An accurate girder dropping method and system for long-span steel truss girders based on force monitoring

Abstract

The present invention provides a precise girder lowering method and system for long-span steel truss girders based on force monitoring, which relates to the technical field of force monitoring. The method includes: obtaining the beam body data of the steel truss girder; obtaining the environmental data of the construction site; 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 beam 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 beam body data, the wire rope tension, the pier top reaction force and the second girder lowering plan; determining whether to adjust the girder lowering process according to the first control discrimination parameter and the second control discrimination parameter. According to the present invention, the precision of the girder lowering of the steel truss girder 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 for the stress state of a steel-concrete composite beam based on a computer and a monitoring method, including the following steps: frame arrangement, installation of a driving member, preset connection members, installation of a monitoring component, and application. The beneficial effect is that the real-time monitoring method for the stress state of the 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 on the data display control center through a computer, facilitating people to timely discover the stress state of the steel-concrete composite beam.

[0004] Based on the above related technologies, the stress condition of the composite beam can be monitored in real time. However, the related technologies do not consider the influence of the stress condition on the accuracy of beam lowering, that is, the beam lowering process cannot be adjusted according to the environmental condition, the stress condition of the beam body, and the beam lowering stage to ensure the precise 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 an indication in any form 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, where the girder body data includes the girder body weight and the girder body span; obtaining the environmental data of the construction site, where 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 pressure sensors arranged at the positions of the two side supports; determining a 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 steel wire rope tension and the pier top reaction force; determining a second control discrimination parameter according to the environmental data, the girder body data, the steel 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, where 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, 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 in the first girder-lowering stage; a first control module for determining a 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 steel wire rope tension and the pier top reaction force in the second girder-lowering stage; a second control module for determining a second control discrimination parameter according to the environmental data, the girder body data, the steel 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 judge whether adjustment is required for the first-stage beam lowering based on environmental conditions, support reaction force conditions, beam body data, and the first beam lowering plan, and determine the first control discrimination parameter. It is also possible to judge whether adjustment is required for the second-stage beam lowering based on environmental conditions, beam body 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 body weight, and beam body 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 body 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 body 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 the 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 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 also be obtained based on these drawings.

[0012] Figure 1 Exemplarily shows a schematic flowchart of a precise beam lowering method for a long-span steel truss beam based on force monitoring according to an embodiment of the present invention;

[0013] Figure 2 Exemplarily shows a flowchart of calculating the first control discrimination parameter according to an embodiment of the present invention;

[0014] Figure 3 Exemplarily shows a flowchart of calculating the second control discrimination parameter according to an embodiment of the present invention;

[0015] Figure 4Exemplarily 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. Detailed implementation manners

[0016] 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 some, 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.

[0017] The technical solutions of the present invention will be described in detail below with specific embodiments. These specific embodiments may be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

[0018] Figure 1 Exemplarily shown is a schematic flow chart of a precise girder lowering method for long-span steel truss girders based on force monitoring according to an embodiment of the present invention. The method includes: Step S1, obtaining beam body data of the steel truss girder, where the beam body data includes: beam body weight and beam body span; Step S2, obtaining environmental data of the construction site, where the environmental data includes: rainfall data and wind force data; Step S3, obtaining a first girder lowering plan and a second girder lowering plan for the first girder lowering stage and the second girder lowering stage; Step S4, in the first girder lowering stage, obtaining a first support reaction force through pressure sensors arranged at the positions of the two side supports; Step S5, determining a first control discrimination parameter according to the environmental data, the beam body data, the first girder lowering plan, and the first support reaction force; Step S6, in the second girder lowering stage, obtaining the wire rope tension and the pier top reaction force; Step S7, determining a second control discrimination parameter according to the environmental data, the beam body data, the wire rope tension, the pier top reaction force, and the second girder lowering plan; Step S8, determining whether to adjust the girder lowering process according to the first control discrimination parameter and the second control discrimination parameter.

[0019] According to the precise girder lowering method for long-span steel truss girders based on force monitoring according to an embodiment of the present invention, it is possible to judge whether adjustment is needed for the first-stage girder lowering according to the environmental conditions, support reaction force conditions, beam body data, and the first girder lowering plan, and determine the first control discrimination parameter. It is possible to judge whether adjustment is needed for the second-stage girder lowering according to the environmental conditions, beam body 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 the girder lowering of the steel truss girder.

[0020] According to an embodiment of the present invention, in step S1, the beam data of the steel truss beam is obtained, where the beam data includes: the beam weight and the beam span.

[0021] For example, according to the construction records and design drawings, the beam weight and the beam span of the steel truss beam are obtained.

[0022] According to an embodiment of the present invention, in step S2, the environmental data of the construction site is obtained, where the environmental data includes: rainfall data and wind force data.

[0023] For example, rainfall sensors and wind force sensors are set at the construction site to obtain the rainfall data and wind force data of the construction site.

[0024] According to an embodiment of the present invention, in step S3, the first beam lowering plan and the second beam lowering plan for the first beam lowering stage and the second beam lowering stage are obtained.

[0025] For example, according to the construction plan, the first beam lowering plan and the second beam lowering plan for the first beam lowering stage and the second beam lowering stage are obtained. For example, the first beam lowering plan for the first beam lowering stage is to lower the beam alternately on both sides of the steel truss beam. For example, the beam is lowered alternately on the side of pier No. 1 and the side of pier No. 2, with each beam lowering height of 16 cm and a total beam lowering height of 1.6 m. The second beam lowering plan for the second beam lowering stage is to lower the beam unidirectionally on one side of the steel truss beam. For example, at the side of pier No. 2 where the beam has been lowered in place, a wire rope is used for anti-slip traction, and the beam is lowered unidirectionally on the side of pier No. 1, with each beam lowering height of 16 cm and a total beam lowering height of 2.3 m.

[0026] According to an embodiment of the present invention, in step S4, in the first beam lowering stage, the first support reaction force is obtained through the pressure sensors arranged at the positions of the two side supports.

[0027] For example, pressure sensors are respectively set at the top of pier No. 1 and the top of pier No. 2 on both sides of the steel truss beam. 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 beam lowering on the pier side is determined as the first support reaction force. For example, in the first beam lowering stage, if the first beam lowering is for the side of pier No. 1, the first support reaction force corresponding to the first beam lowering in the first beam lowering stage is the vertical reaction force detected by the pressure sensor at pier No. 1 during the first beam lowering.

[0028] According to an embodiment of the present invention, in step S5, the first control discrimination parameter is determined according to the environmental data, the beam data, the first beam lowering plan, and the first support reaction force.

[0029] Figure 2 Exemplarily, a flowchart of the calculation of the first control discrimination parameter according to an embodiment of the present invention is shown.

[0030] 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, the 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.

[0031] 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 without being affected by external factors under static conditions during the beam lowering process, and determine the foundation support reaction force; obtain 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 during the successful and accurate 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 the 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; 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 to determine the first control discrimination parameter.

[0032] 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) ,

[0033] (1),

[0034] 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.

[0035] According to an embodiment of the present invention, when the first beam lowering height occurs at one pier side , the center of gravity shifts towards this pier side, resulting in an increase in the reaction force of the support at this pier side. In formula (1), can be equivalently expressed as , is the moment of the reaction force at the beam lowering pier side with respect to the non-beam lowering pier side, is the moment of the self-weight of the beam body with respect to the non-beam lowering pier side, is the horizontal distance from the center of gravity of the beam body to the non-beam lowering pier side. When the beam body is not tilted, the distance from the center of gravity of the beam body to the pier side is . When one side of the beam body drops by distance, the center of gravity drops by , and at the same time, the center of gravity of the beam body shifts towards the beam lowering pier side by . Based on the above relevant formulas, the reaction force of the support at the beam lowering pier side under theoretical conditions, that is, the foundation support reaction force, can be determined.

[0036] In this way, the foundation support reaction force can be determined according to the first beam lowering height, the weight of the beam body, and the span of the beam body, which can improve the accuracy of the foundation support reaction force and provide a data basis for subsequent calculations.

[0037] According to an embodiment of the present invention, in step S54, determining the first relationship function among the historical number of supports, the historical support reaction force, the historical rainfall data, the historical weight of the beam body, and the historical beam lowering height includes: determining the first undetermined coefficient equation of the first relationship function according to formula (2), (2),

[0038] wherein, is the historical support reaction force in the k-th historical beam lowering period, is the historical weight of the beam body in the k-th historical beam lowering period, is the acceleration due to gravity, is the historical beam lowering height in the k-th historical beam lowering period, is the historical rainfall data in the k-th historical beam lowering period, is the historical number of supports in the k-th historical beam lowering period, , , , , and are the first undetermined coefficients; solving the first undetermined coefficients according to the historical number of supports, the historical support reaction force, the historical rainfall data, the historical weight of the beam body, and the historical beam lowering 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.

[0039] According to an embodiment of the present invention, is the average value of the beam weight borne by each fulcrum in the k-th historical beam dropping cycle, indicates that the historical fulcrum reaction force in the k-th historical beam dropping cycle has a positive correlation with the average value of the beam weight borne by each fulcrum in the k-th historical beam dropping cycle. For example, the heavier the historical beam weight, the greater the average value of the beam weight borne by each fulcrum, and the greater the fulcrum reaction force. indicates that the historical fulcrum reaction force in the k-th historical beam dropping cycle has a positive correlation with the historical beam dropping height in the k-th historical beam dropping cycle. For example, the energy accumulated due to elastic deformation (such as bending and shearing) during the lowering of the beam body may be suddenly released during displacement adjustment, resulting in an increase in the fulcrum reaction force. The greater the beam dropping height, the greater the energy accumulated by elastic deformation, and the greater the fulcrum reaction force. indicates that the historical fulcrum reaction force in the k-th historical beam dropping cycle has a positive correlation with the historical rainfall data in the k-th historical beam dropping cycle. For example, if rainfall occurs during construction, rainwater accumulates on the surface of the beam body, increasing the self-weight by about 2-5% (depending on the drainage design), resulting in an increase in the fulcrum reaction force. Based on the above relationships, the first undetermined coefficient equation of the first relationship function can be obtained.

[0040] 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 is performed based on the historical number of fulcrums, historical fulcrum reaction force, historical rainfall data, historical beam weight, and historical beam dropping height to solve the above multiple first undetermined coefficients. There are 6 first undetermined coefficients, namely, 、 、 、 、 and , the above 6 first undetermined coefficients are solved according to the historical number of fulcrums, historical fulcrum reaction force, historical rainfall data, historical beam weight, and historical beam dropping height in at least 6 historical beam dropping cycles, and the solution values of the above 6 first undetermined coefficients are obtained. Then, the solution values of the above 6 first undetermined coefficients are substituted into the first undetermined coefficient equation to determine the first relationship function.

[0041] In this way, the first relationship function between the historical number of fulcrums, historical fulcrum reaction force, historical rainfall data, historical beam weight, and historical beam dropping height can be determined, and the influence of the beam self-weight, beam dropping scheme, and environmental factors on the fulcrum reaction force can be accurately analyzed, improving the accuracy and objectivity of the first relationship function.

[0042] 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 fulcrum reaction force identification result according to the first fulcrum reaction force and the set fulcrum reaction force threshold; step S563, determining a first control discrimination parameter according to the wind force identification result and the fulcrum reaction force identification result.

[0043] 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 fulcrum reaction force, resulting in inaccurate placement of the girder during landing. 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 fulcrum reaction force is greater than or equal to the set fulcrum reaction force threshold, it indicates that there is an abnormality in the fulcrum reaction force at this position during girder landing, which may be caused by inaccurate girder landing. The fulcrum reaction force identification result is 1. If the first fulcrum reaction force is less than the set fulcrum reaction force threshold, the fulcrum reaction force identification result is 0. The first control discrimination parameter is determined by adding the wind force identification result and the fulcrum reaction force identification result.

[0044] According to an embodiment of the present invention, in step S6, during the second girder landing stage, the steel wire rope tension and the pier top reaction force are obtained.

[0045] For example, during the second girder landing stage, during the process of landing the girder unilaterally on the top of Pier No. 1, the steel wire rope tension is obtained through a tension sensor provided on the anti-slip steel wire rope on the top of Pier No. 2. The vertical reaction force during the girder landing on the top of Pier No. 1, that is, the pier top reaction force, is obtained through a pressure sensor.

[0046] According to an embodiment of the present invention, in step S7, a second control discrimination parameter is determined according to the environmental data, the girder data, the steel wire rope tension, the pier top reaction force, and the second girder landing plan.

[0047] Figure 3 Exemplarily, a flowchart of calculating the second control discrimination parameter according to an embodiment of the present invention is shown.

[0048] According to an embodiment of the present invention, step S7 includes: step S71, determining a second beam dropping height and a first horizontal distance according to the second beam dropping plan; step S72, determining a foundation pier top reaction force according to the second beam dropping 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 dropping 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.

[0049] For example, according to the construction plan, obtain the beam dropping height in the second beam dropping stage (for example, each beam dropping is 16 cm in the second beam dropping 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 dropped), that is, the first horizontal distance; according to the second beam dropping height, determine the total height of each beam dropping in the second beam dropping stage. Determine the total height of each beam dropping. For example, if each beam dropping is 16 cm, then the total height of the second beam dropping is 32 cm, and the total height of the third beam dropping is 48 cm. According to the total height of each beam dropping, the beam weight, and the beam span, determine the foundation pier top reaction force for each beam dropping. 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 dropping height, and the rainfall data into the first relationship function to determine the set pier top reaction force threshold for each beam dropping; 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 dropping 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 (for example, 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.

[0050] 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 dropping in the second beam dropping stage according to formula (3) , (3),

[0051] 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.

[0052] 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, and there may be an abnormality in the friction force of the support system, resulting in inaccurate beam dropping.

[0053] In this way, the tension abnormality coefficient can be determined according to 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.

[0054] 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.

[0055] For example, if the first control parameter is 0, it indicates that both the wind force identification result and the support 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 indicates that the wind force identification result is 0 and the support reaction force identification result is 1. During the first beam lowering stage, there is an abnormality in the support 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 the balance; if the first control parameter is 2, it indicates that the wind force identification result is 2 and the support 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 amplitude of wind vibration or pause the beam lowering and lock the jacks; if the first control parameter is 3, it indicates that the wind force identification result is 2 and the support 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 support reaction force. The beam lowering on the pier side corresponding to this support is paused, and the beam lowering continues after waiting for the other side to make up the balance; if the second control parameter is 0, it indicates 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 indicates 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 indicates 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 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.

[0056] 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 required 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 required 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 between 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.

[0057] 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 the girder weight and the 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.

[0058] 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.

[0059] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the 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 without departing from the said principles, the embodiments of the present invention may have any variations or modifications.

Claims

1. A precise girder lowering method for long-span steel truss girders based on force monitoring, characterized in that Including: Obtain the beam body data of the steel truss beam, where the beam body data includes the beam body weight and the beam body span; obtain the environmental data of the construction site, where the environmental data includes rainfall data and wind force data; obtain the first beam lowering plan and the second beam lowering plan for the first beam lowering stage and the second beam lowering stage; in the first beam lowering stage, obtain the first support reaction force through the pressure sensors arranged at the positions of the two side supports; according to the environmental data, the beam body data, the first beam lowering plan, and the first support reaction force, determine the first control discrimination parameter; in the second beam lowering stage, obtain the steel wire rope tension and the pier top reaction force; 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, determine the second control discrimination parameter; according to the first control discrimination parameter and the second control discrimination parameter, determine whether to adjust the beam lowering process; Determine the first control discrimination parameter according to the environmental data, the beam body data, the first beam lowering plan, and the first support reaction force, including: according to the first beam lowering plan, obtain the first beam lowering height; according to the first beam lowering height, the beam body weight, and the beam body span, determine the foundation support reaction force; obtain the historical data in the historical beam lowering cycle, where the historical data includes the historical number of supports, the historical support reaction force, the historical rainfall data, the historical beam body weight, and the historical beam lowering height; determine the first relationship function among the historical number of supports, the historical support reaction force, the historical rainfall data, the historical beam body weight, and the historical beam lowering height; according to the first beam lowering height, the first relationship function, the foundation support reaction force, the rainfall data, and the beam body data, 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, determine the first control discrimination parameter; Determine 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 beam lowering plan, including: according to the second beam lowering plan, determine the second beam lowering height and the first horizontal distance; according to the second beam lowering height, the beam body weight, and the beam body span, determine the foundation pier top reaction force; according to the beam body data, the foundation pier top reaction force, the first relationship function, the second beam lowering height, and the rainfall data, determine the set pier top reaction force threshold; according to the pier top reaction force and the set pier top reaction force threshold, determine the pier top reaction force identification result; according to the steel wire rope tension, the pier top reaction force, the beam body span, and the first horizontal distance, determine the tension anomaly coefficient; according to the tension anomaly coefficient and the set tension anomaly coefficient threshold, determine the tension anomaly identification result; according to the tension anomaly identification result and the pier top reaction force identification result, determine the second control discrimination parameter.

2. The precise girder dropping method for long-span steel truss girders based on force monitoring according to claim 1, characterized in that Determine the foundation support reaction force according to the first beam dropping height, the weight of the beam body and the span of the beam body, including: according to the formula Determine the foundation support reaction force Bprf, where Wb is the weight of the beam body, g is the acceleration due to gravity, h1 is the first beam dropping height, and L is the span of the beam body.

3. The precise girder lowering method for long-span steel truss girders based on force monitoring according to claim 1, characterized in that Determine the first relationship function among the number of historical fulcrums, the historical fulcrum reaction forces, the historical rainfall data, the historical beam weight, and the historical beam drop height, including: According to the formula Determine the first undetermined coefficient equation of the first relationship function, where Hprf k is the historical fulcrum reaction force in the k-th historical beam drop period, HWb k is the historical beam weight in the k-th historical beam drop period, g is the acceleration due to gravity, h k is the historical beam drop height in the k-th historical beam drop period, Hrf k is the historical rainfall data in the k-th historical beam drop period, n k is the number of historical fulcrums in the k-th historical beam drop period, and α1, α2, α3, α4, α5, and α6 are the first undetermined coefficients; solve for the first undetermined coefficients according to the number of historical fulcrums, the historical fulcrum reaction forces, the historical rainfall data, the historical beam weight, and the historical beam drop height to obtain the solution values of the first undetermined coefficients; determine the first relationship function according to the solution values of the first undetermined coefficients and the first undetermined coefficient equation.

4. The method for accurately lowering a long-span steel truss girder based on force monitoring according to claim 1, wherein, Determine a first control discrimination parameter according to the wind force data, the set fulcrum reaction force threshold, and the first fulcrum reaction force, including: determine a wind force identification result according to the wind force data and a set wind force data threshold; determine a fulcrum reaction force identification result according to the first fulcrum reaction force and the set fulcrum reaction force threshold; determine the first control discrimination parameter according to the wind force identification result and the fulcrum reaction force identification result.

5. The accurate girder dropping method for long-span steel truss girders based on force monitoring according to claim 1, characterized in that, Determine a tension anomaly coefficient based on the wire rope tension, the pier top reaction force, the beam span, and the first horizontal distance, including: According to the formula Determine the tension anomaly coefficient Scd for the j-th beam lowering in the second beam lowering stage j , where L is the beam span, Drf j is the pier top reaction force for the j-th beam lowering in the second beam lowering stage, Fd is the first horizontal distance, Wrt j is the wire rope tension for the j-th beam lowering in the second beam lowering stage.

6. A large-span steel truss beam precise girder lowering system based on force monitoring for performing the method according to any one of claims 1-5, characterized in that, Including: A beam body data module for obtaining beam body data of the steel truss beam, wherein the beam body data includes: beam body weight and beam body span; an environmental data module for obtaining environmental data of the construction site, wherein the environmental data includes: rainfall data and wind force data; a beam lowering plan module for obtaining a first beam lowering plan and a second beam lowering plan for the first beam lowering stage and the second beam lowering stage; a first force module for obtaining a first fulcrum reaction force through pressure sensors arranged at the positions of the two side fulcrums in the first beam lowering stage; a first control module for determining a first control discrimination parameter according to the environmental data, the beam body data, the first beam lowering plan, and the first fulcrum reaction force; a second force module for obtaining the wire rope tension and the pier top reaction force in the second beam lowering stage; a second control module for determining a second control discrimination parameter according to the environmental data, the beam body data, the wire rope tension, the pier top reaction force, and the second beam lowering plan; an adjustment module for determining whether to adjust the beam lowering process according to the first control discrimination parameter and the second control discrimination parameter.

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