CN114878298A - Upward soil pressure shield excavation surface stability test device and use method thereof - Google Patents
Upward soil pressure shield excavation surface stability test device and use method thereof Download PDFInfo
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- 238000009412 basement excavation Methods 0.000 title claims abstract description 168
- 239000002689 soil Substances 0.000 title claims abstract description 96
- 238000000034 method Methods 0.000 title claims abstract description 59
- 238000013112 stability test Methods 0.000 title claims abstract description 27
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 82
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- 239000000463 material Substances 0.000 claims description 6
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- 238000005452 bending Methods 0.000 claims description 4
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- 239000011521 glass Substances 0.000 claims description 4
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- 238000009434 installation Methods 0.000 claims description 4
- 238000005429 filling process Methods 0.000 claims description 3
- 230000035699 permeability Effects 0.000 claims description 3
- 229910001220 stainless steel Inorganic materials 0.000 claims description 3
- 239000010935 stainless steel Substances 0.000 claims description 3
- 239000005341 toughened glass Substances 0.000 claims description 3
- 210000001503 joint Anatomy 0.000 claims description 2
- 229920006395 saturated elastomer Polymers 0.000 claims description 2
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- 230000005641 tunneling Effects 0.000 description 2
- 238000009933 burial Methods 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
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- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
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Abstract
The invention discloses an upward earth pressure shield excavation surface stability test device and a using method thereof, wherein the device comprises a model main body structure, a propulsion control system, a data acquisition system and a water level control system, wherein the model main body structure comprises a model box, a horizontal tunnel model and an upward shield model; the using method comprises a test preparation stage, an excavation face moving stage and a data processing stage. The method can study the instability process of the excavation face of the upward shield, observe the earth surface displacement, the soil pressure of the excavation face, the supporting force of the excavation face, the pore water pressure of the excavation face, the change of the strain of the horizontal tunnel, the change of the displacement field of the soil body above the excavation face and the change rule of various data in the instability process, and simultaneously can change the working condition by adjusting the test conditions or the test parameters and study the influence of different working conditions on the instability of the excavation face.
Description
Technical Field
The invention belongs to the technical field of civil engineering, and particularly relates to an upward soil pressure shield excavation surface stability test device and a using method thereof.
Background
With the advance of the urbanization process, various pipelines in the city, such as drainage, electric power, communication, gas pipelines and the like, are complicated and complicated, and often need to repeatedly dig a road surface for rush repair, maintenance, capacity expansion, reconstruction and the like, so that the economic cost is very high. The utility tunnel is built underground in the city, is used for laying the public channel of municipal administration pipelines such as drainage, electric power, communication in a concentrated way, can regard as the public space of multiclass pipeline, solves the scheduling problem of "road zip fastener". In the construction of city utility tunnel, in order to satisfy needs such as inside ventilation, people's air defense of piping lane, the construction of shaft often is one of the technological key points. The existing shaft construction method is generally an open cut method, the open cut method has the defects of destroying the surrounding environment, causing inconvenience to the lives of residents, having larger construction risk and the like during construction, and has larger influence on the environment, surrounding traffic and the lives of the residents.
In contrast, the upward earth pressure shield method is widely used in shaft construction because it has advantages of construction in busy urban areas, no need of large-area excavation and large-area road destruction. Under the background, the upward earth pressure shield technology is rapidly developed, the upward earth pressure shield technology is a method that an opening is formed above a comprehensive pipe gallery, a shield machine vertically excavates soil upwards, and vertical shaft construction is completed in the process of continuous earth discharge, and material carrying and supply are performed in an underground tunnel, so that the ground construction operation only includes recovery of the shield machine, the influence on the surrounding environment is small, and vertical shaft construction can be performed in difficult construction places such as train railways, downtown high-rise areas, roofs where large vehicles cannot enter and the like. Compared with open cut construction, the construction period can be greatly saved, the time cost and the economic cost brought by ground traffic control are reduced, and the method has good development and application prospects.
As a brand-new construction method, the upward earth pressure shield technology has few domestic and foreign existing achievements and is still in an exploration stage, and the stability test research of the excavation surface of the upward earth pressure shield is not found.
Disclosure of Invention
In view of the above, the invention provides a stability test device for an excavation face of an upward earth pressure shield and a use method thereof, which are used for simulating the instability of the excavation face in the excavation process of the upward earth pressure shield in actual engineering, and provide certain ideas and references for better applying the technology to the actual engineering.
The utility model provides an earth pressure shield constructs excavation face stability test device up, includes model major structure, propulsion control system, data acquisition system, water level control system, wherein:
the model main body structure comprises a model box, a horizontal tunnel model and an upward shield model, wherein the horizontal tunnel model is formed by sequentially splicing a plurality of 1/4 cylindrical outlines and is placed at the bottom of the model box, and a first through hole and a second through hole are respectively formed in the center of the horizontal tunnel model and the center of the bottom of the model box; the upward shield model is formed by sequentially splicing a plurality of semicircular shield rings in the vertical direction and penetrates through the first through hole and the second through hole, and an excavation panel is arranged at the top of the upward shield model;
the propulsion control system comprises a transmission rod and a hydraulic servo device, the transmission rod is connected with the excavation panel, and the hydraulic servo device drives the upward shield model to advance and retreat and adjust the advancing speed of the upward shield model by controlling the transmission rod;
the data acquisition system comprises a camera, an LED lamp, an axial force meter, a soil pressure meter, an osmometer, an LVDT displacement meter and a strain gauge; the camera and the LED lamp are used for image acquisition in the instability process of the excavation surface; the soil pressure gauge and the osmometer are arranged on the excavation panel and used for collecting soil pressure and pore water pressure of the excavation surface in the instability process of the excavation surface; the axial force meter is arranged on the transmission rod in the uppermost shield ring and used for collecting the supporting force of the excavation surface in the instability process of the excavation surface; the LVDT displacement meter is placed on the earth surface and used for collecting the deformation of earth surface soil when the excavation surface is unstable; the strain gauge is attached to the inner side of the horizontal tunnel model;
the water level control system comprises a water supply tank, a water storage tank, a water injection pipe, an inner water discharge pipe and an outer water discharge pipe, wherein the water injection pipe is connected with the water supply tank and used for injecting water to soil in the model box; one end of the outer drainage pipe is connected with the water storage tank, and the other end of the outer drainage pipe is in butt joint with an overflow hole formed in the side wall of the model box.
Furthermore, the model box is a rectangular box body with an uncovered top, is made of toughened glass and is arranged and fixed on the model bracket.
Furthermore, the excavation panel is a detachable porous structure, and a PVD water filtration film is pasted on the panel.
Furthermore, a groove is formed in the periphery of the top of the model box, a cross beam is erected in the groove, and the LVDT displacement meter is placed on the cross beam.
Furthermore, 1/4 cylinder profile that horizontal tunnel model adopted is made for organic glass, shield the model upwards is detachable construction, and the shield that its adopted encircles and makes for the stainless steel.
The use method of the upward soil pressure shield excavation surface stability test device comprises the following steps:
a test preparation stage: preparing materials needed to be used in the test, firstly pasting a strain gauge on the inner side of the bottom of a horizontal tunnel model, placing a model box on a model bracket, and making corresponding fixing measures; then, the upward shield model penetrates through a second through hole at the bottom of the model box and a first through hole of the horizontal tunnel model, the upward shield model is fixed after the upward shield model reaches a specified position, and sealing work at the first through hole and the second through hole is well done; placing an excavation panel on the top of an upward shield model, filling pores on the excavation panel with waterproof glue, attaching a PVD (physical vapor deposition) water filtration film on the excavation panel, and then installing a soil pressure meter and a osmometer on the excavation panel; after the installation is finished, sand and soil are filled to the surface of a soil layer in a layered mode in the mold box by a sand-rain method, and water is continuously tamped and sprinkled in the filling process to enable the soil layer to be saturated; after the sand filling is finished, erecting a cross beam in a groove on the periphery of the top of the model box, and mounting an LVDT displacement meter on the cross beam; then erecting a camera, turning on an LED lamp, and turning on a water injection pipe and an inner drain pipe/an outer drain pipe to keep the water level in the model box constant; detecting whether each part of measuring equipment of the data acquisition system is normal or not, connecting the measuring equipment to a computer, and then perfecting the sealing and waterproof work of the whole test device to prepare for starting a test;
and (3) moving an excavation surface: opening a hydraulic servo device to drive an excavation panel to retreat at a constant speed through a transmission rod, enabling the excavation panel to generate active instability, and then continuously shooting images of a soil body displacement field above the excavation surface by using a camera; stopping moving the excavation panel after the soil body above the excavation surface is unstable;
and (3) a data processing stage: processing the image acquired by the camera to obtain the change condition of a soil body displacement field above the excavation surface in the instability process of the excavation surface, and analyzing the respective change rules in the instability process of the excavation surface by drawing the change images of the support force of the excavation surface, the soil pressure of the excavation surface, the pore water pressure and the bending moment of the horizontal tunnel model in the instability process of the excavation surface; and drawing a displacement diagram of the surface soil body after the instability of the excavation surface to obtain the displacement condition and the influence range of the surface soil body after the instability of the excavation surface.
Furthermore, in the test preparation stage, the aim of changing the thickness of the covering soil is fulfilled by disassembling the number of the shield rings of the upward shield model, the stability test of the excavation surface is carried out under different covering soil thicknesses, and the influence of the covering soil thickness on the stability of the upward shield excavation surface is researched.
Furthermore, in the excavation face moving stage, the excavation face moving device can be adjusted to drive the excavation face to move upwards, and the passive instability mode of the soil body is researched.
Furthermore, when the non-permeability test process is carried out, a detachable non-porous excavation panel can be adopted, an osmometer does not need to be installed, and dry sand does not need to be added with water.
Furthermore, in the test preparation stage, overflow holes with different heights can be opened to control the test water level, and the stability test of the excavation surface with different water head differences is researched.
Further, in the test preparation stage, soil bodies with other properties such as clay filling, silt sand filling and the like can be used for testing, and the stability test of the excavation surface under different soil quality conditions can be researched.
Based on the technical scheme, the invention has the following beneficial technical effects:
1. according to the invention, the upward shield is manufactured into a plurality of upward shield rings, and the influence of different earthing thicknesses on the instability of the excavation surface of the upward shield can be researched by disassembling the number of the shield rings.
2. The method simultaneously researches the horizontal tunnel and the upward shield tunnel, and can synchronously research the influence of the upward shield tunneling on the horizontal tunnel when the stability of the upward shield excavation surface is researched.
3. The invention provides a matching device and a test method for the stability research of the upward soil pressure shield excavation surface, and is beneficial to promoting the research of the stability of the upward shield excavation surface.
4. The influence factors of the test are controllable; compared with a field test, the method can simulate different burial depth ratios by adjusting the height of the filled soil body, simulate active instability and passive instability by backward movement and forward movement of the excavation surface of an upward shield method, and simulate the influence of factors such as different soil body properties and the like on the stability of the upward shield excavation surface by adjusting different water head differences of water level heights and by using different soil material; the invention can control various test conditions according to different research variables to achieve the aim of research.
Drawings
Fig. 1 is an overall structure front view of the upward soil pressure shield excavation surface stability test device of the present invention.
Fig. 2 is a top view of a horizontal tunnel model.
Fig. 3 is a side view of a horizontal tunnel model.
Fig. 4 is a layout diagram of the LVDT displacement meter on the surface of the soil layer.
Fig. 5 is a layout view of strain gauges inside the horizontal tunnel model.
FIG. 6 is a layout view of an earth pressure gauge and an osmometer on an excavated surface.
Fig. 7 is a side view of the device for testing the stability of the excavation face of the upward earth pressure shield.
Figure 8 is a schematic view of a removable perforated excavation face sheet and a removable imperforate excavation face sheet.
FIG. 9 is a schematic view of the structure of the mold box.
Fig. 10 is a schematic structural view of a model support.
In the figure: 1-a first shield ring, 2-a second shield ring, 3-a third shield ring, 4-a fourth shield ring, 5-a fifth shield ring, 6-a length-adjustable transmission rod, 7-a partition, 8-1-an inner drain pipe, 8-2-an outer drain pipe, 9-an axial force meter, 10-a hydraulic servo device, 11-a horizontal tunnel model, 12-a detachable excavation imperforate panel, 13-a detachable excavation panel with holes, 14-a model box, 15-an overflow hole, 16-a LVDT displacement meter, 17-a water injection pipe, 18-a water supply tank, 19-a water storage tank, 20-a model support, 21-a detachable upward shield model, 22-a first through hole, 23-an osmometer, 24-a soil, 25-a strain gauge, 26-a sandy soil, 27-a groove, 28-a beam, 29-a soil surface, 30-a soil surface, 31-a PVD-an LED lamp, 32-a camera, 33-a water filtration film, 34-a second through hole, 35-a transverse and longitudinal beam support, 36-angle steel and 37-an upward shield test position.
Detailed Description
In order to describe the present invention more specifically, the following detailed description of the present invention is made with reference to the accompanying drawings and the detailed description of the present invention.
As shown in fig. 1, the device for testing the stability of the excavation face of the upward earth pressure shield comprises a model main body structure, a propulsion control system, a data acquisition system and a water level control system, wherein:
the model major structure includes model box 14 that toughened glass made, horizontal tunnel model 11 and the detachable upward shield model 21 of stainless steel that organic glass made, and upward shield model 21 comprises 5 1/2 shield rings 1 ~ 5 concatenation, can study the influence of earthing thickness to excavation face unstability mode through dismantling shield ring number. The model box 14 is a rectangular box body without a cover on the top and is placed on the model support 20 for fixing, the model support 20 is structurally shown in fig. 10 and is formed by connecting a transverse beam support 35 and a longitudinal beam support 35 and angle steel 36, and the front side is an upward shield test position 37.
As shown in fig. 3, the horizontal tunnel model 11 is formed by connecting a plurality of organic glass 1/4 cylindrical profiles in sequence and is placed at the bottom of the model box 14; as shown in fig. 2, a first through hole 22 is left at the center of the horizontal tunnel model 11, and a second through hole 34 is left at the bottom of the model box 14; the upward shield model 21 penetrates through the second through hole 34 and the first through hole 22, the detachable perforated excavation panel 13 is arranged at the top of the upward shield model, the PVD water filtering film 33 is attached to the detachable perforated excavation panel 13, and therefore the situation that soil body permeates into the detachable upward shield model 21 to cause loss and influence on a test result in the test process is avoided.
As shown in fig. 7, the propulsion control system comprises a length-adjustable transmission rod 6 and a hydraulic servo 10, which can be used to automatically adjust the forward, backward and forward speed of the detachable upward shield tunneling model machine 21.
The data acquisition system comprises a camera 32, an LED lamp 31, an axial force gauge 9, a soil pressure gauge 24, an osmometer 23, an LVDT displacement gauge 16 and a strain gauge 25, wherein the camera 32 and the LED lamp 31 are used for acquiring images in the instability process of the excavation surface, the soil pressure gauge 24 and the osmometer 23 are installed on the detachable perforated excavation panel 13 and are specifically arranged as shown in figure 6, the soil pressure gauge 24 is used for acquiring the soil pressure change of the excavation surface in the instability process of the excavation surface, the axial force gauge 9 is used for acquiring the support force change of the excavation surface in the instability process of the excavation surface, the osmometer 23 is used for acquiring the pore water pressure change of the excavation surface, and the LVDT displacement gauge 16 is used for acquiring the displacement of a ground surface soil body when the excavation surface is unstable; the strain gauge 25 is attached to the inside of the lower horizontal tunnel mold 11 for measuring the strain inside the horizontal tunnel mold 11, as shown in fig. 5.
The water level control system comprises a water supply tank 18, a water storage tank 19, a water injection pipe 17, an inner drain pipe 8-1, an outer drain pipe 8-2 and an overflow hole 15 and is used for controlling the adjustment and the stability of the water level in the test process.
As shown in fig. 9, a groove 27 is opened on the top of the mold box 14, a beam 28 is placed in the groove 27, and LVDT displacement meters 16 are placed on the beam 28, and the distribution of the LVDT displacement meters on the surface of the soil layer is shown in fig. 4.
The use method of the device for testing the stability of the excavation surface of the upward earth pressure shield comprises the following steps:
a test preparation stage: preparing materials needed to be used in the test, and firstly, attaching the strain gauge 25 to the inner side of the lower horizontal tunnel model 11; placing the model box 14 on the model support 20, and making corresponding fixing measures to prevent the model box 14 from being displaced in the test process to influence the test result; then, the detachable upward shield model 21 penetrates through the bottom of the model box 14 to leave a second through hole 34 and a first through hole 22 is left at the center of the horizontal tunnel model 11, and the detachable upward shield model reaches a specified position to be fixed, and sealing work of the first through hole 22 and the second through hole 34 is well done; then, the detachable perforated excavation panel 13 is placed above the detachable upward shield model 21, waterproof glue is used for filling pores, a PVD water filtration film 33 is pasted on the detachable perforated excavation panel 13, and then the soil pressure gauge 24 and the osmometer 23 are installed on the detachable perforated excavation panel 13; after the installation is finished, sand 26 is filled in the model box 14 to the soil layer surface 29 in a layering mode by a sand rain method, and water is continuously tamped and sprayed during filling to enable the sand to reach saturation; after the sand 26 is filled, placing a beam 28 in a groove 27 of the model box 14, and mounting the LVDT displacement meter 16 on the beam 28; then erecting a camera 32 and turning on an LED lamp 31, and turning on a water injection pipe 17, an inner water drainage pipe 8-1 and an outer water drainage pipe 8-2 to keep the water level of the water injection pipe constant; and detecting whether instruments of each part are normal or not, connecting measuring equipment of each part into a computer, and then perfecting the sealing and waterproof work of the test model to prepare for starting a test.
And (3) moving an excavation surface: after the preparation stage is completed, the hydraulic servo device 10 is opened, the detachable holed excavation surface 13 retreats at a constant speed to generate active instability, and then a camera 32 is used for continuously shooting images of a soil displacement field above the excavation surface to obtain the change condition of the soil displacement field in the excavation surface moving process; and stopping moving the excavation surface after the soil body above the excavation surface is unstable.
And (3) a data processing stage: after the test is finished, processing the data, and processing the image shot by the camera 32 by using MatPIV 1.7 software to obtain the change condition of a soil body displacement field above the excavation surface in the instability process of the excavation surface; researching respective change rules in the instability process of the excavation face by drawing change images of the support force of the excavation face, the soil pressure of the excavation face and the pore water pressure in the instability process of the excavation face and a bending moment diagram of a horizontal tunnel; and drawing a displacement diagram of the surface soil body after the instability of the excavation surface to obtain the displacement condition and the influence range of the surface soil body after the instability of the excavation surface.
The device can disassemble the number of the shield rings of the upward shield model 21, and carry out stability tests on the excavation surface under different soil covering thicknesses by changing the soil covering thickness so as to research the influence of the soil covering thickness on the stability of the upward shield excavation surface; the moving direction of the detachable perforated excavation panel 13 can be adjusted to be upward advancing, and a passive instability mode of the soil body is analyzed; the overflow holes 15 with different heights can be opened to control the underground water level 30 of the test, the stability test of the excavation surface with different water head differences is researched, the soil body with other properties such as clay and silt can be used for the test, and the stability test of the excavation surface under different soil conditions is researched.
In performing the no-infiltration test procedure, as shown in fig. 8, the removable imperforate excavation face plate 12 may be used instead of the removable perforate excavation face plate 13, without installing the osmometer 23 and using dry sand without water injection, and the other steps are the same as above.
Example (b):
in the embodiment, a reduced-size model test is adopted, the length of a model box 14 is 1m, the width is 1m, the height is 1.25m, a detachable upward shield model 21 is an 1/2 circular ring, the inner diameter is 0.1m, the outer diameter is 0.11m, and the model box is divided into 5 shield rings, wherein the length of a first shield ring 1 of the upward shield and the length of a second shield ring 2 of the upward shield are 0.2m (the middle part of the first shield ring is separated by a partition plate 7), and the length of a third shield ring 3 of the upward shield, the length of a fourth shield ring 4 of the upward shield and the length of a fifth shield ring 5 of the upward shield are 0.1 m; the horizontal tunnel model 11 is an 1/4 circular ring, the outer diameter is 0.169m, and the inner diameter is 0.159 m; the detachable perforated excavation panel 13 is slightly smaller than the inner diameter of the detachable upward shield model 21, so that the detachable perforated excavation panel can be placed in the detachable upward shield model 21 to perform corresponding waterproof work; the first through hole 22 in the middle of the horizontal tunnel model 11 is slightly larger than the outer diameter of the detachable upward shield model 21, so that the detachable upward shield model 21 can smoothly penetrate out of the first through hole 22, and corresponding waterproof measures are taken well.
The method comprises the following steps: and (4) a test preparation stage.
Preparing materials needed to be used in the test, and firstly, attaching the strain gauge 25 to the inner side of the lower horizontal tunnel model 11; placing the model box 14 on the model support 20, and making corresponding fixing measures to prevent the model box 14 from being displaced in the test process to influence the test result; then, the detachable upward shield model 21 penetrates through the bottom of the model box 14 to leave a second through hole 34 and a first through hole 22 is left at the center of the horizontal tunnel model 11, the detachable upward shield model 21 is fixed at a specified position, and waterproof sealing work of the first through hole 22 and the second through hole 34 is well done; then, the detachable perforated excavation panel 13 is placed above the detachable upward shield model 21, waterproof glue is used for filling pores, a PVD (physical vapor deposition) water filtration film 33 is pasted on the detachable perforated excavation panel 13, corresponding waterproof sealing work is well conducted, and then a soil pressure gauge 24 and a current meter 23 are installed on the detachable perforated excavation panel 13; after the installation is finished, sand 26 is filled in the model box 14 to the soil layer surface 29 in a layering mode by a sand rain method (soil with other properties such as clay and silt can also be used for testing, and the stability test of the excavation surface under different soil conditions can also be researched), and water is continuously tamped and sprinkled in the filling process to enable the soil to reach saturation; after the sand 26 is filled, placing a beam 28 in a groove 27 of the model box 14, and mounting the LVDT displacement meter 16 on the beam 28; then erecting a camera 32 and turning on an LED lamp 31, and turning on a water injection pipe 17, an inner water drainage pipe 8-1 and an outer water drainage pipe 8-2 to keep the water level of the water injection pipe constant; and detecting whether instruments of each part are normal or not, connecting measuring equipment of each part into a computer, and then perfecting the sealing and waterproof work of the test model to prepare for starting a test.
In the experimental process, the number of shield rings of the upward shield model 21 can be disassembled, and the stability test of the excavation surface under different soil covering thicknesses with the soil covering thicknesses of 0.8m, 0.6m, 0.5m, 0.4m and 0.3m is realized; the overflow holes 15 with different heights can be opened to control the water level of the test, and the stability test of the excavation surface with different water head differences can be researched. When the non-permeability test process is carried out, the detachable non-porous excavation panel 12 can be used, the osmometer 23 does not need to be installed, meanwhile, dry sand is directly used, water injection is not needed, and other steps are the same as the above.
Step two: and (5) moving the excavation surface.
After the preparation stage is completed, the hydraulic servo device 10 is opened, the detachable perforated excavation surface 13 retreats at a constant speed, active instability of soil in front of the excavation surface occurs (the moving direction of the detachable perforated excavation surface 13 can also be adjusted to move upwards, and a passive instability mode of the soil is analyzed), and then a camera 32 is used for continuously shooting images of a soil displacement field above the excavation surface, so that the change condition of the soil displacement field in the excavation surface moving process is obtained; and stopping moving the excavation surface after the soil body above the excavation surface is unstable.
Step three: and (5) a data processing stage.
After the test is finished, processing the data, and processing the image shot by the camera 32 by using MatPIV 1.7 software to obtain the change condition of a soil body displacement field above the excavation surface in the instability process of the excavation surface; researching respective change rules in the instability process of the excavation face by drawing change images of the support force of the excavation face, the soil pressure of the excavation face and the pore water pressure in the instability process of the excavation face and a bending moment diagram of a horizontal tunnel; and drawing a displacement diagram of the surface soil body after the instability of the excavation surface to obtain the displacement condition and the influence range of the surface soil body after the instability of the excavation surface.
The foregoing description of the embodiments is provided to enable one of ordinary skill in the art to make and use the invention, and it is to be understood that other modifications of the embodiments, and the generic principles defined herein may be applied to other embodiments without the use of inventive faculty, as will be readily apparent to those skilled in the art. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications to the present invention based on the disclosure of the present invention within the protection scope of the present invention.
Claims (10)
1. The utility model provides an earth pressure shield constructs excavation face stability test device up which characterized in that, includes model major structure, propulsion control system, data acquisition system, water level control system, wherein:
the model main body structure comprises a model box, a horizontal tunnel model and an upward shield model, wherein the horizontal tunnel model is formed by sequentially splicing a plurality of 1/4 cylindrical outlines and is placed at the bottom of the model box, and a first through hole and a second through hole are respectively formed in the center of the horizontal tunnel model and the center of the bottom of the model box; the upward shield model is formed by sequentially splicing a plurality of semicircular shield rings in the vertical direction and penetrates through the first through hole and the second through hole, and an excavation panel is arranged at the top of the upward shield model;
the propulsion control system comprises a transmission rod and a hydraulic servo device, the transmission rod is connected with the excavation panel, and the hydraulic servo device drives the upward shield model to advance and retreat and adjust the advancing speed of the upward shield model by controlling the transmission rod;
the data acquisition system comprises a camera, an LED lamp, an axial force meter, a soil pressure meter, an osmometer, an LVDT displacement meter and a strain gauge; the camera and the LED lamp are used for image acquisition in the instability process of the excavation surface; the soil pressure gauge and the osmometer are arranged on the excavation panel and used for collecting soil pressure and pore water pressure of the excavation surface in the instability process of the excavation surface; the axial force meter is arranged on the transmission rod in the uppermost shield ring and used for collecting the supporting force of the excavation surface in the instability process of the excavation surface; the LVDT displacement meter is placed on the earth surface and used for collecting the deformation of earth surface soil when the excavation surface is unstable; the strain gauge is attached to the inner side of the horizontal tunnel model;
the water level control system comprises a water supply tank, a water storage tank, a water injection pipe, an inner water discharge pipe and an outer water discharge pipe, wherein the water injection pipe is connected with the water supply tank and used for injecting water to soil in the model box; one end of the outer drainage pipe is connected with the water storage tank, and the other end of the outer drainage pipe is in butt joint with an overflow hole formed in the side wall of the model box.
2. The upward earth pressure shield excavation surface stability test device of claim 1, characterized in that: the model box is a rectangular box body without a cover on the top, is made of toughened glass and is arranged and fixed on the model bracket.
3. The upward earth pressure shield excavation surface stability test device of claim 1, characterized in that: the excavation panel is a detachable porous structure, and a PVD water filtering film is pasted on the panel.
4. The upward earth pressure shield excavation surface stability test device of claim 1, characterized in that: the periphery of the top of the model box is provided with a groove, a beam is erected in the groove, and the LVDT displacement meter is placed on the beam.
5. The upward earth pressure shield excavation surface stability test device of claim 1, characterized in that: the 1/4 cylinder profile that horizontal tunnel model adopted is made for organic glass, shield the model upwards for detachable construction, the shield that its adopted encircles and makes for the stainless steel.
6. A use method of the upward soil pressure shield excavation surface stability test device according to any one of claims 1 to 5, comprising:
a test preparation stage: preparing materials needed to be used in the test, firstly pasting a strain gauge on the inner side of the bottom of a horizontal tunnel model, placing a model box on a model bracket, and making corresponding fixing measures; then, the upward shield model penetrates through a second through hole at the bottom of the model box and a first through hole of the horizontal tunnel model, the upward shield model is fixed after the upward shield model reaches a specified position, and sealing work at the first through hole and the second through hole is well done; placing an excavation panel on the top of an upward shield model, filling pores on the excavation panel with waterproof glue, attaching a PVD (physical vapor deposition) water filtration film on the excavation panel, and then installing a soil pressure meter and a osmometer on the excavation panel; after the installation is finished, sand and soil are filled to the surface of a soil layer in a layered mode in the mold box by a sand-rain method, and water is continuously tamped and sprinkled in the filling process to enable the soil layer to be saturated; after the sand filling is finished, erecting a cross beam in a groove on the periphery of the top of the model box, and mounting an LVDT displacement meter on the cross beam; then erecting a camera, turning on an LED lamp, and turning on a water injection pipe, an inner water discharge pipe and an outer water discharge pipe to keep the water level in the model box constant; detecting whether each part of measuring equipment of the data acquisition system is normal or not, connecting the measuring equipment to a computer, and then perfecting the sealing and waterproof work of the whole test device to prepare for starting a test;
and (3) excavating surface moving stage: opening a hydraulic servo device to drive an excavation panel to retreat at a constant speed through a transmission rod, enabling the soil body above the excavation surface to generate active instability, and then continuously shooting images of a displacement field of the soil body above the excavation surface by using a camera; stopping moving the excavation panel after the soil body above the excavation surface is unstable;
and (3) a data processing stage: processing the image acquired by the camera to obtain the change condition of a soil body displacement field above the excavation surface in the instability process of the excavation surface, and analyzing the respective change rules in the instability process of the excavation surface by drawing the change images of the support force of the excavation surface, the soil pressure of the excavation surface, the pore water pressure and the bending moment of the horizontal tunnel model in the instability process of the excavation surface; and drawing a displacement diagram of the surface soil body after the instability of the excavation surface to obtain the displacement condition and the influence range of the surface soil body after the instability of the excavation surface.
7. Use according to claim 6, characterized in that: in the test preparation stage, the shield ring number of the upward shield model can be disassembled to achieve the purpose of changing the earthing thickness and carry out the stability test of the excavation surface under different earthing thicknesses, and the influence of the earthing thickness on the stability of the upward shield excavation surface is researched.
8. Use according to claim 6, characterized in that: in the excavation face moving stage, the device can be adjusted to drive the excavation panel to move upwards, and the passive instability mode of the soil body is researched.
9. Use according to claim 6, characterized in that: when the non-permeability test process is carried out, a detachable non-porous excavation panel can be adopted, an osmometer does not need to be installed, and dry sand does not need to be added with water.
10. Use according to claim 6, characterized in that: in the test preparation stage, overflow holes with different heights can be opened to control the test water level, the stability test of the excavation surface with different water head differences can be researched, and the stability test of the excavation surface under different soil quality conditions can also be researched by adopting soil bodies with other properties such as clay filling, silt and the like.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210599948.8A CN114878298A (en) | 2022-05-26 | 2022-05-26 | Upward soil pressure shield excavation surface stability test device and use method thereof |
| PCT/CN2022/119298 WO2023226249A1 (en) | 2022-05-26 | 2022-09-16 | Upward earth pressure shield excavation face stability test apparatus and use method thereof |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202210599948.8A CN114878298A (en) | 2022-05-26 | 2022-05-26 | Upward soil pressure shield excavation surface stability test device and use method thereof |
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| CN114878298A true CN114878298A (en) | 2022-08-09 |
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| CN202210599948.8A Pending CN114878298A (en) | 2022-05-26 | 2022-05-26 | Upward soil pressure shield excavation surface stability test device and use method thereof |
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| CN (1) | CN114878298A (en) |
| WO (1) | WO2023226249A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023226249A1 (en) * | 2022-05-26 | 2023-11-30 | 浙大城市学院 | Upward earth pressure shield excavation face stability test apparatus and use method thereof |
| CN118408884A (en) * | 2024-07-03 | 2024-07-30 | 中铁十五局集团有限公司 | Stability test method for shield tunnel excavation face |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115615910B (en) * | 2022-09-30 | 2024-10-15 | 福建农林大学 | Karst area vegetation soil slope unstability destructive device under simulation multifactor |
| CN117538509B (en) * | 2024-01-10 | 2024-03-12 | 北京交通大学 | Tunnel excavation test device for simulating groundwater seepage in water-rich stratum |
| CN118425019A (en) * | 2024-07-03 | 2024-08-02 | 中铁十五局集团有限公司 | Test method considering influence of seepage on stability of tunnel excavation surface |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103278376B (en) * | 2013-05-29 | 2015-01-14 | 浙江大学 | Test device of stability control model of earth pressure balance shield excavation surface |
| CN110554165A (en) * | 2019-07-31 | 2019-12-10 | 浙江杭海城际铁路有限公司 | Device and method for testing influence of shield underpass construction on existing subway tunnel |
| CN110954676B (en) * | 2019-12-03 | 2021-06-29 | 同济大学 | Visual test device for simulating shield tunneling existing tunnel construction |
| AU2021104053A4 (en) * | 2021-07-12 | 2021-09-09 | Tongji University | Visual simulator for the progressive destruction of a shield tunnel excavation face under seepage conditions |
| CN113418691A (en) * | 2021-07-16 | 2021-09-21 | 浙大城市学院 | Vertical pipe jacking indoor model test device capable of discharging soil and test method |
| CN114878298A (en) * | 2022-05-26 | 2022-08-09 | 浙大城市学院 | Upward soil pressure shield excavation surface stability test device and use method thereof |
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2022
- 2022-05-26 CN CN202210599948.8A patent/CN114878298A/en active Pending
- 2022-09-16 WO PCT/CN2022/119298 patent/WO2023226249A1/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023226249A1 (en) * | 2022-05-26 | 2023-11-30 | 浙大城市学院 | Upward earth pressure shield excavation face stability test apparatus and use method thereof |
| CN118408884A (en) * | 2024-07-03 | 2024-07-30 | 中铁十五局集团有限公司 | Stability test method for shield tunnel excavation face |
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| WO2023226249A1 (en) | 2023-11-30 |
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