阅读说明：本技术 基于可调节式渗漏点的盾构隧道可视化模型试验装置 (Shield tunnel visual model test device based on adjustable leakage points ) 是由 雷华阳 程泽宇 路平 李汝嘉 施福硕 刘敏 刘英男 于 2021-08-16 设计创作，主要内容包括：本发明涉及一种基于可调节式渗漏点的盾构隧道可视化模型试验装置,包括箱体、隧道模型和水压加载设备,其特征在于,箱体包括透明底箱和有机玻璃顶盖,在箱体的相对两侧开孔,在开孔处设置箱体的连接端头,用于连接位于箱体内的隧道模型；隧道模型由透明材质的管片拼接而成,拼接方式为通缝拼装和错缝拼装中的一种或两种；在不同的位置设置有漏缝,在所设置的漏缝位置处,使用卡板填塞和临时密封接缝；水压加载设备,用于向箱体内施加水压。本发明漏缝位置和数目可控,可以用来研究单线、双线乃至多线盾构隧道不同漏点漏水漏土时地层变形和隧道位移。(The invention relates to a shield tunnel visual model test device based on adjustable leakage points, which comprises a box body, a tunnel model and a hydraulic loading device, and is characterized in that the box body comprises a transparent bottom box and an organic glass top cover, holes are formed in two opposite sides of the box body, and connecting ends of the box body are arranged at the holes and used for being connected with the tunnel model in the box body; the tunnel model is formed by splicing segments made of transparent materials in one or two of through joint splicing and staggered joint splicing; the method comprises the following steps that (1) leaks are arranged at different positions, and joints are filled and temporarily sealed by using a clamping plate at the arranged leaks; and the water pressure loading device is used for applying water pressure to the box body. The method has controllable positions and numbers of leaks, and can be used for researching stratum deformation and tunnel displacement when water leaks and soil leaks from different leak points of a single-line, double-line or even multi-line shield tunnel.)

1. A shield tunnel visual model test device based on adjustable leakage points comprises a box body, a tunnel model and a hydraulic loading device, and is characterized in that,

the box body comprises a transparent bottom box and an organic glass top cover, holes are formed in two opposite sides of the box body, and connecting ends of the box body are arranged at the holes and used for being connected with a tunnel model in the box body;

the tunnel model is formed by splicing segments made of transparent materials in one or two of through joint splicing and staggered joint splicing; the method comprises the following steps that (1) leaks are arranged at different positions, and joints are filled and temporarily sealed by using a clamping plate at the arranged leaks;

and the water pressure loading device is used for applying water pressure to the box body.

2. The shield tunnel visualization model test device based on the adjustable leakage points as claimed in claim 1, wherein leaks with different widths are arranged at different positions, and the clamping plate has different thicknesses and is selectable to simulate leaks with different widths.

3. The mobile shield tunnel model test device of claim 1, wherein the clamping plate is provided with a circular threading hole for drawing a pull wire and opening a leak during a test.

4. The shield tunnel visual model test device based on the adjustable leakage points as claimed in claim 1, wherein the box connecting end of each opening comprises a flange and a steel pipe connected with the flange, and the box connecting end is connected with one end of the tunnel model through a ribbed pipe and a pipe hoop.

5. The shield tunnel visualization model test device based on the adjustable leakage point as claimed in claim 1, further comprising a mechanical measurement system, wherein the mechanical measurement system comprises strain gauges arranged on the inner wall of the tunnel model, and the strain gauges are arranged near the leakage position in an encrypted manner.

6. The shield tunnel visualization model test device based on the adjustable leakage point as claimed in claim 6, wherein the mechanical measurement system further comprises an embedded displacement meter, a soil pressure cell and a pore water pressure meter.

7. The shield tunnel visualization model test device based on the adjustable leakage points as claimed in claim 7, wherein the embedded displacement meters are arranged in a square shape in a horizontal plane at intervals of 100mm x 100mm, and are arranged every 100mm in the vertical direction; the soil pressure cell and the pore water pressure gauge are arranged as close as possible, are arranged in a square shape in a horizontal plane at the interval of 100mm multiplied by 100mm, and are arranged at intervals of 100mm in the vertical direction; the plane on which the embedded displacement meter is located is vertically separated from the plane on which the soil pressure cell and the pore water pressure meter are located by 50 mm.

8. The shield tunnel visualization model test device based on the adjustable leakage points as claimed in claim 1, further comprising an optical measurement system, wherein the optical measurement system comprises a camera and a computer, the axial direction of the camera is perpendicular to the side surface or the top surface of the box body, when the tunnel model leaks, the computer is used for controlling the industrial camera to take pictures of the side surface and the top surface of the box body at regular intervals, the picture files are transmitted to the computer, and Particle Image Velocimetry (PIV) software is used for processing to obtain the displacement vector diagram of the corresponding plane.

Technical Field

The invention relates to a test device for simulating water leakage and soil leakage of a shield tunnel, in particular to a test device capable of considering the position of tunnel leaks, the number of leaks and the change characteristics of tunnel displacement.

Background

A large number of shield tunnels below the ground water level are constructed or built in China, such as a mansion subway No. 2 line sea-crossing tunnel, a south river-crossing tunnel in a turnip lake city, a pearl river mouth tunnel in a deep Mao railway and the like. In the long-term operation process, water leakage and soil leakage are difficult to avoid at the shield tunnel joint in the water-containing stratum, the traffic safety is affected by light persons, and the safety of the tunnel structure is threatened by heavy persons.

At present, relevant research at home and abroad focuses on the engineering phenomenon analysis of water leakage on the one hand, but the actual tunnel structure design is biased to be unsafe according to the calculation of a classical seepage theory; on the other hand, the research on water leakage and soil leakage of the shield tunnel is mostly embodied on the aspects of theoretical analysis and numerical simulation. In the existing few model test researches, Zhenggang, etc. in the text of test research and numerical simulation of development process of underground engineering water and sand leakage disaster (report of rock mechanics and engineering 2014,33(12):2458 and 2471), a leakage test device capable of changing the width of a horizontal gap is designed, and consists of a water head control and water inlet device at the upper part, a soil body deformation observation panel at the middle part and a sand leakage and water leakage measuring device at the lower part so as to research the skeleton particle diameter D₉₀Water and soil loss and evolution rules when 5 kinds of underwater sand in the range of 0.4-4.1mm leak to gaps with different widths; on the basis, Zhenggang et al developed a shield tunnel leakage test system with combined action of elastic sealing gasket, soil and water, which consists of a test box, an air pump and a pressurization system 3 in the geotechnical engineering research (2018, 40(06):969-The law of water and soil loss around the tunnel under different opening amounts of the horizontal joint of the segments of the middle shield tunnel; a model test device for shield tunnel leakage under constant water pressure is designed in the text of model test research on leakage rules of underwater shield tunnel joints (report of rock mechanics and engineering, 2019,38(05): 993) of Luping et al, and comprises a visual box body, a tunnel model, an iron sheet cluster, a pressurizing device, a water sand collecting device and the like, and the model test device is used for carrying out test research on the leakage and sand leakage rules when the tunnel assembly mode, the leakage width and the leakage position are different, and revealing the influence of leakage on stress and deformation of soil around the leakage.

Although the existing model test device can be used for researching the law of water and soil leakage of the tunnel, the existing model test device still has the following defects:

(1) the existing model test only develops research aiming at water and soil loss mechanisms of different leakage points of a single-line tunnel, and under increasingly complex tunnel construction environments, the water and soil leakage rules and mechanisms of a close-distance double-line tunnel and even a multi-line tunnel in different overlapping modes also need to be researched urgently;

(2) the tunnel model and the model box of the existing model test are rigidly connected, the end part of the tunnel cannot move, the displacement of the tunnel generated along with the movement of the soil body cannot be well observed, and once water leakage occurs, the displacement of the tunnel is very worthy of attention;

(3) the existing model test adopts colored sand for measuring the formation displacement, and the obtained displacement information is limited.

Disclosure of Invention

The invention aims to provide a visual model test device which is controllable in leaking position and number and can be used for researching stratum deformation and tunnel displacement when water and soil leak occurs at different leaking points of a single-line, double-line or even multi-line shield tunnel. In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a shield tunnel visual model test device based on adjustable leakage points comprises a box body, a tunnel model and a hydraulic loading device, and is characterized in that,

the box body comprises a transparent bottom box and an organic glass top cover, holes are formed in two opposite sides of the box body, and connecting ends of the box body are arranged at the holes and used for being connected with a tunnel model in the box body;

the tunnel model is formed by splicing segments made of transparent materials in one or two of through joint splicing and staggered joint splicing; the method comprises the following steps that (1) leaks are arranged at different positions, and joints are filled and temporarily sealed by using a clamping plate at the arranged leaks;

and the water pressure loading device is used for applying water pressure to the box body.

Furthermore, the leaks with different widths are arranged at different positions, and the clamping plate has different thicknesses and can be selected to simulate the leaks with different widths. The clamping plate is provided with a circular threading hole for drawing the pull wire and opening the leak during the test.

Furthermore, the box body connecting end at each opening comprises a flange plate and a steel pipe connected with the flange plate, and the box body connecting end is connected with one end of the tunnel model through a ribbed pipe and a pipe hoop.

Further, the tunnel model further comprises a mechanical measurement system, wherein the mechanical measurement system comprises strain gauges arranged on the inner wall of the tunnel model, and the strain gauges are arranged near the position of the leak in an encrypted mode.

Further, the mechanical measurement system also comprises an embedded displacement meter, a soil pressure cell and a pore water pressure meter.

Further, the embedded displacement meters are arranged in a square shape in a horizontal plane at intervals of 100mm × 100mm, and are arranged every 100mm in the vertical direction; the soil pressure cell and the pore water pressure gauge are arranged as close as possible, are arranged in a square shape in a horizontal plane at the interval of 100mm multiplied by 100mm, and are arranged at intervals of 100mm in the vertical direction; the plane on which the embedded displacement meter is located is vertically separated from the plane on which the soil pressure cell and the pore water pressure meter are located by 50 mm.

And further, the device also comprises an optical measurement system, wherein the optical measurement system comprises a camera and a computer, the axial direction of the camera is vertical to the side surface or the top surface of the box body, the computer is used for controlling the industrial camera to take pictures of the side surface and the top surface of the box body at regular intervals from the beginning of leakage of the tunnel model, the picture file is transmitted to the computer and processed by Particle Image Velocimetry (PIV) software to obtain a displacement vector diagram of a corresponding plane.

Has the advantages that: firstly, the test device of the invention arranges leaks at any plurality of positions on the surface of the tunnel model, highly simulates the actual engineering tunnel, can effectively research the evolution process and corresponding mechanism of water and soil leakage at different leak positions, different leak numbers and different leak widths of the single-line or multi-line model shield tunnel under different water pressures, and provides construction data and safety guarantee for the tunnel engineering; the testing device connects the tunnel model and the box body with certain flexibility, and can realize displacement of the tunnel model along with movement of the soil body; the displacement information of the soil body obtained by colored sand adopted in the traditional test is relatively limited, the optical measurement system of the test device can obtain the displacement of each point of the soil body in the picture through continuous photographing and PIV technology, and the finally obtained displacement field information is more detailed; the tunnel model of the test device is made of transparent materials, so that the moving process of the soil body around the leak and the forming process of the soil arch can be better observed.

Drawings

FIG. 1 is a perspective view of a test apparatus according to example 1;

FIG. 2 is a side view of the case of embodiment 1;

FIG. 3 is a front view of the test apparatus of example 1;

FIG. 4 is a cross-sectional view A-A of FIG. 3;

FIG. 5 is a part view of a chuck plate of the test device in example 1;

FIG. 6 is an assembly view of the tunnel mold and the chuck plate of the test apparatus of example 1;

FIG. 7 is a detailed view of a portion of the connection of the box connection end and the tunnel mold of the test apparatus of example 1.

Reference numerals:

a box body: 1. a bottom box; 101. an overflow hole with a controllable switch; 102. a water injection hole; 103. a wire guide hole; 2. an organic glass top cover; 201. a top cover buckle; 3. a flange plate; 4. a steel pipe;

box and tunnel model connecting piece: 5. a ribbed tube; 6. a pipe hoop;

and (3) tunnel model: 7. a tunnel model; 8. clamping a plate;

a stratum model: 9. a soil body; 10. a colored sand layer;

the hydraulic loading equipment comprises: 11. a booster water pump;

the mechanical measurement system comprises: 12. an embedded displacement meter; 13. a soil pressure cell; 14. a pore water pressure gauge; 15. a strain gauge;

an optical measurement system: 16. an industrial camera; 17. and (4) a computer.

Detailed Description

The technical scheme of the invention is as follows: the movable shield tunnel visual model test device based on the adjustable leakage points comprises a box body, a tunnel model, a box body and tunnel model connecting piece, water pressure loading equipment, a mechanical measurement system and an optical measurement system.

The box body consists of a bottom box and an organic glass top cover, wherein the bottom box is made of high-strength organic glass (if the bottom box is required to bear higher water pressure, an outer frame is made of a steel plate, and the organic glass is embedded into the outer frame); according to the planned research on the number of the tunnels, holes are formed in the two opposite sides of the bottom box, flange plates are arranged at the holes, and a small section of steel pipe (the outer diameter of the steel pipe is consistent with the outer diameter of a tunnel model as much as possible) is welded to serve as a connecting end of the box body; an overflow hole with a controllable switch is arranged on the side surface of the box body, so that a test with lower water pressure is conveniently carried out; the side surface of the box body is simultaneously provided with a water injection hole and a wire guide hole;

the tunnel model is formed by splicing segments cut from transparent acrylic tubes (or transparent PVC tubes and PC tubes) (the segments made of transparent materials are used for better observing the leakage process of soil bodies at the leak seams of the tunnel and the formation process of soil arches), the geometric dimension of the tunnel model can be obtained according to the geometric similarity ratio by the segment dimension of the actual tunnel engineering, and the splicing mode comprises through seam splicing and staggered seam splicing; splicing the duct pieces by adopting glue corresponding to the material of the duct pieces, and sticking; at the position of a leak seam of the duct piece, a seam is filled by using a clamping plate (which can be made of a plastic thin plate), and is temporarily sealed by waterproof glue, the clamping plate has different thicknesses and can be selected to simulate leak seams with different widths, and a circular threading hole is formed in the clamping plate, so that a stay wire can be conveniently extracted during a test, and the leak seam can be opened; the length of the finally pasted and assembled tunnel model is smaller than the distance between the two connecting ends;

the box body and tunnel model connecting piece is a ribbed pipe and a pipe hoop, and the ribbed pipe has certain flexibility and can ensure that the tunnel model can generate displacement along with the movement of a soil body; during connection, one end of the reinforced pipe is sleeved on the connecting end of the box body, the other end of the reinforced pipe is sleeved on the tunnel model, then the pipe hoop is sleeved, and finally waterproof materials (silica gel and the like) are coated;

the hydraulic loading equipment comprises: when the water level depth simulated by the test exceeds the height of a water head which can be provided by the box body, closing an overflow hole on the side surface of the box body, covering a top cover, and connecting a water pressure loading device (a booster water pump and the like) to a water injection hole on the side surface of the box body to provide hydraulic residual pressure required by the test;

the mechanical measurement system consists of an embedded displacement meter, a soil pressure cell, a pore water pressure meter and a strain gauge; the embedded displacement meters are arranged in a square shape in a horizontal plane at intervals of 100mm multiplied by 100mm, and are arranged every 100mm in the vertical direction; the soil pressure cell and the pore water pressure gauge are arranged as close as possible, are arranged in a square shape in a horizontal plane at the interval of 100mm multiplied by 100mm, and are arranged at intervals of 100mm in the vertical direction; the distance between the plane where the embedded displacement meter is located and the plane where the soil pressure cell and the pore water pressure meter are located in the vertical direction is 50 mm; the strain gauge is adhered to the inner wall of the tunnel model, and is adhered in an encrypted manner near the position of the leak;

the optical measurement system consists of an industrial camera and a computer; installing an industrial camera on a support frame, adjusting the position of the support frame to enable the axial direction of the industrial camera to be perpendicular to the side face or the top face of a box body, starting from the leakage of a tunnel model, using a computer to control the industrial camera to shoot photos of the side face and the top face of the box body at regular intervals, transmitting the photo files to the computer, processing by PIV (particle image velocimetry) software to obtain a displacement vector diagram of the plane, and combining the displacement measured by a displacement sensor to obtain the spatial displacement of the plane.

The present invention will be further described with reference to the following examples.

Example 1

As shown in fig. 1, fig. 3 and fig. 4, the movable shield tunnel model test device with controllable leak position and number and tunnel of the embodiment includes a bottom box 1, an overflow hole 101 with controllable switch, a water injection hole 102, a wire guide hole 103, an organic glass top cover 2, a top cover buckle 201, a flange plate 3, a steel pipe 4, a reinforced pipe 5, a pipe hoop 6, a tunnel model 7, a clamping plate 8, sandy soil 9, a colored sand layer 10, a booster water pump 11, an embedded displacement meter 12, a soil pressure box 13, a pore water pressure meter 14, a strain gauge 15, an industrial camera 16 and a computer 17;

the bottom box 1 is made of high-strength organic glass, a protective frame made of a steel plate is tightly attached to the outer surface of the organic glass, and the right side surface of the bottom box is provided with an overflow hole 101, a water injection hole 102 and a wire guide hole 103, wherein the switch of the overflow hole 101, the water injection hole 102 and the wire guide hole 103 are controllable; the front and the back of the bottom box 1 are respectively provided with two holes, the flange plate 3 passes through the hole of the organic glass, and then a section of short steel pipe 4 passes through the flange plate 3 to be welded to form four connecting ends;

the tunnel model 7 is made of transparent acrylic segments, and the concrete method comprises the following steps: customizing a transparent acrylic duct piece, wherein the size of the transparent acrylic duct piece is obtained by the size of the actual tunnel duct piece according to the designed reduction proportion, and the duct piece is bonded and spliced into a tunnel model 7 with a through joint or a staggered joint by using strong glue (the transparent acrylic duct piece is adopted to aim at observing the movement of a soil body near a leak point position and the formation of a soil arch); temporarily sealing leak points at different positions by using a clamping plate 8 and waterproof glue, wherein the clamping plate 8 has different thicknesses and can be selected to control the widths of gaps with different sizes; the clamping plate is provided with a threading hole, so that the clamping plate can be conveniently taken down; the concrete structure of the clamping plate 8 is shown in fig. 5, and the effect of the assembled tunnel model is shown in fig. 6;

the connection of the tunnel model 7 and the box body 1 adopts a reinforced pipe 5 and a pipe hoop 6, one end of the reinforced pipe 5 is sleeved on the connecting end of the bottom box, the other end of the reinforced pipe is sleeved on the tunnel model 7, the connecting part is hooped by the pipe hoop 6, and waterproof materials (such as silica gel) are coated, and the specific connection method is shown in figure 7;

the industrial camera 16 is pre-installed above the top surface and in front of the front surface of the test box, the position and height of the camera are adjusted to enable the plane where the lens is located to be parallel to the outer surface of the model box, the view field of the camera is adjusted to enable the camera to cover the whole soil body, and images are collected and transmitted to the computer 17 through a data line.

The working steps of the test device of the embodiment are as follows:

(1) the sand to be used in the test was tested for its maximum dry density ρ_dmaxAnd minimum dry density ρ_dmin；

(2) Installing the assembled tunnel model 7 in the bottom box 1, temporarily sealing the preset leak by using a clamping plate 8 with the width equal to that of the leak, threading the clamping plate 8, and guiding a pull wire out of the bottom box 1 for later use; repeating twice, and finishing the installation of the double-line tunnel model;

(3) pasting the strain gauge 15 on the inner wall of the tunnel model 7;

(4) preparing a stratum by using a rain falling method, and always keeping the vertical distance between the sand falling position and the surface of the sandy soil 9 in the box body equal; paving a layer of colored sand 10 every 50mm in vertical height; while the formation is being made, the embedded displacement meter 12, the soil pressure cell 13, and the pore water pressure meter 14 are installed, the mass of the used sand and the volume of the sand in the box are recorded, and the dry density ρ of the sand at that time is obtained_dFurther determining the relative compactness of the sandy soil

(5) Closing the overflow hole and filling the bottom box 1 with water;

(6) covering the top cover 2, and tightly connecting the top cover 2 with the bottom box 1 by using a top cover buckle 201;

(7) connecting a water pipe of the booster water pump 11 to a preformed hole 201 of the top cover, increasing water pressure in the box body 1 to a set value, and then pulling out the clamping plate 8 by using a pull wire;

(8) setting the shooting interval of the industrial camera 16 to be 5s by using the computer 17, and continuously shooting to obtain a soil deformation photo sequence in the leakage process;

(9) importing the photo sequence into PIV software, and calculating a displacement field of a soil body;

(10) after the test is finished, the test device is cleaned. Changing the positions of the missing points and the number of the missing points, and repeating the steps (2) to (9);

(11) the data is analyzed.

The above is only a preferred embodiment of the present invention, but the present invention is not limited to the above-mentioned specific embodiments, and those skilled in the art can make several variations and modifications without departing from the inventive concept of the present invention, which fall into the protection scope of the present invention.