Test device suitable for simulation loading of underpass water conveyance tunnel

Abstract

The utility model discloses a test device suitable for simulation loading of an underpass water tunnel, which is characterized in that holes are respectively formed in a left side plate and a right side plate of a model box, the hole positions are mounting positions of a tunnel model, the size of the holes is the same as that of the tunnel model, the hole at one end is a water inlet end, and the hole at the other end is a water outlet end; at least three monitoring sections are arranged on the center section of the tunnel model, sensors are installed at the positions of the monitoring sections, and the sensors comprise a strain gauge sensor, a soil pressure sensor and a pore water pressure and soil moisture content sensor; the system further comprises a water delivery device which is used for injecting flowing water into the simulation tunnel, and influence factors of railway loads on the water delivery tunnel are researched through a simulation test.

Description

Technical Field

[0001] This utility model belongs to the field of tunnel model testing technology, specifically relating to a test device suitable for simulating loading in underpass water conveyance tunnels. Background Technology

[0002] With the rapid development of railway construction in my country, many tunnel projects have emerged that pass close to or beneath existing structures. For newly constructed tunnels passing under unlined water conveyance tunnels, water from the tunnel can seep into the surrounding rock and the tunnel itself during construction and subsequent operation. This alters the stress state of the tunnel structure, potentially making the underpass section a weak point. Rising water levels can then cause serious consequences, potentially creating seepage channels or cracking the tunnel lining. Furthermore, tunnels passing under water conveyance tunnels are often surrounded by water. Fluctuations in the water level within the tunnel, once causing cracks, can further impede seepage, exacerbating damage and deformation. Therefore, water level changes are a direct cause of tunnel damage and deformation, and the indirect factor of rising water levels causing cracks further intensifies this damage and deformation.

[0003] Due to various factors and objective limitations, current model test research on tunnel structures under water level change loads has not yet achieved substantial breakthroughs, and research on the mechanical response characteristics of railway tunnels passing under water conveyance tunnels is almost non-existent. Simulation tests using similar materials can be conducted by artificially altering test conditions based on actual geological data to study the mechanical response characteristics of tunnel structures under water level changes. Model tests can be carried out at spatial intersections to analyze the changes in tunnel surface strain, earth pressure, pore water pressure, and water content as the water level rises. Therefore, an easy-to-operate, reliable, and reasonably designed model test device is crucial for achieving these objectives. Utility Model Content

[0004] This invention provides a test device suitable for simulating loading on water conveyance tunnels, with the aim of studying the influence factors of railway load on water conveyance tunnels through simulation tests.

[0005] Therefore, the present invention adopts the following technical solution:

[0006] A test device suitable for simulating loading under a water conveyance tunnel has holes on the left and right side plates of the model box. The holes are located at the installation positions of the tunnel model, and the size of the holes is the same as that of the tunnel model. One end of the hole is the water inlet, and the other end is the water outlet.

[0007] At least three monitoring sections are set up on the central section of the tunnel model. Sensors are installed at the monitoring section locations, including strain gauge sensors, earth pressure sensors, pore water pressure and soil moisture content sensors.

[0008] It also includes a water conveying device, which includes a water tank with an outlet at the front end. A slide valve is connected to the outlet to control the water level. A guide cylinder of the same size as the tunnel model is connected to the front end of the slide valve. The guide cylinder adjusts the shape of the outlet end of the slide valve to the shape of the tunnel model, which facilitates the control of the water level in the tunnel model. The water tank is placed at the inlet end, and the front end of the guide cylinder is horizontally fixed to the inlet end of the model box. The water in the tank enters the tunnel model after passing through the slide valve and the guide cylinder. A water receiving bucket is provided at the outlet end of the simulated tunnel.

[0009] Furthermore, tempered glass is installed on the front and back sides of the model box, and wooden boards are installed on the left and right sides of the model box with holes made in the wooden boards; the bottom of the model box is not sealed to facilitate water seepage.

[0010] Furthermore, the tunnel model has a rectangular inverted arch and a semi-circular dome-shaped arch top.

[0011] The beneficial effects of this utility model are: it can effectively simulate the impact of water level changes on tunnel structures. Based on the geometric similarity ratio, it designs the similarity relationship and similarity ratio between corresponding quantities in the model test and the actual project, selects and proportions similar materials; it includes the model box and structural model, including the dimensions of the model box, the casting of the tunnel model, the fabrication of the water conveyance tunnel model, and the modification and installation of the water tank and manual slide valve for the water level control device. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the layout of the model box of this utility model;

[0013] Figure 2 This is a schematic diagram of the tunnel model of this utility model;

[0014] In the diagram: 1-Model box, 2-Tunnel model, 201-Central section, 202-Head section, 203-Tail section, 204-Inlet end, 205-Outlet end, 3-Water guide channel, 4-Water tank, 5-Slide valve. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0016] like Figure 1 and 2 As shown, a test device suitable for simulating loading under a water conveyance tunnel is provided. Holes are opened on the left and right side plates of the model box 1, the locations of which correspond to the installation positions of the tunnel model 2. The size of the holes is the same as that of the tunnel model 2. One end of the hole is the water inlet 204, and the other end is the water outlet 205. The tunnel model 2 is constructed according to determined parameters. The tunnel model 2 consists of three sections: a central section 201, a head section 202, and a tail section 203.

[0017] At least three monitoring sections are set up on the central section 201 of tunnel model 2. Sensors are installed at the monitoring section locations, including strain gauge sensors, earth pressure sensors, pore water pressure sensors, and soil moisture sensors. Strain gauges and earth pressure sensors are respectively installed at the monitoring points on the outer side of each section, and strain gauge sensors are also installed at the monitoring points on each section on the inner side of tunnel model 2. Pore water pressure sensors and moisture sensors are respectively installed at the measuring points on the outer side of section I. In addition, pore water pressure sensors and moisture sensors are installed at the very center of the tunnel-tunnel intersection section, and a pore water pressure sensor is installed at the tunnel invert arch.

[0018] It also includes a water conveying device, which includes a water tank 7. The water tank 7 has an outlet at its front end, and a slide valve 8 is connected to the outlet. The slide valve 8 is used to control the water level. The front end of the slide valve 8 is connected to a guide tube that is the same size as the tunnel model 2. The guide tube adjusts the shape of the outlet end 205 of the slide valve 8 to the shape of the tunnel model 2, which facilitates the control of the water level in the tunnel model 2. The water tank 7 is placed at the inlet end 204. The front end of the guide tube is horizontally fixed to the inlet end 204 of the model box 1. The water in the water tank 7 enters the tunnel model 2 after passing through the slide valve 8 and the guide tube. A water receiving bucket is provided at the outlet end 205 of the simulated tunnel.

[0019] Tempered glass is installed on the front and back sides of model box 1, and wooden boards are installed on the left and right sides of model box 1, with holes made in the wooden boards; the bottom of model box 1 is not sealed to facilitate water seepage. The invert arch of tunnel model 2 is rectangular, and the arch top is semi-circular.

[0020] After the model is filled, the head section 202 and tail section 203 of the tunnel model 2 are slowly extracted from the water inlet 204 and water outlet 205 of the model box 1. At this time, an unlined arched straight wall tunnel structure is presented in the surrounding rock.

[0021] The experimental method is as follows: During the experiment, the influence of rising water level in the water conveyance tunnel on the mechanical response characteristics of the tunnel structure was simulated. The water level started from 0 cm and rose by 1 cm each time, for a total rise of 3 cm, i.e., a total of 4 working conditions were set. During this time, the data acquisition interface was constantly observed, and experimental records were kept.

[0022] Based on the data measured in the experiment, strain-time history curves were plotted, including the original strain curves and smoothed strain curves corresponding to each measuring point. Then, the strain change characteristics at each cross-section measuring point under each working condition were analyzed, mainly the strain maximum and minimum values ​​and the tensile and compressive conditions at each point. Here, positive strain is defined as tensile strain, which elongates the body, and negative strain is defined as compressive strain, which shortens the body. That is, the sign of the strain does not indicate its magnitude. Curve fitting was performed on the relationship between strain and time to illustrate the law of strain change with time.

Claims

1. A test device suitable for simulating loading under a water conveyance tunnel, characterized in that, Holes are made on the left and right side plates of the model box (1). The holes are located at the installation positions of the tunnel model (2). The size of the holes is the same as that of the tunnel model (2). One end of the hole is the water inlet (204), and the other end is the water outlet (205). At least three monitoring sections are set on the central section (201) of the tunnel model (2). Sensors are installed at the monitoring section locations, including strain gauge sensors, earth pressure sensors, pore water pressure and soil moisture sensors. It also includes a water conveying device, which includes a water tank (7), with an outlet at the front end of the water tank (7) and a slide valve (8) connected to the outlet. The slide valve (8) is used to control the water outlet height. The front end of the slide valve (8) is connected to a guide tube of the same size as the tunnel model (2). The guide tube adjusts the shape of the outlet end (205) of the slide valve (8) to the shape of the tunnel model (2), which is convenient for controlling the water level in the tunnel model (2). The water tank (7) is placed at the inlet end (204), and the front end of the guide tube is horizontally fixed to the inlet end (204) of the model box (1). The water in the water tank (7) enters the tunnel model (2) after passing through the slide valve (8) and the guide tube. A water receiving bucket is provided at the outlet end (205) of the simulated tunnel.

2. The test apparatus for simulating loading under a water conveyance tunnel according to claim 1, characterized in that, Tempered glass is installed on the front and back sides of the model box (1), and wooden boards are installed on the left and right sides of the model box (1), with holes made in the wooden boards; the bottom of the model box (1) is not sealed to facilitate water seepage.

3. The test apparatus for simulating loading under a water conveyance tunnel according to claim 1, characterized in that, The tunnel model (2) has a rectangular arch and a semi-circular dome.

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