A model test system for seepage field during construction and operation of urban small-clearance tunnels

Abstract

The present application discloses a seepage field model test system for construction and operation of urban small-clearance tunnels, which relates to the field of civil engineering tests. The system comprises a seepage model box, a first tunnel test structure, a water pressure collection device and a water volume collection device. The seepage model box comprises a box body, a first bracket, a first cover plate and a second cover plate. Tunnel holes are opened on the front plate surface and the rear plate surface of the box body. After the first tunnel test structure is aligned with the tunnel holes at both ends under the support of the first bracket, a horizontal double-hole tunnel can be simulated. A water inlet for connecting to an external water supply device providing a water head is opened at the bottom of the box body and / or a rainfall simulation device is arranged above the box body. The present application collects the water pressure at the pre-buried position through the water pressure collection device and the water volume at the drainage pipe through the water volume collection device, so as to truly test the water pressure, drainage volume and seepage field changes of the urban small-clearance double-hole tunnel at various stages of tunnel excavation and operation period under the rainfall environment or different groundwater effects.

Description

Technical Field

[0001] The invention relates to the field of civil engineering tests, and in particular to a seepage field model test system for construction and operation periods of urban small-clearance tunnels. Background Art

[0002] Considering the diversity of use functions and the particularity of geographical location, urban tunnels have some significant characteristics. Due to the limitations of terrain, urban planning land and existing structures (buildings), urban tunnels are usually buried at a shallow depth. In order to ensure the smooth flow of existing lines and the normal use of ground buildings, it is difficult to use the open-cut method for construction. Its spatial position and plane position are difficult to meet the requirements of the existing highway tunnel design specifications. Therefore, the thickness of the middle rock column of the double tunnels is often less than the recommended value of the specification based on the surrounding rock grade. In a broad sense, the thickness of the middle rock column is between that of the double-arch tunnel and the separated tunnel.

[0003] At the same time, the traffic volume in cities is large. In order to avoid traffic bottlenecks, urban tunnels are often built with large or even extra-large sections. However, from an economic point of view, the height should not be increased too much. Such flat large-section tunnels have poor stress resistance, which increases the difficulty of design and construction. Therefore, large-section urban small-clearance double-hole tunnels came into being. Among them, solving the problem of water leakage in urban small-clearance double-hole tunnels will help ensure the safety of tunnel structures, extend their service life, and protect the surrounding ecological environment. The core is to understand the relationship between tunnel structures and seepage fields. However, the underground seepage field will change at each stage of tunnel excavation. Therefore, it is crucial to analyze the changes in groundwater in urban small-clearance double-hole tunnels, the impact of water pressure on tunnel structures, and tunnel drainage. Summary of the invention

[0004] The embodiment of the present invention provides a seepage field model test system for construction and operation of urban small-clearance tunnels to overcome the above-mentioned technical problems.

[0005] In order to solve the above problems, the embodiment of the present invention discloses a seepage field model test system for construction and operation of urban small-clearance tunnels. The system includes: a seepage model box, a first tunnel test structure, a water pressure collection device for collecting water pressure, and a water volume collection device for collecting water flow. The seepage model box includes: a box body, a first bracket and a first cover plate and a second cover plate arranged in the box body. The front plate surface of the box body is provided with two first tunnel holes located on the same horizontal line, and the rear plate surface is provided with two second tunnel holes corresponding to the first tunnel holes one by one, so that after the two first tunnel test structures are aligned with the two first tunnel holes and the two second tunnel holes respectively, the simulated water A flat double-hole tunnel, wherein a water inlet for connecting to an external water supply device providing a water head is opened at the lower part of the box body and / or a rainfall simulation device is arranged above the box body, and the rainfall simulation device is used to cause rainfall to fall into the box body according to the test requirements; the first bracket corresponds to the first tunnel test structure one by one to support the first tunnel test structure corresponding thereto; a drainage pipe is arranged on the first cover plate, the first cover plate is used to seal the first tunnel hole, and the second cover plate is used to seal the second tunnel hole; wherein the water pressure collection device is pre-buried in the first tunnel test structure and in the rock and soil layer filled in the box body; the water volume collection device is connected to the drainage pipe on the first cover plate.

[0006] Furthermore, the system also includes a second tunnel test structure, and two third tunnel holes parallel to each other are opened on one side plate surface of the box body that is oppositely arranged, wherein the third tunnel hole located above the two third tunnel holes parallel to each other is higher than the highest point of the first tunnel hole, and the third tunnel hole located below is lower than the lowest point of the first tunnel hole, so that one end of at least one second tunnel test structure is aligned with any third tunnel hole, and is connected to the other side plate surface of the box body that is oppositely arranged after passing through the top and / or bottom of the horizontal double-hole tunnel, simulating the adjacent tunnel of the horizontal double-hole tunnel; a second bracket is also arranged in the box body, and the second bracket corresponds to the second tunnel test structure one by one to support the corresponding second tunnel test structure; the first cover plate and / or the second cover plate are also used to seal the two third tunnel holes.

[0007] Furthermore, the first bracket and the second bracket are both height-adjustable structures.

[0008] Furthermore, the front panel of the box body and the first cover plate and the second cover plate are all made of transparent materials.

[0009] Furthermore, the seepage model box also includes: a soil-proof and water-permeable plate, which is arranged close to the other side plate surface opposite to the box body and parallel to the side plate surface; an overflow port is also opened at the lower part of the box body, and the overflow port is arranged at the lower part of the other side plate surface opposite to the box body, and a valve is arranged on the overflow port; the two second tunnel test structures are respectively aligned with the two third tunnel holes, and are sealed and fixed with the soil-proof and water-permeable plate after passing through the upper and lower parts of the horizontal double-hole tunnel.

[0010] Furthermore, the soil-isolating and water-permeable board comprises a perforated steel plate and a soil-isolating layer formed by a mixture of a steel mesh and a non-woven fabric, and the soil-isolating layer is fixed to the plate surface of the perforated steel plate.

[0011] Furthermore, a plurality of universal wheels are installed at the bottom of the box.

[0012] Furthermore, the first tunnel test structure is a grouting ring simulating the rock mass in the grouting reinforcement area during the construction period and a full-section curtain grouting area as a whole, wherein a face water retaining plate is installed close to the tunnel side of the full-section curtain grouting area, and a plate surface of the face water retaining plate facing the tunnel side is provided with a similar material for simulating the tunnel lining, and a water pressure collection device is pre-buried in the grouting ring.

[0013] Furthermore, the first tunnel test structure is a grouting ring that simulates the rock mass in the grouting reinforcement area during the operation period, wherein the inner wall of the first tunnel test structure is provided with similar materials for simulating the tunnel lining, the lining has a secondary lining structure built in, and the water pressure collection device is pre-buried in the grouting ring and the secondary lining structure.

[0014] Furthermore, the second tunnel test structure is a whole of the grouting ring, primary lining and secondary lining of adjacent tunnels simulating a horizontal twin-hole tunnel.

[0015] The embodiments of the present invention include the following advantages:

[0016] A seepage field model test system for construction and operation periods of urban small-clearance tunnels provided in an embodiment of the present application includes: a seepage model box, a first tunnel test structure, a water pressure collection device for collecting water pressure, and a water volume collection device for collecting water flow, wherein the seepage model box includes: a box body, a first bracket, a first cover plate, and a second cover plate, the front plate surface of the box body is provided with two first tunnel holes located on the same horizontal line, and the rear plate surface is provided with two second tunnel holes corresponding to the first tunnel holes one by one, so that the two first tunnel test structures are respectively aligned with the two first tunnel holes and the two second tunnel holes under the support of the two first brackets to simulate a horizontal double-hole tunnel, a water inlet for connecting to an external water supply device providing a water head is provided at the bottom of the box body and / or a rainfall simulation device is provided above the box body, so that the present application can simulate the influence of groundwater infiltration, seabed environment or rainfall environment on the two first tunnel test structures in the seepage model box for simulating a double-hole tunnel.

[0017] A drainage pipe is arranged on the first cover plate, the first cover plate is used to seal the first tunnel hole, and the second cover plate is used to seal the second tunnel hole; a water pressure collection device is pre-buried in the first tunnel test structure and in the rock and soil layer filled in the box, and the water volume collection device is connected to the drainage pipe on the first cover plate; the present application collects the water pressure at the pre-buried position through the water pressure collection device, and collects the water volume at the drainage pipe through the water volume collection device, and can truly test the water pressure, drainage volume and seepage field changes of the urban small-clearance double-hole tunnel (i.e., the horizontal double-hole tunnel composed of two first tunnel test structures) in various stages of tunnel excavation (construction period) and operation period under the action of rainfall or dynamic head, static head and variable head. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a seepage model box according to an embodiment of the present application;

[0019] Figure 2 It is a schematic cross-sectional structure diagram of measuring the drainage volume of a tunnel under water retaining conditions at the face when conducting a tunnel seepage field test during the construction period in an embodiment of the present application;

[0020] Figure 3 It is a schematic diagram of the cross-sectional structure of measuring the total drainage volume of a tunnel when conducting a tunnel seepage field test during the construction period in an embodiment of the present application;

[0021] Figure 4 It is a schematic diagram of the cross-sectional structure of the embodiment of the present application when conducting a tunnel seepage field test during the operation period;

[0022] Figure 5 is a schematic diagram of the structure of the first bracket in an embodiment of the present application;

[0023] Figure 6 It is a schematic diagram of the connection between the embodiment of the present application and the rainfall simulation device when simulating different rainfall amounts or the seepage field of the submarine tunnel;

[0024] Figure 7 It is a schematic diagram of the connection between the embodiment of the present application and the external water supply equipment when simulating the seepage field of an urban tunnel or a mountain tunnel.

[0025] Description of reference numerals:

[0026] 1-box, 2-first tunnel hole, 3-second tunnel hole, 4-water inlet, 5-first bracket, 6-first cover plate, 7-second cover plate, 8-third tunnel hole, 9-rainfall simulation device, 10-soil-isolating and water-permeable board, 11-overflow port, 12-universal wheel, 13-first tunnel test structure, 14-second tunnel test structure, 15-second bracket. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] Related technologies have proposed model test systems for designing and solving water problems in mining methods and shield tunnels, but these systems still have the following shortcomings:

[0029] 1) These systems are all seepage tests simulating single-tunnel tests, and the simulation effect is single. They cannot simulate the seepage conditions of urban double-tunnels with small clearance distances, and cannot perform seepage field analysis on the seepage conditions of urban double-tunnels with small clearance distances and adjacent tunnels (overpass tunnels, underpass tunnels, overpass and underpass tunnels);

[0030] 2) For areas with frequent rainfall, surface rainfall will also have a huge impact on the tunnel seepage field, thereby affecting the safety of the tunnel during construction and operation. However, existing systems are unable to complete the analysis of the effects of different rainfall on the seepage field during tunnel construction and operation.

[0031] In view of this, the present application provides a seepage field model test system for construction and operation of urban small-clearance tunnels, which may include: a seepage model box, a first tunnel test structure 13, a water pressure collection device for collecting water pressure (not shown in the figure), and a water volume collection device for collecting water flow (not shown in the figure). Figure 1 The seepage model box comprises: a box body 1, a first bracket 5, a first cover plate 6 and a second cover plate 7, wherein the front plate surface of the box body 1 is provided with two first tunnel holes 2 located on the same horizontal line, and the rear plate surface is provided with two second tunnel holes 3 corresponding to the first tunnel holes 2, so that the two first tunnel test structures 13 are respectively aligned with the two first tunnel holes 2 and the two second tunnel holes 3 to simulate a horizontal double-hole tunnel; wherein the lower part of the box body 1 is provided with a water inlet 4 for connecting to an external water supply device (not shown) providing a water head, and / or the top of the box body 1 is provided with a rainfall simulation device 9, and the rainfall The rain simulation device 9 is used to cause rainfall to fall into the box body 1 according to the test requirements; the first bracket 5 is arranged in the box body 1, and the first bracket 5 corresponds to the first tunnel test structure 13 one by one to support the first tunnel test structure 13 corresponding thereto; a drainage pipe (not shown) is arranged on the first cover plate 6, and the first cover plate 6 is used to seal the first tunnel hole 2, and the second cover plate 7 is used to seal the second tunnel hole 3; wherein, the water pressure collection device is pre-buried in the first tunnel test structure 13 and in the rock and soil layer filled in the box body 1; the water volume collection device is connected to the drainage pipe on the first cover plate 6.

[0032] Through the design of the seepage model box structure as described above, when two first brackets 5 are used to place the two first tunnel test structures 13 in the seepage model box and align them with the first tunnel hole 2 and the second tunnel hole 3, the present application can simulate a horizontal double-hole tunnel; then the water inlet 4 is supplied with water by an external water supply device, and the present application can control the water head in the seepage model box; then the water pressure at the pre-buried position is collected by a water pressure collection device, and the water volume at the drainage pipe is collected by a water volume collection device, and the water pressure, gushing water volume and seepage field changes of the urban small-clearance double-hole tunnel (i.e., the horizontal double-hole tunnel composed of two first tunnel test structures 13) at various stages of tunnel excavation (such as construction period and operation period) under the action of dynamic head, static head and variable head can be truly tested. Among them, the water pressure collection device can use a water pressure gauge sold on the existing market, and the water volume collection device can use a water flow meter sold on the existing market.

[0033] Considering that in areas with frequent rainfall, surface rainfall will also have a huge impact on the tunnel seepage field, thus affecting the safety of the tunnel construction and operation period. However, the existing systems are unable to complete the analysis of the seepage field of the tunnel construction and operation period under different rainfall. Figure 1 As shown, the seepage model box of the present application also includes a rainfall simulation device 9 arranged above the box body 1, and rainfall of different rainfall amounts can be applied to the box body 1 through the rainfall simulation device 9 according to the test requirements. Among them, the rainfall simulation device 9 can adopt the existing artificial rainfall simulation device 9, and can also be realized by installing a water tank with holes on the bottom surface above the box body 1. By controlling the number and size of the holes on the bottom surface of the water tank, that is, replacing water tanks with different apertures and numbers, different rainfall amounts can be simulated, so as to study the state of the tunnel under different rainfall amounts. Through the design of the above structure, the present application can control the rainfall size of the rainfall simulation device 9 on the basis of only a horizontal double-hole tunnel or on the basis of adjacent tunnels at the same time, and truly and accurately test the water pressure, drainage and seepage field changes of the urban small-clearance double-hole tunnel during the construction period and operation period under the action of different rainfall amounts.

[0034] It should be noted that "and / or" means only one or both. Therefore, in the present application, the seepage model box of the present application may only include the water inlet 4 opened at the lower part of the box body 1, or only include the rainfall simulation device 9 arranged above the box body 1. Of course, it may also include the water inlet 4 opened at the lower part of the box body 1 and the rainfall simulation device 9 arranged above the box body 1 to meet different test requirements.

[0035] In the present application, each stage of tunnel excavation can be effectively simulated by controlling the specific structure of the first test tube. In one embodiment of the present application, the first tunnel test structure 13 is a grouting ring simulating the rock mass of the grouting reinforcement area during the construction period and the entire curtain grouting area, or a grouting ring simulating the rock mass of the grouting reinforcement area during the operation period; optionally, Figure 2 and Figure 3 As shown, when the first tunnel test structure 13 is a grouting ring simulating the rock mass of the grouting reinforcement area during the construction period and the whole curtain grouting area, the full-section curtain grouting area is installed with a face water retaining plate near the tunnel side, and a plate surface of the face water retaining plate facing the tunnel side is provided with a geotextile for simulating the tunnel lining, and a water pressure collection device is pre-buried in the grouting ring. Figure 4 As shown, when the first tunnel test structure 13 is a grouting ring simulating the rock mass of the grouting reinforcement area during operation, optionally, the inner wall of the first tunnel test structure 13 is provided with similar materials for simulating tunnel lining, the lining is built with a secondary lining structure, and the water pressure collection device is pre-buried in the grouting ring and the secondary lining structure. The test methods for different first test tube structures are different. The specific process of the test method will be described in detail later, and will not be repeated here.

[0036] Considering the problem that the prior art cannot currently perform seepage field analysis on the seepage conditions of a double-hole tunnel with a small clearance in an urban area with adjacent tunnels, in one embodiment of the present application, the following structure is also provided: Figure 1The system also includes a second tunnel test structure 14, and two third tunnel holes 8 are opened on one side plate surface of the box body 1 that is oppositely arranged, wherein the third tunnel hole 8 located above the two third tunnel holes 8 that are parallel to each other is higher than the highest point of the first tunnel hole 2, and the third tunnel hole 8 located below is lower than the lowest point of the first tunnel hole 2, so that one end of at least one second tunnel test structure 14 is aligned with any third tunnel hole 8, and is connected to the other side plate surface of the box body 1 that is oppositely arranged after passing through the top and / or bottom of the horizontal double-hole tunnel, simulating the adjacent tunnel of the horizontal double-hole tunnel; a second bracket 15 is also arranged in the box body 1, and the second bracket 15 corresponds to the second tunnel test structure 14 one by one to support the corresponding second tunnel test structure 14; the first cover plate 6 and / or the second cover plate 7 are also used to seal the two third tunnel holes 8. Through the design of the seepage model box structure as described above, when a second bracket 15 is used to place the second tunnel test structure 14 in the seepage model box and align it with one of the third tunnel holes 8, the present application can simulate the upper span or lower tunnel of the horizontal double-hole tunnel; when two second brackets 15 are used to place two second tunnel test structures 14 in the seepage model box and align them with two third tunnel holes 8, the present application can simulate the upper span and lower tunnel of the horizontal double-hole tunnel. Furthermore, after water is passed into the water inlet 4 through an external water supply device, the present application can analyze the seepage field of the urban small clear distance double-hole tunnel with adjacent tunnels (upper span tunnel, lower tunnel, upper span and lower tunnel) according to the water pressure data collected by the water pressure collection device at each pre-buried position and the water volume data collected by each water volume collection device. Among them, considering that the urban small clear distance double-hole tunnel and its adjacent tunnels are usually not constructed at the same time, the second tunnel test structure 14 can be selected as the grouting ring, primary lining and secondary lining of the adjacent tunnel simulating the horizontal double-hole tunnel.

[0037] In one embodiment of the present application, Figure 2-Figure 4 As shown, the front panel of the box 1 and the first cover plate 6 and the second cover plate 7 are all made of transparent materials. The transparent material may be glass, such as the front panel of the box 1 may be tempered glass, the first cover plate 6 may be an organic glass cover plate with a drain pipe, and the second cover plate 7 may be a completely closed organic glass cover plate. By limiting the material of the front panel of the box 1 to a transparent material, the seepage path of water in the rock and soil body can be conveniently and intuitively observed during the test. Similarly, it is also convenient to observe the water level in the box 1. By also limiting the first cover plate 6 and the second cover plate 7 to transparent materials, it is convenient for the experimenter to observe the seepage field conditions in the simulated horizontal double-hole tunnel and the adjacent tunnel. The rear panel, the two side panels and the bottom panel of the box 1 may be made of steel plates.

[0038] In one embodiment of the present application, Figure 1As shown, the seepage model box also includes: a soil-proof and water-permeable plate 10, which is arranged close to the other side plate surface opposite to the box body 1 and parallel to the side plate surface; the lower part of the box body 1 is also provided with an overflow port 11 for drainage, and the overflow port 11 is arranged at the lower part of the other side plate surface opposite to the box body 1, and a valve is arranged on the overflow port 11; the two second tunnel test structures 14 are respectively aligned with the two third tunnel holes 8, and are sealed and fixed with the soil-proof and water-permeable plate 10 after passing through the upper and lower parts of the horizontal double-hole tunnel. The present application can effectively separate the soil layer in the seepage model box from the overflow port 11 through the arrangement of the above structure to avoid blockage of the overflow port 11. Optionally, as Figure 1 As shown, the soil-insulating and water-permeable board 10 may include a perforated steel plate and a soil-insulating layer made of a mixture of steel mesh and non-woven fabric, and the soil-insulating layer is fixed to the plate surface of the perforated steel plate. The perforated steel plate can ensure the strength of the entire soil-insulating and water-permeable board 10, and the soil-insulating layer made of a mixture of steel mesh and non-woven fabric limits the gap and can effectively isolate the soil.

[0039] In the embodiments of the present application, Figure 5 As shown, the structures of the first bracket 5 and the second bracket 15 can be different or the same. Furthermore, the first bracket 5 and the second bracket 15 are both height-adjustable structures. In this way, by adjusting the height of the first bracket 5, the two ends of the first tunnel test structure 13 can be aligned with the first tunnel hole 2 and the second tunnel hole 3 respectively; similarly, by adjusting the height of the second bracket 15, the second tunnel test structure 14 can be aligned with the third tunnel hole 8. Regarding the structures of the first bracket 5 and the second bracket 15, reference can be made to the relevant prior art, and no further limitations are given here.

[0040] In one embodiment of the present application, a plurality of universal wheels 12 are installed at the bottom of the box 1, so that the seepage model box can be easily moved. Figure 1 As shown, 10 universal wheels 12 are installed at the bottom of the box 1. The 10 universal wheels 12 are evenly distributed at the bottom of the box 1, so that the box 1 can be easily moved while ensuring a good load-bearing effect.

[0041] Based on the above system, this application provides the following examples of test methods to realistically simulate and test the seepage field conditions of urban small-spacing double-hole tunnels during the construction and operation periods under different groundwater heads or different surface rainfalls.

[0042] Example 1:

[0043] like Figure 2 , Figure 3 and Figure 6As shown, a test method for simulating the tunnel seepage field of a double-hole tunnel during construction under different rainfall on the surface or undersea tunnel using the system provided by the present application, wherein the first tunnel test structure 13 is a grouting ring (also called reinforced rock and soil layer) simulating the rock mass of the grouting reinforcement area during construction and the entire curtain grouting area of ​​the entire section, and the method may include the following steps:

[0044] Step A1: install and fix the first tunnel test structure 13 on the first bracket 5, embed a water pressure gauge in the reinforced rock and soil layer, install a face water retaining plate (removable) on the tunnel side formed by the first tunnel test structure 13 in the full-section curtain grouting area, and then fit similar materials simulating lining to the inner wall of the grouting ring on the tunnel side of the face water retaining plate to simulate the lining of the tunnel; adjust the height of the first bracket 5 to align the inner circle of the grouting ring of the first tunnel test structure 13 with the first tunnel hole 2 on the front panel of the box 1 (the front panel is tempered glass), and seal the grouting ring close to the glass surface with glass glue, and then cover it with a first cover plate 6 with a drainage hose, and cover the second tunnel hole 3 on the rear panel of the box 1 with a second cover plate 7 made of organic glass, and seal it with glass glue;

[0045] Step A2: Install the integral second tunnel test structure 14 prepared by the grouting ring, primary lining and secondary lining simulating the adjacent tunnel (overpassing and underpassing tunnel) on two second brackets 15 respectively, adjust the height of the second bracket 15, align the inner circle of one end of the second tunnel test structure 14 with the third tunnel hole 8 on the right side of the box body 1, and seal the other end with the soil-isolating and water-permeable plate 10 with a water-stop pad and glass glue, and then seal the second cover plate 7 covering the third tunnel hole 8 with glass glue;

[0046] Step A3: laying the rock and soil body simulating the surrounding rock in layers according to the set compaction degree, filling it into the box 1 of the seepage model box, and pre-burying a water pressure gauge in the rock and soil layer;

[0047] Step A4: using a water tank with holes on the bottom as the rainfall simulation device 9, and then connecting the top of the box body 1 to the water tank with holes on the bottom;

[0048] Step A5: collecting the water pressure of the rock and soil layer reinforced in step A1, the water pressure of the rock and soil body laid in the box 1 and the amount of water flowing out of the first tunnel hole 2; ending the test, that is, simulating the distribution of the seepage field during the construction period of the urban small-clearance double-hole tunnel under the conditions of adjacent tunnels, specific surrounding rocks, and grouting reinforcement, and the drainage of the tunnel under the condition of water retaining at the heading face when the surface rainfall is different or the submarine tunnel is under the condition of water retaining at the heading face;

[0049] Step A6: remove the water retaining plate on the face of the full-section curtain grouting area near the tunnel side in step A1, and re-collect the water pressure of the reinforced rock and soil layer in step A1, the water pressure of the rock and soil body laid in the box 1, and the amount of water flowing out of the first tunnel hole 2; end the test, that is, simulate the seepage field distribution and total drainage during the construction period of the urban small-clearance double-hole tunnel with adjacent tunnels, specific surrounding rocks, and grouting reinforcement conditions under different surface rainfall or submarine tunnels.

[0050] Example 2:

[0051] like Figure 2 , Figure 3 and Figure 7 As shown, a test method for simulating the tunnel seepage field of a small-clearance urban or mountain double-hole tunnel during construction using the system provided by the present application, wherein the first tunnel test structure 13 is a grouting ring (also called a reinforced rock and soil layer) simulating the rock mass of the grouting reinforcement area during construction and the entire full-section curtain grouting area, and the method may include the following steps:

[0052] Step B1: install and fix the first tunnel test structure 13 on the first bracket 5, embed a water pressure gauge in the reinforced rock and soil layer, install a face water retaining plate (removable) on the tunnel side formed by the first tunnel test structure 13 in the full-section curtain grouting area, and fit similar materials simulating lining to the inner wall of the grouting ring on the tunnel side of the face water retaining plate to simulate the lining of the tunnel; adjust the height of the first bracket 5 to align the inner circle of the grouting ring of the first tunnel test structure 13 with the first tunnel hole 2 on the front panel of the box 1 (the front panel is tempered glass), seal with glass glue close to the periphery of the glass surface, and then cover with the first cover plate 6 with a drainage hose, and cover the second tunnel hole 3 on the rear panel of the box 1 with a second cover plate 7 made of organic glass, and seal with glass glue;

[0053] Step B2: Install the integral second tunnel test structure 14 prepared by the grouting ring, primary lining and secondary lining simulating the adjacent tunnel (overpassing and underpassing tunnel) on two second brackets 15 respectively, adjust the height of the second bracket 15, align the inner circle of one end of the second tunnel test structure 14 with the third tunnel hole 8 on the right side of the box body 1, and seal the other end with the soil-isolating and water-permeable plate 10 with a water-stop pad and glass glue, and then seal the second cover plate 7 covering the third tunnel hole 8 with glass glue;

[0054] Step B3: laying the rock and soil body simulating the surrounding rock in layers according to the set compaction degree, filling it into the box 1 of the seepage model box, and pre-burying a water pressure gauge in the rock and soil layer;

[0055] Step B4: Connect the water inlet 4 at the bottom of the side wall of the box body 1 to an external water supply device, and adjust the external water supply device to a set height;

[0056] Step B5: Collect the water pressure of the reinforced rock and soil layer in step B1, the water pressure of the rock and soil body laid in the box 1, and the amount of water flowing out from the first tunnel hole 2; end the test, that is, simulate the seepage field distribution during the construction period of the urban small clear distance or mountain double-hole tunnel under the conditions of adjacent tunnels, specific surrounding rocks, and grouting reinforcement, and the drainage volume of the tunnel under the condition of water retaining at the heading face;

[0057] Step B6: remove the water retaining plate on the face of the full-section curtain grouting area near the tunnel side in step B1, and re-collect the water pressure of the reinforced rock and soil layer in step B1, the water pressure of the rock and soil body laid in the box 1, and the amount of water flowing out of the first tunnel hole 2; end the test, that is, simulate the seepage field distribution and total drainage during the construction period of urban small-clearance or mountain double-hole tunnels under the conditions of adjacent tunnels, specific surrounding rocks, and grouting reinforcement.

[0058] Through the methods shown in Examples 1 and 2, the present application can truly, effectively, conveniently and accurately test the water pressure, drainage and seepage field changes of urban small-clearance double-hole tunnels and tunnels with overspans and underpasses during the construction period under the action of the seepage field. The parameters of rainfall, surrounding rock, grouting reinforcement area, face pre-grouting area, lining and adjacent tunnels can be freely configured and changed according to the needs of specific tests, which can restore the actual situation of the seepage field in the tunnel and its surroundings to the greatest extent.

[0059] Example 3:

[0060] like Figure 4 and Figure 6 As shown, the test method for simulating the seepage field of a double-hole tunnel in operation period under different rainfall on the surface or undersea tunnel by using the system provided by the present application, wherein the first tunnel test structure 13 is a grouting ring for simulating the rock mass in the grouting reinforcement area during operation period, can include the following steps:

[0061] Step C1: fix the first tunnel test structure 13 on the first bracket 5, and embed a water pressure gauge in the grouting ring; attach similar materials of simulated lining to the inner wall of the grouting ring to simulate the lining of the tunnel, and place a tubular second lining structure with a horseshoe-shaped end face on the inner side of the lining, and embed a water pressure gauge in the second lining; adjust the height of the first bracket 5 so that the inner circles of the two opening ends of the grouting ring of the first tunnel test structure 13 are respectively aligned with the first tunnel hole 2 on the front plate surface of the box body 1 and the second tunnel hole 3 on the rear plate surface, and seal the grouting ring close to the glass surface with glass glue, and then cover it with a first cover plate 6 with a drainage hose, and cover the second tunnel hole 3 on the rear plate surface of the box body 1 with a second cover plate 7 made of organic glass, and seal it with glass glue;

[0062] Step C2: Install the integral second tunnel test structure 14 prepared by the grouting ring, primary lining and secondary lining simulating the adjacent tunnel (overpassing and underpassing tunnel) on two second brackets 15 respectively, adjust the height of the second bracket 15, align the inner circle of one end of the second tunnel test structure 14 with the third tunnel hole 8 on the right side of the box body 1, and seal the other end with the soil-isolating and water-permeable plate 10 with a water-stop pad and glass glue, and then seal the second cover plate 7 covering the third tunnel hole 8 with glass glue;

[0063] Step C3: laying the rock and soil body simulating the surrounding rock in layers according to the set compaction degree, filling it into the box 1 of the seepage model box, and pre-burying a water pressure gauge in the rock and soil layer;

[0064] Step C4: using a water tank with holes on the bottom as the rainfall simulation device 9, and then connecting the top of the box body 1 to the water tank with holes on the bottom;

[0065] Step C5: Collect the water pressure of the grouting circle in step C1, the water pressure of the rock and soil laid in the box 1, and the amount of water flowing out of the first tunnel hole 2; end the test, that is, simulate the seepage field distribution and total drainage of the urban small-clearance double-hole tunnel in the operation period under the conditions of adjacent tunnels, specific surrounding rocks, and grouting reinforcement, with different surface rainfall or submarine tunnels.

[0066] Example 4:

[0067] like Figure 4 and Figure 7 As shown, a test method for simulating the tunnel seepage field of a small-clearance urban or mountain double-hole tunnel during operation using the system provided by the present application, wherein the first tunnel test structure 13 is a grouting ring simulating the rock mass of the grouting reinforcement area during operation, and the method may include the following steps:

[0068] Step D1: The first tunnel test structure 13 is fixedly mounted on the first bracket 5, and a water pressure gauge is embedded in the reinforced rock and soil layer; a similar material for simulating lining is attached to the inner wall of the grouting ring to simulate the lining of the tunnel, and a tubular second lining structure with a horseshoe-shaped end face is placed on the inner side of the geotextile, and a water pressure gauge is embedded in the second lining; the height of the first bracket 5 is adjusted so that the inner circles of the two opening ends of the grouting ring of the first tunnel test structure 13 are respectively aligned with the first tunnel hole 2 on the front plate surface of the box body 1 and the second tunnel hole 3 on the rear plate surface, and glass glue is applied to seal the grouting ring close to the periphery of the glass surface, and then the first cover plate 6 with a drainage hose is covered, and the second tunnel hole 3 on the rear plate surface of the box body 1 is covered with a second cover plate 7 made of organic glass, and sealed with glass glue;

[0069] Step D2: The second tunnel test structure 14 prepared by grouting ring, primary lining and secondary lining simulating the adjacent tunnel (overpassing and underpassing tunnel) is respectively installed on two second brackets 15, and the height of the second bracket 15 is adjusted so that the inner circle of one end of the second tunnel test structure 14 is aligned with the third tunnel hole 8 on the right side of the box body 1, and the other end is sealed with the soil-isolating and water-permeable plate 10 with a water-stop pad and glass glue, and the second cover plate 7 covering the third tunnel hole 8 is sealed with glass glue;

[0070] Step D3: laying the rock and soil body simulating the surrounding rock in layers according to the set compaction degree, filling it into the box 1 of the seepage model box, and pre-burying a water pressure gauge in the rock and soil layer;

[0071] Step D4: Connect the water inlet 4 at the bottom of the side wall of the box body 1 to an external water supply device, and adjust the external water supply device to a set height;

[0072] Step D5: Collect the water pressure of the grouting circle in step D1, the water pressure of the rock and soil laid in the box 1, and the amount of water flowing out of the first tunnel hole 2; end the test, that is, simulate the seepage field distribution and total drainage during the operation period of the urban small clearance or mountain double-hole tunnel under the conditions of adjacent tunnels, specific surrounding rocks, and grouting reinforcement.

[0073] Through the methods shown in Examples 3 and 4, the present application can truly, effectively, conveniently and accurately test the water pressure, drainage and seepage field changes of urban small-clearance double-hole tunnels and tunnels with overspans and underpasses during operation under the action of the seepage field. The parameters of rainfall, surrounding rock, grouting reinforcement area, lining and adjacent tunnels can be freely configured and changed according to the needs of specific tests, which can restore the actual situation of the seepage field in the tunnel and its surroundings to the greatest extent.

[0074] In summary, this application can have the following beneficial effects:

[0075] 1. By filling the material simulating different rock and soil surrounding rocks in the box 1 to reinforce the outside of the rock and soil layer (grouting ring), different hydrological and geotechnical conditions of urban small-clearance tunnels can be simulated. A water tank with holes on the bottom is installed on the top wall of the model box to realistically simulate the seepage field of small-clearance tunnels (overpass and underpass tunnels) under different rainfall amounts, and also to simulate the seepage field of submarine tunnels; by connecting the lower water inlet 4 at the bottom of the right side wall of the model box to an external water supply device that provides a water head, the seepage field of urban small-clearance tunnels (including overpass and underpass tunnels) and mountain tunnels can be realistically simulated; thereby providing a reliable test basis for the anti-seepage design and construction of small-clearance tunnel projects to ensure the safety of tunnels during construction and operation.

[0076] 2. Through the design of two parallel horseshoe-shaped tunnels (i.e., two third tunnel holes 8) on the steel plate on the right side of the box body 1, the situation of having adjacent tunnels (overpassing and underpassing) can be simulated, which is convenient and reliable.

[0077] 3. The height of the first bracket 5 can be adjusted up and down, and the thickness of the reinforced rock and soil layer (grouting ring) of the tunnel structure and the position of the earth partition plate and the face water retaining plate during the construction period can be adjusted according to the actual situation, which is practical and flexible; the primary lining and the secondary lining of the tunnel structure can also be adjusted according to the specific actual situation, which is simple to operate and practical. In this way, the tunnel seepage field and its drainage volume at different positions of the tunnel excavation during the construction period can be simulated and measured, providing a reliable test basis for the design and construction of the tunnel project and ensuring the safety of the tunnel construction.

[0078] 4. The test device can simulate and analyze the seepage field of a small-clearance double-tunnel in an urban area when the excavation of the left and right tunnels is inconsistent during the construction period.

[0079] 5. The test device can directly observe the seepage path of water inside the box body 1 from the outside of the box body 1, and also overcomes the defect that other test systems cannot accurately control the water level height.

[0080] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0081] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. "And / or" means that either one of the two can be selected, or both can be selected. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0082] The scheme provided by the present invention is introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A seepage field model test system for urban small-clearance tunnel construction and operation period, characterized in that: The system comprises: a seepage model box, a first tunnel test structure (13), a water pressure collection device for collecting water pressure, and a water volume collection device for collecting water flow. The seepage model box comprises: A box (1), wherein the front panel of the box (1) is provided with two first tunnel holes (2) located on the same horizontal line, and the rear panel is provided with two second tunnel holes (3) corresponding to the first tunnel holes (2) one by one, so that two first tunnel test structures (13) are respectively aligned with the two first tunnel holes (2) and the two second tunnel holes (3), so as to simulate a horizontal double-hole tunnel, wherein a water inlet (4) for connecting to an external water supply device for providing a water head is provided at the bottom of the box (1) and / or a rainfall simulation device (9) is provided above the box (1), and the rainfall simulation device (9) is used to cause rainfall to fall into the box (1) according to test requirements; A first bracket (5) is arranged in the box (1), the first bracket (5) corresponds to the first tunnel test structure (13) one by one, so as to support the first tunnel test structure (13) corresponding thereto; and a first cover plate (6) and a second cover plate (7), wherein the first cover plate (6) is provided with a drainage pipe, the first cover plate (6) is used to seal the first tunnel hole (2), and the second cover plate (7) is used to seal the second tunnel hole (3); The water pressure collection device is pre-buried in the first tunnel test structure (13) and in the rock and soil layer filled in the box (1); the water volume collection device is connected to the drainage pipe on the first cover plate (6); The system further comprises a second tunnel test structure (14), wherein two third tunnel holes (8) are opened on one side plate surface of the box body (1) which is arranged opposite to each other, wherein the third tunnel hole (8) located on the upper side of the two third tunnel holes (8) which are arranged opposite to each other is higher than the highest point of the first tunnel hole (2), and the third tunnel hole (8) located on the lower side is lower than the lowest point of the first tunnel hole (2), so that one end of at least one of the second tunnel test structures (14) is aligned with any of the third tunnel holes (8), and passes through the upper side and / or the lower side of the horizontal double-hole tunnel and is connected to the other side plate surface of the box body (1) which is arranged opposite to each other, so as to simulate the adjacent tunnel of the horizontal double-hole tunnel; A second bracket (15) is also provided in the box body (1), and the second bracket (15) corresponds to the second tunnel test structure (14) one by one to support the second tunnel test structure (14) corresponding thereto; The first cover plate (6) and / or the second cover plate (7) are also used to seal the two third tunnel holes (8).

2. The system according to claim 1, characterized in that The first bracket (5) and the second bracket (15) are both height-adjustable structures.

3. The system according to claim 1, characterized in that The front panel surface of the box body (1) and the first cover plate (6) and the second cover plate (7) are all made of transparent materials.

4. The system according to claim 1, characterized in that The seepage model box further comprises: a soil-insulating water-permeable plate (10), the soil-insulating water-permeable plate (10) being arranged close to the other side plate surface arranged opposite to the box body (1) and being parallel to the side plate surface; an overflow port (11) is also provided at the lower part of the box body (1), the overflow port (11) being arranged at the lower part of the other side plate surface arranged opposite to the box body (1), and a valve is arranged on the overflow port (11); The two second tunnel test structures (14) are respectively aligned with the two third tunnel holes (8), and are sealed and fixed with the soil-isolating and water-permeable plates (10) after passing through the upper and lower parts of the horizontal double-hole tunnel.

5. The system according to claim 4, characterized in that The soil-isolating and water-permeable plate (10) comprises a perforated steel plate and a soil-isolating layer formed by a mixture of a steel mesh and non-woven fabric, wherein the soil-isolating layer is fixed to the plate surface of the perforated steel plate.

6. The system according to claim 1, characterized in that A plurality of universal wheels (12) are installed at the bottom of the box body (1).

7. The system according to claim 1, characterized in that The first tunnel test structure (13) is a grouting ring and a full-section curtain grouting area as a whole that simulates the rock mass in the grouting reinforcement area during the construction period, wherein the full-section curtain grouting area is installed with a face water retaining plate (15) close to the tunnel side, and a plate surface of the face water retaining plate (15) facing the tunnel side is provided with a similar material for simulating tunnel lining, and the water pressure collection device is pre-buried in the inner and outer surfaces of the grouting ring.

8. The system according to claim 1, characterized in that The first tunnel test structure (13) is a grouting ring for simulating the rock mass in the grouting reinforcement area during the operation period, wherein the inner wall of the first tunnel test structure (13) is provided with a similar material for simulating the tunnel lining, the simulated tunnel lining is provided with a secondary lining structure, and the water pressure collection device is pre-buried in the grouting ring and the secondary lining structure.

9. The system according to claim 1, characterized in that The second tunnel test structure (14) is a whole of the grouting ring, the primary lining and the secondary lining of the adjacent tunnel simulating the horizontal twin-hole tunnel.

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