A multi-working-condition model tunnel test device

Abstract

The application discloses a multi-condition model tunnel test device, which comprises a hydraulic machine, a push rod, a pressurizing pump, a water pumping pump, a heater, a test box, a water permeable plate, a model tunnel, a soil pressure sensor, a water pressure sensor, a strain gauge, a data collector and a water collector. The device can construct multiple test conditions including different soil pressure conditions, different water pressure conditions and different temperature conditions for different test targets, and is suitable for multiple model tunnel tests. The water body layer of the multi-condition model tunnel test device is respectively connected with the pressurizing pump and the water pumping pump, so that flowing water can be formed in the test box to form a "running water" condition, which is more in line with the actual condition and is suitable for model test of a river-crossing or sea-crossing shield tunnel.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of tunnel engineering, and more particularly, relates to a multi-working-condition model tunnel test device. BACKGROUND

[0002] Due to the multi-joint structural characteristics of the shield tunnel and the large difference in longitudinal load of the stratum where the shield tunnel is located, the shield tunnel is prone to joint leakage. Joint leakage has a great impact on the durability of the shield tunnel structure and also poses a great threat to driving safety. Research on joint leakage of the shield tunnel helps to ensure the safety of the tunnel structure and prolong its service life. In order to understand the position in the tunnel cross section where leakage is most likely to occur and the influence of different joint leakage positions on the model tunnel, current model test devices are generally used to simulate tests on the shield tunnel according to the similarity theory, so as to study the severity, leakage trend, and pipe stress and earth pressure at the leakage position of joint leakage at different positions and to different degrees.

[0003] However, the current model tunnel test device has certain limitations. Most of the existing model tunnel test devices are targeted test devices, and these devices are designed for single test conditions. Therefore, these model tunnel test devices can only simulate single tunnel leakage conditions and cannot simulate the actual situation of tunnel leakage under multiple factors. Although some model tunnel test devices can simulate the underground water leakage condition, the water pressure borne by the model tunnel under this condition is small, and it cannot be applied to the simulation test of the shield tunnel crossing the river or the sea under the condition of large water pressure and turbulent water flow. SUMMARY

[0004] To solve the problems in the prior art, the present application provides a multi-working-condition model tunnel test device, which can construct multiple test conditions including different soil pressure conditions, different water pressure conditions and different temperature conditions for different test targets, and is suitable for various model tunnel tests.

[0005] The technical scheme of the present application is as follows:

[0006] A multi-working-condition model tunnel test device, comprising a hydraulic machine, a push rod, a pressure pump, a water pumping pump, a heater, a test box, a water-permeable plate, a model tunnel, a soil pressure sensor, a water pressure sensor, a strain gauge, a data collection instrument and a water collector.

[0007] The test box is arranged on a worktable of a hydraulic machine, and a filling layer and a water body layer are sequentially arranged in the test box from bottom to top; the water permeable plate is arranged on the filling layer; two symmetrical side walls of the test box are respectively provided with mounting holes corresponding to the middle part of the filling layer; the model tunnel is embedded in the filling layer, and two ends of the model tunnel respectively pass through two mounting holes on the test box; the water collector is connected with one end of the model tunnel; a through hole is arranged on the top cover of the test box, one end of the push rod is connected with the output end of the hydraulic machine, and the other end of the push rod passes through the through hole and is connected with the water permeable plate; the two symmetrical side walls of the test box are respectively provided with a water inlet communicated with the pressurizing pump and a water outlet communicated with the water pumping pump corresponding to the position of the water body layer; the heater and the water pressure sensor are arranged in the water body layer and are respectively connected with the data collection instrument; the earth pressure sensor is embedded in the filling layer and is arranged on the side of the model tunnel and is connected with the data collection instrument; the strain gauge is attached to the outer side wall of the model tunnel.

[0008] Further, the hydraulic machine comprises a support beam, a worktable, a guide column connecting the support beam and the worktable, an oil cylinder arranged on the support beam, and a lifting platform slidingly connected to the guide column and located between the support beam and the worktable and connected with the output end of the oil cylinder; the electromagnet is fixedly connected to the lower end surface of the lifting platform, and the push rod is magnetically connected with the electromagnet.

[0009] Further, the electromagnet is provided with a clamping groove matched with the size of the push rod at the matching connection surface of the electromagnet and the push rod.

[0010] Further, the push rod is fixedly connected with the water permeable plate through the connecting flange.

[0011] Further, the inner side bottom of the model tunnel adopts a slope structure, and the water collector is connected with one end of the lower side of the slope structure of the model tunnel.

[0012] Further, the matching connection parts of the model tunnel and the mounting hole, the matching connection parts of the push rod and the through hole, and the water inlet and the water outlet are respectively provided with sealing rings and are sealed by sealing glue.

[0013] Further, the water permeable plate is provided with a water permeable opening and a filter screen.

[0014] Further, the side wall of the test box is provided with a wire outlet, and the earth pressure sensor, the water pressure sensor and the strain gauge are respectively connected with the data collection instrument through data lines passing through the wire outlet.

[0015] Further, the side wall of the test box is provided with a box door.

[0016] Further, the model tunnel is provided with a joint matched with the test target.

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

[0018] The application provides a multi-condition model tunnel test device, which can construct multiple test conditions containing different earth pressure conditions, different water pressure conditions and different temperature conditions for different test targets, and is suitable for multiple model tunnel tests.

[0019] The water body layer of the multi-condition model tunnel test device is connected with a pressurizing pump and a water pumping pump respectively on both sides, so that flowing water can be formed in the test box to form a 'running water' condition, which is more in line with the actual condition and is suitable for model test of a river-crossing or sea-crossing shield tunnel.

[0020] The multi-condition model tunnel test device is provided with an electromagnet and a coil at the lower end surface of the lifting platform of the hydraulic cylinder, the electromagnet is magnetically connected with the push rod by electrifying the coil, the lifting platform is moved upward to drive the push rod to be lifted upward, and the test device is convenient to disassemble and replace. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a structural schematic view of the multi-condition model tunnel test device;

[0022] Figure 2 It is a push rod connection schematic view;

[0023] Figure 3 It is a permeable plate structural schematic view;

[0024] Figure 4 It is a disassembly schematic view of the test box top cover;

[0025] Figure 5 It is an assembly schematic view of the test box top cover;

[0026] In the figure, 1 is a hydraulic machine; 11 is a support beam; 12 is a workbench; 13 is a guide column; 14 is an oil cylinder; 15 is a lifting platform; 16 is an electromagnet; 17 is a coil; 2 is a push rod; 3 is a heater; 4 is a test box; 41 is a filling layer; 42 is a water body layer; 43 is a top cover; 431 is a through hole; 5 is a permeable plate; 51 is a permeable port; 52 is a filter screen; 6 is a model tunnel; and 7 is a connecting flange. DETAILED DESCRIPTION

[0027] The application will be further described below in combination with the drawings.

[0028] Example 1

[0029] A multi-condition model tunnel test device of the example is shown in the figure, Figures 1-5As shown, the device comprises a hydraulic machine 1, a push rod 2, a pressurizing pump, a water pumping pump, a heater 3, a test box 4, a water permeable plate 5, a model tunnel 6, a soil pressure sensor, a water pressure sensor, a strain gauge, a data collector and a water collector; wherein the test box 4, the model tunnel 6 and the water permeable plate 5 provided with a water permeable opening 51 and a filter screen 52 constitute a model tunnel test box device; wherein the top cover 43 of the test box 4 is provided with a through hole 431, the side wall is provided with a box door, and the inside of the test box 4 is sequentially provided with a soil filling layer 41 and a water body layer 42 from bottom to top; the two symmetrical side walls of the test box 4 are respectively and symmetrically provided with mounting holes corresponding to the middle position of the soil filling layer 41; the model tunnel 6 can be provided with a joint suitable for the test target, the model tunnel 6 is buried in the soil filling layer 41, and the two ends of the model tunnel 6 respectively pass through the two mounting holes on the test box 4; as shown Figure 3 As shown, the water permeable plate 5 is provided with the water permeable opening 51 and the filter screen 52 and is pressed on the soil filling layer 41;

[0030] The hydraulic machine 1 and the push rod 2 constitute a soil pressure setting device, as shown Figure 1 and Figure 2 As shown, the hydraulic machine 1 comprises a support beam 11, a workbench 12, a guide column 13 connecting the support beam 11 and the workbench 12, an oil cylinder 14 arranged on the support beam 11, and a lifting platform 15 slidingly connected to the guide column 13 and located between the support beam 11 and the workbench 12 and connected to the output end of the oil cylinder 14; the lower end surface of the lifting platform 15 is fixedly connected to an electromagnet 16 through bolts, a coil 17 is wound around the electromagnet 16, and the test box 4 of the model tunnel test box device is arranged on the workbench 12 of the hydraulic machine 1; the push rod 2 is made of a metal with magnetism, is vertically arranged, one end is magnetically connected to the electromagnet 16 of the lifting platform 15, and the other end passes through the through hole 431 in the top cover 43 of the test box 4 and is fixedly connected to the water permeable plate 5 in the test box 4 through a connecting flange 7. The electromagnet 16 is magnetically connected to the push rod 2 by electrifying the coil 17, the lifting platform 15 moves upward to lift the push rod 2 upward, which facilitates the disassembly and replacement of the test device. As shown Figure 4 and Figure 5 As shown, the top cover 43 of the test box 4 can adopt a split top cover assembled by left and right top covers, which facilitates the assembly of the test device.

[0031] The pressurizing pump and the water pumping pump constitute a water pressure setting device, the two symmetrical side walls of the test box 4 are respectively provided with an inlet and an outlet corresponding to the position of the water body layer 42; the input end of the pressurizing pump is connected to a water source, and the output end is connected to the inlet; the input end of the water pumping pump is connected to the outlet, and the output end is connected to the water source; the pressurizing pump and the water pumping pump can form flowing water in the test box 4, constitute a “moving water” working condition, and are more suitable for actual working conditions, which are suitable for model test of shield tunnel crossing rivers and seas.

[0032] The heater 3 constitutes a temperature setting device, and the heater 3 is arranged in the water body layer 42.

[0033] The data collection instrument, the soil pressure sensor, the water pressure sensor, the strain gauge and the water collector connected with the data collection instrument constitute a data acquisition device; the soil pressure sensor is buried in the filling layer 41 and arranged at the leakage joint position of the tunnel model; the water pressure sensor is arranged in the water body layer 42; the strain gauge is pasted at the joint position of the outer lateral wall of the model tunnel 6; the water collector can be made of a PVC pipe and a plastic film, different water collectors are prefabricated according to different leakage positions of the tunnel, and are used for leading the leakage water in the tunnel to flow into a water measuring container to measure the real-time leakage water quantity; the water collector is connected with one end of the model tunnel 6 in communication. The model tunnel 6, the matching connection part of the installation hole, the matching connection part of the push rod 2 and the through hole 431, the water inlet and the water outlet are respectively provided with sealing rings and sealed by sealing glue. The side wall of the test box 4 is provided with a wire outlet, and the soil pressure sensor, the water pressure sensor and the strain gauge are respectively connected with the data collection instrument through data lines passing through the wire outlet. In this example, the model of the soil pressure sensor is BW-28, the model of the water pressure sensor is BWK-S, the model of the strain gauge is a resistance strain gauge 5AA, and the model of the data collection instrument is a DHDAS dynamic signal collection instrument.

[0034] The soil pressure given device, the water pressure given device and the temperature given device can simulate different soil pressure working conditions, different water pressure working conditions and different temperature working conditions, can meet the needs of various test working conditions of different model tunnel tests, and are suitable for various model tunnel tests.

[0035] Example Two

[0036] In this example, the inner side bottom of the model tunnel is designed to have a slope structure, and the water collector is connected with one end of the lower side of the slope structure of the model tunnel.

[0037] Example Three

[0038] In this example, the electromagnet 16 is provided with a clamping groove matched with the size of the push rod 2 at the matching connection surface of the push rod 2, so as to facilitate the connection of the electromagnet 16 and the push rod 2.

[0039] Example Four

[0040] In this example, the model tunnel joint leakage test is carried out by using the test device of the present application, including the following steps:

[0041] 1) According to the test target, a model tunnel is prefabricated, and a leakage joint matched with the test target is arranged on the model tunnel;

[0042] 2) Installation of the test device, the specific steps are as follows:

[0043] 2.1) Use waterproof tape to seal the leaking joint from the inner side of the model tunnel and place the strain gauge on the leaking joint position on the outer side of the model tunnel;

[0044] 2.2) Fill the soil in the test box to the lower side of the installation hole, install the two ends of the model tunnel through the installation hole in the test box, continue to fill the soil to the target position, place the soil pressure sensor near the leaking joint position on the side of the model tunnel during the filling process, and connect the water collector to one end of the model tunnel;

[0045] 2.3) Press the water permeable plate on the soil layer and pass the push rod of the hydraulic machine through the test box and connect it with the water permeable plate in the test box;

[0046] 2.4) Inject water into the test box until it is filled, connect the output end of the pressurizing pump to the water inlet, connect the input end of the water pumping pump to the water outlet, and place the heater in the water layer;

[0047] 2.5) Connect the data lines of the soil pressure sensor, water pressure sensor, and strain gauge to the data collection instrument through the outlet on the side wall of the test box, and seal the through holes, installation holes, water inlets, and water outlets of the test box with waterproof glue.

[0048] 3) Adjustment of the working conditions of the test device:

[0049] Drive the push rod with the water permeable plate tightly pressing the soil layer by the output end of the oil cylinder of the hydraulic machine until the soil pressure monitored by the soil pressure sensor reaches the target soil pressure of the test;

[0050] Pressurize the water layer by the pressurizing pump until the water pressure detected by the water pressure sensor reaches the target water pressure of the test, and control the water pressure of the water layer to be constant by adjusting the water pumping pump and the pressurizing pump;

[0051] Adjust the temperature of the heater to the target temperature of the test;

[0052] 4) Record the test data, remove the waterproof tape at the leaking joint corresponding to the test working condition, start the leakage test, obtain the deformation of the model tunnel under the target working condition by the reading change of the strain gauge, collect the amount of leakage water in the model tunnel by the water collector, and obtain the changes of soil pressure and water pressure caused by tunnel leakage under the target working condition by the soil pressure sensor and the water pressure sensor.

[0053] The leakage time-leakage amount, leakage time-soil pressure increase, and leakage site depth-tunnel bending moment broken line graphs can be drawn based on the amount of leakage water, soil pressure change, water pressure change, and tunnel deformation, to study the leakage rules under different working conditions and the impact of leakage on the surrounding soil and tunnel structure.

[0054] Example Five:

[0055] The tunnel operation life prediction test is carried out by using the test device of the application, and includes the following steps:

[0056] 1) Preparing a model tunnel according to the test target;

[0057] 2) Installing the test device, and the specific steps are as follows:

[0058] 2.1) Filling the soil in the test box to the lower side of the installation hole, installing the two ends of the model tunnel through the installation hole in the test box, installing the strain gauge in the model tunnel detection ring (the ring segment that detects deformation), continuing to fill the soil to the leakage position of the model tunnel, setting the soil pressure sensor at the positions close to the model tunnel crown, haunch, waist and the like on the side of the model tunnel, and connecting the water collector with one end of the model tunnel;

[0059] 2.2) Pressing the water permeable plate on the soil layer and passing the push rod of the hydraulic machine through the test box and connecting the water permeable plate in the test box;

[0060] 2.3) Injecting the water body into the test box to fill the test box, connecting the output end of the pressurizing pump with the water inlet, connecting the input end of the water pumping pump with the water outlet, and placing the heater in the water body layer;

[0061] 2.4) Connecting the data lines of the soil pressure sensor, the water pressure sensor and the strain gauge with the data collection instrument through the wire outlets on the side wall of the test box, and sealing the through holes, installation holes, water inlets and water outlets on the test box with the waterproof glue.

[0062] 3) Adjusting the working conditions of the test device:

[0063] Driving the push rod by the output end of the oil cylinder of the hydraulic machine to make the water permeable plate tightly press the soil layer until the soil pressure monitored by the soil pressure sensor reaches the test target working condition soil pressure;

[0064] Pressurizing the water body layer by the pressurizing pump until the water pressure detected by the water pressure sensor reaches the test target working condition water pressure, and keeping the water pressure of the water body layer unchanged by adjusting the water pumping pump and the pressurizing pump;

[0065] Adjusting the temperature of the heater to the test target working condition temperature;

[0066] 4) Recording the test data, starting the accelerated test, obtaining the deformation amount of the model tunnel under the target working condition through the reading change of the strain gauge, obtaining the water and soil pressure change caused by the tunnel leakage under the target working condition through the soil pressure sensor and the water pressure sensor, stopping the test when the tunnel deformation reaches the critical value that affects the structure stability, calculating the operation time of the tunnel when the structure is unstable according to the accelerated test parameters at this time and the accelerated life test calculation formula, and predicting the actual engineering operation life.

[0067] Example six:

[0068] This example uses the test device of the present application to carry out leakage plugging and grouting test, including the following steps:

[0069] 1) According to the test target, prefabricate the model tunnel, set the leakage joint on the model tunnel which is suitable for the test target;

[0070] 2) Installation of the test device, the specific steps are as follows:

[0071] 2.1) Use the water stop rubber strip from the inside of the model tunnel to seal the leakage position, and set the strain gauge on the outside of the model tunnel at the leakage position;

[0072] 2.2) Fill the soil in the test box to the lower side of the installation hole, install the two ends of the model tunnel through the installation hole in the test box, continue to fill the soil to the leakage position of the model tunnel, set the soil pressure sensor on the side of the model tunnel near the leakage position, fix the grouting pipe inside the model tunnel corresponding to the inside of the leakage joint position, make the grouting pipe opening correspond to the leakage position, continue to fill the soil to the target position, and connect the water collector with one end of the model tunnel;

[0073] 2.3) Press the water permeable plate on the top of the soil layer, and pass the push rod of the hydraulic machine through the test box and connect it with the water permeable plate in the test box;

[0074] 2.4) Inject water into the test box until it is filled, connect the output end of the pressurizing pump with the water inlet, connect the input end of the water pump with the water outlet, and place the heater in the water layer;

[0075] 2.5) Connect the soil pressure sensor, water pressure sensor and strain gauge with the collection instrument through the wire outlets on the side wall of the test box, and use waterproof glue to seal and block the through holes, installation holes, water inlets and water outlets on the test box with silicone.

[0076] 3) Adjustment of the working condition of the test device:

[0077] Drive the push rod with the lifting platform through the output end of the oil cylinder of the hydraulic machine to make the water permeable plate tightly press the soil layer until the soil pressure monitored by the soil pressure sensor reaches the target soil pressure of the test;

[0078] Pressurize the water layer with the pressurizing pump until the water pressure detected by the water pressure sensor reaches the target water pressure of the test, and control the water pressure of the water layer to be constant by adjusting the water pump and the pressurizing pump;

[0079] Adjust the temperature of the heater to the target temperature of the test;

[0080] Connect the grouting pipe with the grouting machine, and turn on the grouting machine and adjust it to the grouting state.

[0081] 4) Test data record, uncover the rubber stopper corresponding to the test working condition leakage site, start the leakage test, start the grouting after 1 min, the grouting time and pressure are set according to the grouting material, the target working condition model tunnel deformation is obtained through the strain gauge reading change; the model tunnel leakage water volume is collected through the water collector, the soil pressure and water pressure changes caused by the tunnel leakage under the target working condition are obtained through the soil pressure sensor and the water pressure sensor.

[0082] The leakage time-leakage amount, leakage time-soil pressure increment, leakage site depth-tunnel bending moment broken line graph can be drawn according to the leakage water volume, soil pressure change, water pressure change and tunnel deformation, the grouting material plugging effect on the tunnel leakage is evaluated by comparing the leakage amount, soil pressure increment, tunnel bending moment and other data with the non-grouting test.

Claims

1. A multi-condition model tunnel test device, characterized in that: Includes hydraulic press, push rod, pressure pump, water pump, heater, test chamber, permeable plate, model tunnel, soil pressure sensor, water pressure sensor, strain gauge, data collector and water collector; The test chamber is set on the workbench of the hydraulic press. Inside the test chamber, from bottom to top, there are layers of fill and water. A permeable plate covers the fill layer. Two symmetrical sidewalls of the test chamber have symmetrical mounting holes corresponding to the middle of the fill layer. The model tunnel is buried within the fill layer, with both ends of the tunnel extending through the two mounting holes on the test chamber. A water collector is connected to one end of the model tunnel. The top cover of the test chamber has a through hole; one end of the push rod is connected to the output end of the hydraulic press, and the other end passes through the through hole and connects to the permeable plate. Two symmetrical sidewalls of the test chamber, corresponding to the water layer, have inlets connected to a pressure pump and outlets connected to a water pump. A heater and a water pressure sensor are located within the water layer and connected to a data collector. An earth pressure sensor is buried within the fill layer and located around the model tunnel, connected to the data collector. Strain gauges are attached to the outer wall of the model tunnel. The connection points between the model tunnel and the mounting hole, the connection points between the push rod and the through hole, the inlet and the outlet are respectively equipped with sealing rings and sealed with sealant. The permeable plate is equipped with water inlets and a filter screen.

2. The multi-condition model tunnel test device according to claim 1, characterized in that: It also includes an electromagnet and a coil wound on the electromagnet; the hydraulic press includes a support beam, a worktable, a guide column connecting the support beam and the worktable, a hydraulic cylinder mounted on the support beam, and a lifting platform slidably connected to the guide column and located between the support beam and the worktable and connected to the output end of the hydraulic cylinder; the electromagnet is fixedly connected to the lower end face of the lifting platform, and the push rod is magnetically connected to the electromagnet.

3. The multi-condition model tunnel test device according to claim 2, characterized in that: The electromagnet has a slot on the mating surface with the push rod that is adapted to the size of the push rod.

4. The multi-condition model tunnel test device according to claim 2, characterized in that: The push rod is fixedly connected to the permeable plate via a connecting flange.

5. The multi-condition model tunnel test device according to any one of claims 1 to 4, characterized in that: The bottom of the inner side of the model tunnel adopts a sloping structure, and the water collector is connected to one end of the lower side of the sloping structure of the model tunnel.

6. The multi-condition model tunnel test device according to claim 5, characterized in that: The test chamber has a cable outlet on its side wall. The earth pressure sensor, water pressure sensor, and strain gauge are connected to the data collector via data cables passing through the cable outlet.

7. The multi-condition model tunnel test device according to claim 1, characterized in that: The test chamber has a door on its side wall.

8. The multi-condition model tunnel test device according to claim 1, characterized in that: The model tunnel is equipped with joints that are adapted to the test target.

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