Classifications

• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
  • E01D19/00—Structural or constructional details of bridges
  • E01D19/04—Bearings; Hinges
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
  • E01D22/00—Methods or apparatus for repairing or strengthening existing bridges ; Methods or apparatus for dismantling bridges

Definitions

• the field of application of the present invention relates to the modernization of the structures of bridges and viaducts.
• the invention focuses on the introduction of new technologies aimed at computerizing such infrastructures, in order to obtain useful information in many areas, ranging from the maintenance of the structures themselves to their better operational management.
• the invention concerns the so-called "bearings" which constitute particular elements of support on which the structures are laid.
• these support elements can provide a number of information that can be used in various areas: both to highlight the status of the viaducts themselves, and to monitor their operation.
• these "bearings” are real structural elements, designed to withstand over time the strong stresses transmitted from the deck to the pylons of the structures. They are very expensive elements, precisely due to the characteristics of mechanical strength and durability that they must have, and they are mainly made up of mechanical components in stainless steel with surfaces normally coated in Teflon (to reduce friction in the relative movements between the various steel components).
• the most recent known technique also offers a large number of innovative solutions based on the introduction of particular sensors.
• the state of one of these "bearings” can be defined through a plurality of state variables, which can be correlated to various quantities, some of which are subject to very small variations, but which can still be appreciated with modem sensors.
• a family of considerations, aimed at monitoring the state of the "bearings”, can be conducted on the basis of the analysis of the overheating dynamics of the "bearings" themselves, therefore temperature measurements can be made, for which various technologies are available to create special sensors.
• Other analyzes may be based on the detection of changes in electrical properties (for example impedances offered between appropriate pairs of points of the monitored element), as these changes can be correlated with the physical integrity of the material. Other considerations may be based on the analysis of the vibrations to which the "bearing" is subject, in fact, even the frequency response of the element can highlight its degradation. Still other analyzes can then be based on the measurement of the deformation of the "bearing”.
• the "bearings" for bridges and viaducts are elements subject to wear and, therefore, they are elements whose replacement is substantially foreseen. Gradually over time, then, taking advantage of the necessary replacements, it will be convenient to spread sensorized “bearings", and it is foreseeable that in the medium term a large number of viaducts will be supported on sensorized "bearings".
• information that can certainly be made available by a sensorized “bearing” is the information, over time, of the weight downloaded over the single “bearing”.
• This weight is a variable quantity over time as each “bearing”, in addition to supporting the bridge, or viaduct, contributes to supporting the weight of the vehicles that cross this bridge or viaduct. While the weight of the bridge, or viaduct, is substantially known and constant over time (at least in observation intervals of medium duration), the weight of the vehicles obviously varies rapidly over time depending on the transit of vehicles.
• the main purpose of the present invention is to exploit in a new way the availability of data measured on the sensorized "bearings" installed on bridges and viaducts.
• the present invention teaches to realize a system, which takes advantage of the load information that can be obtained from the presence of said sensorized "bearings” and, by integrating further information regarding the transit of vehicles, aims to define an analysis method, which allows to calculate the weight of vehicles passing over a bridge or viaduct, in which particular sensorized "bearings" are installed.
• a further object of the present invention is to indicate the overall system that must be implemented on bridges and viaducts in order to achieve the main object.
• the present invention defines a method for estimating the weight of vehicles passing over a bridge or viaduct in which the overall system taught in the present invention has been implemented.
• This main objective can be achieved by means of a system implemented on a bridge or viaduct, and this system includes a plurality of sensorized “bearings”, installed in said bridge or viaduct, suitable to perform a series of measurements, over time, of the vertical load exerted on each of said sensorized “bearings”, and a video coverage system suitable for identifying, over time, the number of vehicles and their position on the trait of road corresponding to said bridge or viaduct; furthermore, said system makes use of suitable computing means configured for processing the information produced by said sensorized "bearings” and by said video coverage system, in order to estimate the weight of said vehicles passing on said stretch of road corresponding to said bridge or viaduct.
• the weight of the vehicles is estimated using the knowledge of the mathematical structural model of the bridge or viaduct, implemented by said computing means, as it is previously programmed on them.
• the main advantage of the present invention consists in the fact that its teachings allow to satisfy all the main objectives for which it was conceived.
• FIG. 1 shows a typical example of a stretch of road on a viaduct, supported by pylons, on which it is supported by specific "bearings".
• Figure 2 shows a top view of the stretch of road on the viaduct, shown in Figure 1 , in which a vehicle, whose weight is not known, is passing.
• FIG. 3 shows the example shown in Figure 2, of a stretch of road on the viaduct in which a vehicle is passing, which also highlights a video detection system that is able to determine the position of said vehicle instant by instant.
• FIG. 4 shows a top view of a stretch of road on a viaduct in which two vehicles are passing, whose weight of is not known.
• Figure 1 presents an axonometric view of a stretch of road on a viaduct. The number
• 310 indicates the pylons that support the viaduct.
• Figure 2 shows a top view of the stretch of road 300 included in a span of a viaduct and, as in the example of Figure 1 , said stretch of road 300 is supported on four "bearings" whose projection on the surface is, once again, marked with an “X” and indicated with the numbers 101 , 102, 103 and 104.
• the weight of the vehicle 200 is distributed over the four "bearings" underlying the points 101 , 102, 103 and 104, and it will typically weigh more on the closest bearing, and to a lesser extent on the more distant ones.
• the variation of the constraint reaction on each of the "bearings" underlying the four points indicated with the numbers 101 , 102, 103 and 104 can be formally calculated using the mathematical modeling of the viaduct structure.
• Figure 3 shows, in an axonometric view, the example presented in Figure 2, in which a vehicle 200 passes through the stretch of road 300.
• Figure 3 also shows a video recording system, indicated with the number 150.
• Said video recording system 150 performs the function of determining the position of the vehicle 200 over time. It should be noted that the function of determining the position of a vehicle on a road can be performed using numerous systems, including those based on technologies other than video recording technology; in fact, the following invention requires a generic system capable of detecting the position, over time, of vehicles passing on a stretch of road corresponding to said bridge or viaduct.
• Some improvements, to speed up and to make the calculation of the information about the position more precise, can resort to the installation on said stretch of road 300, in the field of view of the video recording camera, of easily recognizable reference tags placed in known positions, such as, for example, poles similar to that indicated with the number 151 in Figure 3, placed along the edge of the stretch of road 300, or else other types of reference can be marked on the road.
• Figure 4 shows a top view of the stretch of road in which there are two vehicles, and the stretch of road shown is longer than the stretch included in a span of a viaduct.
• Figure 4 allows to specify some further details regarding the construction of the equations associated with the computation of the constraint reaction on each “bearing”.
• the vehicles that stress each "bearing” are all those located in the two contiguous spans on both sides of the cross section determined by the pylons 310.
• the stretch of road represented is longer, therefore, in addition to vehicle 200, which weighs on the "bearing” below points 101 , 102, 103 and 104, there is also a second vehicle, indicated with the number 210, which weighs, in part, on the "bearings” underlying the points 103 and 104, while it does not burden (at least not as a first approximation) on the "bearings" underlying the points 101 and 102.
• the accuracy of the estimate will obviously depend on the quality of the sensors applied on the "bearings" (obviously, the more precise the measurements, the more accurate the system result will be), however the accuracy of the estimate can also be refined by increasing the number and frequency of measurements over time, in fact increasing the number of measurements will have the effect of reducing the statistical error. Obviously, increasing the frequency of measurements corresponds to increasing the number of equations, and then the complexity of the system.
• iterative methods allow to converge towards the solution of the system, through successive corrections, at each iteration, of an approximate previous solution.
• the solution of this system with iterative methods of numerical computation can be speeded up, even considerably, by resorting to particular iterative computation methods, also known as "warm start methods", being able to start from starting solutions close to the convergence solution of the system.
• video analysis in addition to providing the position, and possibly the speed, of the vehicles, can recognize some types of vehicles, and can therefore provide a hypothetical approximate weight of the same; therefore, through video analysis of the images produced by the video coverage system 150, a first approximate starting solution of the system can be easily determined. In this way the calculation iterations of the system will certainly be able to converge directly and quickly towards the optimal solution of the system.
• the construction of the system can be carried out considering, even particularly long road sections, with many "bearings” and many vehicles, producing frequently repeated measurements, for relatively long-time intervals: ultimately very large systems, with many equations, can be built.
• the choice of large systems, and the use of a large number of measurements, in space and time, allows to reduce measurement errors, and, therefore, it is a choice that improves measurement accuracy, at the expense of the calculation complexity that, however, for the above considerations, it should not be considered a problem.
• said vehicle weighing method comprises at least the following steps.
• Equations that express the constraint reactions on said plurality of "bearings” in the generic instant ⁇ t>.
• These equations being characterized by various types of parameters: i. Structural parameters of the bridge (or viaduct), available from the project; ii. Parameters related to the number of vehicles in transit at instant ⁇ t> and their position over time, i.e. , the position of each vehicle and its derivatives over time up to a certain order, depending on the approximation chosen for the mathematical model; iii. Parameters corresponding to the weight of the vehicles in transit, which, in the instant ⁇ t>, weigh on said plurality of "bearings", the latter being the unknown values in the equations.
• this method of estimating the weights of vehicles transiting on a stretch of road placed over a bridge or viaduct is based on measurement and monitoring elements that can also be used for other purposes; and the accuracy of the estimate can be refined purely through calculation processes, which can make use of repeated measurements, in order to considerably reduce statistical errors.
• the dynamic weighing systems proposed today are based on the preliminary preparation of a cross-section of a road so that the weight of the axles is detected as the vehicles pass over, then reconstructing the weight of the entire vehicle with appropriate calculation algorithms.
• the system proposed by the present invention represents an evolution of the current dynamic weighing systems: instead of having a single road cross section prepared for weighing the axles as the vehicles pass, in this case, they are made "m" measurements over time, consisting of "n” punctual weight values, each corresponding to the “n” constraint reactions on the “n” sensorized bearings comprised in the overall system. With modern computing powers, the number “m” can be very high and in any case increased until the "m” weighted with “n” constraint reactions univocally converge to define the single "p” traveling loads with great precision.
• the video camera (or video cameras) included in the video coverage system are typically positioned in correspondence with the extrados of the bridge or viaduct and, in addition to detecting the positions over time of the various "p" traveling vehicles, they can also easily detect their license plates, and consequently allow to intercept any overweight vehicles.
• the weighing system according to the invention can be used in all situations where it is necessary, or useful, to accurately weigh moving vehicles. For example, in approach to toll stations, perhaps to match the tariff to the real weight of the vehicles with great precision. It is observed that one of the great advantages of the system is given by the fact that it requires two subsystems whose usefulness is evident also for other applications:
• the system of "intelligent bearings" appears to be very efficient in supporting the needs of control of the loads transiting on the roads, in the name of the growing sensitivity with respect to the themes of structural control of infrastructures, of their use and, ultimately, their management and maintenance.
• the present invention lends itself to numerous variations while maintaining the claimed prerogatives.
• it can be developed using different technologies for the realization of the "bearings” and for their “sensorization”, as well as the systems for determining the position over time of the vehicles can be based on various technologies, and can resort to various measures to create visible references that facilitate the estimation of the detection of vehicle positions.
• the invention itself can then be partially realized as all the details described can be replaced by technically equivalent elements. Basically, and as previously mentioned, the use of specific technologies and materials does not constitute an essential part of the present invention.
• ITS Intelligent Transport

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Bridges Or Land Bridges (AREA)
• Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)

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• 2020
  • 2020-12-15 IT IT102020000030800A patent/IT202000030800A1/it unknown
• 2021
  • 2021-12-06 WO PCT/IB2021/061367 patent/WO2022130114A1/en unknown
  • 2021-12-06 EP EP21831355.9A patent/EP4263947A1/en active Pending

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