CN203745170U - Bridge Static Deflection Monitoring Device - Google Patents

Abstract

Provided is a bridge static flexibility monitoring device. A semi-closed container is formed by a space encircled by the outer wall of a small water tank and the inner wall of a large water tank. The large water tank is provided with a drain outlet, and the small water tank is provided with a drain hole, and the drain hole is higher than the drain outlet. A submersible pump is disposed in the semi-closed container, and the water outlet end of the submersible pump is communicated with the small water tank. The submersible pump is capable of pumping water from the semi-closed container to the small water tank. Two throw-in type liquid level sensors are respectively disposed in the small water tank and the semi-closed container. One end of a U-shaped communicating pipe penetrates through the bottom part of the large water tank and is communicated with the bottom part of the small water tank, and the other end of a U-shaped communicating pipe is communicated with the measuring end of a high-precision liquid level sensor. The throw-in type liquid level sensor, the high-precision liquid level sensor, and a serial port relay are all electrically connected to a controller, and the serial port relay is electrically connected to the submersible pump. The bridge static flexibility monitoring device is advantageous in that height difference between the water level of the small water tank and the high-precision horizontal plane can be always maintained at a constant value.

Description

Bridge Static Deflection Monitoring Device

technical field

The utility model relates to a bridge health monitoring device, in particular to a bridge static deflection monitoring device.

Background technique

With the growth of bridge age, the problem of bridge deflection is inevitable. In order to prevent the bridge structure from being damaged due to excessive deflection, it is necessary to carry out long-term deflection monitoring on the bridge, and the maintenance personnel are more concerned about the static deflection change of the bridge. Therefore, long-term monitoring and early warning should be carried out especially for the static deflection of bridges.

Throughout the research on bridge deflection measurement technology at home and abroad, the basic methods are: dial indicator (foot), dial gauge (foot), suspension method (suspended wire method), theodolite, level (general level, automatic leveling level, precision level, electronic level), total station, measuring robot (intelligent total station), static leveling device, photogrammetry, linear variable differential transformer (Linear Variable Differential Transformer, LVDT), laser Doppler vibrometer (Laser Doppler Vibrometer, LDV), acceleration sensor, special deflection measuring instrument (such as laser deflection meter), GPS deformation measurement method, Microwave Interferometer (Microwave Interferometer) measurement method, tension line method, vertical rod deflection monitoring method, low frequency vibration pickup, Gyroscopes, a series of methods for indirectly estimating bridge deflection based on acceleration sensors or inclination sensors, a series of devices and methods based on photoelectric images, a series of devices and methods based on connecting pipes, etc. Each deflection measurement technology has its own characteristics and scope of application. At present, the deflection monitoring technology based on the connecting pipe method is the most widely used because of its clear physical concept and relatively reliable measurement results.

The basic principle of the deflection monitoring technology based on the connecting pipe method is: laying a connecting pipe on the bridge, and the connecting pipe is connected with the sensors at each measuring point and the container at the reference position, and the whole connecting pipe is filled with liquid. , the liquid level at the measuring point changes, and the deflection is obtained indirectly by collecting the liquid level change through the sensor. According to the type of sensor used to collect liquid level changes, it can be divided into liquid level sensor method and hydraulic sensor method. According to whether the liquid in the connecting pipe flows during the deformation process, it can be divided into the liquid flow type connecting pipe method deflection monitoring technology and the liquid static type connecting pipe method deflection monitoring technology.

The basic principle of the liquid flow connected pipe method deflection monitoring technology is: based on the static pressure balance principle of the connected pipe, that is, the liquid level in each connected branch pipe is at the same horizontal position under the action of atmospheric pressure, and the method used to measure the change of the liquid level is The sensors are both liquid level sensors and hydraulic sensors, and are mainly used to monitor the static deflection of the bridge. For example, the "a deflection monitoring system" disclosed by the authorized announcement number CN201387376Y is based on this principle, but the sensor used is a fiber grating deflection sensor, but the disadvantage is that when the liquid evaporates, it will cause the entire liquid level to drop. The readings from the point sensors will vary, resulting in inaccurate deflection measurements. There are also some methods to install a liquid level sensor at the reference point (water tank), and the difference between the liquid level value measured by other measuring points and the liquid level value of the reference sensor is used as the deflection of this point, although it can better solve the problem caused by liquid volatilization. However, the accuracy and stability of the reference sensor are very important. The relative system error between the measuring point sensor and the base point sensor may reduce the accuracy and accuracy. phenomenon, the liquid level in the connecting pipe will change, which will also lead to inaccurate deflection results.

The basic principle of liquid static connecting pipe method deflection monitoring technology: the liquid in the connecting pipe remains static, and the liquid level plane remains unchanged. When the deflection of the bridge deforms, the position of the measuring point sensor changes accordingly. The distance between the sensor and the liquid level surface The pressure difference will change, and the pressure difference signal of the sensor before and after the bridge deformation is collected by the hydraulic sensor, and the deflection deformation value is obtained through indirect conversion. However, this series of methods are greatly affected by the liquid density ρ in the connecting pipe, the local atmospheric pressure g, and the change of the ambient temperature. The connecting pipe device and sensor on the bridge will also vibrate accordingly, resulting in a large additional pressure in the connecting pipe. Since the hydraulic sensor is particularly sensitive to force, it increases the measurement noise and limits the accuracy. It is not suitable for bridge static deflection monitoring.

Utility model content

Aiming at the problems in the background technology, the utility model proposes a bridge static deflection monitoring device, its structure is: the bridge static deflection monitoring device consists of a large water tank, a small water tank, a submersible pump, two drop-in liquid level sensors, a U The small water tank is arranged in the large water tank, the bottom surface of the small water tank is fixedly connected with the inner bottom surface of the large water tank, and the outer wall of the small water tank and the inner wall of the large water tank form a space A semi-closed container; a drain port is provided on the side wall of the large water tank, and a drain hole is provided on the side wall of the small water tank, and the height of the drain hole is higher than the drain port; the submersible pump is arranged in the semi-closed container, and the submersible The water outlet of the pump is connected to the upper end of the small water tank, and the height of the water outlet of the submersible pump is higher than the drain hole, and the submersible pump can pump the water in the semi-closed container into the small water tank; the first drop-in liquid level sensor is set in the small water tank Inside, the second drop-in liquid level sensor is set in the semi-closed container; one end of the U-shaped connecting pipe runs through the bottom of the large water tank and then communicates with the bottom of the small water tank, and the other end of the U-shaped connecting pipe communicates with the measuring end of the high-precision liquid level sensor; An input liquid level sensor, a high-precision liquid level sensor and a serial port relay are all electrically connected to the controller, and the serial port relay is electrically connected to the submersible pump.

The principle of the utility model is: the first drop-in liquid level sensor can detect the water level in the small water tank. The water in the semi-closed container is pumped into the small water tank. The amount of water pumped by the submersible pump should be large, and it must overflow the drain hole. After the submersible pump stops, the excess water will flow back to the semi-closed container along the drain hole. so that the water level in the small water tank is always stable at the height of the lower edge of the drain hole; the second drop-in liquid level sensor can detect the water level in the semi-closed container. According to the set threshold, if the water level is lower than the threshold, then The controller sends a message to the maintenance personnel to remind the maintenance personnel to add water to the large water tank. The large water tank can also be directly connected to the drainage pipe on the bridge deck. In the rainy season, the rainwater can be used to supplement the water in the large water tank ( The drain port can prevent the water from being injected too much);

In specific applications, set a high-precision horizontal plane near the reference point on the bridge (generally set on the pier), set the large water tank and its internal devices on the high-precision horizontal plane, and then place the measuring point (generally set on the pier) In the middle of the main span), a high-precision liquid level sensor is installed, and the measurement part of the high-precision liquid level sensor is connected with the bottom of the small water tank through a U-shaped connecting pipe; during specific measurement, the internal liquid level reading is measured by the high-precision liquid level sensor , and the difference between the initial liquid level reading of the liquid level sensor is the static deflection of the current bridge; after adopting the scheme of the utility model, the height difference between the water level in the small water tank and the high-precision horizontal surface can always be kept at a certain level Constant value, that is, there is a constant reference liquid level reference surface, which avoids the influence of factors such as liquid evaporation, liquid deterioration, liquid density change, atmospheric pressure change, ambient temperature change, connecting pipe shape change, etc., so that the measurement accuracy can be improved. Guarantee, at the same time, only need to install a high-precision liquid level sensor at the measuring point, the static deflection value at a certain moment is the difference between the liquid level value at that moment and the initial liquid level value, which can reduce the influence of the sensor system error.

Preferably, a liquid feeding pipe is connected to the upper end of the large water tank, and a filter screen is arranged on the liquid feeding pipe. The liquid feeding pipe can be used to communicate with the drainage pipe on the bridge deck, and the filter screen can be used to filter out sundries in the water to avoid the accumulation of sundries in the large water tank.

Preferably, the high-precision liquid level sensor adopts a magnetostrictive static level.

The beneficial technical effect of the utility model is: the height difference between the water level in the small water tank and the high-precision horizontal surface can be kept at a constant value all the time, that is, there is a constant reference liquid level reference surface, which avoids liquid evaporation, The influence of factors such as liquid deterioration, liquid density change, atmospheric pressure change, ambient temperature change, connecting pipe shape change, etc., so that the measurement accuracy is guaranteed. At the same time, only a high-precision liquid level sensor needs to be installed at the measuring point. The static deflection value of is the difference between the liquid level value at this moment and the initial liquid level value, which can reduce the influence of the sensor system error.

Description of drawings

Fig. 1, the structural representation of the utility model;

The names corresponding to each mark in the figure are: large water tank 1, liquid discharge port 1-1, liquid filling pipe 1-2, small water tank 2, liquid discharge hole 2-1, submersible pump 3, submersible liquid level sensor 4 , U-shaped connecting pipe 5, controller 6, high-precision liquid level sensor 7, serial port relay 8.

Detailed ways

A bridge static deflection monitoring device, the structure of which is: the bridge static deflection monitoring device consists of a large water tank 1, a small water tank 2, a submersible pump 3, two input liquid level sensors 4, a U-shaped connecting pipe 5, and a controller 6 , a high-precision liquid level sensor 7 and a serial port relay 8; the small water tank 2 is arranged in the large water tank 1, the bottom surface of the small water tank 2 is fixedly connected with the inner bottom surface of the large water tank 1, and the outer wall of the small water tank 2 is surrounded by the inner wall of the large water tank 1 The space forms a semi-closed container; the side wall of the large water tank 1 is provided with a drain port 1-1, and the side wall of the small water tank 2 is provided with a drain hole 2-1, and the height of the drain hole 2-1 is higher than that of the drain hole. The liquid port 1-1; the submersible pump 3 is arranged in a semi-closed container, the water outlet of the submersible pump 3 communicates with the upper end of the small water tank 2, and the height of the water outlet of the submersible pump 3 is higher than the drain hole 2-1, the submersible pump 3 can Pump the water in the semi-closed container to the small water tank 2; the first drop-in liquid level sensor 4 is set in the small water tank 2, and the second drop-in liquid level sensor 4 is set in the semi-closed container; one end of the U-shaped connecting pipe 5 After passing through the bottom of the large water tank 1, it communicates with the bottom of the small water tank 2, and the other end of the U-shaped connecting pipe 5 communicates with the measuring end of the high-precision liquid level sensor 7; two input-type liquid level sensors 4, high-precision liquid level sensors 7 and serial port relays 8 are electrically connected with the controller 6, and the serial port relay 8 is electrically connected with the submersible pump 3.

Further, the upper end of the large water tank 1 is connected with a liquid-feeding pipe 1-2, and a filter screen is arranged on the liquid-feeding pipe 1-2.

Further, the high-precision liquid level sensor 7 adopts a magnetostrictive static level.

Claims (3)

1. a bridge static deflection monitoring device, is characterized in that: described bridge static deflection monitoring device is made up of large water tank (1), little water tank (2), submersible pump (3), two throw-in type liquid level sensors (4), U-shaped communicating pipe (5), controller (6), high-accuracy liquid level sensor (7) and serial ports relay (8); Described little water tank (2) is arranged in large water tank (1), and little water tank (2) bottom surface is fixedly connected with large water tank (1) inner bottom surface, and little water tank (2) outer wall and large water tank (1) inwall enclosed space form a semienclosed container; On the sidewall of large water tank (1), be provided with leakage fluid dram (1-1), be provided with outage (2-1) on the sidewall of little water tank (2), the height of outage (2-1) is higher than leakage fluid dram (1-1); Submersible pump (3) is arranged in semienclosed container, the water side of submersible pump (3) is communicated with little water tank (2) upper end, and the water side height of submersible pump (3) is higher than outage (2-1), and submersible pump (3) can be pumped the water in semienclosed container to little water tank (2); The first throw-in type liquid level sensor (4) is arranged in little water tank (2), and the second throw-in type liquid level sensor (4) is arranged in semienclosed container; U-shaped communicating pipe (5) one end run through behind large water tank (1) bottom with little water tank (2) bottom be communicated with, U-shaped communicating pipe (5) other end be communicated with the measuring junction of high-accuracy liquid level sensor (7); Two throw-in type liquid level sensors (4), high-accuracy liquid level sensor (7) and serial ports relay (8) are all electrically connected with controller (6), serial ports relay (8) and submersible pump (3) electrical connection.

2. bridge static deflection monitoring device according to claim 1, is characterized in that: described large water tank (1) upper end is connected with a liquid-feeding tube (1-2), on liquid-feeding tube (1-2), is provided with filter screen.

3. bridge static deflection monitoring device according to claim 1, is characterized in that: described high-accuracy liquid level sensor (7) adopts magnetostriction hydrostatic level.