An experimental device and method for simulating the connection fracture of geogrids

Abstract

The present invention relates to a test device and a test method for simulating the connection fracture of geogrids. The test device includes a connection component (1) and a control box (2); the connection component (1) includes a low-melting-point high-strength alloy metal sheet (11) and wires (12) arranged at both ends of the low-melting-point high-strength alloy metal sheet (11). The low-melting-point high-strength alloy metal sheet (11) is arranged at the fracture of the geogrid (3) or between the geogrid (3) and the retaining wall panel (4), and is connected to the control box (2) through the wires (12); the control box (2) includes a capacitor (21), a start switch (22) and a terminal (23). The capacitor (21) and the start switch (22) are connected in series with the low-melting-point high-strength alloy metal sheet (11) through the terminal (23). Compared with the prior art, the present invention can simulate the fracture of the geogrid ribs or the failure of the connection between the retaining wall panel and the geogrid without disturbing the soil mass (i.e., without excavating the soil mass) and during the test process.

Description

Technical Field

[0001] The present invention relates to the technical field of civil engineering, and particularly relates to a test device and a test method for simulating the connection fracture of geogrids. Background Art

[0002] A geogrid is a geosynthetic material with relatively high tensile strength. By burying the geogrid inside the soil mass, the soil strength can be greatly improved, and it is often widely used in earthwork projects, roadbeds, water conservancy projects and other fields in the form of structures such as reinforced soil retaining walls, reinforced soil slopes and reinforced soil embankments. However, the problem of connection fracture may occur in the actual use of geogrids. This problem may cause the overall performance of the geogrids to be damaged, and even pose a potential threat to engineering safety. Therefore, the research on the connection fracture of geogrids has important background and significance. Since the filling soil needs to be compacted during the actual construction process of the reinforced soil structure, sharp objects such as gravel and angular gravel in the filling soil may cut off the ribs of the geogrid. In addition, the connection between the retaining wall panel and the geogrid often fails under the action of external load in the reinforced soil retaining wall. In order to study the above situations, it is usually necessary to simulate the fracture of the geogrid ribs or the failure of the connection between the retaining wall panel and the geogrid. There is no research in this aspect in the prior art, and most of the current simulations of geogrid fracture can only rely on numerical simulation methods, and the accuracy and reliability of this method have certain limitations. Therefore, in order to better study the fracture problem of geogrids and the failure of the connection between the retaining wall panel and the geogrid, more comprehensive and accurate experimental research needs to be carried out. Summary of the Invention

[0003] The purpose of the present invention is to provide a test device and a test method for simulating the connection fracture of geogrids.

[0004] The purpose of the present invention can be achieved by the following technical solutions: A test device for simulating the connection fracture of geogrids includes a connection component and a control box;

[0005] The connection component includes a low-melting-point high-strength alloy metal sheet and wires arranged at both ends of the low-melting-point high-strength alloy metal sheet. The low-melting-point high-strength alloy metal sheet is arranged at the geogrid fracture or between the geogrid and the retaining wall panel, and is connected to the control box through the wires;

[0006] The control box includes a capacitor, a start switch and a terminal. The capacitor and the start switch are connected in series with the low-melting-point high-strength alloy metal sheet through the terminal.

[0007] The main principle of the present invention is to energize the metal sheet to make it short-circuited, and then achieve the fracture of the geogrid or the failure of the connection between the retaining wall panel and the geogrid by fusing the metal sheet.

[0008] Preferably, an inward circular arc notch is provided in the middle of the low melting point and high strength alloy metal sheet.

[0009] Preferably, the low melting point and high strength alloy metal sheet is made of a tin-bismuth alloy, with a melting point of 138 °C and a tensile strength of more than 80 MPa.

[0010] Preferably, the connecting assembly further includes an upper clamping piece, a lower clamping piece and a bolt;

[0011] The upper clamping piece is welded to the low melting point and high strength alloy metal sheet. The upper clamping piece and the lower clamping piece are respectively arranged on the upper and lower sides of the geogrid or the retaining wall panel connecting piece. The low melting point and high strength alloy metal sheet is fixed on the geogrid or between the geogrid and the retaining wall panel through the upper clamping piece, the lower clamping piece and the bolt.

[0012] The retaining wall panel connecting piece is arranged on the retaining wall panel.

[0013] Further preferably, the low melting point and high strength alloy metal sheet straddles above the geogrid fracture, and a set of upper clamping pieces, lower clamping pieces and bolts are respectively arranged at both ends.

[0014] Even more preferably, the upper clamping piece and the lower clamping piece are provided with grooves matching the ribs of the geogrid.

[0015] Further preferably, the low melting point and high strength alloy metal sheet is arranged on the ribs of the geogrid and the retaining wall panel connecting piece, and a set of upper clamping pieces, lower clamping pieces and bolts are respectively arranged at both ends.

[0016] Preferably, the control box further includes a battery, a charging switch and a charging indicator light;

[0017] The battery is connected in series with the capacitor, the charging switch and the charging indicator light.

[0018] Further preferably, the control box further includes an inspection switch and an inspection indicator light;

[0019] The inspection switch and the inspection indicator light are connected in series with the battery and the connecting assembly.

[0020] Preferably, the control box includes a control box housing, and the end of the wiring terminal extends out of the control box housing to be connected with a wire.

[0021] Preferably, the battery is a rechargeable lithium battery with a rated voltage of 12 V and a capacity of more than 10,000 mAh.

[0022] Preferably, the capacitor is an electrolytic capacitor with a specification of more than 100 V 33,000 μF.

[0023] A test method for simulating the connection fracture of a geogrid is carried out using the above test device.

[0024] Further preferably, the charging switch is a sliding switch, and the start switch is a normally open self - reset push - button switch.

[0025] Preferably, the test method for simulating the connection breakage of the geogrid includes the following steps:

[0026] S1: According to the test plan, determine the position where the geogrid needs to be simulated to break, and cut the grid ribs at this position to form a fracture;

[0027] S2: Install a connection component at the fracture position;

[0028] S3: According to the test plan, bury the geogrid inside the soil mass and lead out the two - side wires;

[0029] S4: After the model is built, connect the two led - out wires to the two terminal posts of the control box;

[0030] S5: Press the charging switch to charge the capacitor. Wait until the charging indicator light changes from red to green, then end the charging and disconnect the charging switch;

[0031] S6: According to the test plan, when it is necessary to simulate the breakage of the geogrid, press the start switch to fuse the low - melting - point high - strength metal sheet;

[0032] S7: Press the inspection switch. At this time, the inspection indicator light should be in the off state. If the inspection indicator light is on, repeat S5 and S6 until the inspection indicator light is off when the inspection switch is turned on.

[0033] Compared with the prior art, the present invention has the following advantages:

[0034] 1. The present invention can simulate the breakage of the geogrid ribs or the connection failure between the retaining wall panel and the geogrid without disturbing the soil mass (i.e., without excavating the soil mass) during the test process;

[0035] 2. The present invention can not only simulate the breakage of the geogrid ribs, but also simulate the disconnection of the connection between the geogrid and the retaining wall panel and the connection failure between the geogrid and other structures such as guardrails, anchor rods, piles, etc. The implementation methods are basically the same;

[0036] 3. The present invention can simultaneously achieve multi - point, linear or even overall breakage of the geogrid by arranging multiple devices for simulating connection breakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic structural diagram of the connection component of the present invention;

[0038] Figure 2Schematic diagram of the installation of the connection component in Embodiment 1 of the present invention on the geogrid;

[0039] Figure 3 External shape schematic diagram of the control box of the present invention;

[0040] Figure 4 Circuit diagram of the control box of the present invention;

[0041] Figure 5 Schematic diagram of the installation of the connection component in Embodiment 2 of the present invention on the geogrid;

[0042] In the figure: 1 - connection component, 11 - low melting point high strength alloy metal sheet, 12 - wire, 13 - upper clip, 14 - lower clip, 15 - bolt, 2 - control box, 21 - capacitor, 22 - start switch, 23 - terminal, 24 - battery, 25 - charging switch, 26 - charging indicator light, 27 - inspection switch, 28 - inspection indicator light, 29 - control box housing, 3 - geogrid, 31 - fracture, 4 - retaining wall panel, 5 - retaining wall panel connecting piece. Detailed implementation manners

[0043] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0044] Embodiment 1

[0045] A test device and test method for simulating the connection fracture of a geogrid, wherein the main structure of the test device is divided into two parts: a connection component 1 and a control box 2.

[0046] As Figure 1 shown, the connection component 1 includes: a low melting point high strength alloy metal sheet 11, two wires 12 are respectively welded to the upper parts of both ends thereof, and the lower parts of both ends of the low melting point high strength alloy metal sheet 11 are two metal clips (an upper clip 13 and a lower clip 14, wherein the upper clip 13 is welded thereto, and the upper and lower clips are connected by two bolts 15.

[0047] There is an inward circular arc notch in the middle of the low melting point high strength alloy metal sheet 11, the purpose of which is to reduce the cross-section and increase its resistance, so that melting can be achieved at the middle position of the metal sheet after power-on short circuit. The wires 12 welded to both ends of the metal sheet are used to supply power to the metal sheet, and the surfaces of the metal clips have grooves, the purpose of which is to increase the friction when connecting with the geogrid.

[0048] As Figure 2As shown, the geogrid 3 needs to first cut the ribs at the simulated fracture position to form a fracture 31. Then, the connection component 1 is fixed at the fracture position by the clip, and then the wire 12 is connected to the terminal 23 of the control box 2.

[0049] As Figures 3 - 4 shown, the control box 2 mainly consists of a control box housing 29, terminals 23, a charging switch 25, a charging indicator light 26, a start switch 22, an inspection switch 27, an inspection indicator light 28, a capacitor 21, and a battery 24. Among them, the wire 12 is connected to the terminal 23. The charging switch 25 controls the charging of the capacitor 21 (since charging takes some time, the switch here is a sliding switch). The charging indicator light 26 is a diode that can display the charging status. The charging process is red, and when full, it is green. The start switch 22 is a switch that controls the power supply to the low melting point and high strength alloy metal sheet 11. Pressing it supplies power, and releasing it stops the power supply. It should be noted that for the protection of the circuit and safety considerations, it is the capacitor 21 that directly supplies power to the metal sheet. The inspection switch 27 is used to check whether the metal sheet is melted. Since the metal sheet conducts electricity, when the inspection switch 27 is pressed, if the small light bulb (inspection indicator light 28) lights up, it means the metal sheet is not melted, and the charging and fusing need to be repeated. On the contrary, if the small light bulb (inspection indicator light 28) does not light up, it means the fusing is successful. (Since both starting and inspection are only completed instantaneously, for the protection of the circuit, the switch is selected as a normally open self - reset push - button switch. This switch is in the off state under normal conditions, turns on when pressed, and automatically disconnects after releasing the hand).

[0050] The test method includes the following steps:

[0051] 1. According to the test plan, it is necessary to simulate the situation where some ribs of the geogrid 3 are fractured due to the compaction of the soil mass during the construction of the reinforced soil retaining wall. Determine the position where the geogrid 3 needs to be simulated for fracture, and cut the grid ribs at this position to form a fracture 31.

[0052] 2. Install the connection component 1 at the fracture 31 position, mainly clamping the clip to the ribs on both sides and strengthening with bolts to make the connection tight.

[0053] 3. According to the test plan, bury the geogrid 3 inside the soil mass and lead out the two wires 12 on both sides.

[0054] 4. After the reinforced soil retaining wall model is built, connect the two led - out wires 12 to the two terminals 23 of the control box 2.

[0055] 5. Turn on the charging switch 25 to charge the capacitor 21, and turn off the charging switch after the charging indicator light 26 changes from red to green.

[0056] 6. According to the test plan, press the start switch 22 when it is necessary to simulate the fracture of the geogrid 3 to fuse the metal sheet.

[0057] 7. Press the inspection switch 27 to check for fusing. If the inspection indicator light 28 does not light up, it indicates successful fusing. If it lights up, it means that the fusing was not successful, and steps 5 and 6 need to be repeated until the fusing is successful.

[0058] 8. Continue with the subsequent tests.

[0059] Example 2

[0060] An experimental device and experimental method for simulating the connection fracture of geogrids are as Figure 5 shown. The low-melting-point high-strength alloy metal sheet 11 is arranged between the geogrid 3 and the retaining wall panel 4. One end of the low-melting-point high-strength alloy metal sheet 11 is connected to the geogrid 3 through upper and lower clamping pieces and bolts, and one end is connected to the retaining wall panel connecting piece 5 through upper and lower clamping pieces and bolts.

[0061] The experimental method includes the following steps:

[0062] 1. According to the experimental scheme, it is necessary to simulate the situation where the connection between the middle panel (retaining wall panel 4) and the geogrid 3 of the reinforced soil retaining wall fails under seismic action.

[0063] 2. When building the retaining wall model, install the connection component 1 at the positions of the geogrid 3 and the retaining wall panel connecting piece 5, and reinforce it with bolts to make the connection tight.

[0064] 3. Continue building the model until it is completed, and lead out the two side wires 12 to the outside of the model.

[0065] 4. After the model is built, lift the entire model onto the shaking table by a crane and fix it.

[0066] 5. Connect the two lead wires 12 to the two terminal posts 23 of the control box 2.

[0067] 6. Turn on the charging switch 25 to charge the capacitor 21, and turn off the charging switch after the charging indicator light 26 changes from red to green.

[0068] 7. Apply seismic loads to the reinforced soil retaining wall model through the shaking table, and press the start switch 22 during the application of the seismic loads to fuse the metal sheet.

[0069] 8. Press the inspection switch 27 to check for fusing. If the inspection indicator light 28 does not light up, it indicates successful fusing. If it lights up, it means that the fusing was not successful, and steps 6 and 7 need to be repeated until the fusing is successful.

[0070] 9. Continue with the subsequent tests.

[0071] The above description of the embodiments is to enable those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. An experimental device for simulating the connection fracture of geogrids, characterized in that, It includes a connection component (1) and a control box (2); The described connection component (1) includes a low-melting-point high-strength alloy metal sheet (11) and wires (12) arranged at both ends of the low-melting-point high-strength alloy metal sheet (11). The low-melting-point high-strength alloy metal sheet (11) is arranged at the fracture of the geogrid (3) or between the geogrid (3) and the retaining wall panel (4), and is connected to the control box (2) through the wires (12); The described control box (2) includes a capacitor (21), a start switch (22) and a terminal (23). The capacitor (21) and the start switch (22) are connected in series with the low-melting-point high-strength alloy metal sheet (11) through the terminal (23).

2. The test device for simulating the connection fracture of geogrids according to claim 1, characterized in that, An inward circular arc notch is provided in the middle of the low-melting-point high-strength alloy metal sheet (11).

3. The test device for simulating the connection fracture of geogrids according to claim 1, characterized in that, The described connection component (1) further includes an upper clip (13), a lower clip (14) and a bolt (15); The upper clip (13) is welded to the low-melting-point high-strength alloy metal sheet (11). The upper clip (13) and the lower clip (14) are respectively arranged on the upper and lower sides of the geogrid (3) or the retaining wall panel connector (5). The low-melting-point high-strength alloy metal sheet (11) is fixed on the geogrid (3) or between the geogrid (3) and the retaining wall panel (4) through the upper clip (13), the lower clip (14) and the bolt (15).

4. The test device for simulating the connection fracture of geogrids according to claim 3, characterized in that, The low-melting-point high-strength alloy metal sheet (11) straddles above the fracture of the geogrid (3), and a set of upper clip (13), lower clip (14) and bolt (15) are respectively arranged at both ends.

5. The test device for simulating the connection fracture of geogrids according to claim 3, wherein, The low-melting-point high-strength alloy metal sheet (11) is arranged on the ribs of the geogrid (3) and the retaining wall panel connector (5), and a set of upper clip (13), lower clip (14) and bolt (15) are respectively arranged at both ends.

6. The test device for simulating the connection fracture of geogrids according to claim 1, wherein, The described control box (2) further includes a battery (24), a charging switch (25) and a charging indicator light (26); The battery (24) is connected in series with the capacitor (21), the charging switch (25) and the charging indicator light (26).

7. The test device for simulating the connection fracture of a geogrid according to claim 6, characterized in that, The described control box (2) further includes an inspection switch (27) and an inspection indicator light (28); The inspection switch (27) and the inspection indicator light (28) are connected in series with the battery (24) and the connection component (1).

8. The test device for simulating the connection fracture of a geogrid according to claim 1, characterized in that, The described control box (2) includes a control box housing (29), and the end of the terminal (23) extends out of the control box housing (29) to be connected to the wire (12).

9. A test method for simulating the connection fracture of geogrids, characterized in that, The test is carried out using the test device described in any one of claims 1 to 8, and includes the following steps: S1: According to the test plan, determine the position where the geogrid (3) needs to be simulated to break, and cut off the grid ribs at this position to form a fracture; S2: Install the connection component (1) at the fracture position; S3: According to the test plan, bury the geogrid (3) into the soil body and lead out the two wires (12) on both sides; S4: After the model is built, connect the two led-out wires (12) to the two terminals (23) of the control box (2); S5: Press the charging switch (25) to charge the capacitor (21). Wait until the charging indicator light (26) changes from red to green, then end the charging and disconnect the charging switch (25); S6: According to the test plan, when it is necessary to simulate the fracture of the geogrid (3), press the start switch (22) to fuse the low melting point high strength metal sheet (11); S7: Press the inspection switch (27). At this time, the inspection indicator light (28) should be in the off state. If the inspection indicator light (28) is on, repeat S5 and S6 until the inspection indicator light (28) is off when the inspection switch (27) is turned on.

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