Large-span steel truss girder accurate girder falling method and system based on stress monitoring

Abstract

The invention provides a large-span steel truss girder accurate girder falling method and system based on stress monitoring, and relates to the technical field of stress monitoring, and the method comprises the steps: obtaining girder body data of a steel truss girder; acquiring environment data of a construction site; a first beam falling scheme and a second beam falling scheme of the first beam falling stage and the second beam falling stage are obtained; in the first beam falling stage, first fulcrum counterforce is obtained through pressure sensors arranged at the fulcrum positions on the two sides; determining a first control discrimination parameter according to the environment data, the beam body data, the first beam falling scheme and the first fulcrum counterforce; in the second beam falling stage, steel wire rope tension and pier top counter-force are obtained; according to the environment data, the beam body data, the steel wire rope tension, the pier top counter-force and the second beam falling scheme, second control judgment parameters are determined; and according to the first control judgment parameter and the second control judgment parameter, whether the beam falling process is adjusted or not is determined. According to the invention, the accuracy of steel truss girder falling can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of force monitoring, and in particular, to a precise beam-lowering method and system for long-span steel truss girders based on force monitoring. Background Art

[0002] In the related art, CN114486007A discloses a bridge force monitoring system and its usage method, belonging to the field of bridges, which solves the problem of high cost of the current bridge force monitoring system. It includes bridge bearings, multiple piezoelectric sensors, multiple piezoelectric ceramic sheets, a signal collector, a signal converter, a data transmitter, and an electric energy storage device. The bridge bearings are arranged between the bridge piers and the bridge main girders. Multiple piezoelectric sensors are embedded in the bridge bearings so that when the bridge bearings are compressed, the piezoelectric sensors can be compressed to generate electrical signals. Multiple piezoelectric ceramic sheets are embedded in the bridge bearings so that when the bridge bearings are compressed, the piezoelectric ceramic sheets can be compressed to generate charges. The piezoelectric sensors are electrically connected to the signal collector. The signal collector is electrically connected to the signal converter. The signal converter is electrically connected to the data transmitter. The piezoelectric ceramic sheets are electrically connected to the electric energy storage device. The signal collector, the signal converter, and the data transmitter are all electrically connected to the electric energy storage device. This solution has a low cost.

[0003] CN112729635B discloses a real-time monitoring bearing and monitoring method for the force state of a steel-concrete composite beam based on a computer, including the following steps: framework arrangement, installation of a driving member, preset connection members, installation of monitoring components, and application. The beneficial effect is that the real-time monitoring method for the force state of a steel-concrete composite beam proposed in this solution controls the connection between the pressure sensor installed between the steel lining plate and the upper seat plate of the bearing and the data display control center, so that the data real-time monitored by the pressure sensor can be integrated and displayed at the data display control center through a computer, facilitating people to timely discover the force state of the steel-concrete composite beam.

[0004] Based on the above related technologies, the force condition of the composite beam can be monitored in real time. However, the related technologies do not consider the influence of the force condition on the accuracy of beam lowering, that is, it is impossible to adjust the beam-lowering process according to the environmental condition, the force condition of the beam body, and the beam-lowering stage of the beam body to ensure the accurate positioning of the beam body.

[0005] The information disclosed in the background art part of the present application is only intended to deepen the understanding of the general background art of the present application, and should not be regarded as an admission or any form of implication that this information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0006] The present invention provides a precise girder-lowering method and system for long-span steel truss girders based on force monitoring, which can solve the technical problem that the related art cannot adjust the girder-lowering process according to the environmental conditions, the force conditions of the girder body, and the girder-lowering stages to ensure the precise positioning of the girder body.

[0007] According to a first aspect of the present invention, there is provided a precise girder-lowering method for long-span steel truss girders based on force monitoring, including: obtaining the girder body data of the steel truss girder, wherein the girder body data includes the girder body weight and the girder body span; obtaining the environmental data of the construction site, wherein the environmental data includes rainfall data and wind force data; obtaining the first girder-lowering plan and the second girder-lowering plan for the first girder-lowering stage and the second girder-lowering stage; in the first girder-lowering stage, obtaining the first support reaction force through the pressure sensors arranged at the positions of the two side supports; determining the first control discrimination parameter according to the environmental data, the girder body data, the first girder-lowering plan, and the first support reaction force; in the second girder-lowering stage, obtaining the wire rope tension and the pier top reaction force; determining the second control discrimination parameter according to the environmental data, the girder body data, the wire rope tension, the pier top reaction force, and the second girder-lowering plan; and determining whether to adjust the girder-lowering process according to the first control discrimination parameter and the second control discrimination parameter.

[0008] According to a second aspect of the present invention, there is provided a precise girder-lowering system for long-span steel truss girders based on force monitoring, including: a girder body data module for obtaining the girder body data of the steel truss girder, wherein the girder body data includes the girder body weight and the girder body span; an environmental data module for obtaining the environmental data of the construction site, wherein the environmental data includes rainfall data and wind force data; a girder-lowering plan module for obtaining the first girder-lowering plan and the second girder-lowering plan for the first girder-lowering stage and the second girder-lowering stage; a first force module for obtaining the first support reaction force through the pressure sensors arranged at the positions of the two side supports in the first girder-lowering stage; a first control module for determining the first control discrimination parameter according to the environmental data, the girder body data, the first girder-lowering plan, and the first support reaction force; a second force module for obtaining the wire rope tension and the pier top reaction force in the second girder-lowering stage; a second control module for determining the second control discrimination parameter according to the environmental data, the girder body data, the wire rope tension, the pier top reaction force, and the second girder-lowering plan; and an adjustment module for determining whether to adjust the girder-lowering process according to the first control discrimination parameter and the second control discrimination parameter.

[0009] Technical effects: According to the present invention, it is possible to determine whether adjustment is required for the first-stage beam lowering based on environmental conditions, support reaction force conditions, beam data, and the first beam lowering plan, and determine the first control discrimination parameter. It is possible to determine whether adjustment is required for the second-stage beam lowering based on environmental conditions, beam data, wire rope tension, pier top reaction force, and the second beam lowering plan, and determine the second control discrimination parameter, thereby improving the accuracy of the steel truss beam lowering. When determining the foundation support reaction force, the foundation support reaction force can be determined based on the first beam lowering height, beam weight, and beam span, which can improve the accuracy of the foundation support reaction force and provide a data basis for subsequent calculations. When determining the first relationship function, the first relationship function between the historical number of supports, historical support reaction force, historical rainfall data, historical beam weight, and historical beam lowering height can be determined, which can accurately analyze the influence of beam self-weight, beam lowering plan, and environmental factors on the support reaction force, and improve the accuracy and objectivity of the first relationship function. When determining the tension anomaly coefficient, the tension anomaly coefficient can be determined based on the wire rope tension, pier top reaction force, beam span, and the first horizontal distance. During the calculation process, the balance relationship between the wire tension and the pier top reaction force can be accurately analyzed, and the tension anomaly coefficient can be determined based on the relative error between the actual wire tension and the theoretical wire rope tension, thereby improving the comprehensiveness and accuracy of the tension anomaly coefficient.

[0010] It should be understood that the above general description and the following detailed description are merely exemplary and explanatory, and do not limit the present invention. Other features and aspects of the present invention will become clearer from the following detailed description of exemplary embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other embodiments can be obtained based on these drawings. Figure 1 Exemplarily shows a flowchart of a method for accurately lowering a long-span steel truss beam based on force monitoring according to an embodiment of the present invention; Figure 2 Exemplarily shows a flowchart of calculating the first control discrimination parameter according to an embodiment of the present invention; Figure 3 Exemplarily shows a flowchart of calculating the second control discrimination parameter according to an embodiment of the present invention; Figure 4 Exemplarily shows a block diagram of a system for accurately lowering a long-span steel truss beam based on force monitoring according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are only a part rather than all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0013] The technical solutions of the present invention will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

[0014] Figure 1 The flowchart of the method for accurately lowering a long-span steel truss beam based on force monitoring according to an embodiment of the present invention is exemplarily shown. The method includes: Step S1, obtaining the beam body data of the steel truss beam, where the beam body data includes the beam body weight and the beam body span; Step S2, obtaining the environmental data of the construction site, where the environmental data includes rainfall data and wind force data; Step S3, obtaining the first lowering beam plan and the second lowering beam plan for the first lowering beam stage and the second lowering beam stage; Step S4, in the first lowering beam stage, obtaining the first support reaction force through the pressure sensors arranged at the positions of the two side supports; Step S5, determining the first control discrimination parameter according to the environmental data, the beam body data, the first lowering beam plan, and the first support reaction force; Step S6, in the second lowering beam stage, obtaining the steel wire rope tension and the pier top reaction force; Step S7, determining the second control discrimination parameter according to the environmental data, the beam body data, the steel wire rope tension, the pier top reaction force, and the second lowering beam plan; Step S8, determining whether to adjust the lowering beam process according to the first control discrimination parameter and the second control discrimination parameter.

[0015] According to the method for accurately lowering a long-span steel truss beam based on force monitoring according to an embodiment of the present invention, it is possible to judge whether the first-stage lowering beam needs to be adjusted according to the environmental conditions, the support reaction force conditions, the beam body data, and the first lowering beam plan, and determine the first control discrimination parameter. It is possible to judge whether the second-stage lowering beam needs to be adjusted according to the environmental conditions, the beam body data, the steel wire rope tension, the pier top reaction force, and the second lowering beam plan, and determine the second control discrimination parameter, improving the accuracy of the steel truss beam lowering.

[0016] According to an embodiment of the present invention, in Step S1, the beam body data of the steel truss beam is obtained, where the beam body data includes the beam body weight and the beam body span.

[0017] For example, according to the construction records and the design drawings, the beam body weight and the beam body span of the steel truss beam are obtained.

[0018] According to an embodiment of the present invention, in step S2, environmental data of the construction site is acquired, wherein the environmental data includes rainfall data and wind force data.

[0019] For example, rainfall sensors and wind force sensors are arranged at the construction site to acquire the rainfall data and wind force data of the construction site.

[0020] According to an embodiment of the present invention, in step S3, the first girder dropping plan and the second girder dropping plan for the first girder dropping stage and the second girder dropping stage are acquired.

[0021] For example, according to the construction plan, the first girder dropping plan and the second girder dropping plan for the first girder dropping stage and the second girder dropping stage are acquired. For example, the first girder dropping plan for the first girder dropping stage is to alternately drop the steel truss girder on both sides, such as alternately dropping the girder on the side of Pier 1 and the side of Pier 2, with a dropping height of 16 cm each time and a total dropping height of 1.6 m. The second girder dropping plan for the second girder dropping stage is to drop the steel truss girder unidirectionally on one side. For example, at the side of Pier 2 where the girder has been dropped in place, wire ropes are used for anti-slip traction, and the girder is dropped unidirectionally on the side of Pier 1, with a dropping height of 16 cm each time and a total dropping height of 2.3 m.

[0022] According to an embodiment of the present invention, in step S4, in the first girder dropping stage, the first support reaction force is acquired through the pressure sensors arranged at the positions of the two side supports.

[0023] For example, pressure sensors are respectively arranged at the top of Pier 1 and the top of Pier 2 on both sides of the steel truss girder. The vertical reaction force of the support points at the top of the pier (such as jacks or pads) is directly measured through the pressure sensors, and the vertical reaction force detected during the girder dropping on the pier side is determined as the first support reaction force. For example, in the first girder dropping stage, if the first girder dropping is for the side of Pier 1, the first support reaction force corresponding to the first girder dropping in the first girder dropping stage is the vertical reaction force detected by the pressure sensor at Pier 1 during the first girder dropping.

[0024] According to an embodiment of the present invention, in step S5, the first control discrimination parameter is determined based on the environmental data, the beam body data, the first girder dropping plan, and the first support reaction force.

[0025] Figure 2 Exemplarily shows a flowchart of the calculation of the first control discrimination parameter according to an embodiment of the present invention.

[0026] According to an embodiment of the present invention, step S5 includes: step S51, obtaining a first beam lowering height according to the first beam lowering scheme; step S52, determining the foundation support reaction force according to the first beam lowering height, the weight of the beam body, and the span of the beam body; step S53, obtaining historical data in the historical beam lowering period, where the historical data includes: the number of historical supports, the historical support reaction force, historical rainfall data, the historical weight of the beam body, and the historical beam lowering height; step S54, determining a first relationship function among the number of historical supports, the historical support reaction force, the historical rainfall data, the historical weight of the beam body, and the historical beam lowering height; step S55, determining a set support reaction force threshold according to the first beam lowering height, the first relationship function, the foundation support reaction force, the rainfall data, and the beam body data; step S56, determining a first control discrimination parameter according to the wind force data, the set support reaction force threshold, and the first support reaction force.

[0027] For example, obtain the beam lowering height for each time in the first beam lowering stage, that is, the first beam lowering height; according to the first beam lowering height, the weight of the beam body, and the span of the beam body, calculate the support reaction forces at the positions of the two pier tops under static conditions without being affected by external factors during the beam lowering process, and determine the foundation support reaction force; obtain the number of historical supports, the historical support reaction force, historical rainfall data, the historical weight of the beam body, and the historical beam lowering height during the successful and precise beam lowering process of the historical steel truss beam; the support reaction force is related to the rainfall data, the number of supports, the weight of the beam body, and the beam lowering height to a certain extent. For example, the heavier the beam body weight, the greater the support reaction force. Based on the correlation of the above data, determine a first relationship function among the number of historical supports, the historical support reaction force, historical rainfall data, the historical weight of the beam body, and the historical beam lowering height; substitute the first beam lowering height, the foundation support reaction force, the rainfall data, and the beam body data into the first relationship function to determine the set support reaction force threshold; according to the wind force data, the set support reaction force threshold, and the first support reaction force, judge whether adjustment is required in the first beam lowering stage, and determine the first control discrimination parameter.

[0028] According to an embodiment of the present invention, in step S52, determining the foundation support reaction force according to the first beam lowering height, the weight of the beam body, and the span of the beam body includes: determining the foundation support reaction force according to formula (1) , (1), where, is the weight of the beam body, is the acceleration due to gravity, is the first beam lowering height, is the span of the beam body.

[0029] According to an embodiment of the present invention, when the first beam lowering height is lowered at one pier side When the center of gravity shifts towards the pier side, the reaction force at the pier side increases. In formula (1), can be equivalently expressed as , is the moment of the reaction force at the pier side where the beam drops relative to the non-beam-dropping pier side, is the moment of the self-weight of the beam relative to the non-beam-dropping pier side, is the horizontal distance from the center of gravity of the beam to the non-beam-dropping pier side. When the beam is not tilted, the distance from the center of gravity of the beam to the pier side is When one side of the beam drops by distance, the center of gravity drops by , and at the same time, the center of gravity of the beam shifts towards the pier side where the beam drops by . Based on the above relevant formulas, the reaction force at the pier side where the beam drops under theoretical conditions can be determined, that is, the foundation reaction force.

[0030] In this way, the foundation reaction force can be determined according to the first beam-dropping height, the weight of the beam, and the span of the beam, which can improve the accuracy of the foundation reaction force and provide a data basis for subsequent calculations.

[0031] According to an embodiment of the present invention, in step S54, determining the first relationship function among the historical number of supports, the historical reaction force of the supports, the historical rainfall data, the historical weight of the beam, and the historical beam-dropping height includes: determining the first undetermined coefficient equation of the first relationship function according to formula (2), (2), wherein, is the historical reaction force of the supports in the k-th historical beam-dropping cycle, is the historical weight of the beam in the k-th historical beam-dropping cycle, is the acceleration due to gravity, is the historical beam-dropping height in the k-th historical beam-dropping cycle, is the historical rainfall data in the k-th historical beam-dropping cycle, is the historical number of supports in the k-th historical beam-dropping cycle, , , , , and are the first undetermined coefficients; solving the first undetermined coefficients according to the historical number of supports, the historical reaction force of the supports, the historical rainfall data, the historical weight of the beam, and the historical beam-dropping height to obtain the solution values of the first undetermined coefficients; determining the first relationship function according to the solution values of the first undetermined coefficients and the first undetermined coefficient equation.

[0032] According to an embodiment of the present invention, is the average value of the beam weight borne by each support in the k-th historical beam lowering period, indicates that there is a positive correlation between the historical support reaction force in the k-th historical beam lowering period and the average value of the beam weight borne by each support in the k-th historical beam lowering period. For example, the heavier the historical beam weight, the greater the average value of the beam weight borne by each support, and the greater the support reaction force. indicates that there is a positive correlation between the historical support reaction force in the k-th historical beam lowering period and the historical beam lowering height in the k-th historical beam lowering period. For example, the energy accumulated due to elastic deformation (such as bending, shear) during the lowering of the beam may be suddenly released during displacement adjustment, resulting in an increase in the support reaction force. The greater the beam lowering height, the greater the energy accumulated by elastic deformation, and the greater the support reaction force. indicates that there is a positive correlation between the historical support reaction force in the k-th historical beam lowering period and the historical rainfall data in the k-th historical beam lowering period. For example, if rainfall occurs during construction, the rainwater accumulates on the surface of the beam, increasing the self-weight by about 2 - 5% (depending on the drainage design), resulting in an increase in the support reaction force. Based on the above relationships, the first undetermined coefficient equation of the first relationship function can be obtained.

[0033] According to an embodiment of the present invention, fitting can be performed based on multiple parameters involved in the above first undetermined coefficient equation, that is, fitting based on the historical number of supports, historical support reaction force, historical rainfall data, historical beam weight, and historical beam lowering height, and solving the above multiple first undetermined coefficients. There are 6 first undetermined coefficients, namely, , , , , and . Solve the above 6 first undetermined coefficients according to the historical number of supports, historical support reaction force, historical rainfall data, historical beam weight, and historical beam lowering height in at least 6 historical beam lowering periods, obtain the solution values of the above 6 first undetermined coefficients, and substitute the solution values of the above 6 first undetermined coefficients into the first undetermined coefficient equation to determine the first relationship function.

[0034] In this way, the first relationship function between the historical number of supports, historical support reaction force, historical rainfall data, historical beam weight, and historical beam lowering height can be determined, and the influences of the beam self-weight, beam lowering scheme, and environmental factors on the support reaction force can be accurately analyzed, improving the accuracy and objectivity of the first relationship function.

[0035] According to an embodiment of the present invention, step S56 includes: step S561, determining a wind force identification result according to the wind force data and a set wind force data threshold; step S562, determining a support reaction force identification result according to the first support reaction force and the set support reaction force threshold; step S563, determining a first control discrimination parameter according to the wind force identification result and the support reaction force identification result.

[0036] For example, if the wind force data is greater than or equal to the set wind force data threshold (e.g., 8 m / s), wind-induced vibration may cause periodic changes in the support reaction force, resulting in inaccurate placement of the beam during the beam-lowering process. In this case, the wind force identification result is 2. If the wind force data is less than the set wind force data threshold, the wind force identification result is 0. If the first support reaction force is greater than or equal to the set support reaction force threshold, it indicates that there is an abnormality in the support reaction force at this position during the beam-lowering process, which may be caused by inaccurate beam-lowering. In this case, the support reaction force identification result is 1. If the first support reaction force is less than the set support reaction force threshold, the support reaction force identification result is 0. The first control discrimination parameter is determined by adding the wind force identification result and the support reaction force identification result.

[0037] According to an embodiment of the present invention, in step S6, during the second beam-lowering stage, the steel wire rope tension and the pier top reaction force are obtained.

[0038] For example, during the second beam-lowering stage, during the process of lowering the beam unilaterally at the top of Pier 1, the steel wire rope tension is obtained through a tension sensor provided on the anti-slip steel wire rope at the top of Pier 2, and the vertical reaction force during the beam-lowering at the top of Pier 1, that is, the pier top reaction force, is obtained through a pressure sensor.

[0039] According to an embodiment of the present invention, in step S7, a second control discrimination parameter is determined according to the environmental data, the beam body data, the steel wire rope tension, the pier top reaction force, and the second beam-lowering plan.

[0040] Figure 3 Exemplarily, a flowchart of calculating the second control discrimination parameter according to an embodiment of the present invention is shown.

[0041] According to an embodiment of the present invention, step S7 includes: step S71, determining a second beam lowering height and a first horizontal distance according to the second beam lowering plan; step S72, determining the foundation pier top reaction force according to the second beam lowering height, the beam weight, and the beam span; step S73, determining a set pier top reaction force threshold according to the beam data, the foundation pier top reaction force, the first relationship function, the second beam lowering height, and the rainfall data; step S74, determining a pier top reaction force identification result according to the pier top reaction force and the set pier top reaction force threshold; step S75, determining a tension anomaly coefficient according to the wire rope tension, the pier top reaction force, the beam span, and the first horizontal distance; step S76, determining a tension anomaly identification result according to the tension anomaly coefficient and a set tension anomaly coefficient threshold; step S77, determining a second control discrimination parameter according to the tension anomaly identification result and the pier top reaction force identification result.

[0042] For example, according to the construction plan, obtain the beam lowering height in the second beam lowering stage (e.g., each beam lowering is 16 cm in the second beam lowering stage), and the horizontal distance from the anti-slip wire rope to the fulcrum on the other pier side (the side where the beam has not been lowered), that is, the first horizontal distance; according to the second beam lowering height, determine the total height of each beam lowering in the second beam lowering stage, determine the total height of each beam lowering. For example, if each beam lowering is 16 cm, then the total height of the second beam lowering is 32 cm, and the total height of the third beam lowering is 48 cm. According to the total height of each beam lowering, the beam weight, and the beam span, determine the foundation pier top reaction force for each beam lowering. The calculation process of the foundation pier top reaction force is similar to formula (1) and will not be elaborated here; substitute the beam data, the foundation pier top reaction force, the second beam lowering height, and the rainfall data into the first relationship function to determine the set pier top reaction force threshold for each beam lowering; if the pier top reaction force is greater than the corresponding set pier top reaction force threshold, then there is an anomaly in the pier top reaction force on the beam lowering side, and the pier top reaction force identification result is 1. If the pier top reaction force is less than the corresponding set pier top reaction force threshold, the pier top reaction force identification result is 0; evaluate the tension condition of the fixed-side wire rope according to the wire rope tension, the pier top reaction force, the beam span, and the first horizontal distance to determine the tension anomaly coefficient; if the tension anomaly coefficient is greater than or equal to the set tension anomaly coefficient (e.g., 0.05), then determine the tension anomaly identification result as 2. If the tension anomaly coefficient is less than the set tension anomaly coefficient, then determine the tension anomaly identification result as 0. Determine the second control discrimination parameter according to the sum of the pier top reaction force identification result and the tension anomaly identification result.

[0043] According to an embodiment of the present invention, in step S75, determining a tension anomaly coefficient according to the wire rope tension, the pier top reaction force, the beam span, and the first horizontal distance includes: determining the tension anomaly coefficient of the j-th beam lowering in the second beam lowering stage according to formula (3) , (3), Wherein, is the span of the beam body, is the pier top reaction force of the j-th beam dropping in the second beam dropping stage, is the first horizontal distance, is the wire rope tension of the j-th beam dropping in the second beam dropping stage.

[0044] According to an embodiment of the present invention, in the second beam dropping stage, taking the side of the pier where the beam has not been dropped as the moment balance center, the balance equation is , from which it can be obtained that represents the theoretical wire rope tension, is the relative difference between the wire rope tension of the j-th beam dropping in the second beam dropping stage and the theoretical wire rope tension of the j-th beam dropping. The larger this ratio is, the greater the difference between the pier top reaction force of the j-th beam dropping in the second beam dropping stage and the theoretical wire rope tension of the j-th beam dropping. There may be an abnormality in the friction force of the support system, resulting in inaccurate beam dropping.

[0045] In this way, the tension abnormality coefficient can be determined based on the wire rope tension, pier top reaction force, beam body span and the first horizontal distance. When determining the tension abnormality coefficient, the balance relationship between the wire tension and the pier top reaction force can be accurately analyzed during the calculation process, and the tension abnormality coefficient can be determined according to the relative error between the actual wire tension and the theoretical wire rope tension, improving the comprehensiveness and accuracy of the tension abnormality coefficient.

[0046] According to an embodiment of the present invention, in step S8, determine whether to adjust the beam dropping process according to the first control discrimination parameter and the second control discrimination parameter.

[0047] For example, if the first control parameter is 0, it means that both the wind force identification result and the fulcrum reaction force identification result are 0, and there is no need to adjust the beam lowering process during the first beam lowering stage; if the first control parameter is 1, it means that the wind force identification result is 0 and the fulcrum reaction force identification result is 1. During the first beam lowering stage, there is an abnormality in the fulcrum reaction force. The beam lowering on the pier side is paused, and the beam lowering continues after waiting for the other side to make up for the balance; if the first control parameter is 2, it means that the wind force identification result is 2 and the fulcrum reaction force identification result is 0. During the first beam lowering stage, the wind force is too large. Wind cables or temporary supports are set on both sides of the beam body to reduce the wind vibration amplitude or pause the beam lowering and lock the jacks; if the first control parameter is 3, it means that the wind force identification result is 2 and the fulcrum reaction force identification result is 1. During the first beam lowering stage, the wind force is too large and there is an abnormality in the fulcrum reaction force. The beam lowering on the pier side corresponding to this fulcrum is paused, and the beam lowering continues after waiting for the other side to make up for the balance; if the second control parameter is 0, it means that both the pier top reaction force identification result and the tension abnormality identification result are 0, and there is no need to adjust the beam lowering process during the second beam lowering stage; when the first control parameter is 2 and the pier top reaction force identification result is 0 and the tension abnormality identification result is 2, it means that the wire rope tension is abnormal, triggering an alarm, and pausing the beam lowering to check whether the friction of the support system is abnormal. If the second control parameter is 3, it means that the pier top reaction force identification result is 1 and the tension abnormality identification result is 2. The beam lowering on the pier side is paused, and the beam lowering continues after waiting for the other side to make up for the balance, and check whether the friction of the support system is abnormal. When the pier top reaction force identification result is 1 and the pier top reaction force at the beam lowering pier side is abnormal, it will also cause the wire rope tension to be abnormal, making the tension abnormality identification result 2. That is, the second control discrimination parameter will not produce a situation equal to 1.

[0048] The precise girder-lowering method for long-span steel truss girders based on force monitoring according to an embodiment of the present invention can determine whether adjustment is needed for the first-stage girder lowering based on the environmental conditions, support reaction force conditions, girder data, and the first girder-lowering plan, and determine the first control discrimination parameter. It can also determine whether adjustment is needed for the second-stage girder lowering based on the environmental conditions, girder data, wire rope tension, pier top reaction force, and the second girder-lowering plan, and determine the second control discrimination parameter, thereby improving the precision of steel truss girder lowering. When determining the foundation support reaction force, the foundation support reaction force can be determined based on the first girder-lowering height, girder weight, and girder span, which can improve the accuracy of the foundation support reaction force and provide a data basis for subsequent calculations. When determining the first relationship function, the first relationship function among the historical number of supports, historical support reaction force, historical rainfall data, historical girder weight, and historical girder-lowering height can be determined, which can accurately analyze the influence of girder self-weight, girder-lowering plan, and environmental factors on the support reaction force, and improve the accuracy and objectivity of the first relationship function. When determining the tension anomaly coefficient, the tension anomaly coefficient can be determined based on the wire rope tension, pier top reaction force, girder span, and the first horizontal distance. During the calculation process, the balance relationship between the wire tension and the pier top reaction force can be accurately analyzed, and the tension anomaly coefficient can be determined based on the relative error between the actual wire rope tension and the theoretical wire rope tension, which improves the comprehensiveness and accuracy of the tension anomaly coefficient.

[0049] Figure 4 Exemplarily shown is a block diagram of a precise girder-lowering system for long-span steel truss girders based on force monitoring according to an embodiment of the present invention. The system includes: a girder data module for obtaining the girder data of the steel truss girder, where the girder data includes girder weight and girder span; an environmental data module for obtaining the environmental data of the construction site, where the environmental data includes rainfall data and wind force data; a girder-lowering plan module for obtaining the first girder-lowering plan and the second girder-lowering plan for the first girder-lowering stage and the second girder-lowering stage; a first force module for obtaining the first support reaction force through pressure sensors arranged at the positions of the two side supports during the first girder-lowering stage; a first control module for determining the first control discrimination parameter based on the environmental data, the girder data, the first girder-lowering plan, and the first support reaction force; a second force module for obtaining the wire rope tension and the pier top reaction force during the second girder-lowering stage; a second control module for determining the second control discrimination parameter based on the environmental data, the girder data, the wire rope tension, the pier top reaction force, and the second girder-lowering plan; and an adjustment module for determining whether to adjust the girder-lowering process based on the first control discrimination parameter and the second control discrimination parameter.

[0050] The present invention may be a method, apparatus, system, and / or computer program product. The computer program product may include a computer-readable storage medium having thereon computer-readable program instructions for performing various aspects of the present invention.

[0051] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are only examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and illustrated in the embodiments, and the embodiments of the present invention may have any variations or modifications without departing from the said principles.

Claims

1. A method for accurately dropping a large-span steel truss beam based on force monitoring, characterized in that: include: Obtain beam data of a steel truss beam, wherein the beam data includes: beam weight and beam span; obtain environmental data of the construction site, wherein the environmental data includes: rainfall data and wind data; obtain a first beam dropping scheme and a second beam dropping scheme in a first beam dropping stage and a second beam dropping stage; in the first beam dropping stage, obtain a first fulcrum reaction force by means of pressure sensors provided at fulcrum positions on both sides; determine a first control discrimination parameter based on the environmental data, the beam data, the first beam dropping scheme and the first fulcrum reaction force; in the second beam dropping stage, obtain a wire rope tension and a pier top reaction force; determine a second control discrimination parameter based on the environmental data, the beam data, the wire rope tension, the pier top reaction force and the second beam dropping scheme; determine whether to adjust the beam dropping process based on the first control discrimination parameter and the second control discrimination parameter.

2. The method for accurately dropping a large-span steel truss beam based on force monitoring according to claim 1 is characterized in that: According to the environmental data, the beam body data, the first beam dropping scheme and the first fulcrum reaction force, a first control discrimination parameter is determined, including: according to the first beam dropping scheme, obtaining a first beam dropping height; determining a basic fulcrum reaction force according to the first beam dropping height, the beam body weight and the beam body span; obtaining historical data in historical beam dropping cycles, wherein the historical data includes: historical fulcrum number, historical fulcrum reaction force, historical rainfall data, historical beam body weight and historical beam dropping height; determining a first relationship function between the historical fulcrum number, the historical fulcrum reaction force, the historical rainfall data, the historical beam body weight and the historical beam dropping height; determining a set fulcrum reaction force threshold value according to the first beam dropping height, the first relationship function, the basic fulcrum reaction force, the rainfall data and the beam body data; determining a first control discrimination parameter according to the wind force data, the set fulcrum reaction force threshold value and the first fulcrum reaction force.

3. The method for accurately dropping a large-span steel truss beam based on force monitoring according to claim 2 is characterized in that: According to the first drop beam height, the beam weight and the beam span, the foundation support reaction force is determined, including: according to the formula , determine the reaction force of the foundation support ,in, is the weight of the beam, is the acceleration due to gravity, is the first beam drop height, is the span of the beam.

4. The method for accurately dropping a large-span steel truss beam based on force monitoring according to claim 2 is characterized in that: Determining a first relationship function between the number of historical fulcrums, the reaction force of the historical fulcrums, the historical rainfall data, the historical beam weight and the historical beam drop height comprises: according to the formula , determine the first undetermined coefficient equation of the first relationship function, where, is the historical support reaction force in the kth historical beam drop cycle, is the historical beam weight of the kth historical beam-dropping cycle, is the acceleration due to gravity, is the historical beam drop height of the kth historical beam drop cycle, is the historical rainfall data of the kth historical beam-falling cycle, is the number of historical pivots in the kth historical beam-dropping cycle, , , , , and is the first undetermined coefficient; according to the historical number of fulcrums, the historical fulcrum reaction force, the historical rainfall data, the historical beam weight and the historical beam drop height, the first undetermined coefficient is solved to obtain the solution value of the first undetermined coefficient; according to the solution value of the first undetermined coefficient and the first undetermined coefficient equation, the first relationship function is determined.

5. The method for accurately dropping a large-span steel truss beam based on force monitoring according to claim 2 is characterized in that: Determine a first control discrimination parameter based on the wind data, the set fulcrum reaction force threshold and the first fulcrum reaction force, including: determine a wind force identification result based on the wind data and the set wind data threshold; determine a fulcrum reaction force identification result based on the first fulcrum reaction force and the set fulcrum reaction force threshold; determine a first control discrimination parameter based on the wind force identification result and the fulcrum reaction force identification result.

6. The method for accurately dropping a large-span steel truss beam based on force monitoring according to claim 4 is characterized in that: According to the environmental data, the beam data, the wire rope tension, the pier top reaction force and the second beam dropping scheme, a second control discrimination parameter is determined, including: according to the second beam dropping scheme, the second beam dropping height and the first horizontal distance are determined; according to the second beam dropping height, the beam weight and the beam span, the basic pier top reaction force is determined; according to the beam data, the basic pier top reaction force, the first relationship function, the second beam dropping height and the rainfall data, a set pier top reaction force threshold is determined; according to the pier top reaction force and the set pier top reaction force threshold, a pier top reaction force identification result is determined; according to the wire rope tension, the pier top reaction force, the beam span and the first horizontal distance, a tension anomaly coefficient is determined; according to the tension anomaly coefficient and the set tension anomaly coefficient threshold, a tension anomaly identification result is determined; according to the tension anomaly identification result and the pier top reaction force identification result, a second control discrimination parameter is determined.

7. The method for accurately dropping a large-span steel truss beam based on force monitoring according to claim 6 is characterized in that: Determining the tension anomaly coefficient according to the wire rope tension, the pier top reaction force, the beam span and the first horizontal distance includes: according to the formula , determine the abnormal tension coefficient of the jth beam drop in the second beam drop stage ,in, is the beam span, is the pier top reaction force of the jth beam drop in the second beam drop stage, is the first horizontal distance, is the wire rope tension of the j-th beam dropping in the second beam dropping stage.

8. A large-span steel truss beam precision drop system based on force monitoring, characterized in that: include: a beam data module for obtaining beam data of a steel truss beam, wherein the beam data includes: beam weight and beam span; an environmental data module for obtaining environmental data of a construction site, wherein the environmental data includes: rainfall data and wind data; a beam drop scheme module for obtaining a first beam drop scheme and a second beam drop scheme in a first beam drop stage and a second beam drop stage; a first force module for obtaining a first fulcrum reaction force in the first beam drop stage by means of pressure sensors provided at the fulcrum positions on both sides; a first control module for determining a first control discrimination parameter according to the environmental data, the beam data, the first beam drop scheme and the first fulcrum reaction force; a second force module for obtaining a wire rope tension and a pier top reaction force in the second beam drop stage; a second control module for determining a second control discrimination parameter according to the environmental data, the beam data, the wire rope tension, the pier top reaction force and the second beam drop scheme; and an adjustment module for determining whether to adjust the beam drop process according to the first control discrimination parameter and the second control discrimination parameter.

Images