Evaluation method for bridge pile foundation damage caused by ship collision

Abstract

The embodiment of the invention discloses a method for evaluating damage of a ship colliding with a bridge pile foundation, relates to the technical field of intelligent traffic, can guarantee the accuracy and evaluation efficiency of collision and false alarm discrimination, and gives consideration to the passing efficiency and the safety degree of bridge deck traffic at the same time. According to the method, the video and data before the bridge is collided are utilized, and collision and false alarm are effectively discriminated by means of trajectory tracking, video recognition, aiming analysis and the like, so that the alarm accuracy is improved. Impact force generated by impact is calculated by analyzing and detecting ship tonnage, ship speed and impact position; and calculating the influence condition of the bridge in the collision through the design information of the bridge.

Description

Technical Field

[0001] The present invention relates to the field of intelligent transportation technology, and in particular to a method for assessing damage caused by a ship impacting a bridge pile foundation. Background Art

[0002] my country naturally has the geographical features of dense river networks and developed water systems, and many bridges have been built on the rivers. Some of the navigable bridges were completed and opened to traffic in the last century. Some have been in service for a long time and have aged, making it easy for them to be damaged in later operations. In particular, the original design loads of most bridges can no longer meet the existing traffic conditions. Once a ship hits a bridge, the bridge piers may be seriously damaged, causing significant economic losses and casualties.

[0003] It often takes 2 hours or more to wait from the time a ship hits a bridge to the time it takes to obtain collision information and then to handle the situation on site. Unless there is significant damage visible to the naked eye, and the bridge needs to be stopped immediately, during this waiting time, the bridge deck traffic will still be maintained normally, and all kinds of vehicles will continue to pass, which poses a serious safety hazard. Therefore, how to obtain bridge-ship collision information in a timely and accurate manner and quickly determine the damage to the bridge after the collision is a topic that needs further research.

[0004] At present, some relevant solutions and equipment are mainly aimed at anti-collision facilities and collision alarms for bridges, which realize the alarm function after being hit. However, the analysis of the degree of damage to the bridge needs to rely on manual inspection to issue an inspection report to analyze the damage of the bridge, which takes a lot of time and manpower. Before the manual analysis after the collision is completed, it is impossible to effectively identify the collision / false alarm that affects the normal passage of the bridge, and it is also impossible to immediately determine the degree of the collision after the real collision occurs, so it is difficult to determine whether it will affect the normal passage of the bridge. At this time, the personnel of the transportation department can only take conservative measures, that is, directly restrict traffic, or, when it is inconvenient to enforce the law in remote areas, or when the collision does not cause obvious visible damage to the bridge, they can only take a "do nothing" approach, that is, continue to allow the bridge to pass normally, but this will have certain safety hazards. In short, the existing technology can neither guarantee the accuracy and evaluation efficiency of identifying collisions and false alarms, nor take into account the efficiency and safety of bridge traffic. Summary of the invention

[0005] An embodiment of the present invention provides a method for assessing damage caused by a ship impacting a bridge pile foundation, which can ensure the accuracy and efficiency of distinguishing impacts and false alarms, while taking into account the efficiency and safety of bridge deck traffic.

[0006] To achieve the above object, the embodiments of the present invention adopt the following technical solutions: The method provided by an embodiment of the present invention is used for a bridge ship collision alarm perception system, the bridge ship collision alarm perception system comprising: a detection device group consisting of a video monitoring device and a radar device, a vibration sensor and an edge gateway, the video monitoring device, the radar device and the vibration sensor are connected to the edge gateway; The method comprises: S1. Collecting ship data in real time through the detection equipment group, the ship data including: ship tonnage, ship speed, navigation track data and water flow speed; S2. When the ship reaches the specified distance in front of the bridge, the ship number information, the angle information and the position information of the ship hitting the bridge are obtained through the camera of the video surveillance equipment; wherein, after the video surveillance equipment obtains the angle of the ship when it is traveling, it can further follow up the ship's driving angle and the ship's driving speed to further determine whether the ship will hit the bridge at the current driving angle and speed; if so, the current driving angle of the ship is recorded as the angle information of the ship hitting the bridge, and the vibration sensor can also be activated at the same time, wherein the vibration sensor is in an unactivated energy-saving state when in standby mode. S3. The event information when the collision occurs is collected through the vibration sensor, and the event information includes: the angular velocity information of the ship's collision, the amplitude and frequency information of the bridge after the impact; S4, calibrate each other through video monitoring equipment and vibration sensor, and detect whether collision occurs; S5. If a collision is detected, the impact force of the ship collision is obtained using the collected ship data; the gateway can follow up the amplitude, frequency and other information of the vibration sensor to calculate the impact force of the ship collision.

[0007] S6. According to the impact force of the ship collision and the bearing capacity of the bridge, the damage level information of the bridge is obtained, and the damage level information is sent to and displayed on a designated device, wherein the designated device includes: a display device of a monitoring platform, and / or a terminal device.

[0008] The embodiment of the present invention provides a method for assessing damage caused by a ship hitting a bridge pile foundation. In the solution of this embodiment, the video and data before the bridge is hit can be used to effectively identify the collision and false alarms through trajectory tracking, video recognition, targeted analysis and other means, thereby improving the accuracy of the alarm. The impact force generated by the collision is calculated by analyzing and detecting the ship's tonnage, ship speed, and collision position; the impact of the bridge in the collision is calculated using the design information of the bridge. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0010] Figure 1 A schematic diagram of a system architecture provided by an embodiment of the present invention; Figure 2~Figure 5 A schematic diagram of a specific example provided for an embodiment of the present invention. DETAILED DESCRIPTION

[0011] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention. It can be understood by those skilled in the art that, unless specifically stated, the singular forms "one", "one", "said" and "the" used herein may also include plural forms. It should be further understood that the term "including" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups. It should be understood that when we say that an element is "connected" or "coupled" to another element, it can be directly connected or coupled to other elements, or there may also be intermediate elements. In addition, the "connection" or "coupling" used here may include wireless connection or coupling. The term "and / or" used herein includes any unit and all combinations of one or more associated listed items. It can be understood by those skilled in the art that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the field to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0012] The embodiment of the present invention provides a method for assessing damage caused by a ship hitting a bridge pile foundation, the method being used in a bridge ship collision alarm sensing system, such as Figure 1As shown, the bridge-ship collision alarm perception system includes: video surveillance equipment, radar equipment, vibration sensors and edge gateways, and the video surveillance equipment, the radar equipment and the vibration sensors are connected to the edge gateway; specifically, the bridge-ship collision alarm perception system includes: a detection equipment group composed of video surveillance equipment and radar equipment, a vibration sensor and an edge gateway, and the video surveillance equipment, the radar equipment and the vibration sensors are connected to the edge gateway.

[0013] Among them, the video surveillance equipment is used to monitor the passing ships in advance to collect the tonnage, speed, trajectory and other information of the ships, and at the same time, the collected vibration data is linked with the snapshot. When the ship arrives in front of the bridge, we use the camera to identify the ship number, and identify the angle and position of the ship hitting the bridge, and calibrate with the vibration sensor to ensure the accuracy of the detection; the radar equipment is used to measure the tonnage and speed of the ship, and analyze the ship's travel trajectory and measure the current water flow speed. When the ship hits the bridge, we use the ship's running trajectory; the vibration sensor is used to collect the angular velocity information of the ship's impact, collect the amplitude and frequency of the impact received by the bridge; and calibrate with the video acquisition system to ensure the accuracy of the impact; the edge gateway is used to collect vibration data, calculate vibration data, video data, radar data, and perform trajectory calculation and false alarm screening. At the same time, it can store the design information of the bridge, calculate the impact resistance threshold of the bridge and compare the data, judge the degree of damage, and issue a diagnostic report. In actual applications, the vibration sensor is installed with a standard process, and the forward position of the pier can be selected optimally according to the on-site conditions, and the beam position can be selected secondarily. The edge gateway and the video surveillance device / radar device communicate using an Ethernet interface but are not limited to the Ethernet interface, and the vibration sensor uses wireless communication.

[0014] The method comprises: S1. Collecting ship data in real time through the detection equipment group.

[0015] Among them, the ship data includes: the ship's tonnage, ship speed, navigation track data and water flow speed; specifically, the ship's tonnage, ship speed and navigation track data can be collected through the video surveillance equipment, and the ship's speed, navigation track data and water flow speed can be collected through the radar equipment; the ship's speed and navigation track data collected by the video surveillance equipment are weightedly fused with the ship's speed and navigation track data collected by the radar equipment.

[0016] S2. When the ship reaches the specified distance in front of the bridge, the ship number information, the angle information and the position information of the ship hitting the bridge are obtained through the camera of the video surveillance device; wherein, after the video surveillance device obtains the angle of the ship, it can further follow up the ship's driving angle and the ship's driving speed to further determine whether the ship will hit the bridge at the current driving angle and speed; if so, the current driving angle of the ship is recorded as the angle information of the ship hitting the bridge, and the vibration sensor can also be activated at the same time, wherein the vibration sensor is in an inactivated energy-saving state when in standby state.

[0017] S3. Collect event information when a collision occurs through a vibration sensor, wherein the event information includes: angular velocity information of the ship's impact, amplitude and frequency information of the bridge after the impact; wherein, based on the angle information, the direction and impact force of the bridge's impact can be analyzed according to the angle of the ship's impact, and the damage to the bridge can be calculated.

[0018] S4. Use video surveillance equipment and vibration sensors to check each other and detect whether a collision has occurred; for example, use video to analyze whether the ship's trajectory will collide or scrape the bridge, and then use vibration sensors to verify data changes. Once a collision or scrape occurs, the sensor data will change significantly. Figure 2-5 As shown, Figure 2 It was a false alarm caused by the passing of a truck. Figure 3 This is a photo taken when a truck was passing by. At this time, the ship was not scratched, the data axis was not aligned, and the data magnitude was low. Figure 4 , 5 It is the picture and data of the actual scratch. The waveform is the vibration data uploaded by the acceleration sensor, and the data is large. It is used to determine the scratch and damage analysis.

[0019] S5. If a collision is detected, the impact force of the ship collision is obtained using the collected ship data; the gateway can follow up the amplitude, frequency and other information of the vibration sensor to calculate the impact force of the ship collision.

[0020] S6. According to the impact force of the ship collision and the bearing capacity of the bridge, the damage level information of the bridge is obtained, and the damage level information is sent to a designated device for display, wherein the designated device includes: a display device of the monitoring platform, and / or a terminal device. The type of terminal device is not limited, such as: a terminal for law enforcement personnel of the traffic and public security departments, a personal terminal for bridge caretakers, a large screen of a traffic control center, or a traffic information screen near the bridge. In view of the problems that the vehicle-ship collision alarm data and video capture cannot be linked and the high false alarm rate of traditional vehicle-ship collision monitoring and alarm equipment, in this embodiment, an independent video monitoring system and a radar system are used to monitor the passing ships in advance, collect the trajectory tracking of the ship, measure the water flow speed and other information, and collect the amplitude and frequency of the vibration data generated when the bridge is hit. Combined with the video capture linkage and filtering the vibration data at the same time, it can accurately determine whether a collision has occurred. Among them, the damage caused by the ship hitting the bridge can be accurately determined by combining the data measured by the sensing device with the design information of the bridge and then through the theoretical analysis of the finite element analysis model and the LS-DYNA simulation model. At the same time, when the bridge collides, the vibration signal of the bridge will change accordingly. Combined with video and ultrasonic detection for comparison, multiple detection technologies are combined, and the data is more sensitive and accurate than other detection and alarm methods. The advantage of the vibration sensor sensing method is that the program automatically alarms and can notify the bridge management department in time.

[0021] In this embodiment, S5 includes: using the collected ship data to obtain the impact force of the ship collision ,in, is the impact force of the ship collision, unit is MN, DWT is the deadweight tonnage of the ship, unit is T, V is the impact speed of the ship, unit is M / S.

[0022] Furthermore, it also includes: using the ship data to determine the ship impact speed V, wherein: , Indicates that the ship speed in the ship data is equal to the normal speed of the ship in the waterway, represents the average value of the water velocity as the minimum design impact velocity of the ship, X represents the distance from the centerline of the pier to the centerline of the channel determined by the navigation trajectory data, Indicates the distance from the centerline of the channel to the edge of the channel. It represents the distance from the center line of the channel to n times the ship length, where n is a positive integer.

[0023] In S6, the bridge capacity model includes: , where Vyd represents the design value of the bearing capacity of the component, Vcd represents the design value of the bearing capacity of the concrete part, Vwd represents the design value of the shear bearing capacity of the stirrup part (kN), Vsd represents the design value of the shear bearing capacity of the steel frame part (kN), Фs represents the shear impact effect reduction factor, Vc represents the shear strength of concrete (kPa), and Ag represents the gross cross-sectional area of ​​the component cross section (m2); where, , fc' represents the standard value of the compressive strength of a 28d concrete cylinder (MPa), and fc'=0.8 / fcuk+8MPa, fcuk is the standard value of the compressive strength of a concrete cube (MPa), c1 and c2 are the reinforcement calculation coefficient and axial force calculation coefficient respectively, and C2 is the standard parameter of the steel bar.

[0024] In the preferred embodiment, n in the above parameters is 3. < c1 < 0.25. Фs=0.7.

[0025] In S6, obtaining the damage level information of the bridge includes: if P s ≤5%*Vyd, the damage level of the bridge is level 1; if 5%*Vyd≤P s ≤30%*Vyd, the damage level of the bridge is level 2; if P s >30%*Vyd, the damage level of the bridge is level three.

[0026] Among them, if the damage level of the bridge is determined to be level one, a regular inspection notification is sent to the terminal device through the edge gateway; if the damage level of the bridge is determined to be level two, an immediate on-site inspection notification is sent to the terminal device through the edge gateway; if the damage level of the bridge is determined to be level three, a road blocking notification is sent to the terminal device through the edge gateway. For example: according to the bearing capacity of the bridge, if the impact force is less than 5%, it is determined to be level one damage, and only regular inspections are required. If it is higher than 5% and lower than 30%, a professional team is required to conduct on-site inspections to determine the degree of damage and specify a maintenance plan. If it is higher than 30%, the road needs to be blocked and overhauled.

[0027] The study of ship collision with bridge involves many factors, such as ship type, sailing speed, collision angle, channel water depth, flow velocity, pier shape, pier foundation stability, bridge structure, collision position, bridge type, etc. A large number of theoretical studies, collision case investigations and model tests at home and abroad have shown that the focus of the problem is on the ship's collision kinetic energy, the impact force of the ship on the bridge pier or anti-collision system, and the energy dissipation effect of the anti-collision system.

[0028] In the existing scheme, the calculation results of different empirical formulas may vary greatly. The finite element transient dynamic analysis method is to establish a finite element model of the impact ship and the bridge pier, and use the nonlinear finite element transient dynamic method to calculate the deformation, instability and damage of the structure during the ship collision process. Considering the sensitivity of the material dynamic yield strain rate, this method can simulate real scenes and working conditions, and the calculation results have a high reference value. In this embodiment, LS-DYNA software is used to calculate and analyze the bridge ship impact force.

[0029] The existing bridge damage monitoring requires professional technicians to carry professional flaw detection equipment to regularly detect bridge damage and issue bridge use reports, which consumes a lot of labor costs and cannot detect the status of the bridge in real time. At the same time, there is a lack of effective monitoring methods for bridge collisions. There are also a small number of bridge collision monitoring devices on the market, but they lack accuracy and effective data and video information before and after the collision. There is a lack of damage judgment after the collision.

[0030] In the scheme of this embodiment, the video and data before the bridge is hit can be used to effectively identify collisions and false alarms through trajectory tracking, video recognition, targeted analysis and other means, thereby improving the accuracy of the alarm. The impact force generated by the collision is also calculated by analyzing and detecting the ship's tonnage, speed, and collision position; the impact of the bridge in the collision is calculated through the design information of the bridge. In practical applications, a complete set of integrated monitoring and surveillance systems can be used, including vibration sensors, radio frequency acquisition systems and radar systems, and edge gateways; radar, video and vibration multiple verification mechanisms are used to ensure the accuracy of ship collision detection; radar and video are combined to track the trajectory of the ship and calculate the tonnage and speed of the ship; the vibration sensor detects the vibration data and analyzes the amplitude, frequency and other data to calculate the impact force of the ship hitting the bridge in combination with the ship's tonnage and speed and water flow speed; the ship collision situation is calculated and graded in combination with the type and material of the bridge.

[0031] The bridge structure vehicle and vessel collision monitoring and alarm system is designed to solve the monitoring and early warning of sudden collisions between passing vehicles and ships and bridge piers and beam structures. At present, the common methods for identifying vehicle and vessel collision bridge accidents in the industry mainly include: computer vision, infrared thermal imaging, ship automatic identification system, etc., but these methods still have the problem of low accuracy in identifying collisions / false alarms in practical applications. Among them, computer vision technology installs cameras on the bridge to obtain the speed and path of passing ships, and then uses algorithms to analyze the obtained ship information to evaluate the probability of collision with bridge piers. The camera has visual blind spots and is easily affected by foggy weather and night, resulting in false alarms, which will greatly affect the efficiency of public resource use. Infrared thermal imaging technology uses the thermal radiation emitted by the observed object itself to capture the temperature distribution on the surface of the object and then confirm the type of the object. Compared with light, temperature is not affected by darkness, and the wavelength of thermal radiation is longer than visible light, so rain, snow, smoke, fog and other bad weather cannot block the propagation of thermal radiation. However, its image receiving element is to receive the thermal radiation energy of the object. In order to obtain a certain signal-to-noise ratio, the area of ​​the receiving element unit should not be too small, so the image resolution is low. The resolution of mainstream equipment on the market is 320×240 pixels, which is far from the current resolution of hundreds of millions of pixels, and cannot perform high-precision positioning. Most of the current related equipment cannot meet the requirements of vehicle and ship collision perception and photo evidence collection.

[0032] This embodiment is based on the evaluation method of the vulnerability of bridge piers to ship collisions. Based on the tonnage of the ship, the speed of the ship, the collision position, and the design information of the existing bridge including the concrete compressive strength of the piers and the yield strength of the longitudinal reinforcement of the piers, the different damage degrees of the piers under the impact of the vehicle are quickly calculated, and the degree of damage to the piers caused by the impact is analyzed. Considering the simultaneous effect of multiple design parameters, based on the finite element analysis model of the ship-bridge pier collision and the LS-DYNA simulation model, the degree of damage to the piers can be accurately calculated to provide a basis for the maintenance and subsequent operation management of the bridge.

[0033] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The above is only a specific implementation method of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for assessing damage to bridge pile foundation caused by ship collision, characterized in that: The method is used for a bridge ship collision alarm perception system, which includes: a detection device group consisting of a video monitoring device and a radar device, a vibration sensor and an edge gateway, wherein the video monitoring device, the radar device and the vibration sensor are connected to the edge gateway; The method comprises: S1. Collecting ship data in real time through the detection equipment group, the ship data including: ship tonnage, ship speed, navigation track data and water flow speed; S2. When the ship reaches a specified distance in front of the bridge, the ship number information, the angle information and the position information of the ship hitting the bridge are obtained through the camera of the video surveillance device; S3, collecting event information when the collision occurs through a vibration sensor, wherein the event information includes: angular velocity information of the ship collision, amplitude and frequency information of the bridge after the impact; S4, calibrate each other through video monitoring equipment and vibration sensor, and detect whether collision occurs; S5. If a collision is detected, the impact force of the collision is obtained by using the collected ship data; S6. According to the impact force of the ship collision and the bearing capacity of the bridge, the damage level information of the bridge is obtained, and the damage level information is sent to and displayed on a designated device, wherein the designated device includes: a display device of a monitoring platform, and / or a terminal device.

2. The method according to claim 1, characterized in that In S1, it includes: The tonnage, speed and navigation track data of the ship are collected by the video monitoring equipment, and the speed, navigation track data and water flow speed of the ship are collected by the radar equipment; The ship speed and navigation track data collected by the video monitoring equipment are weightedly fused with the ship speed and navigation track data collected by the radar equipment.

3. The method according to claim 1, characterized in that S5 include: Use the collected ship data to obtain the impact force of the ship collision ,in, is the impact force of the ship collision, unit is MN, DWT is the deadweight tonnage of the ship, unit is T, V is the impact speed of the ship, unit is M / S.

4. The method according to claim 3, characterized in that Also includes: The ship impact velocity V is determined using the ship data, where: , Indicates that the ship speed in the ship data is equal to the normal speed of the ship in the waterway, represents the average value of the water velocity as the minimum design impact velocity of the ship, X represents the distance from the centerline of the pier to the centerline of the channel determined by the navigation trajectory data, It represents the distance from the centerline of the channel to the edge of the channel. It represents the distance from the center line of the channel to n times the ship length, where n is a positive integer.

5. The method according to claim 4, characterized in that n=3。 6. The method according to claim 1 or 3, characterized in that: In S6, the bridge capacity model includes: , where Vyd represents the design value of the bearing capacity of the component, Vcd represents the design value of the bearing capacity of the concrete part, Vwd represents the design value of the shear bearing capacity of the stirrup part (kN), Vsd represents the design value of the shear bearing capacity of the steel frame part (kN), Фs represents the shear impact effect reduction factor, Vc represents the shear strength of concrete (kPa), and Ag represents the gross cross-sectional area of ​​the component cross section (m2); where, , fc' represents the standard value of the compressive strength of a 28d concrete cylinder (MPa), and fc'=0.8 / fcuk+8MPa, fcuk is the standard value of the compressive strength of a concrete cube (MPa), c1 and c2 are the reinforcement calculation coefficient and axial force calculation coefficient respectively.

7. The method according to claim 6, characterized in that 0.02 < c1 < 0.25。 8. The method according to claim 6, characterized in that Фs=0.

7.

9. The method according to claim 6, characterized in that In S6, obtaining the damage level information of the bridge includes: if P s ≤5%*Vyd, the damage level of the bridge is level 1; if 5%*Vyd≤P s ≤30%*Vyd, the damage level of the bridge is level 2; if P s >30%*Vyd, the damage level of the bridge is level three.

10. The method according to claim 9, characterized in that Also includes: If the damage level of the bridge is determined to be level one, a regular inspection notification is sent to the terminal device through the edge gateway; if the damage level of the bridge is determined to be level two, an immediate on-site inspection notification is sent to the terminal device through the edge gateway; if the damage level of the bridge is determined to be level three, a road blockage notification is sent to the terminal device through the edge gateway.

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