Rapid detection device for dynamic load test of large-span bridge

Abstract

The utility model discloses a rapid detection device for a dynamic load test of a large-span bridge, which relates to the technical field of bridge load detection and comprises a grating array vibration sensing optical cable, a signal demodulation instrument and a vibration signal analyzer which are connected in sequence. The grating array vibration sensing optical cable collects vibration sensing signals of the bridge under the action of random excitation; the signal demodulator demodulates the vibration signal to obtain a demodulated signal; and the vibration signal analyzer analyzes the demodulation signal and determines a bridge dynamic load test result. The device has the advantages that the arrangement process of the grating array vibration sensing optical cable is simple, full-bridge overall measurement can be realized, the capability of resisting interference of environmental factors such as electromagnetism and rainy days is strong, acquisition point positions are dense, and test data are more detailed and accurate.

Description

Technical Field

[0001] The utility model relates to the technical field of bridge load detection, in particular to a fast detection device for dynamic load test of a large-span bridge. Background Art

[0002] Newly built bridges, reinforced or rebuilt bridges, and bridges with technical status grades of four or five need to undergo load tests to verify whether the normal use status and bearing capacity of the bridge structure meet the design requirements. Bridge load tests include static load tests and dynamic load tests. The dynamic load test generally uses the environmental excitation method to obtain the natural vibration characteristics of large-span bridges. This method identifies the parameters of the structural natural vibration characteristics by measuring the micro-vibrations caused by random excitations such as wind loads, ground pulsations, and water flows when there is no traffic load on the bridge deck and no regular vibration sources near the bridge site. For large-span bridges with low natural vibration frequencies such as suspension bridges and cable-stayed bridges, it takes a long time to collect signals to ensure frequency resolution and increase the signal-to-noise ratio.

[0003] The existing bridge dynamic test equipment often uses single-point vibration pickups, which are weak point equipment. The equipment needs to be away from electromagnetic interference sources, and shielding measures need to be taken during the test. At the same time, the span of a long-span bridge is large, and single-point sensors need to be deployed in multiple locations or moved in different areas for testing, which takes a long time and consumes a lot of manpower. Since most commonly used sensors are electrical sensors, they are not suitable for testing in heavy or moderate rain. When conducting pulsation tests in light rain, rain protection measures must be taken for on-site instruments and transmission lines.

[0004] Therefore, the existing technology has problems such as being unable to measure the entire bridge as a whole, insufficient anti-electromagnetic interference capability, difficult deployment process, and being unable to test on rainy days. Utility Model Content

[0005] In view of this, it is necessary to provide a rapid detection device for dynamic load tests on large-span bridges to solve the problems of the existing technology being unable to measure the entire bridge as a whole, insufficient anti-electromagnetic interference capability, difficult deployment process, and inability to test on rainy days.

[0006] In order to solve the above problems, the utility model provides a fast detection device for dynamic load test of a large-span bridge, comprising a grating array vibration sensor optical cable, a signal demodulator and a vibration signal analyzer, wherein the grating array vibration sensor optical cable, the signal demodulator and the vibration signal analyzer are connected in sequence;

[0007] The grating array vibration sensing optical cable collects the vibration sensing signal of the bridge under random excitation;

[0008] The signal demodulator demodulates the vibration signal to obtain a demodulated signal;

[0009] The vibration signal analyzer analyzes the demodulated signal to determine the bridge dynamic load test results;

[0010] The bridge comprises a bridge deck and a bridge tower, and the grating array vibration sensing optical cable comprises a first grating array vibration sensing optical cable arranged on the bridge deck and a second grating array vibration sensing optical cable arranged on the bridge tower.

[0011] In a possible implementation, the first grating array vibration sensing optical cable is laid out at the center line of the bridge deck.

[0012] In one possible implementation, the bridge deck is divided into an upstream area and a downstream area, and the upstream area and the downstream area use the center line of the bridge deck as the boundary line. The first grating array vibration sensor optical cable includes a first sub-grating array vibration sensor optical cable arranged in the upstream area and a second sub-grating array vibration sensor optical cable arranged in the downstream area.

[0013] In one possible implementation, the first sub-grating array vibration sensor cable is laid out at 2 / 3 of the distance from the bridge deck edge to the bridge deck centerline in the upstream area, and the second sub-grating array vibration sensor cable is laid out at 2 / 3 of the distance from the bridge deck edge to the bridge deck centerline in the downstream area.

[0014] In one possible implementation, the upstream area includes at least two lanes, and the first sub-grating array vibration sensor optical cable includes each upstream area sub-grating array vibration sensor optical cable arranged in each lane of the upstream area; the downstream area includes at least two lanes, and the second sub-grating array vibration sensor optical cable includes each downstream area sub-grating array vibration sensor optical cable arranged in each lane of the downstream area.

[0015] In a possible implementation, each upstream region sub-grating array vibration sensor cable and each downstream region sub-grating array vibration sensor cable are laid out at the center line of each lane.

[0016] In a possible implementation, the second grating array vibration sensing optical cable is arranged along the height direction of the inner wall of the bridge tower.

[0017] In a possible implementation, the grating array vibration sensing optical cable is laid out in a surface mounting manner.

[0018] The beneficial effects of the utility model are as follows: the large-span bridge dynamic load test rapid detection device provided by the utility model has the advantages of simple grating array vibration sensor cable laying process, can measure the entire bridge as a whole, strong resistance to interference from electromagnetic and environmental factors such as rainy days, dense collection points, and more detailed and accurate test data. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the overall structure of an embodiment of a fast detection device for dynamic load testing of a large-span bridge provided by the utility model;

[0020] Figure 2This is a schematic diagram of the layout of the grating array vibration sensor optical cable according to an embodiment of the utility model. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0022] like Figure 1 As shown, the utility model provides a fast detection device for dynamic load test of a large-span bridge, including a grating array vibration sensor optical cable 1, a signal demodulator 2 and a vibration signal analyzer 3, wherein the grating array vibration sensor optical cable 1, the signal demodulator 2 and the vibration signal analyzer 3 are connected in sequence.

[0023] In this device, the grating array vibration sensing optical cable 1 collects the vibration sensing signal of the bridge under random excitation;

[0024] The signal demodulator 2 demodulates the vibration signal to obtain a demodulated signal;

[0025] The vibration signal analyzer 3 analyzes the demodulated signal to determine the bridge dynamic load test result.

[0026] In some embodiments, the bridge includes a bridge deck, and the grating array vibration sensor optical cable 1 includes a first grating array vibration sensor optical cable arranged on the bridge deck.

[0027] In some embodiments, the first grating array vibration sensing optical cable is laid out at the center line of the bridge deck.

[0028] Specifically, the grating array vibration sensing optical cable in the embodiment is laid on the bridge deck to collect vibration sensing signals generated by micro-vibrations of the bridge caused by random excitations such as wind load, ground pulsation, and water flow. In order to evenly collect signals generated by micro-vibrations of the entire bridge deck, the first grating array vibration sensing optical cable is laid at the center line of the bridge deck.

[0029] In some embodiments, Figure 2 Schematic diagram of the layout position of the grating array vibration sensor optical cable in the upstream and downstream areas of the embodiment, as shown in FIG. Figure 2 As shown, the bridge deck is divided into an upstream area and a downstream area, and the center line of the bridge deck is used as the boundary line between the upstream area and the downstream area. The first grating array vibration sensor optical cable includes a first sub-grating array vibration sensor optical cable 110 arranged in the upstream area and a second sub-grating array vibration sensor optical cable 120 arranged in the downstream area.

[0030] In some embodiments, the first sub-grating array vibration sensor cable 110 is arranged at 2 / 3 of the distance from the bridge deck edge to the bridge deck centerline in the upstream area, and the second sub-grating array vibration sensor cable 123 is arranged at 2 / 3 of the distance from the bridge deck edge to the bridge deck centerline in the downstream area.

[0031] Specifically, in an embodiment, the bridge deck can be divided into an upstream area and a downstream area by the center line of the bridge deck, and grating array vibration sensing optical cables are arranged at 2 / 3 of the distance from the edge of the bridge deck to the center line of the bridge deck, dividing the entire bridge deck into three equal parts, and measuring the bridge deck areas in different vehicle travel directions respectively to obtain a more comprehensive vibration sensing signal.

[0032] In some embodiments, if the upstream area includes at least two lanes, the first sub-grating array vibration sensor optical cable includes each upstream area sub-grating array vibration sensor optical cable arranged in each lane of the upstream area; if the downstream area includes at least two lanes, the second sub-grating array vibration sensor optical cable includes each downstream area sub-grating array vibration sensor optical cable arranged in each lane of the downstream area.

[0033] In some embodiments, each upstream region sub-grating array vibration sensor cable and each downstream region sub-grating array vibration sensor cable are laid out at the center line of each lane.

[0034] Specifically, considering that long-span bridges are usually wider multi-lane bridges, and there are certain differences in the types of vehicles passing through different lanes, the road conditions of the bridges are different. In order to obtain more accurate vibration sensing signals, for multi-lane long-span bridges, the embodiment can set multiple sub-grating array vibration sensing optical cables, and lay each sub-grating array vibration sensing optical cable at the center line position of each lane. During demodulation analysis, the calculation results of each sub-grating array vibration sensing optical cable in the upstream and downstream areas are averaged to obtain more accurate dynamic load test results of long-span bridges.

[0035] In some embodiments, the bridge includes a bridge tower, and the grating array vibration sensing optical cable includes a second grating array vibration sensing optical cable disposed on the bridge tower.

[0036] In some embodiments, the second grating array vibration sensing optical cable is arranged along the height direction of the inner wall of the bridge tower.

[0037] Specifically, for a long-span bridge with a bridge tower, a grating array vibration sensing optical cable is arranged along the height direction on the inner wall of the bridge tower to measure the vibration sensing signal of the bridge tower structure. In addition, as a preferred embodiment, considering that the side of the bridge tower close to the bridge deck is slightly more affected by random vibration excitation than the side away from the bridge deck, the second grating array vibration sensing optical cable at the bridge tower can be arranged on the inner wall of the bridge tower close to the bridge deck in the embodiment.

[0038] In some embodiments, the grating array vibration sensing optical cable 1 is arranged in a surface mounting manner.

[0039] Specifically, the grating array vibration sensing optical cable 1 is a continuous grating array prepared on a large scale by a drawing tower. Due to its industrial preparation and cabling, it can be laid in an integral manner at the bridge site, thereby improving the efficiency of construction and installation. Moreover, its laying method adopts a surface mounting method, which can be quickly laid and is also convenient for recycling and secondary use.

[0040] Compared with the prior art, the utility model has simple laying and recycling process of grating array vibration sensor optical cable, strong ability to resist electromagnetic and rainy environmental factors, and can achieve overall measurement of the whole bridge at one time. In addition, the collection points of grating array vibration sensor optical cable are dense, and the test data is more detailed and accurate.

[0041] The above specific implementation methods of the utility model do not constitute a limitation on the protection scope of the utility model. Any other corresponding changes and modifications made according to the technical concept of the utility model should be included in the protection scope of the claims of the utility model.

Claims

1. A fast detection device for dynamic load test of long-span bridges, characterized in that: It comprises a grating array vibration sensor optical cable, a signal demodulator and a vibration signal analyzer, wherein the grating array vibration sensor optical cable, the signal demodulator and the vibration signal analyzer are connected in sequence; The grating array vibration sensing optical cable collects vibration sensing signals of the bridge under random excitation; The signal demodulator demodulates the vibration signal to obtain a demodulated signal; The vibration signal analyzer analyzes the demodulated signal to determine the bridge dynamic load test result; The bridge comprises a bridge deck and a bridge tower, and the grating array vibration sensing optical cable comprises a first grating array vibration sensing optical cable arranged on the bridge deck and a second grating array vibration sensing optical cable arranged on the bridge tower.

2. The long-span bridge dynamic load test rapid detection device according to claim 1 is characterized in that: The first grating array vibration sensing optical cable is arranged at the center line of the bridge deck.

3. The fast detection device for dynamic load test of long-span bridge according to claim 1 is characterized in that: The bridge deck is divided into an upstream area and a downstream area, and the upstream area and the downstream area have a bridge deck centerline as a boundary line. The first grating array vibration sensor optical cable includes a first sub-grating array vibration sensor optical cable arranged in the upstream area and a second sub-grating array vibration sensor optical cable arranged in the downstream area.

4. The long-span bridge dynamic load test rapid detection device according to claim 3 is characterized in that: The first sub-grating array vibration sensor cable is laid out at 2 / 3 of the distance from the bridge deck edge to the bridge deck centerline in the upstream area, and the second sub-grating array vibration sensor cable is laid out at 2 / 3 of the distance from the bridge deck edge to the bridge deck centerline in the downstream area.

5. The long-span bridge dynamic load test rapid detection device according to claim 3 is characterized in that: If the upstream area includes at least two lanes, the first sub-grating array vibration sensor optical cable includes each upstream area sub-grating array vibration sensor optical cable arranged in each lane of the upstream area; if the downstream area includes at least two lanes, the second sub-grating array vibration sensor optical cable includes each downstream area sub-grating array vibration sensor optical cable arranged in each lane of the downstream area.

6. The long-span bridge dynamic load test rapid detection device according to claim 5 is characterized in that: The layout positions of the vibration sensing optical cables of each upstream area sub-grating array and the vibration sensing optical cables of each downstream area sub-grating array are the center lines of each lane.

7. The long-span bridge dynamic load test rapid detection device according to claim 1 is characterized in that: The second grating array vibration sensing optical cable is arranged along the height direction of the inner wall of the bridge tower.

8. The long-span bridge dynamic load test rapid detection device according to claim 1 is characterized in that: The grating array vibration sensor optical cable is arranged in a surface mounting manner.

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