Concrete structure underwater blasting autonomous acquisition system

Abstract

The application discloses an underwater explosion autonomous acquisition system for a concrete structure, which comprises a test pier body, a sensor group and a data acquisition device; a concrete base block is arranged at the middle part of the concrete structure; the sensor group comprises stress sensors, strain sensors, wall surface reflection pressure sensors and free field pressure sensors; and the data acquisition device is arranged in a sealed box which is embedded into the soil layer of the water bottom; the acquisition system is used for acquiring explosive explosion information, and is favorable for test personnel to acquire accurate test data and to make a blasting plan.

Description

TECHNICAL FIELD

[0001] The present application relates to a concrete structure underwater blasting autonomous acquisition system and belongs to the technical field of concrete structure blasting. BACKGROUND

[0002] In some shallow water areas, some artificial concrete pier groups are left at a certain distance from the shore, which affects the berthing of ships, so it is necessary to blast and damage the concrete pier groups to facilitate the berthing of ships. In shallow water blasting, the weakening effect of water pressure on explosives and the impact of water pressure are different from the concrete blasting damage test in the air. In addition, the principle of blasting and damaging concrete structures by explosives in the air is different from the effect of explosive load on concrete piers in shallow water. The reaction of the pier under the action of the explosive load mainly reflects compression and stretching. The positive pressure and compressive stress peak of the pier surface is mainly caused by the shock wave and the water bottom reflection wave. The negative pressure and tensile stress is mainly caused by the reflection of the sparse wave of the water surface and the pier surface. Due to the flowability and isotropy of the water medium, the concrete pier is subjected to the confining pressure of the shock wave, so that it is in a multi-directional stress state.

[0003] The damage effect of the concrete pier in the shallow water blasting is the result of the superposition of complex stress in many ways. The existing technology does not have relevant acquisition and exploration on how explosives damage concrete structures in water pressure environment. When various stress waves are transmitted underwater, they are easily affected by the slight movement of the signal line and the joint of the collector, causing the fluctuation of the signal curve. After data collection, it is difficult to eliminate the numerous data waveforms, so there is an urgent need for a concrete pier explosion effect test device in shallow water to obtain accurate data from the test. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art, provide a concrete structure underwater blasting autonomous acquisition system, and obtain accurate test data to develop a blasting plan.

[0005] To achieve the above purpose, the technical scheme adopted by the present application is:

[0006] The present application provides a concrete structure underwater blasting autonomous acquisition system, which comprises a test pier, a sensor group and a data acquisition device.

[0007] The test pier comprises a shell and a concrete structure poured in the shell, and a concrete base block is arranged in the middle of the concrete structure,

[0008] The sensor group comprises stress sensors, strain sensors, wall reflection pressure sensors and free field pressure sensors, the stress sensors are arranged in the concrete structure and face the side wall of the concrete structure, the strain sensors are arranged on the surface of the concrete base, the wall reflection pressure sensors are installed on the inner wall of the side wall of the shell, and the free field pressure sensors are arranged on the side of the explosive away from the test pier.

[0009] The data acquisition device is arranged in a sealed box embedded into the soil layer of the water bottom, the data acquisition device comprises a first data acquisition device and a second data acquisition device, the strain sensors and the stress sensors are connected with the upper computer through the first data acquisition device, the wall reflection pressure sensors and the free field pressure sensors are connected with the upper computer through the second data acquisition device, and the second data acquisition device is electrically connected with the explosive and used for collecting explosive explosion information.

[0010] Further, the sealed box comprises a box body and a box cover, a sealing gasket is arranged between the box body and the box cover, a jack is arranged on the box cover, the first data acquisition device and the second data acquisition device are connected with the upper computer through the water-proof cable passing through the jack, the data line joint is arranged in the sealed box and embedded under the soil layer, can avoid the shock wave caused by underwater blasting, and avoid signal loss or interference caused by joint shaking and cable pulling.

[0011] Further, the upper surface of the concrete base and the two adjacent side surfaces are each provided with a group of strain sensors, and each group of strain sensors comprises two strain gauges vertically distributed.

[0012] Further, the stress sensors are arranged in the concrete structure through a support, the support comprises a vertical rod and an inclined rod, and the stress sensors are arranged at the end of the inclined rod.

[0013] Further, the stress sensors are arranged on the outer side of the two opposite surfaces of the concrete base or the outer side of the two adjacent side surfaces through the support.

[0014] Further, two inclined rods cross-distributed are arranged on the vertical rod, and the stress sensors are respectively fixed to the ends of the two inclined rods, which is beneficial to analyze the damage to the concrete.

[0015] Further, the wall reflection pressure sensor is provided with a mounting sleeve around the periphery, the mounting sleeve comprises a first sleeve body and a second sleeve body fixed through bolts, a sealing ring is arranged between the first sleeve body and the second sleeve body, screw holes are arranged on the first sleeve body and used for mounting to the side wall of the shell, a lead hole is arranged in the second sleeve body, and the data line of the wall reflection pressure sensor is led out from the lead hole.

[0016] Further, the outer wall of the data line is sleeved with a bellows, so that the sensor reflects the reflected pressure data of the concrete pier after receiving the blasting impact from the inside of the concrete pier, and the connection of the sensor and the data line is stable and reliable after being impacted, thereby avoiding data loss.

[0017] Compared with the prior art, the present application has the following beneficial effects:

[0018] The present application sets a concrete base block at the center of the concrete target, and a strain sensor is attached to the surface of the concrete base block, which is different from the prior art of attaching a strain sensor to the surface of the concrete structure, so that the strain data of the target under the blasting damage effect can be detected in the inside center of the target, and the strain of each direction in the target is accurately reflected.

[0019] Two stress sensors are arranged outside the concrete base block, which are arranged to detect the pressure data of adjacent surfaces or opposite surfaces as needed, and through real-time monitoring of the stress data, the stress condition at each stage after the blasting moment is detected, and the data of the strain data, the wall surface reflected pressure sensor and the free field pressure test are combined to obtain the pressure of each point under the action of what kind of shock wave or reflected wave, so as to facilitate the analysis of the blasting damage mechanism; at the same time, it can be analyzed that each surface or each part of the target body belongs to compression damage or tension damage, and whether there is a superposition effect under the influence of the explosion shock wave, the water bottom reflected wave and the water surface reflected wave in each damage area.

[0020] The data collector is arranged in the sealed box to ensure the sealing and electromagnetic shielding effect, so as to avoid signal loss or damage under the action of the blasting shock wave and the reflected wave. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a structure schematic diagram of the underwater blasting autonomous acquisition system of the concrete structure shown in the embodiment of the present application;

[0022] Figure 2 is a schematic diagram of the layout position of the sealed box shown in the embodiment of the present application;

[0023] Figure 3 is a structure schematic diagram of the test pier shown in the embodiment of the present application;

[0024] Figure 4 is a structure schematic diagram of the wall surface reflected pressure sensor shown in the embodiment of the present application;

[0025] Figure 5 is a structure schematic diagram of the stress sensor adjacent to each other arranged in the test pier shown in the embodiment of the present application;

[0026] Figure 6 is a structure schematic diagram of the stress sensor adjacent to each other arranged in the test pier shown in the embodiment of the present application;

[0027] Figure 7 is a distribution diagram of the strain sensor shown in the embodiment of the present application;

[0028] Figure 8 is a structural diagram of the sealed box shown in the embodiment of the present application;

[0029] Figure 9 is a blasting environment diagram shown in the second embodiment of the present application;

[0030] Figure 10 is a definition diagram of the strain gauge shown in the second embodiment of the present application;

[0031] In the figure: 10, test pier; 101, concrete base block; 11, strain sensor; 12, stress sensor; 121, vertical rod; 122, inclined rod; 13, wall reflection pressure sensor; 131, first sleeve; 132, second sleeve; 133, bolt; 134, probe; 135, sealing ring; 136, screw hole; 20, sealed box; 201, box body; 203, box cover; 202, sealing gasket; 21, first data acquisition device; 22, second data acquisition device; 30, float; 40, explosive; 50, free field pressure sensor. DETAILED DESCRIPTION

[0032] The present application will be further described below in conjunction with the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and cannot be used to limit the protection scope of the present application.

[0033] In conjunction with Figure 1 the present application proposes a kind of concrete structure underwater blasting autonomous acquisition system, including test pier 10, sensor group and data acquisition device.

[0034] Test pier 10 includes shell and concrete structure poured in shell, in order to simulate the object of blasting, the shell is set into frustum shape in the embodiment, and the formed concrete structure is also frustum shape;

[0035] Further, in order to accurately reflect the damage effect of the shock wave generated by explosive blasting on test pier 10 to test pier 10, sensor group includes stress sensor 12, strain sensor 11, wall reflection pressure sensor 13, free field pressure sensor 50.

[0036] Due to the large number of strain sensors 11, and to prevent the loss or defect of sensor signal, two data acquisition devices are used for data acquisition respectively, and data acquisition device includes first data acquisition device 21 and second data acquisition device 22;

[0037] The stress sensor 12 can be arranged in the concrete structure, and a testing surface of the stress sensor 12 faces a side wall of the concrete structure. The strain sensor 11 is arranged on a surface of the concrete base 101 located in the center of the concrete structure. The wall surface reflection pressure sensor 13 is mounted to an inner wall of the side wall of the shell. The strain sensor 11 and the stress sensor 12 are connected to the upper computer through the first data collector 21. The wall surface reflection pressure sensor 13 and the free field pressure sensor 50 are connected to the upper computer through the second data collector 22.

[0038] The second data collector 22 is electrically connected to the explosive 40. When the explosive 40 explodes, the electric wire wound on the surface of the explosive 40 is broken, and the electric signal disappears. The electric signal can be transmitted to the second data collector 22 in the first time as a starting point of signal collection.

[0039] In the embodiment, the first data collector 21 and the second data collector 22 are arranged in the sealed box 20, and the sealed box 20 is buried in the soil layer under the water. In this way, the pushing effect of the stress wave generated by the explosion on the data collector can be reduced, and the pulling of the cable can be reduced.

[0040] In combination Figure 2 As shown, the first data collector and the second data collector are connected to the upper computer through the 4G antenna. The sealed box 20 leads the feeder to the antenna of the buoy 30, and transmits the data to the upper computer through the 4G network signal for storage and analysis.

[0041] In combination Figure 8 As shown, the sealed box is made of stainless steel. The sealed box 20 includes a box body 201 and a box cover 203. The box body 201 and the box cover 203 are provided with a sealing gasket 202. The box cover 203 is provided with three jacks. The first data collector 21 and the second data collector 22 are connected to the water-proof cable, and the water-proof cable passes through the jacks.

[0042] The female connector of the connector is fixedly installed on the box cover 203, and the male connector is connected to the test cable. When the connector used for the test is less than three sets, the plug can be used to plug the holes of the cover plate.

[0043] In the embodiment, the first data collector 21 and the second data collector 22 are provided with three sets of 16-core waterproof plugs. One set is used for communication signal transmission, and the other two sets are used for data collection.

[0044] The communication connector in the embodiment adopts 8-core for wired network communication, which can be used for short-distance network communication. 2-core is used for wireless WiFi signal transmission, which is used for long-distance network communication. 2-core is used for trigger signal input. The above total of 12-core shares one set of 16-core connector.

[0045] Data acquisition connector: DH5902G data acquisition instrument can be used for strain gauge, voltage signal, IEPE sensor, charge output sensor signal bar and collection, according to different working conditions, the following wiring mode can be set: for common pressure signal acquisition, a set of 16 core connector can be connected with 8 channel charge acquisition channel, another set of 16 core connector can be connected with 8 channel IEPE acquisition channel; for strain signal acquisition, two sets of connectors can be connected with 8 channel strain acquisition channel according to the actual connection bridge mode.

[0046] After waterproof function test, the waterproof device can work reliably under the condition of 10m water depth.

[0047] Combined Figure 7 As shown in the figure, the concrete base block 101 is set in a cubic shape, the upper surface of the concrete base block 101 is provided with a first group of strain sensors, and the adjacent two side surfaces of the concrete base block are provided with a second and a third group of strain sensors. Each group of strain sensors includes two strain gauges vertically distributed.

[0048] In a specific embodiment, the concrete base block 101 is formed by pouring precast C35 grade concrete, the strain gauges are attached to the surface, and two iron rods with a diameter of 10mm are used to fix the concrete base block 101 to the test pier 10 position.

[0049] Example one

[0050] The strain sensor installation method specifically includes the following steps:

[0051] ① Use a water abrasive disc to polish the center of the top surface of the test sample (top surface strain) and the center of the side surface (side surface strain);

[0052] ② Polish the area of the strain gauge patch after water grinding, cross 45° according to the direction of the strain gauge, first use 180 grit sandpaper for rough polishing, then use 400 grit sandpaper for fine polishing, and optimize the surface roughness;

[0053] ③ Use industrial alcohol to wipe the surface of the area to be coated with AB glue after polishing, and remove the dust;

[0054] ④ According to the set area, use a pencil to outline the area line;

[0055] ⑤ In the strain gauge patch area, apply an appropriate amount of AB glue mixed evenly, and wait for solidification;

[0056] ⑥ According to the direction of the strain gauge, cross 45° polish the AB glue area, and use 400 grit sandpaper to optimize the surface roughness and the thickness of the AB glue.

[0057] ⑦ After polishing the AB glue area, use industrial alcohol to wipe and remove dust.

[0058] ⑧ Use 10-second slow-drying 502 glue to attach the strain gauge and terminals to the patch area; there should be a gap of about 5mm between the strain gauge and the terminals.

[0059] ⑨ Use soldering to connect strain gauges to terminals, and terminals to leads;

[0060] ⑩ Apply Nanda 703 silicone rubber evenly to the strain gauge area and wiring area. After applying the silicone rubber, press it gently with your fingertip to remove air bubbles. The silicone rubber will be fully cured after 24 hours.

[0061] Combination Figure 3 As shown, feasiblely, the stress sensor 12 is a PVDF pressure sensor, which is fixed on the bracket and fixed at a specific position inside the test pier 10. The wall reflection pressure sensor 13 is installed at the center of the front, top, and back surfaces of the test pier 10, respectively.

[0062] Combination Figures 5-6 As shown, other feasible configurations include stress sensors 12 positioned at the center of the front, top, and side surfaces of the test pier 10, and wall-reflective pressure sensors 13 installed at the center of the front, top, and side surfaces of the target on the top side of the test pier 10. The vertical distance between the four wall-reflective pressure sensors 13 and the bottom surface of the target is 400 mm.

[0063] In this embodiment, the stress sensor is installed inside the concrete structure by a bracket, which includes a vertical rod and an inclined rod, and the stress sensor is installed at the end of the inclined rod.

[0064] In one embodiment, stress sensors 12 are respectively disposed on the outer sides of two opposite surfaces of the concrete base block 101, and two supports are provided, with the two stress sensors respectively located on the corresponding supports.

[0065] In another embodiment, stress sensors 12 are disposed on the outer sides of two adjacent sides of the concrete base block 101, and two diagonal bars 122 are provided on the vertical bar 121, with the two stress sensors 12 respectively fixed to the ends of the two diagonal bars 122.

[0066] The end of the inclined rod 122 of this invention is provided with a PVDF mounting steel plate with a width of 20mm, and the PVDF mounting steel plate is parallel to the bonding surface of the sensor. When installing the sensor, the circular outer shell needs to be tangent to the upper surface, and the angle with the reinforcing bar can be achieved by making a right-angled triangle mold with two right-angled sides satisfying 80:20.

[0067] The supporting steel plate for the top stress sensor should be welded to the vertical rod 121, and its length should not exceed 42mm.

[0068] Combination Figure 4As shown, the wall surface reflection pressure sensor 13 is externally provided with a mounting sleeve, the mounting sleeve comprises a first sleeve body 131 and a second sleeve body 132, a sealing ring 135 is arranged between the first sleeve body 131 and the second sleeve body 132, the first sleeve body 131 and the second sleeve body 132 are fixed through bolts 133, screw holes 136 are arranged on the first sleeve body 131 for mounting to the side wall of the shell, the probe 134 of the wall surface reflection pressure sensor is directed to the direction of the side wall of the shell, a lead hole is arranged in the second sleeve body 132, the data line of the probe 134 is led out from the lead hole, and the outer wall of the data line is sleeved with a bellows. Through the above arrangement, the stress reflected by the wall surface can be accurately detected, and the accuracy of data transmission is ensured.

[0069] The wall surface reflection pressure sensor 13 in the embodiment of the application selects a PCB company 109C11 series ICP type pressure sensor.

[0070] Embodiment two

[0071] Test is carried out, and a test environment is as shown in Figure 9 As shown, the test environment: the free field pressure sensor 50 is arranged on the side of the explosive 40 away from the test pier 10, the distance between the explosive 40 and the test pier 10 is 10 m, the interval between the explosive 40 and the test pier 10 is 4.5 m, the arrangement height of the free field pressure sensor 50 is 0.5 m deep and 1.5 m deep, the free field pressure sensor 50 is connected with the second data collector 22, the pressure data collected by the free field pressure sensor 50 is collected and uploaded to the upper computer, the free field pressure sensor data obtained is as shown in Table 1, the wall surface reflection pressure sensor data is as shown in Table 2, and the PVDF pressure sensor data is as shown in Table 3.

[0072] Table 1: Free field pressure sensor

[0073]

[0074] Table 2: Wall surface reflection pressure sensor data

[0075]

[0076]

[0077] Table 3: PVDF pressure sensor data

[0078]

[0079] Combined Figure 10 As shown, S1 is defined as a front surface, that is, a blast-facing surface, S2, S3 and S4 are sequentially arranged counterclockwise, T is a top surface, and B is a bottom surface.

[0080] S1-1 is X direction, S1-2 is Z direction.

[0081] S3-1 is X direction, S3-2 is Z direction. S4-1 is Y direction, S4-2 is Z direction.

[0082] T-1 is X direction, T-2 is Y direction. B-1 is X direction, B-2 is Y direction.

[0083] The obtained strain data is shown in Table 4:

[0084] Table 4:

[0085]

[0086]

[0087] It can be known from the above embodiment that the stress strain sensor is arranged in the concrete pier body, the reflection pressure sensor is arranged on the wall surface, the blasting damage effect of the explosive on the concrete structure after blasting at different positions and distances can be accurately reflected through the stress, strain and reflection pressure sensors; in addition, the data collector is arranged in the sealed box, the sealing effect is guaranteed, the obtained data is prevented from being lost, and it is beneficial for the tester to summarize the law and make a blasting plan according to the obtained data.

[0088] The above only describes the preferred embodiments of the present application, and it should be pointed out that, for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications should be considered as the protection scope of the present application.

Claims

1. An autonomous acquisition system for underwater blasting of concrete structures, characterized in that, This includes the test pier, sensor array, and data acquisition device; The test pier includes a shell and a concrete structure cast within the shell, with a concrete base block positioned in the center of the concrete structure. The sensor group includes a stress sensor, a strain sensor, a wall reflection pressure sensor, and a free field pressure sensor. The stress sensor is installed inside the concrete structure and faces the side wall of the concrete structure. The strain sensor is installed on the surface of the concrete block. The wall reflection pressure sensor is installed on the inner wall of the shell side wall. The free field pressure sensor is installed on the side of the explosive away from the test pier. The data acquisition device is installed in a sealed box buried in the underwater soil layer. The data acquisition device includes a first data acquisition unit and a second data acquisition unit. The strain sensor and stress sensor are connected to the host computer through the first data acquisition unit. The wall reflection pressure sensor and free field pressure sensor are connected to the host computer through the second data acquisition unit. The second data acquisition unit is electrically connected to the explosive and is used to collect explosive explosion information.

2. The autonomous acquisition system for underwater blasting of concrete structures according to claim 1, characterized in that, The sealed box includes a box body and a box cover, with a sealing gasket between the box body and the box cover. The box cover has an insertion hole, and the first data acquisition device and the second data acquisition device are connected to the host computer through a watertight cable passing through the insertion hole.

3. The autonomous acquisition system for underwater blasting of concrete structures according to claim 1, characterized in that, Each of the concrete base blocks is provided with a set of strain sensors on its upper surface and two adjacent sides. Each set of strain sensors includes two strain gauges that are vertically distributed.

4. The autonomous acquisition system for underwater blasting of concrete structures according to claim 1, characterized in that, The stress sensor is mounted inside the concrete structure by a bracket, which includes a vertical rod and an inclined rod, with the stress sensor attached to the end of the inclined rod.

5. The autonomous acquisition system for underwater blasting of concrete structures according to claim 4, characterized in that, The stress sensor is mounted on the outer side of two opposite faces of the concrete block, or on the outer side of two adjacent sides, via a bracket.

6. The autonomous acquisition system for underwater blasting of concrete structures according to claim 4 or 5, characterized in that, The vertical rod is provided with two diagonally distributed diagonal rods, and the stress sensor is fixed to the ends of the two diagonal rods respectively.

7. The autonomous data acquisition system for underwater blasting of concrete structures according to claim 1, characterized in that, The wall-reflective pressure sensor is provided with a mounting sleeve on its outer periphery. The mounting sleeve includes a first sleeve body and a second sleeve body that are fixed by bolts. A sealing ring is provided between the first sleeve body and the second sleeve body. The first sleeve body is provided with a screw hole for mounting to the side wall of the housing. The second sleeve body is provided with a lead wire hole, through which the data line of the wall-reflective pressure sensor is led out.

8. The autonomous data acquisition system for underwater blasting of concrete structures according to claim 7, characterized in that, The data cable is fitted with a corrugated tube on its outer wall.

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