential pull-down cables are mainly used to apply a pulling force to the circumferential cable clamps or their nearby nodes, and the radial pull-down cables are mainly used to apply a pulling force to the radial cable clamps or their nearby nodes. During construction, the cable net composed of circumferential cables 2 and radial cables 3 is first lifted into place. Then, the cable net is counter-tensioned to the designed position using the pull-down cables. Finally, the roof module is placed on the counter-tensioned cable net.

[0025] The counter-tensioning of cable nets is carried out in stages and regions. However, the structural state of the cable-supported mesh structure continuously changes during construction, such as during the initial cable net lifting stage, the circumferential temporary lower cable counter-tensioning stage, the radial temporary lower cable counter-tensioning stage, the upper steel structure installation stage, and the temporary lower cable unloading and final adjustment stage. In each stage, the structural stiffness, cable force level, boundary constraints, construction loads, and the state of installed components are different. Adding the same counter-tension force may produce completely different displacement responses in different stages. Therefore, sensitivity parameters should be established separately for each construction stage and continuously corrected, rather than applying the same set of parameters to all stages. Furthermore, the cable-supported mesh structure is a continuous force-bearing system; counter-tensioning adjustments in one area not only affect that area but may also affect adjacent areas, symmetrical areas, and support nodes. Therefore, sensitivity parameters should include regional coupling relationships. This invention, in obtaining sensitivity parameters, uses finite element analysis and on-site measurements for correction to ensure the accuracy of the sensitivity parameters, thereby ensuring that the cable net counter-tensioning achieves the expected results.

[0026] like Figure 1 , 2 As shown in Figures 3 and 4, a method for reverse tensioning construction of a cable-supported grid roof based on sensitivity feedback includes the following steps: S1, Construct a control table: Construct a control table based on construction stage k, response control node i, anti-tension control group j, control quantity ΔQ, control response ΔR, sensitivity parameter S, and deviation parameter e; Construct the control table to record values, and use it as a unified entry point for subsequent forming deviation evaluation, sensitivity parameter retrieval, force value closed-loop verification, support slip verification, and anti-tension control quantity calculation; S2, Obtaining Initial Sensitivity: Obtain the theoretical sensitivity parameter S of the control node in stage k through finite element analysis. 理论 , S 理论 =ΔR 理论 / ΔQ 理论; S3, Obtain the measured deviation: Perform actual measurements on the construction structure and calculate the deviation parameter e for stage k; S4, Calculate the counter-tensioning adjustment amount: using the theoretical sensitivity parameter S 理论 The counter-tension adjustment ΔQ for stage k is calculated using the deviation parameter e. min‖W·[S 理论 (k)·ΔQ(k)+e(k)]‖², in, W represents the weight matrix of the control parameters in the control response ΔR. S 理论 (k) represents the theoretical sensitivity parameter matrix for stage k. e(k) is the deviation parameter vector for stage k; S5, Anti-tensioning construction: Perform anti-tensioning construction in stage k; S6, Sensitivity Correction: Collect the actual control quantity ΔQ during the K-stage anti-tensioning construction. 实际 and actual control response ΔR 实际 And calculate the measured sensitivity parameter S for stage k. 实测 Based on the measured sensitivity parameter S 实测 and theoretical sensitivity parameter S 理论 Calculate the correction sensitivity parameter S 修正 ; S 修正 =αS 理论 +(1-α)S 实测 , In the formula, α is the fusion weight of the theoretical sensitivity parameter and the measured sensitivity parameter, with a value range of 0.5-0.9. Specifically, when there is little or no field measured data or the data dispersion is large in the early stage of construction, α is taken as 0.7-0.9. When no less than 2-3 levels of effective measured data have been obtained in the same construction stage, and the measured response change trend is stable, α is taken as 0.5-0.7. If there are obvious abnormalities in the field measured data or the measurement error exceeds the preset threshold, the measured data of that level will not participate in the sensitivity correction, and α will maintain the value of the previous stage or be taken as 0.8-0.9. S7, Parameter Correction: Use the correction sensitivity parameter S in the control table. 修正 Alternative theoretical sensitivity parameter S 理论 , used for anti-tensioning construction in stage k+1; S8, Repeated Construction: Obtain the deviation parameter e of stage k+1, and adjust the sensitivity parameter S according to the correction. 修正 The counter-tensioning adjustment amount ΔQ for stage k+1 is calculated from the deviation parameter e of stage k+1, and counter-tensioning construction for this stage is carried out according to the counter-tensioning adjustment amount ΔQ. Repeat construction steps S6-S8 until the current area is tensioned.

[0027] The specific principle of this invention is as follows: Since both the cable net and the downstay cable are flexible structures, and the cable clamp is not a simple point structure but a complex three-dimensional structure, the length of the downstay cable's counter-tensioning is not equal to the response height of the cable clamp when counter-tensioning is performed. Therefore, the relationship between the control quantity of the counter-tensioning control group and the change in the control response of the response control node is first analyzed through finite element simulation, i.e., the sensitivity parameter, so that the counter-tensioning length of the downstay cable corresponds precisely to the response height of the cable clamp. Then, counter-tensioning is performed according to the control quantity calculated according to the sensitivity parameter to ensure that the cable clamp can correctly respond to the required height. In addition, the finite element analysis uses theoretical values, which deviate from the measured values ​​during actual construction. Therefore, the accuracy of the control quantity is further improved by integrating the forming deviation based on the sensitivity parameter. Due to the structural characteristics of the cable net, counter-tensioning will affect the surrounding response control nodes. Therefore, after each counter-tensioning operation, the control quantity needs to be corrected to avoid the accumulation of errors caused by the previous counter-tensioning operation, thereby ensuring the accuracy of the results.

[0028] Specifically, theoretical sensitivity parameters are first obtained through finite element analysis, and then measured sensitivity parameters from the previous construction are obtained. The theoretical sensitivity parameters and measured sensitivity parameters are combined to obtain corrected sensitivity parameters. In the next construction, the corrected sensitivity parameters are used to calculate the anti-tensioning adjustment amount in order to accurately control the cable net response so that the cable net can be anti-tensioned to the design configuration.

[0029] Further, in step S1, the anti-tension control group j is the pull cable, the response control node i is the cable clamp, the response control node i and the anti-tension control group j correspond one-to-one, the control quantity ΔQ is the change in the anti-tension length of the pull cable, and the control indicators of the control response ΔR include the change in cable clamp elevation, the change in the height difference between cable clamps, the change in the displacement of the support node, the change in the cable net tension, and the change in the slippage of the support node. The control response ΔR takes the change in cable clamp elevation and the change in the height difference between cable clamps as the main control indicators, and the change in the displacement of the support node, the change in the cable net tension, and the change in the slippage of the support node as the secondary control indicators.

[0030] In a specific embodiment of the present invention, the control tables include Tables 0 to 5. Table 0, the real-time monitoring table for cable clamp elevation, is used to provide the stage target configuration, target elevation, and measured elevation of the cable clamp or node, and is used to display and record the cable clamp elevation or displacement. Table 1, the real-time monitoring table for cable clamp plane deformation, is used to provide the measured coordinates, design coordinates, plane deviation, elevation deviation, and inter-cable clamp differences of the cable clamp, and is used to display and record the plane deformation or deviation of the cable clamp. Table 2, the real-time monitoring table for circumferential cable counter-tensioning, is used to provide the control group, design tension force, theoretical pressure, and design displacement of the circumferential cable staged counter-tensioning, and is used to display and record the circumferential cable counter-tensioning. The anti-tension control quantity of cable 7; the real-time monitoring table for anti-tension of radial cable No. 3 is used to provide the anti-tension control quantity for different clamp positions of radial cable, and to display and record the anti-tension control quantity of radial cable 8; the real-time monitoring table for cable force No. 4 is used to provide the pressure gauge number, jack number, oil pressure gauge reading, measured force value, theoretical force value and deviation percentage, and to display and record the cable force of the cable net; the real-time monitoring table for slippage value of support node No. 5 is used to provide the measured coordinates, design coordinates, slippage or displacement difference, circumferential difference, radial difference and elevation difference of support node, and to display and record the slippage of support node 6.

[0031] Furthermore, the theoretical control quantity ΔQ is obtained by simulating the reverse tensioning operation of the cable in the finite element analysis. 理论 and theoretical control response ΔR 理论 And calculate the theoretical sensitivity parameter S. 理论 Specifically, a unit counter-tension control quantity is applied to the counter-tension control group, and the response changes at each control point are extracted. The sensitivity parameter S for each individual control index is... S ＿ ij(k, p, q) = ΔR ＿ i, p(k) / ΔQ ＿ j, q(k), in, K stands for: Construction phase p represents the region where the response control point is located. q represents the area where the anti-tensioning control group is located. i represents the response control point number. j represents the anti-tensioning control group number.

[0032] The response changes can be changes in elevation, elevation difference, cable force or counter-tension force, and support slippage or displacement. The counter-tension control quantity can be the unit counter-tension force of the cable, the unit jack stroke of the cable, or the unit cable length change of the cable. Preferably, the most intuitive counter-tension length change of the cable is adopted.

[0033] Sensitivity parameters vary with construction stage, control area, response control point, and control index type. Flexible cable net structures, in particular, have a significant impact on other areas. Therefore, when counter-tensioning the lower cables, it will simultaneously affect this area and other areas. The impact of the control response ΔR on different areas is as follows: ΔR ＿ i, p(k) = ΣS ＿ ij(k, p, q)·ΔQ ＿ j, q(k), in, ΔR ＿ i, p(k) represents the change in structural response at the i-th response point in region p during the k-th stage. ΔQ ＿ j,q(k) represents the change in control quantity for the j-th control group in region q during stage k. S ＿ ij(k, p, q) represents the sensitivity parameter of the j-th control group in region q during the k-th stage to the i-th response point in region p. When p=q, it represents the effect of the anti-tensioning operation on the control response of this region; when p≠q, it represents the effect of the anti-tensioning operation on the control response of other regions.

[0034] Furthermore, in step S2, since the cable clamp is a three-dimensional solid structure, the actual physical center of the cable clamp needs to be determined when calculating the deviation parameter e. To determine the actual physical center of the cable clamp, multiple measuring points are first set on the cable clamp, then the coordinates of different measuring points are statistically analyzed, and finally the coordinates of multiple measuring points are fitted to obtain the actual physical center of the cable clamp. Among them, the circumferential cable clamp 4 is fitted with six measuring points, and the radial cable clamp 5 is fitted with two measuring points.

[0035] Further, in step S3, the deviation parameter e includes the cable clamp elevation deviation, the elevation difference between cable clamps deviation, the support node displacement deviation, the cable net tension deviation, and the support node slippage deviation, which correspond to the changes in cable clamp elevation, the elevation difference between cable clamps, the displacement of support nodes, the cable net tension, and the slippage of support nodes, respectively.

[0036] like Figure 2 As shown, when calculating the deviation parameter e, the corresponding deviation parameter is obtained by comparing the measured value with the target value in the control table. Elevation deviation is calculated as measured elevation - target elevation; cable clamp height difference deviation is calculated as measured height difference between adjacent control points - target height difference between adjacent control points; cable force or force value deviation is calculated as measured force value - theoretical force value or target force value; deviation percentage is calculated as force value deviation / theoretical force value or target force value; support slippage or support displacement deviation is calculated as measured slippage or displacement - allowable slippage or displacement.

[0037] Furthermore, in step S4, the control indicators in the control response ΔR have different importance and priority, and therefore different weights. For example, the height difference between cable clamps directly affects the installation of steel components, so it has a higher control priority; the displacement of the support node involves safety and can be used as a strong constraint; the deviation of ordinary cable force can be used as an auxiliary control indicator. The weight W is determined according to the allowable deviation of the control indicator in the control response ΔR. The smaller the allowable deviation, the more important the indicator is, and the greater its weight. W ＿ i=1 / δ ＿ i², in, W ＿ i represents the weight of the i-th control indicator. δ ＿ i² represents the allowable deviation of the i-th control index, which is determined according to design requirements.

[0038] Furthermore, in step S4, when calculating the anti-tension adjustment amount ΔQ, the sensitivity matrix may have ill-conditioned, coupled, or constrained problems, leading to distorted results. Therefore, constrained optimization calculation is adopted and limitations are set to avoid excessive adjustment amount. The limitations include: the single-stage anti-tension adjustment amount does not exceed the allowable value; the temporary lower cable anti-tension force does not exceed the limit; the cable force does not exceed the allowable cable force; the support node displacement does not exceed the allowable deviation; the adjustment difference between adjacent control groups does not exceed the allowable value; and the adjustment difference between symmetrical control groups does not exceed the allowable value.

[0039] Furthermore, in step S4, since the anti-tensioning control group simultaneously affects multiple control indicators when performing anti-tensioning, when the weight of a single control indicator is too high, a single control indicator can be used for calculation. When the differences between multiple control indicators are not significant, matrix calculation is used. This matrix is ​​used to describe the linkage effect of multiple temporary cable control groups on the elevation, height difference, cable force, and slippage of multiple cable clamps.

[0040] Furthermore, in step S7, the sensitivity parameter S is corrected. 修正 When the threshold is exceeded, the finite element model is corrected, and the theoretical sensitivity parameter S is re-acquired. 理论 And with a new theoretical sensitivity parameter S 理论 Perform the calculation.

[0041] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for reverse tensioning construction of cable-supported grid roof based on sensitivity feedback, characterized in that, Includes the following steps, S1, Construct a control table: Construct a control table based on construction stage k, response control node i, anti-tension control group j, control quantity ΔQ, control response ΔR, sensitivity parameter S, and deviation parameter e; S2, Obtaining Initial Sensitivity: Obtain the theoretical sensitivity parameter S of the control node in stage k through finite element analysis. 理论 , S 理论 =ΔR 理论 / ΔQ 理论 , S3, Obtain the measured deviation: Perform actual measurements on the construction structure and calculate the deviation parameter e for stage k; S4, Calculate the counter-tensioning adjustment amount: using the theoretical sensitivity parameter S 理论 The counter-tension adjustment ΔQ for stage k is calculated using the deviation parameter e. min‖W·[S 理论 (k)·ΔQ(k)+e(k)]‖², in, W represents the weight matrix of the control parameters in the control response ΔR. S 理论 (k) represents the theoretical sensitivity parameter matrix for stage k. e(k) is the deviation parameter vector for stage k; S5, Anti-tensioning construction: Perform anti-tensioning construction in stage k; S6, Sensitivity Correction: Collect the actual control quantity ΔQ during the K-stage anti-tensioning construction. 实际 and actual control response ΔR 实际 And calculate the measured sensitivity parameter S for stage k. 实测 Based on the measured sensitivity parameter S 实测 and theoretical sensitivity parameter S 理论 Calculate the correction sensitivity parameter S 修正 ; S 修正 =αS 理论 +(1-α)S 实测 , In the formula, α is the fusion weight of the theoretical sensitivity parameter and the measured sensitivity parameter; S7, Parameter Correction: Use the correction sensitivity parameter S in the control table. 修正 Alternative theoretical sensitivity parameter S 理论 , used for anti-tensioning construction in stage k+1; S8, Repeated Construction: Obtain the deviation parameter e of stage k+1, and adjust the sensitivity parameter S according to the correction. 修正 The counter-tensioning adjustment amount ΔQ for stage k+1 is calculated from the deviation parameter e of stage k+1, and counter-tensioning construction for this stage is carried out according to the counter-tensioning adjustment amount ΔQ. Repeat construction steps S6-S8 until the current area is tensioned.

2. The method for reverse tensioning construction of a cable-supported grid roof based on sensitivity feedback according to claim 1, characterized in that: step In S1, the anti-tension control group j is the down cable, the response control node i is the cable clamp, and the response control node i and the anti-tension control group j correspond one-to-one. The control quantity ΔQ is the change in the anti-tension length of the down cable. The control indicators of the control response ΔR include the change in cable clamp elevation, the change in the height difference between cable clamps, the change in the displacement of the support node, the change in the cable net tension, and the change in the slippage of the support node. The control response ΔR takes the change in cable clamp elevation and the change in the height difference between cable clamps as the main control indicators, and the change in the displacement of the support node, the change in the cable net tension, and the change in the slippage of the support node as the secondary control indicators.

3. The method for reverse tensioning construction of a cable-supported grid roof based on sensitivity feedback according to claim 2, characterized in that: The sensitivity parameter S for a single control indicator is, S ＿ ij(k,p、q)=ΔR ＿ i,p(k) / ΔQ ＿ j,q(k), in, K stands for: Construction phase p represents the region where the response control point is located. q represents the area where the anti-tensioning control group is located. i represents the response control point number. j represents the anti-tensioning control group number; When the cable is reverse-tensioned, it simultaneously affects this region and other regions. The impact on the control response ΔR of different regions is as follows: ΔR ＿ i,p(k)=ΣS ＿ ij(k,p、q)·ΔQ ＿ j,q(k), in, ΔR ＿ i, p(k) represents the change in structural response at the i-th response point in region p during the k-th stage. ΔQ ＿ j,q(k) represents the change in control quantity for the j-th control group in region q during stage k. S ＿ ij(k, p, q) represents the sensitivity parameter of the j-th control group in region q during the k-th stage to the i-th response point in region p. When p=q, it represents the effect of the anti-tensioning operation on the control response of this region; when p≠q, it represents the effect of the anti-tensioning operation on the control response of other regions.

4. The method for reverse tensioning construction of a cable-supported grid roof based on sensitivity feedback as described in claim 1, characterized in that: In step S2, the reverse tensioning operation of the cable is simulated in the finite element analysis to obtain the theoretical control quantity ΔQ. 理论 and theoretical control response ΔR 理论 And calculate the theoretical sensitivity parameter S. 理论 .

5. The method for reverse tensioning construction of a cable-supported grid roof based on sensitivity feedback as described in claim 1, characterized in that, In step S3, the deviation parameter e includes the deviation of cable clamp elevation, the deviation of the height difference between cable clamps, the deviation of the support node displacement, the deviation of the cable net tension, and the deviation of the support node slippage, which correspond to the changes in cable clamp elevation, the changes in the height difference between cable clamps, the changes in the support node displacement, the changes in the cable net tension, and the changes in the support node slippage, respectively.

6. The method for reverse tensioning construction of a cable-supported grid roof based on sensitivity feedback according to claim 1, characterized in that, In step S4, the weight W is determined based on the allowable deviation of the control index in the control response ΔR. W ＿ i=1 / δ ＿ i², in, W_i represents the weight of the i-th control indicator. δ_i² represents the allowable deviation of the i-th control index.

7. The method for reverse tensioning construction of a cable-supported grid roof based on sensitivity feedback according to claim 1, characterized in that: In step S7, the sensitivity parameter S is corrected. 修正 When the threshold is exceeded, the finite element model is corrected, and the theoretical sensitivity parameter S is re-acquired. 理论 .

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