Intelligent monitoring system for catastrophe of prestressed prefabricated segment assembled pier

Abstract

The invention provides an intelligent monitoring system for catastrophe of a prestressed prefabricated segment assembled pier. The system comprises a monitoring module and a control module, wherein the monitoring module is made of high-strength and high-sensitivity fine aggregate concrete, a galvanized copper mesh electrode is arranged on the bottom surface of the high-strength and high-sensitivity fine aggregate concrete, and a direct-current power supply system is configured to be connected with the galvanized copper mesh electrode to form a loop and is used for monitoring deformation of the bridge pier under the action of a dynamic load in real time; the control module is composed of a shape memory alloy beam, a controller and a photovoltaic power source energy input and storage device connected with the controller and used for starting the energy recovery process when the bridge pier deforms greatly. According to the invention, important characteristics of two intelligent materials are combined and utilized to form the intelligent monitoring system for catastrophe of the prestressed prefabricated segment assembled pier. And in combination with a semi-active control theory, the control force can be automatically adjusted under the action of a dynamic load, and good effects are achieved in the aspects of energy consumption and recovery.

Description

Technical Field

[0001] The invention belongs to the technical field of disaster reduction of civil engineering structures, and in particular relates to an intelligent disaster monitoring system for prestressed prefabricated segment assembled bridge piers. Background Art

[0002] As the main load-bearing components of bridge engineering, piers are subject to varying degrees of damage due to material aging, environmental corrosion, fatigue and creep, which reduces the piers' disaster response capabilities. Prestressed prefabricated segmental piers can be modularized and industrialized, and have the advantages of short construction period, small environmental impact and fast construction speed. However, the deformation capacity of prestressed tendons is small, which limits their recovery and energy consumption. Under normal service conditions, the pier system often bears dynamic loads, which has an adverse effect on the dynamic characteristics and dynamic response of the piers, and requires greater energy consumption and recovery capacity. Therefore, it is the key to solve the problem to monitor the operating status of the bridge structure in real time and conveniently, discover the safety hazards of the bridge early, and control them in time. However, the current monitoring technology mostly relies on computer technology and sensor technology, and its applicability and durability under dynamic loads are usually poor, which is not suitable for large-scale long-term use in field service environments.

[0003] Therefore, it is particularly important to use smart materials to develop a monitoring system that can effectively reduce the dynamic response of the pier structure, enhance the energy consumption and recovery capacity of the structure, and has strong operability. Summary of the invention

[0004] In order to overcome the above-mentioned shortcomings of the existing technology, the purpose of the present invention is to provide an intelligent monitoring system for disasters of prestressed prefabricated segment assembled bridge piers, which uses high-strength and high-sensitivity intelligent concrete as the monitoring system and SMA bundles as the control system. When the deformation reaches a certain level, it is assisted by semi-active control means to enhance the recovery and energy consumption capacity of the prestressed prefabricated segment assembled bridge piers.

[0005] The technical solution of the present invention is as follows:

[0006] An intelligent monitoring system for disasters of prestressed prefabricated segmented piers, the system comprising a monitoring module and a control module;

[0007] The monitoring module is a high-strength and high-sensitivity fine stone concrete, a galvanized copper mesh electrode is arranged on the bottom surface of the high-strength and high-sensitivity fine stone concrete, and a DC power supply system is configured to connect the galvanized copper mesh electrode to form a loop, which is used to monitor the deformation of the bridge pier under the action of dynamic load in real time;

[0008] The control module is composed of a shape memory alloy bundle, a controller, and a photovoltaic power source energy input and storage device connected thereto, and is used to start the energy recovery process when a large deformation occurs in the bridge pier.

[0009] Furthermore, the high-strength and high-sensitivity fine stone concrete selects aggregates with a particle size of no more than 15 mm as coarse aggregates, and is mixed with iron tailings, slag, steel fibers and carbon fibers.

[0010] Furthermore, four galvanized copper mesh electrodes are arranged at equal intervals at the bottom of the high-strength and high-sensitivity fine stone concrete, and the DC power supply system is connected to the four galvanized copper mesh electrodes to form a four-electrode method resistance measurement circuit.

[0011] Furthermore, the DC power supply system is connected to the photovoltaic power supply energy input and storage device via a conductor.

[0012] Furthermore, the shape memory alloy bundle is composed of a plurality of SMA wires, and the upper and lower ends are connected to the prestressed tendons through insulating flanges.

[0013] Furthermore, the number of the SMA wires, the length of the shape memory alloy bundle and the initial tensile strain value are determined by the prestress value applied by the prefabricated segment assembly of the bridge pier and the allowable deformation value of the bridge pier.

[0014] Furthermore, the controller is connected to the photovoltaic power input and the storage device through a wire.

[0015] Furthermore, the system also includes a bottom beam, a bridge, a cap beam, an assembled segment and a support. The bottom beam, the cap beam, the assembled segment and the high-strength and high-sensitivity fine stone concrete are all provided with channels for prestressed tendons to pass through. The various parts are connected by relying on the pre-tensioning force of the prestressed tendons, and the prestressed tendons are tensioned to a predetermined state. The two ends of the prestressed tendons are respectively fixed with high-strength anchors.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1. The present invention utilizes high-strength and high-sensitivity fine stone concrete as both a structural force-bearing material and a monitoring material, and does not require the installation of other devices. This overcomes the shortcomings of traditional sensors in long-term and complex field service environments, such as poor applicability and durability, large differences from the monitored structural materials, and discontinuous deformation. At the same time, the purpose of real-time monitoring can be achieved more conveniently.

[0018] 2. The present invention makes full use of the shape memory and pseudo-elastic properties of shape memory alloys to achieve reset and energy dissipation effects when the prestressed prefabricated assembled bridge piers are deformed under dynamic loads, thereby effectively limiting the deformation of the main structure and the high-strength and high-sensitivity fine stone concrete at the bottom.

[0019] 3. The present invention provides external energy for the prestressed prefabricated segment assembly piers conveniently and quickly through the photovoltaic power source energy input and storage device set on the bridge, ensuring that the monitoring system can carry out monitoring work in real time and without interruption, and also provides an energy source for semi-active control when the pier structure is greatly deformed, thereby avoiding excessive deformation of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings generally illustrate various embodiments by way of example and not limitation, and together with the description and claims, serve to illustrate the embodiments of the invention. Where appropriate, the same reference numerals are used throughout the drawings to refer to the same or similar parts. Such embodiments are illustrative and are not intended to be exhaustive or exclusive embodiments of the present apparatus or method.

[0021] Figure 1 is a structural diagram of the monitoring system of the present invention;

[0022] Figure 2 It is a schematic diagram of the SMA bundle structure of the present invention;

[0023] Figure 3 It is a schematic diagram of the structure of the high-strength and high-sensitivity fine stone concrete of the present invention. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0025] like Figure 1-3 As shown, the present invention provides a technical solution: a prestressed prefabricated segmented pier disaster intelligent monitoring system, including a bottom beam 1, a bridge 2, a cap beam 3, an assembled segment 4, and a support 5. The bottom of the assembled segment 4 is provided with a high-strength and high-sensitivity fine stone concrete 6, and its height depends on the plastic hinge height of the pier structure. The high-strength and high-sensitivity fine stone concrete 6 is provided with holes through which the prestressed tendons 9 pass, and the bottom thereof is provided with four 2mm wide galvanized copper mesh electrodes 7 and a DC power supply system 8 at equal intervals, forming a four-electrode method resistance measurement circuit. When the structure is subjected to dynamic load and deformed, the high-strength and high-sensitivity fine stone concrete 6 is compressed on one side and pulled on the other side. The change of the conductive circuit causes the resistance value to change, and the change is quantitatively monitored in real time, which indirectly reflects the main stress and deformation characteristics of the pier column structure. The DC power supply system 8 is connected to the photovoltaic power supply energy input and storage device 14 to ensure the continuous input of energy and achieve the purpose of real-time monitoring.

[0026] High-strength and high-sensitivity fine stone concrete 6 selects high-quality aggregate with a particle size not greater than 15 mm and good grading as coarse aggregate, and adds iron tailings (20%-40%), slag (20%-40%), steel fiber (0.8%-1.2%) and carbon fiber (0.6%-0.9%) to improve its sensitivity.

[0027] Channels for prestressed tendons 9 to pass through are reserved on the bottom beam 1, the cap beam 3, the assembled segment 4, and the high-strength and high-sensitivity fine stone concrete 6. The various parts are connected by the pre-tension of the prestressed tendons 9, and the prestressed tendons 9 are stretched to a predetermined state, and the two ends are fixed with high-strength anchors 15. When the prestressed tendons 9 with large deformation near the outer side of the pier are subjected to force, they are cut off and connected to the shape memory alloy bundle 11. When the pier is deformed and the deformation is small, the SMA bundle 11 on one side is stretched and elongated, and the deformation capacity of the main structure is increased by the deformation of the SMA, the energy consumption of the SMA bundle 11 is increased, and the damage accumulation of the prestressed tendons 9 is reduced, so as to ensure that the main structure is not damaged.

[0028] The shape memory alloy bundle 11 is composed of multiple SMA wires, and the upper and lower ends are connected to the prestressed steel strand 9 through insulating flanges 10. The number of SMA wires, the length of the SMA bundle and the initial tensile strain value (3%-5%) are comprehensively coordinated and determined by the prestress value applied by the prefabricated segment assembly piers and the allowable deformation value of the piers.

[0029] A controller 12 is provided on the upper part of the shape memory alloy bundle 11, and both ends are connected to the truncated prestressed tendons 9 through insulating flanges 10, and are connected to the photovoltaic power source energy input and storage device 14 fixed on both sides of the bridge 2 through wires 13. When the deformation is small, the SMA bundle 11 relies on pseudo-elasticity to consume and recover energy, and the controller 12 does not need to drive the photovoltaic power source energy input and storage device 14 to work. When the deformation of the main structure pier is large and reaches the set threshold, the controller 12 starts to work and drives the photovoltaic power source energy input and storage device 14 to work immediately, realizing semi-active control, and using the shape memory characteristics of the SMA bundle 11 to generate very high recovery stress and recovery strain, which plays a role in resetting and energy consumption, thereby limiting the excessive deformation of the main structure and preventing the high-strength and high-sensitivity fine stone concrete 6 in the plastic hinge area from being damaged. The photovoltaic power source energy input and storage device 14 can freely switch between energy consumption and energy storage, make up for the consumed electric energy at any time, and ensure the continuity and reliability of energy input.

[0030] In summary, the high-strength and high-sensitivity fine stone concrete 6 serves as both a structural stress-bearing material and a monitoring material, and does not require the installation of other devices. It can overcome the shortcomings of traditional sensors in long-term and complex field service environments, such as poor applicability and durability, large differences with the monitored structural materials, and discontinuous deformation. It is a reasonable material choice for engineering monitoring in field environments. When the deformation is small, the SMA bundle 11 relies on pseudo-elasticity for energy consumption and recovery; when the deformation of the main structure is large and reaches the set threshold, the controller 12 drives the photovoltaic power supply energy input and storage device 14 to work immediately, realizing semi-active control, and using the shape memory characteristics of the SMA bundle 11 to generate very high recovery stress and recovery strain, which plays a role in resetting and consuming energy, thereby limiting the main structure from excessive deformation, preventing the high-strength and high-sensitivity fine stone concrete 6 in the plastic hinge area from being damaged, and protecting the safety of the upper structure.

[0031] In the present invention, the high-strength and high-sensitivity fine stone concrete at the bottom of the assembled segment is used to monitor the resistance of the prefabricated assembled segment pier in real time, which indirectly reflects the stress and deformation conditions of the pier.

[0032] When the deformation of the bridge pier is small, the phase change pseudo-elastic properties of the SMA bundle are used to consume the catastrophic energy for passive energy dissipation control.

[0033] When the deformation value of the SMA bundle reaches a certain predetermined value, the controller can drive the photovoltaic power supply and storage device to work immediately, turn on the power to heat the shape memory alloy bundle, and use its shape memory characteristics to generate very high recovery stress and recovery strain, which plays a role in resetting and energy consumption, thereby effectively reducing the deformation of the bridge pier, protecting the high-strength and high-sensitivity fine stone concrete, and consuming the energy of the disaster.

[0034] The present invention combines and utilizes the important characteristics of two intelligent materials to form an intelligent monitoring system for disasters of prestressed prefabricated segmented piers. Combined with the semi-active control theory, it can autonomously adjust the control force under the action of dynamic loads, and has achieved good results in energy consumption and recovery.

[0035] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An intelligent monitoring system for disasters of prestressed prefabricated segmented piers, characterized in that: The system includes a monitoring module and a control module; The monitoring module is a high-strength and high-sensitivity fine stone concrete, a galvanized copper mesh electrode is arranged on the bottom surface of the high-strength and high-sensitivity fine stone concrete, and a DC power supply system is configured to connect the galvanized copper mesh electrode to form a loop, which is used to monitor the deformation of the bridge pier under the action of dynamic load in real time; The control module is composed of a shape memory alloy bundle, a controller, and a photovoltaic power source energy input and storage device connected thereto, and is used to start the energy recovery process when a large deformation occurs in the bridge pier.

2. The intelligent monitoring system for disasters of prestressed prefabricated segmented piers according to claim 1 is characterized in that: The high-strength and high-sensitivity fine stone concrete selects aggregates with a particle size of no more than 15 mm as coarse aggregates, and is mixed with iron tailings, slag, steel fibers and carbon fibers.

3. The intelligent monitoring system for disasters of prestressed prefabricated segmented piers according to claim 1 is characterized in that: Four galvanized copper mesh electrodes are arranged at equal intervals at the bottom of the high-strength and high-sensitivity fine stone concrete, and the DC power supply system is connected to the four galvanized copper mesh electrodes to form a four-electrode method resistance measurement circuit.

4. The intelligent monitoring system for disasters of prestressed prefabricated segmented piers according to claim 1 is characterized in that: The DC power supply system is connected to the photovoltaic power supply energy input and storage device through a conductor.

5. The intelligent monitoring system for disasters of prestressed prefabricated segmented piers according to claim 1 is characterized in that: The shape memory alloy bundle is composed of a plurality of SMA wires, and the upper and lower ends are connected to the prestressed tendons through insulating flanges.

6. The intelligent monitoring system for disasters of prestressed prefabricated segmented piers according to claim 5 is characterized in that: The number of the SMA wires, the length of the shape memory alloy bundle and the initial tensile strain value are determined by the prestress value applied by the prefabricated segment assembly of the bridge pier and the allowable deformation value of the bridge pier.

7. The intelligent monitoring system for disasters of prestressed prefabricated segmented piers according to claim 1 is characterized in that: The controller is connected to the photovoltaic power input and the storage device through wires.

8. The intelligent monitoring system for disasters of prestressed prefabricated segmented piers according to claim 1 is characterized in that: The system also includes a bottom beam, a bridge, a cap beam, an assembled segment and a support. The bottom beam, the cap beam, the assembled segment and the high-strength and high-sensitivity fine stone concrete are all provided with reserved channels for prestressed tendons to pass through. The various parts are connected by the pre-tensioning force of the prestressed tendons, and the prestressed tendons are stretched to a predetermined state. The two ends of the prestressed tendons are respectively fixed with high-strength anchors.

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