Systems and methods for monitoring tensioned steel members

Abstract

Systems and methods for monitoring a tensioned steel member for faults. An example system can include a sensor positioned near a tensioned steel member along its longitudinal axis and a magnet coupled to the member and aligned with the sensor in an initial state. The system can further include a data acquisition system that periodically checks the electrical state of the sensor to determine if it has changed, which would indicate movement of the steel member due to a fault.

Description

FDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOlSYSTEMS AND METHODS FOR MONITORING TENSIONED STEEL MEMBERSFIELD

[0001] The present disclosure generally relates to systems and methods for monitoring tensioned steel members to detect when faults occur.BACKGROUND

[0002] Tensioned steel members are widely used throughout multiple industries as they provide a combination of strength, efficiency, and design flexibility. Proper tension in steel members is vital for safety, performance, and durability, making it essential to the overall success of any structural design. Identifying the onset of failures in these steel members is essential for effective asset management. This proactive approach minimizes both the costs and time required for investigation and repairs, ultimately enhancing safety protocols.

[0003] For example, in dams, post-tensioned trunnion anchor rods are used to secure the gates to the structure. Over the years, numerous failures of dam trunnion rods have been documented, prompting extensive research focused on the prediction and identification of these failures prior to occurrence. The objective is to minimize any impact on the serviceability and load capacity of the dam.

[0004] However, it is difficult, expensive, and dangerous to inspect non-grouted trunnion anchor rods. Measurement of in-situ post-tension loads is typically accomplished through lift-off testing which involves applying additional load to the rods via heavy hydraulic and test equipment. The live ends, or jacking ends, of the trunnion rods are situated away from the dam face and are often not regularly monitored. This is primarily due to their placement and the cost-prohibitive nature of accessing them, as they are typically housed within rectangular steel enclosures. The failure of these trunnion anchor rods presents a significant challenge for dam owners, as they are vital for securing the radial gates to the dam and supporting the weight of the water exerted on the gates. When these rods fail, the load is redistributed to adjacent rods, increasing the risk of further failures that could lead to catastrophic gate failure.

[0005] Thus, there is a need for a cost-effective, safe, robust, flexible, and efficient way to monitor tensioned steel members in- situ to determine when faults occur.FDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WO01SUMMARY

[0006] The present disclosure relates generally to a system for monitoring a tensioned steel member in-situ, substantially as illustrated by and described in connection with at least one of the figures, as set forth more completely in the claims.DRAWINGS

[0007] The foregoing and other objects, features, and advantages of the devices, systems, and methods described herein will be apparent from the following description of particular embodiments thereof, as illustrated in the accompanying figures, where like reference numbers refer to like structures. The figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the devices, systems, and methods described herein.

[0008] FIG. 1 is a schematic diagram illustrating an example system for monitoring a tensioned steel member in-situ.

[0009] FIG. 2 is a schematic diagram of the system of FIG. 1 illustrating lateral movement of the tensioned steel member.

[0010] FIG. 3 is a schematic diagram of an example system for monitoring a tensioned steel member in-situ.

[0011] FIGS. 4-6 are schematic diagrams of the system of FIG. 3 illustrating lateral movement of the tensioned steel member.

[0012] FIG. 7 is a schematic diagram of an example system for monitoring a tensioned steel member in-situ.

[0013] FIGS. 8-10 are schematic diagrams of the system of FIG. 7 illustrating lateral movement of the steel member.

[0014] FIG. 11 is a block diagram of an example ADAS enclosure and sample components it may house.

[0015] FIG. 12 is a schematic diagram illustrating an example system for monitoring a plurality of tensioned steel members.

[0016] FIG. 13 is a cut-away side view of the system shown in FIG. 12.

[0017] FIG. 14 is a schematic diagram illustrating an example system for monitoring a plurality of tensioned steel members arranged in a circular fashion.FDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOlDESCRIPTION

[0018] References to items in the singular should be understood to include items in the plural, and vice versa, unless explicitly stated otherwise or clear from the text. Grammatical conjunctions are intended to express any and all disjunctive and conjunctive combinations of conjoined clauses, sentences, words, and the like, unless otherwise stated or clear from the context. Recitation of ranges of values herein are not intended to be limiting, referring instead individually to any and all values falling within the range, unless otherwise indicated herein, and each separate value within such a range is incorporated into the specification as if it were individually recited herein. In the following description, it is understood that terms such as “first,” “second,” “top,” “bottom,” “side,” “front,” “back,” and the like are words of convenience and are not to be construed as limiting terms unless otherwise stated or clear from context.

[0019] As used herein, the terms “about,” “approximately,” “substantially,” or the like, when accompanying a numerical value, are to be construed as indicating a deviation as would be appreciated by one of ordinary skill in the art to operate satisfactorily for an intended purpose. Ranges of values and / or numeric values are provided herein as examples only, and do not constitute a limitation on the scope of the described embodiments. The use of any and all examples, or exemplary language (“e.#.,” “such as,” or “the like”) provided herein, is intended merely to better illuminate the embodiments and does not pose a limitation on the scope of the embodiments. The terms “e.g.,” and “for example” set off lists of one or more non-limiting examples, instances, or illustrations. No language in the specification should be construed as indicating any unclaimed element as essential to the practice of the embodiments.

[0020] As used herein, the term “and / or” means any one or more of the items in the list joined by “and / or.” As an example, “x and / or y” means any element of the three-element set { (x), (y), (x, y) }. In other words, “x and / or y” means “one or both of x and y.” As another example, “x, y, and / or z” means any element of the seven-element set { (x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}. In other words, “x, y, and / or z” means “one or more of x, y, and z.”

[0021] As used herein, the terms “exemplary” and “example” mean “serving as an example, instance or illustration.” The embodiments described herein are not limiting, but rather are exemplary only. It should be understood that the described embodiments are not necessarily to be construed as preferred or advantageous over other embodiments. Moreover, the termsFDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl“embodiments of the invention,” “embodiments,” or “invention” do not require that all embodiments of the invention include the discussed feature, advantage or mode of operation.

[0022] As used herein, the term “data” is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art, and refers without limitation to any indicia, signals, marks, symbols, domains, symbol sets, representations, and any other physical form or forms representing information, whether permanent or temporary, whether visible, audible, acoustic, electric, magnetic, electromagnetic, or otherwise manifested. The term “data” is used to represent predetermined information in one physical form, encompassing any and all representations of corresponding information in a different physical form or forms.

[0023] As used herein, the terms “memory” and “memory device” are broad terms and are to be given their ordinary and customary meaning to a person of ordinary skill in the art, and refer without limitation to computer hardware or circuitry to store information. Memory or memory device can be any suitable type of computer memory or other electronic storage means including, for example, read-only memory (ROM), random access memory (RAM), dynamic RAM (DRAM), static RAM (SRAM), ferroelectric RAM (FRAM), cache memory, compact disc read-only memory (CDROM), electro-optical memory, magneto-optical memory, masked read-only memory (MROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically-erasable programmable read-only memory (EEPROM), rewritable read-only memory, flash memory, or the like. Memory or memory device can be implemented as an internal storage medium and / or as an external storage medium. For example, memory or memory device can include hard disk drives (HDDs), solid-state drives (SSDs), optical disk drives, plug-in modules, memory cards (e.g., xD, SD, miniSD, microSD, MMC, etc.), flash drives, thumb drives, jump drives, pen drives, USB drives, zip drives, a computer readable medium, or the like.

[0024] As used herein, the term “processor” is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art, and refers without limitation to processing devices, apparatuses, programs, circuits, components, systems, and subsystems, whether implemented in hardware, tangibly embodied software, or both, and whether or not it is programmable. The term “processor” includes, but is not limited to, one or more computing devices, hardwired circuits, signal-modifying devices and systems, devices and machines for controlling systems, central processing units, microprocessors, microcontrollers, programmableFDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl devices and systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), systems on a chip (SoC), systems comprising discrete elements and / or circuits, state machines, virtual machines, data processors, processing facilities, digital signal processing (DSP) processors, and combinations of any of the foregoing. A processor can be coupled to, or integrated with, memory or a memory device.

[0025] As used herein, the term “network” is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art, and refers without limitation to any communication network including, for example, an extranet, intranet, inter-net, the Internet, local area network (LAN), wide area network (WAN), metropolitan area network (MAN), wireless local area network (WLAN), ad hoc network, wireless ad hoc network (WANET), mobile ad hoc network (MANET), or the like.

[0026] The structural health monitoring (SHM) system described herein utilizes continuous monitoring to detect in-service failures of tensioned steel members (such as post-tensioned tendons in building and bridges, soil nails, micropiles, ground anchors, and dam trunnion rods) as they occur. The system is designed to detect two primary failure modes: (1) fractures occurring at any point along the steel member between the dead end and the live end, resulting in a portion of the steel member moving outward from an anchorage plate with significant force, and (2) failures of the wedge-insert locking mechanism, which cause the live end to be drawn into the anchorage plate due to a reduction or total loss of the existing tension force.

[0027] The SHM system described herein can comprise a sensor, such as a Reed switch, proximity sensor, hall effect sensor, or the like, and a magnet. The sensor can be pre-installed on a sensor assembly at the live end of the tensioned steel member. When the steel member fails, the attached magnet will move away from the sensor causing the system to register movement upon scan. The sensor can be connected to an automatic data acquisition system (ADAS) that can automatically check the sensor for failure conditions at regular time intervals on a continuous schedule. A flag can be recorded in the measurement data when failure is detected.

[0028] If a remote communications component of the data acquisition system fails during the service life of the SHM system, or the system goes temporarily offline, the failure condition of the member can still be readily assessed by manual inspection of the electrical continuity of the sensor using a hand-held multimeter. Data recorded by the ADAS can be sent to a cloud database which can feed both an asset management dashboard (for remote monitoring) as well as a finiteFDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl element model (FEM) for updated structural analysis and safety factor determination. This enables the SHM system to automatically send alerts to specific personnel whenever a member failure occurs. The SHM system can also be equipped with an indicator to alert personnel that a failure has occurred. Potential indicators could include a flashing led light, a motor-actuated mechanical flag, a siren or horn, or the like.

[0029] The present disclosure relates to a system and method for monitoring a tensioned steel member for faults, displacements, or failures. The system comprises a magnet secured to the live end of the tensioned steel member and a sensor positioned in close proximity to the magnet. The sensor is configured to change state when the magnet moves beyond a predetermined range. A data acquisition system (ADAS) communicates with the sensor and determines whether the tensioned steel member has moved by at least a threshold amount indicative of a fault or failure condition.

[0030] In one aspect, the sensor may be a reed switch, proximity sensor, or Hall effect sensor. The sensor can be either a normally-open or normally-closed type, with the ADAS monitoring circuit continuity to determine whether the magnet remains within range. A sensor assembly may be mounted adjacent to an anchor plate associated with the tensioned steel member, supporting the sensor in alignment with the magnet. This sensor assembly can include a rigid channel or bracket with mounting slots allowing multiple sensors to be positioned in alignment with a corresponding plurality of steel members.

[0031] The magnet may be secured to the tensioned member via a corrosion-resistant fastener, clamp, or similar attachment designed to maintain alignment with the sensor. The ADAS may perform periodic continuity checks of the sensor at predefined intervals and store the resulting measurements in a time-series database. These continuity checks can be implemented using single- ended voltage or half-bridge measurements to evaluate the electrical condition of the sensor. To ensure reliability, the ADAS may be housed within a sealed enclosure providing environmental protection for all internal components and may be powered by a mains supply, battery, or solar power source.

[0032] In some configurations, a plurality of sensors may be positioned at different distances from the anchor plate, allowing the ADAS to determine both direction and displacement of movement based on which sensors change state. The displacement can be calculated from the known spacing between adjacent sensors that register a state change. These sensors may beFDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl arranged linearly along a channel or circumferentially around the anchor plate. A local indicator may be connected to the ADAS to provide visual, audible, or mechanical alerts in the event a failure is detected. The ADAS may further communicate data to a remote client portal via wired or wireless connection, allowing for real-time visualization of measurement data, alert notifications, and finite element analysis (FEA) results.

[0033] The ADAS enclosure may include a multiplexer for aggregating signals from multiple sensors prior to data processing. The system may be deployed to monitor tensioned members arranged linearly, vertically, or radially about an anchor plate. Upon detection of a fault, the ADAS can automatically initiate a finite element analysis of the associated structure to assess potential changes in overall structural integrity.

[0034] A corresponding method is provided for monitoring tensioned steel members for faults. The method includes securing a magnet to the live end of the member, positioning a sensor such that it changes state when the magnet moves beyond a threshold range, and periodically checking circuit continuity via the ADAS. The ADAS determines whether the member has moved by a threshold amount based on a detected change in state. Continuity data can be stored in a timeseries database and transmitted to a remote portal for analysis. When multiple sensors are installed, the system can determine both direction and displacement of movement. A local alert — visual or audible — may be generated when a failure is detected.

[0035] The disclosure also encompasses a computer-readable medium containing instructions that, when executed by an ADAS processor, cause the system to receive sensor data, detect changes in continuity, determine direction and displacement of movement, and generate alerts or initiate finite element analysis. These instructions may also transmit data and analysis results to a client portal and log continuity measurements at defined intervals in a local or cloud database.

[0036] An alternative system configuration includes at least one sensor positioned near a tensioned steel member and a magnet coupled to the member to control the sensor’ s state. In this aspect, a reed switch may be employed, and the ADAS determines displacement by detecting state changes of the reed switch corresponding to a threshold movement distance. Communication between the ADAS and sensor may occur over wired or wireless interfaces.

[0037] Another aspect includes a magnetic element attached to the structural member, at least one proximity sensor configured to detect changes in magnetic field strength or position, andFDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl a controller that interprets the sensor signal to determine whether displacement exceeds a threshold value. The controller may distinguish between displacement directions corresponding to tension reduction or fracture. Multiple sensors may be positioned incrementally along or around an anchor plate, with the magnetic element attached using a corrosion-resistant, non-ferrous clip or strap. The controller may perform voltage or continuity measurements using half-bridge excitation techniques and may activate local visual or audible indicators upon detection of excessive displacement. A network interface enables transmission of status data to remote monitoring platforms.

[0038] A structural health monitoring system for multiple tensioned members may include a sensor assembly with multiple sensors aligned to corresponding magnets, a multiplexer to collect continuity data, and a data acquisition system that polls sensors, detects continuity changes, and stores or transmits time-series results. The ADAS and multiplexer may be enclosed in liquid-tight housings, powered by solar energy for remote operation, and configured to aggregate data across large structures such as bridges or dams. A client portal may receive transmitted data, display operational status, and generate automated user alerts.

[0039] Methods for detecting failure include attaching magnetic elements to live ends of tensioned members, arranging multiple sensors adjacent to the magnets, and measuring electrical continuity periodically. Displacement direction and magnitude are identified based on which sensors change state. Continuity data can be logged in a time-series database and transmitted to a remote platform for analysis, with displacement estimates determined from known sensor spacing. Site-specific alarms may be triggered when displacement exceeds predefined thresholds, and the system may automatically initiate finite element analyses to reassess safety factors.

[0040] A computer-implemented monitoring platform may include one or more processors executing instructions that receive sensor state data, detect changes corresponding to displacement, determine displacement direction, generate alerts, and initiate analysis routines to evaluate structural integrity. The platform may visualize displacement data in a web-based interface and perform finite element computations to update stress and safety factors. Notifications may be sent via email, SMS, or push messages. Distributed ADAS units can communicate through wired or wireless channels to a central monitoring platform.

[0041] Finally, the disclosure provides a structural health monitoring platform comprising multiple sensor assemblies with associated magnets, a data acquisition system configured toFDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl periodically measure continuity states, a communications interface for remote data transmission, and a software analytics module for detecting fault events, determining displacement direction and magnitude, and updating a structural integrity model such as a finite element model of a dam, bridge, or building. The ADAS may include a multiplexer for consolidating signals, and the system may incorporate a local alarm subsystem for visual or audible fault indication. The analytics module may maintain a historical database of fault events, generate timestamped notifications with displacement data, and transmit alerts to authorized users through wired, wireless, or cellular communications.

[0042] The SHM system disclosed herein can detect the failure of tensioned steel members. It is designed to detect failure modes that occur when the member experiences excessive movement in the inward or outward direction of the post-tensioned force. For example, a post-tensioned steel trunnion rod supporting a Tainter gate on a hydroelectric dam will typically fail in one of two ways: (1) fracture of the anchor rod at any point between the dead end and live end of a rod, which results in a portion of the rod moving outwards from the anchor plate at great force, and (2) wedgeinsert locking mechanism failures, which results in the live end of the anchor rod being drawn into the anchor plate due to a reduction, or total loss, of the existing tension force. Similar failures can be observed in other applications of post-tensioned steel members such as ground anchors, soil nails, cable stayed bridges, and post-tensioned tendons in bridges and buildings, all to which this system could be applied.

[0043] Example sensing mechanisms to detect failures include Reed switches, proximity sensors, and Hall effect sensors, paired with a magnet. When the sensor is in close proximity to the magnet, it will engage the sensor, either opening or closing an electrical circuit depending on its type. For example, a “normally-closed” sensor will present an open circuit when the magnet is in close proximity and aligned with the sensor. When the magnet moves out of range of the sensor, the circuit becomes closed. On the other hand, a “normally- open” sensor will present a closed (short) circuit when the magnet is in close proximity and aligned with the sensor. When the magnet moves out of range of the sensor, the circuit becomes open. The sensor can be checked for continuity at any time to determine if the circuit is opened or closed. Knowing the type of sensor used, it can be determined if the magnet is engaging the sensor.

[0044] In the disclosed SHM system, a magnet is secured to the live end of tensioned steel members and sensors are strategically installed close, but not in contact with, the magnets in anFDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl orientation that will not interfere with the members’ movement. When there is excess movement in a tensioned member, the magnet that is secured to the member will move away from the sensor, switching the continuity status of the circuit, thus indicating a failure. The use of a single sensor will indicate that a failure has occurred but does not provide insights on the failure mode (direction of failure) or the displacement of the member. Thus, in alternative systems, multiple sensors can also be used on a single member. A magnet can be strategically secured to the steel member in a way that, when a failure occurs, the direction can be determined, and displacement can be reasonably estimated (provided the failure falls within the bounds of the assembly). The number of sensors and their spacing will determine the resolution and subsequent accuracy of results.

[0045] A sensor or an array of sensors is wired to an Automatic Data Acquisition System (ADAS) to collect measurements of electrical continuity. The ADAS can be programmatically set to collect these measurements at a defined interval and store the measurements in a time- series data table. This allows the user to determine an approximate time frame for when a failure occurred. The interval can be defined depending on user requirements but is typically sparse (hours or days). The ADAS can accommodate multiple measurement types including single-ended voltage or half-bridge measurements to determine continuity. A continuity check with each measurement type can be programmed to return the continuity status of the circuit. The single- ended measurement type requires no excitation voltage whereas the half-bridge measurement type requires an excitation voltage be passed through the circuit to determine continuity. The halfbridge approach is typically more robust, withstanding external electrical noise, but is less economical as it requires more connections to the ADAS and additional power for the excitation voltages. Having both options available provides flexibility depending on the application.

[0046] The SHM system can comprise several components that allow for flexibility and scalability to any number of tensioned steel members. For example, the SHM system can include a sensor assembly, magnet assembly, ADAS enclosure, sensor cable, and an on-site indicator.

[0047] A sensor assembly can be designed with rigid material, such as aluminum or steel, and can be used to hold a single sensor or an array of sensors. The assembly is rigidly mounted adjacent to existing post-tensioned members. The sensors are arranged on the assembly to align with the existing post-tensioned members. The method of adhering the sensors to the assembly can vary depending on the sensor selected, but the sensors should be secure. The sensor assembly can be designed to enclose all sensor wires to protect them from the surrounding environment. AnFDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl example assembly that could be used for trunnion rods at a hydroelectric dam could be an aluminum channel that is bolted to the anchor plate between two columns of trunnion rods. The channel can include slotted holes on each leg of channel aligning with each rod to accommodate threaded sensors that are secured to the channel with nuts and washers. A plate covers the open face of the channel and the open ends can be sealed to minimize moisture intrusion.

[0048] A magnet assembly can be designed to secure the magnet to the tensioned steel member. The magnet assembly can be adjustable so it may align properly with corresponding sensors on the sensor assembly. The magnet assembly can be designed with such materials that it will not corrode over time when constantly exposed to the elements. If such materials are not available for the specific application, weatherproofing methods can be applied to the assembly. An example assembly that could be used for trunnion rods at a hydroelectric dam could be magnets adhered to plastic cable tie clips and secured to the rods using stainless steel cable ties aligned at the locations of the corresponding sensors. Foam mounting tape can be used at the interface between cable ties and rods to prevent corrosion and to reduce slipping.

[0049] An ADAS enclosure can be used to hold the ADAS and ancillary components. In most cases, the enclosure should be liquid-tight and properly sealed to protect the enclosed components and exposed wiring from the surrounding environment. The enclosure is securely mounted to an accessible location that is free from obstructions to provide safe, convenient access to the user for data collection and maintenance.

[0050] The ADAS has multiple available power options depending on the application and user preference. The ADAS in general operates using extremely low amounts of power due to the low frequency of measurement scans, as well as the lack of power required for the measurements. In some cases, the system does not require power at all. Continuity of the circuits for each posttensioned member can be checked manually at any time using a multimeter to probe the connected channels on the ADAS. This is especially useful if the system loses power for a period of time. The ADAS can also operate on battery power, and if equipped with a solar cell can run continuously for an indefinite amount of time. This would be advantageous for applications where monitoring is required in remote areas and where space allows for a solar cell. Finally, the ADAS can operate on provided power from the power grid if available to do so. This would allow for the most reliable continuous operation of the SHM system but may be more challenging to access.FDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl

[0051] The ADAS also has multiple communication options. Data is inherently stored on the ADAS via internal or expandable storage. This data can be collected at any time with a direct connection to the ADAS from a computer over a LAN or USB connection, for example. The ADAS also has the capability to transmit this data to an on-premise database, via wires or wirelessly, where it can be locally accessed by the user, eliminating the need to directly connect to the ADAS. Some users may prefer this method as a means of securely accessing their data. Finally, the data can be transmitted to a cloud database (e.g., via a direct ethernet connection to the internet or wirelessly using a cellular modem). This will allow for remote access to the data, limiting the need to access the ADAS directly.

[0052] A sensor cable is used to connect the sensors on the sensor assembly to the ADAS in its enclosure. The cable selected best suits the requirements of the application, including the number of conductors required to support the sensors on the sensor assembly and resistance to electrical noise. For example, the sensor cable can be twisted pair copper wire. All exposed conductors are properly routed and protected within the enclosed sensor assembly. A liquid-tight seal can be created at the interface of the sensor assembly and insulated portion of the cable to ensure no moisture intrusion to the internal, exposed conductors. The cable is wired in a similar way at the ADAS enclosure, where the stripped portion of the cable is contained within the liquid- tight enclosure protecting the exposed conductors from the surrounding environment. All exposed conductors are wired to the appropriate channels on the ADAS. Between the sensor assembly and ADAS enclosure, the cable can be fully exposed (if weatherproof) or contained in rigid metal / PVC conduit depending on the application and user preference. In applications with many sensors, the sensor cable can be routed to a multiplexer (MUX), which in turn can be wired to the ADAS. This can help maximize the economy of the ADAS for applications in which a very large number of tensioned members are monitored.

[0053] An optional addition to the system is a physical, on-site indicator used to indicate when a failure has occurred. The indicators can be integrated and programmed with the ADAS to notify on-site personnel of a failure without the need to collect the data directly from the ADAS. The actual indicator can vary depending on the application, user preference, or site conditions. Some examples of indicators include LED lights installed on the ADAS enclosure or elsewhere on-site that flash, a mechanical flag that raises when a failure occurs, and a siren or horn.FDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl

[0054] The system can also include a client portal and API designed to access the measurement data remotely. The client portal offers multiple visualization options and summary information to give the user a global understanding of the monitored post-tensioned members as well as to download the collected data. The portal also offers alerts that are defined at intervals set by the user. These alerts can be delivered to the user in multiple ways including email. SMS messages, and push notifications.

[0055] An additional feature to the portal is the autonomous execution of a finite element (FE) analysis on the existing superstructure containing the post-tensioned members. If the data is available, an FE model can be automatically triggered to execute when a failure is detected. The resulting values from this analysis, such as the updated safety factor, stresses, etc., can be published to a web interface or report file and sent to the user or made available to them via the portal. The results of this analysis give the user an updated understanding of the structural integrity of the superstructure.

[0056] Turning now to the figures, FIG. 1 is a schematic diagram illustrating an example system for monitoring a tensioned steel member in-situ. As illustrated, the live end of tensioned steel member 102 extends from an anchor plate 104. Sensor assembly 106 positions sensor 108 near steel member 102. A magnet 110 is coupled to steel member 102 such that it is aligned and in close proximity with sensor 108. Sensor 108 is connected to the ADAS enclosure 112 via transmission media 114. The transmission media 114 can comprise a sensor cable or a wireless interface. The ADAS enclosure 112 can house an ADAS (not shown) as well as other components, which is described later in this disclosure.

[0057] As illustrated in FIG. 1, the magnetic field of magnet 110 maintains the sensor 108 in a state opposite its normal state (e.g., normally-open or normally-closed) because the magnet 110 and sensor 108 are aligned and in close proximity. The ADAS can periodically check the state of sensor 108 to determine if it has changed, and can record and store the results.

[0058] FIG. 2 is a schematic diagram of the system of FIG. 1 illustrating lateral movement of tensioned steel member 102, e.g., due to a fault. As a result of the member’s movement, the magnet 110 has moved outside the range of sensor 108, thus changing the state of sensor 108 (e.g., open to closed, or closed to open, depending on the initial state). When the ADAS checks the continuity of the system shown in FIG. 2, the state of the sensor 108 will have changed compared to the state illustrated in FIG. 1. This changed state can be recorded and stored in memory (e.g., asFDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl a flag). As explained elsewhere herein, the measurement data can be stored and accessed locally, or it can be accessed remotely. Moreover, the changed state of sensor 108 can trigger an indicator.

[0059] FIG. 3 is a schematic diagram of an example system for monitoring a tensioned steel member in-situ. In this example system, two sensors 108a and 108b are used to monitor steel member 102. Sensors 108a and 108b are shown affixed to sensor assembly 106, which is illustrated as a channel mounted to anchor plate 104. The transmission media 114 is illustrated as a wire routed through sensor assembly 106 to connect sensors 108a and 108b to the ADAS (not shown) housed inside ADAS enclosure 112. Alternatively, transmission media 114 could be a wireless interface. Magnet 110 is coupled to steel member 102 and is large enough to span the distance between sensor 108a and 108b such that both sensors are maintained in a state opposite their normal state. When the ADAS periodically checks the states of sensors 108a and 108b, both should in the same state (open or closed, depending on the sensor). These measurement results can be recorded and stored.

[0060] FIGS. 4-6 are schematic diagrams of the system of FIG. 3 illustrating lateral movement of tensioned steel member 102. For example, as illustrated in FIG. 4, member 102 has moved inward, e.g., due to a failure of the wedge-insert locking mechanism, thereby causing magnet 110 to remain aligned with sensor 108a such that its state has not changed, but to become out of range from sensor 108b such that its state changes. When the ADAS periodically checks the states of sensors 108a and 108b, sensor 108a will be in the same state as in FIG. 3, but sensor 108b will have changed states. It can therefore be deduced that the tensioned steel member 102 has moved inward toward anchor plate 104.

[0061] FIG. 5 illustrates the opposite of FIG. 4. As illustrated in FIG. 5, tensioned steel member 102 has moved outward, e.g., due to a fault along member 102, thereby changing the state of sensor 108a while maintaining the state of sensor 108b. From this, it can be deduced that the tensioned steel member 102 has moved outward away from anchor plate 104.

[0062] In FIG. 6, member 102 has moved further outward, resulting in both sensors 108a and 108b changing states. If sensor 108a is mounted a distance from anchor plate 104 such that magnet 110 will always maintain its state when member 102 moves inward, then it can also be deduced that member 102 has moved outward when both sensors have changed states.FDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl

[0063] The system illustrated in FIGS. 3-6 can be expanded so that several sensors are positioned near steel member 102, which can be used to determine the direction and displacement of steel member 102 with more precision. This is illustrated in FIGS. 7-10.

[0064] FIG. 7 is a schematic diagram of an example system for monitoring a tensioned steel member in-situ. The system is illustrated as having 7 sensors, but more or less sensors can be used. The sensors can also be positioned closer to one another to increase precision. When the ADAS checks the status of the sensors shown in FIG. 7, only sensor 108e is in a state opposite its normal state because it is the only sensor aligned with magnet 110. In FIG. 8, member 102 has moved inward toward anchor plate 104, causing sensors 108d and 108e to change states. That is, in FIG. 8, sensor 108d is now in a state opposite its normal state, but because magnet 110 has moved out of range of sensor 108e, it has changed from its initial state shown in FIG. 7. If the spacing between sensors 108d and 108e is known, then the approximate displacement of member 102 can be determined as the distance between the sensors. Moreover, because sensor 108d has changed states, it can be deduced that member 102 has moved inward.

[0065] In FIG. 9, member 102 has moved outward from anchor plate 104 such that the new position of magnet 110 aligns with sensor 108h. Because 108h has changed from its initial state shown in FIG. 7, it can be deduced that member 102 has moved outward. The approximate displacement of member 102 can be determined as the distance between sensor 108e (where magnet was initially aligned in FIG. 7) and sensor 108h (where magnet is finally aligned in FIG. 9). In FIG. 10, member 102 has moved further outward, resulting in all sensors changing states.

[0066] With regard to FIG. 9 in which magnet 110 is aligned with sensor 108h, it should be noted that sensors 108f and 108g will have also temporarily changed states as member 102 was displaced. However, these states may change so rapidly that they may go undetected by the ADAS. For example, if the ADAS periodically checks the continuity of each sensor about every one hour, then it is unlikely to catch the changed states of sensors 108f and 108g (unless the fault happens to occur at the time the ADAS is checking continuity). However, because magnet 110 was initially aligned with sensor 108e, but became aligned with sensor 108h (in FIG. 9), the changed states of sensors 108f and 108g that the ADAS may not have captured are irrelevant. With the disclosed system, it is still possible to know the direction and approximate displacement of member 102.

[0067] FIG. 11 is a block diagram of an example ADAS enclosure 112 and sample components it may house. For example, ADAS enclosure 112 can house an ADAS 120 thatFDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl periodically checks the continuity of sensors 108 as explained above. ADAS 120 may also allow for local access, such as with a laptop, as well as for remote access. For example, ADAS 120 can be connected to a network, such as a LAN or the Internet, so that the system can be accessed, monitored, and / or controlled remotely.

[0068] ADAS enclosure 112 can also include one or more multiplexers (MUX) 130. A MUX can help maximize the economy of the ADAS 120, especially for applications in which a large number of tensioned members 102 are monitored. For example, FIG. 11 illustrates two MUXes 130a and 130b, each of which can be connected to many sensors (114a and 114b). Each MUX, in turn, is wired to ADAS 120 via communication cables (COMM), such as Ethernet cables.

[0069] ADAS enclosure 112 can also include a power source 140. As explained above, the power source can be a mains power supply, a battery, a solar cell, or the like. Power source 140 is wired to each of the components in ADAS enclosure 112 to provide sufficient power for the system to operate.

[0070] Although not shown, ADAS enclosure 112 can include other components, such as networking components (e.g., switches, routers). Moreover, a system that monitors a large number of tensioned members 102 can have multiple ADAS enclosures 112, each connected to one another (e.g., via conduit). For example, a plurality of tensioned members 102 can be wired to a first ADAS enclosure 112 that houses one or more MUXes 130. Another plurality of tensioned members 102 can be wired to a second ADAS enclosure 112 that also houses one or more MUXes 130. The first or the second ADAS enclosure 112 can include a power supply 140 and an ADAS 120. These resources can be shared across the system. Therefore, each ADAS enclosure 112 need not actually house an ADAS 120, as one ADAS 120 can be shared among several ADAS enclosures 112.

[0071] FIG. 12 is a schematic diagram illustrating an example system for monitoring a plurality of tensioned steel members 102. FIG. 12 illustrates 16 tensioned steel members 102 that could be, for example, post- tensioned trunnion anchor rods used to secure a gate of a dam. In FIG. 12, sensor assembly 106 is illustrated as a channel mounted between the members 102 to position a plurality of sensors 108 in close proximity to a plurality of magnets 110, each fastened to a member 102. It should be noted that only the top row of tensioned members 102, magnets 110, and sensors 108 are labeled in FIG. 12 for clarity. As illustrated, the transmission media 114 (e.g., a sensor cable) can be routed through sensor assembly 106, which would be covered to provide a liquid-tight enclosure as explained above.FDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl

[0072] FIG. 13 is a cut-away side view of the system shown in FIG. 12. For example, tensioned members 102 on the right side of FIG. 12 are depicted in FIG. 13, each having a sensor 108 mounted in close proximity via sensor assembly 106. Magnets 110 are mounted to each member 102 but are hidden from view due to sensor assembly 106.

[0073] The arrangement of a plurality of tensioned steel members 102 may not be linear or rectangular as shown in FIG. 13. For example, a plurality of tensioned steel members 102 might be arranged in a circular fashion. FIG. 14 is a schematic diagram illustrating an example system for monitoring a plurality of tensioned steel members arranged in a circular fashion. As shown, a sensor assembly 106 can have circular cut-outs that correspond to each member 102 so that sensor assembly 106 can fit over members 102 and mounted to an anchor plate (not shown). FIG. 15 is a perspective view of the system illustrated in FIG. 14.

[0074] Although not shown in FIGS. 12-14, each member 102 in those figures can be monitored by a plurality of sensors 108 to detect the direction of movement and displacement of a member when it fails as explained in connection with FIGS. 3-10.

[0075] While particular embodiments have been shown and described, it will be apparent to those skilled in the art that various changes and modifications, in form and details, may be made without departing from the spirit and scope of this disclosure and are intended to form a part of the invention as defined by the following claims, which are to be interpreted in the broadest sense allowable by law. Further, the sequence of steps for example methods described or illustrated herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated unless specifically identified as requiring so or clearly identified through context. Moreover, the example methods may omit one or more steps described or illustrated, or may include additional steps in addition to those described or illustrated. Thus, one of ordinary skill in the art, using the disclosures provided herein, will appreciate that various steps of the example methods can be omitted, rearranged, combined, and / or adapted in various ways without departing from the spirit and scope of the inventions.

Claims

FDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOlWhat is claimed is:

1. A system for monitoring a tensioned steel member for faults, the system comprising: a magnet secured to a live end of the tensioned steel member; a sensor positioned in close proximity to the magnet and configured to change state when the magnet moves beyond a predetermined range; and a data acquisition system (ADAS) in communication with the sensor, the ADAS being configured to determine from the sensor whether the tensioned steel member has moved by at least a threshold amount indicative of a failure of the tensioned steel member.

2. The system of claim 1, wherein the sensor comprises a reed switch, proximity sensor, or Hall effect sensor.

3. The system of claim 1, wherein the sensor is one of a normally-open type or a normally- closed type, and wherein the ADAS determines continuity of a circuit associated with the sensor to detect whether the magnet is within range.

4. The system of claim 1, further comprising a sensor assembly mounted adjacent to an anchor plate associated with the tensioned steel member, the sensor assembly supporting the sensor in alignment with the magnet.

5. The system of claim 4, wherein the sensor assembly comprises a rigid channel including one or more mounting slots for positioning a plurality of sensors in alignment with a corresponding plurality of tensioned steel members.

6. The system of claim 1, wherein the magnet is secured to the tensioned steel member via a magnet assembly including a corrosion-resistant fastener or clamp configured to align the magnet with the sensor.

7. The system of claim 1, wherein the ADAS is configured to perform periodic continuity checks of the sensor at predefined intervals and to store corresponding measurement data in a timeseries database.

8. The system of claim 7, wherein the ADAS is configured to perform single-ended voltage or half-bridge measurements to determine the continuity of the sensor.FDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl9. The system of claim 1, wherein the ADAS is housed within a sealed enclosure that provides environmental protection for the ADAS and associated components.

10. The system of claim 9, further comprising a power source configured to supply power to the ADAS, the power source comprising one of a mains connection, a battery, or a solar cell.

11. The system of claim 4, further comprising a plurality of sensors positioned at different distances from the anchor plate, wherein the ADAS is configured to determine both the direction and displacement of movement of the tensioned steel member based on a change in state among the plurality of sensors.

12. The system of claim 11, wherein the ADAS determines the displacement of the tensioned steel member based on known spacing between adjacent sensors that have changed state.

13. The system of claim 11, wherein the plurality of sensors are arranged linearly along a sensor assembly or circumferentially around the anchor plate.

14. The system of claim 1, further comprising an indicator in communication with the ADAS and configured to provide a local alert when the ADAS determines that a failure has occurred.

15. The system of claim 14, wherein the indicator comprises at least one of a visual indicator, audible indicator, or mechanical indicator.

16. The system of claim 1, wherein the ADAS is configured to communicate measurement data to a remote client portal via a wired or wireless network connection.

17. The system of claim 16, wherein the client portal provides a user interface configured to display measurement data, alert notifications, and finite element analysis (FEA) results associated with detected failures.

18. The system of claim 9, wherein the sealed enclosure further comprises a multiplexer configured to aggregate signals from a plurality of sensors before transmission to the ADAS.

19. The system of claim 1, wherein the system is configured to monitor a plurality of tensioned steel members arranged linearly, vertically, or circularly around an anchor plate.FDH Ref. No.: 2024N-0001 MHM Ref. No.: 68602 WOOl20. The system of claim 1, wherein the ADAS is further configured to automatically initiate a finite element structural analysis of a structure associated with the tensioned steel member in response to detection of a fault.

21. A method for monitoring a tensioned steel member for faults, the method comprising: securing a magnet to a live end of the tensioned steel member; positioning a sensor adjacent to the magnet such that the sensor changes state when the magnet moves beyond a threshold range; periodically checking, by a data acquisition system (ADAS), an electrical continuity of the sensor; and determining, by the ADAS, whether the tensioned steel member has moved by at least a threshold amount based on a detected change in state of the sensor.

22. The method of claim 21, further comprising storing the continuity data in a time-series database and transmitting the data to a client portal for remote access.

23. The method of claim 21, wherein the method further comprises determining a direction and displacement of the tensioned steel member based on a state change among multiple sensors positioned at different distances from an anchor plate.

24. The method of claim 21, further comprising generating a local visual or audible alert when a failure is detected.

25. A non-transitory computer-readable medium storing instructions that, when executed by a processor of a data acquisition system (ADAS), cause the ADAS to: receive sensor data from one or more sensors positioned near a tensioned steel member; determine, based on the sensor data, whether a change in continuity has occurred: identify a direction and displacement of movement of the tensioned steel member based on the change in continuity; and generate an alert signal or initiate a finite element analysis in response to detecting a failure condition.FDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl26. The computer-readable medium of claim 26, wherein the instructions further cause the ADAS to transmit the sensor data and analysis results to a remote client portal for visualization and user notification.

27. The computer-readable medium of claim 26, wherein the instructions further cause the ADAS to periodically log continuity measurements at user-defined intervals and store them in a local or cloud-based database.

28. A system for monitoring a tensioned steel member for faults, the system comprising: a sensor positioned in close proximity to a tensioned steel member; and a data acquisition system in communication with the sensor, wherein the data acquisition system is configured to determine from the sensor whether the tensioned steel member has moved by a threshold amount.

29. The system of claim 28, wherein the sensor is a Reed switch, and wherein the system further comprises a magnet coupled to the tensioned steel member to control the state of the Reed switch.

30. The system of claim 29, wherein the data acquisition system is configured to determine from the sensor whether the tensioned steel member has moved by a threshold amount by detecting whether the Reed switch has changed states.

31. The system of claim 30, wherein the threshold amount is the distance needed for the Reed switch to change states.

32. The system of claim 28, wherein the data acquisition system is in communication with the sensor over a wireless interface.

33. A monitoring system for detecting faults in a tensioned structural member, the system comprising: a magnetic element attached to the structural member: at least one proximity sensor positioned to detect a change in magnetic field strength or position of the magnetic element; and a controller configured to interpret a signal from the proximity sensor to determine whether the structural member has experienced a displacement exceeding a threshold value.FDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl34. The system of claim 33, wherein the structural member comprises a post-tensioned steel rod, cable, or tendon.

35. The system of claim 33, wherein the controller is configured to distinguish between displacement in a first direction corresponding to a reduction in tension and displacement in a second direction corresponding to a fracture of the structural member.

36. The system of claim 33, wherein the at least one proximity sensor includes a plurality of sensors positioned at incremental distances from an anchor plate associated with the structural member.

37. The system of claim 33, wherein the magnetic element is attached to the structural member using a corrosion-resistant mount comprising a non-ferrous clip, strap, or tie.

38. The system of claim 33, wherein the controller comprises a data acquisition system (ADAS) configured to perform continuity or voltage measurements to determine a change in sensor state.

39. The system of claim 38, wherein the ADAS performs the continuity measurement using a half-bridge excitation voltage.

40. The system of claim 33, wherein the system further comprises a network interface enabling the controller to transmit status data to a remote monitoring platform.

41. The system of claim 33, wherein the controller is configured to activate a local indicator upon detection of a displacement exceeding the threshold value.

42. The system of claim 41, wherein the local indicator comprises an LED, a mechanical flag, or an audible device.

43. A structural health monitoring system for a plurality of tensioned steel members, the system comprising: a sensor assembly including a plurality of sensors, each aligned with a corresponding magnet mounted to a respective tensioned steel member; a multiplexer configured to receive electrical continuity signals from the plurality of sensors; andFDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl a data acquisition system communicatively coupled to the multiplexer and configured to:(a) periodically poll the sensors to determine their continuity states;(b) detect changes in continuity indicative of movement of one or more of the tensioned steel members; and(c) store and transmit the detected changes for further analysis.

44. The system of claim 43, wherein the data acquisition system and multiplexer are enclosed within separate liquid-tight housings mounted adjacent to the monitored members.

45. The system of claim 43. wherein the data acquisition system is powered by a solar energy source configured to maintain continuous monitoring in remote locations.

46. The system of claim 43, wherein the data acquisition system is configured to aggregate sensor data from multiple housings distributed across a dam or bridge structure.

47. The system of claim 43, wherein the stored data includes a time-series of continuity measurements allowing identification of a time window corresponding to a failure event.

48. The system of claim 43, further comprising a client portal configured to receive transmitted sensor data, display the operational status of the plurality of members, and generate automated alerts to a user.

49. A method for detecting failure in a tensioned steel member, the method comprising: attaching a magnetic element to a live end of the tensioned steel member; arranging multiple sensors adjacent to the magnetic element, each sensor being configured to change electrical continuity when the magnetic element moves beyond its range; periodically measuring the electrical continuity of each sensor; and identifying a direction and magnitude of movement of the tensioned steel member based on which of the sensors have changed continuity state.

50. The method of claim 49, further comprising recording continuity data in a time-series database and transmitting the data to a remote analysis platform.FDH Ref. No.: 2024N-0001MHM Ref. No.: 68602 WOOl51. The method of claim 49, further comprising determining an estimated displacement of the tensioned steel member based on the spacing between sensors that changed state.

52. The method of claim 49. further comprising generating a site-specific alarm when a displacement greater than a predefined threshold is detected.

53. The method of claim 49, further comprising triggering an automated finite element analysis of a structure that includes the tensioned steel member to determine an updated safety factor.

54. A computer-implemented system for evaluating movement of tensioned structural members, comprising: one or more processors; and memory storing instructions that, when executed by the one or more processors, cause the system to:(a) receive state data from a plurality of sensors associated with respective tensioned members;(b) detect a change in sensor state corresponding to a displacement of a member;(c) determine a direction of the displacement;(d) generate an alert indicating a potential failure; and(e) initiate an analysis routine to estimate a resulting change in structural integrity.

55. The system of claim 54, wherein the instructions further cause the system to visualize displacement information in a graphical user interface accessible through a client web portal.

56. The system of claim 54, wherein the analysis routine comprises a finite element analysis configured to compute updated stress and safety factors of a structure comprising the monitored members.

57. The system of claim 54, wherein the instructions further cause the system to transmit alerts via email, SMS, or push notification to registered users.

58. The system of claim 54, wherein the received state data is aggregated from a plurality of distributed ADAS units communicating through wired or wireless channels.FDH Ref. No.: 2024N-0001 MHM Ref. No.: 68602 WOOl59. A structural health monitoring platform for tensioned steel members, comprising: a plurality of sensor assemblies each including one or more sensors aligned with corresponding magnetic elements secured to respective tensioned steel members; a data acquisition system (ADAS) configured to periodically measure continuity states of the sensors and record the continuity states as time-series data; a communications interface configured to transmit the time-series data to a remote computing system; and a software analytics module executed by the remote computing system and configured to:(a) detect a fault event based on the time- series data;(b) identify a direction and displacement of movement associated with the fault event; and(c) update a structural integrity model responsive to the detected fault.

60. The platform of claim 59, wherein the structural integrity model comprises a finite element model of a dam, bridge, or building that includes the monitored tensioned steel members.

61. The platform of claim 59, wherein the ADAS further comprises a multiplexer coupled to a plurality of sensor cables for consolidating continuity signals before transmission to the remote computing system.

62. The platform of claim 59. further comprising a local indicator subsystem configured to generate a visual or audible alarm in response to the detected fault event.

63. The platform of claim 59, wherein the software analytics module is further configured to:(a) store the fault event in a historical database;(b) generate a notification including a timestamp, displacement magnitude, and failure direction; and(c) transmit the notification to one or more user devices.FDH Ref. No.: 2024N-0001 MHM Ref. No.: 68602 WOOl64. The platform of claim 59, wherein the communications interface comprises at least one of a wired Ethernet link, a wireless LAN connection, or a cellular modem.

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