Test device for accelerated corrosion degradation of load-bearing shield tunnel segments under high water pressure

Abstract

The present invention relates to a device for testing accelerated corrosion and degradation of a bearing shield tunnel segment under high water pressure, comprising a high water pressure accelerated corrosion and degradation device and a horizontal mechanical loading device for applying horizontal force to the test segment, the two sides of the test segment are respectively supported on the horizontal mechanical loading device, the two sides of the test segment are respectively in contact with the horizontal mechanical loading device, the high water pressure accelerated corrosion and degradation device comprises a pressurized corrosion water tank and a pressurizing device, the pressurized corrosion water tank is arranged at the upper end of the test segment, the pressurizing device is connected to the pressurized corrosion water tank, and is used to apply pressure to the pressurized corrosion water tank, and the pressure value is read through a pressure detection device. The present invention can test the mechanical properties of a shield tunnel lining structure under the combined effects of a water and soil load environment and a surrounding erosion and degradation environment for a long time, and test the stress and strain, deformation, steel bar corrosion state, crack occurrence and development of the segment specimen through a segment force performance test system.

Description

Technical Field

[0001] The invention relates to a device for accelerating corrosion of a prototype segment structure of a shield tunnel, in particular to a device for testing accelerated corrosion degradation of a load-bearing shield tunnel segment under high water pressure. Background Art

[0002] Currently, accelerated corrosion testing of tunnel lining structures is primarily conducted using corrosive solutions in an unpressurized state. This involves placing a corrosive solution in the component test area (or immersing the component in water) to accelerate corrosion. The corroded specimens or components are then loaded to test their mechanical and engineering properties, including strength, stiffness, and damage. This testing method is inconsistent with the actual environment in which tunnel segment linings operate and cannot truly reflect the corrosion environment of tunnel linings. Summary of the Invention

[0003] The purpose of the present invention is to overcome the defects of the existing technology. Taking into account the characteristics of the shield tunnel lining structure that it is in the combined action of water and soil load environment and the surrounding erosion degradation environment for a long time during its actual service life, a test device for accelerated corrosion degradation of load-bearing shield tunnel segments under high water pressure is provided. The device truly simulates the actual stress state of the shield tunnel segment structure during service, and at the same time constructs a pressurized corrosion degradation system on the outer surface of the segment, which can be used to simulate the occurrence and development process of corrosion, cracking, instability and even catastrophic collapse of the tunnel lining structure, so as to study the evolution law of the decline of the mechanical properties of the shield tunnel segment structure under different load environment conditions, different water pressure effects and different degradation stages.

[0004] The technical solution of the present invention is implemented as follows: The present invention discloses a test device for accelerated corrosion and degradation of load-bearing shield tunnel segments under high water pressure, including a high water pressure accelerated corrosion and degradation device and a horizontal mechanical loading device for applying horizontal force to the test segment. The two sides of the test segment are respectively supported on the horizontal mechanical loading device, and the two sides of the test segment are respectively in contact with the horizontal mechanical loading device. The high water pressure accelerated corrosion and degradation device includes a pressurized corrosion water tank and a pressurizing device. The pressurized corrosion water tank is arranged at the upper end of the test segment. The pressurizing device is connected to the pressurized corrosion water tank and is used to apply pressure to the pressurized corrosion water tank and read the pressure value through a pressure detection device.

[0005] The accelerated corrosion degradation test device for load-bearing shield tunnel segments under high water pressure of the present invention also includes a vertical mechanical loading device for applying vertical force to the test segment. The vertical mechanical loading device is located above the test segment and contacts the upper end of the test segment.

[0006] Furthermore, the horizontal mechanical loading device includes a left loading beam, a right loading beam, a left pipe segment support seat, a right pipe segment support seat, a first power drive device and a transverse pull rod. The left pipe segment support seat and the right pipe segment support seat are respectively located on the left and right sides of the test pipe segment, and are used to contact and support the two sides of the test pipe segment respectively. The left pipe segment support seat is connected to the left loading beam, and the right pipe segment support seat is connected to the first power drive device. The first power drive device is connected to the right loading beam and is used to apply horizontal force to the test pipe segment. The left end of the transverse pull rod is connected to the left loading beam, and the right end of the transverse pull rod is connected to the right loading beam; the vertical mechanical loading device includes an upper loading beam, a base, a loading head, and a vertical pull rod. The loading head is located above the test pipe segment and contacts the top of the test pipe segment. The loading head is connected to the second power drive device, and the second power drive device is connected to the upper loading beam and is used to apply vertical force to the test pipe segment. The upper end of the vertical pull rod is connected to the upper loading beam, and the lower end of the vertical pull rod is connected to the base.

[0007] Furthermore, the left loading beam and the right loading beam are fixed on the base.

[0008] Furthermore, the left segment support seat and the right segment support seat both include a seat body and a support plate for supporting the test segment. The support plate is obliquely arranged on the seat body. The support plate on the left segment support seat is arranged opposite to the support plate on the right segment support seat. The distance between the upper ends of the two support plates is greater than the distance between the lower ends of the two support plates.

[0009] Furthermore, a horizontal pressure sensor is provided between the right segment support seat and the first power drive device; a vertical pressure sensor is provided between the loading head and the second power drive device. The horizontal pressure sensor and the vertical pressure sensor are respectively connected to the input end of the console, and the output end of the console is connected to the power drive system. The power drive system is used to control the first power drive device and the second power drive device to achieve the adjustment of the pressure applied to the test segment.

[0010] The first power driving device and the second power driving device are hydraulic jacks.

[0011] Furthermore, a cathode stainless steel mesh is placed in the pressurized corrosion water tank, and the cathode stainless steel mesh is electrically connected to the cathode of the steady-current DC power supply through a conductive wire, and the steel bars of the test pipe segment are electrically connected to the anode of the steady-current DC power supply through a conductive wire.

[0012] Furthermore, the pressurized corrosion water tank includes four side walls and a tank top. The four side walls and the tank top enclose the top of the test tube segment to form a sealed pressurized corrosion water tank. Sealing gaskets are respectively provided between the four side walls and the top of the test tube segment. The tank wall or the tank top of the pressurized corrosion water tank is provided with a pressurization port, and the pressurization port is connected to the pressurization equipment through a pipeline.

[0013] Furthermore, the pressure detection device is used to detect the pressure in the pressurized corrosion water tank and display or transmit the pressure value to the console; the pressurizing equipment is connected to the console; the pressure detection device uses a pressure gauge, and the pressurizing equipment uses a pressure pump.

[0014] The device for testing accelerated corrosion and degradation of load-bearing shield tunnel segments under high water pressure of the present invention also includes a stress performance testing system, which is used to test the stress and strain, deformation, steel corrosion status, and crack occurrence and development of the test segments.

[0015] The present invention has at least the following beneficial effects: the test device for accelerated corrosion degradation of load-bearing shield tunnel segments under high water pressure of the present invention includes a mechanical loading device, which is used to apply a working load to the segments, and accurately introduce the bending moment and axial force of the segments through a control console and a power drive system, simulating the actual stress state of the segment structure in a water and soil load environment.

[0016] The present invention solves the problem that the existing corrosion test device cannot pressurize the corrosion solution and thus cannot simulate the mechanical properties of the shield tunnel lining structure under high water pressure. On the basis of the mechanical loading device, a high water pressure accelerated corrosion degradation device is added, the corrosion solution is pressurized by a pressurized corrosion water tank, the solution pressure is read by a pressure detection device, and the pressure applied to the corrosion solution is controlled by a pressurizing device to achieve the effect of accurately controlling the water pressure. The mechanical properties of the shield tunnel lining structure under the combined action of a water and soil load environment and a surrounding erosion degradation environment for a long time can be truly tested, and the stress and strain, deformation, steel corrosion state, crack occurrence and development, etc. of the pipe segment test piece can be tested by the pipe segment force performance test system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 It is a structural schematic diagram of the test device for accelerated corrosion degradation of load-bearing shield tunnel segments under high water pressure of the present invention.

[0019] In the accompanying drawings, 1 is a horizontal mechanical loading device, 11 is a left loading beam, 12 is a right loading beam, 13 is a left segment support seat, 14 is a right segment support seat, 15 is a horizontal pull rod, 16 is a first power drive device, 2 is a vertical mechanical loading device, 21 is an upper loading beam, 22 is a base, 23 is a loading head, 24 is a vertical pull rod, 25 is a second power drive device, 3 is a pressurized corrosion water tank, 4 is a pressure pump, 5 is a sealing gasket, 6 is a steady-current DC power supply, 7 is a conductive wire, 8 is a segment stress and strain testing system, 9 is a pressure gauge, and 10 is a test segment. DETAILED DESCRIPTION

[0020] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0021] See also Figure 1 An embodiment of the present invention provides a device for testing accelerated corrosion and degradation of a load-bearing shield tunnel segment under high water pressure, comprising a high water pressure accelerated corrosion and degradation device and a horizontal mechanical loading device 1 for applying a horizontal force to a test segment 10. The test segment 10 is supported on both sides of the horizontal mechanical loading device 1, and both sides of the test segment 10 are in contact with the horizontal mechanical loading device 1. The high water pressure accelerated corrosion and degradation device comprises a pressurized corrosion water tank 3 and a pressurizing device. The pressurized corrosion water tank 3 is located at the upper end of the test segment 10. The pressurizing device is connected to the pressurized corrosion water tank 3 and is used to apply pressure to the pressurized corrosion water tank 3 and read the pressure value through a pressure detection device. The present invention uses the high water pressure accelerated corrosion and degradation device to electrochemically accelerate the corrosion of the segment structure, simulating the effects of high water pressure and the surrounding corrosive environment on the long-term weakening and degradation of the performance of the existing segment structure.

[0022] Furthermore, the accelerated corrosion degradation test device for load-bearing shield tunnel segments under high water pressure of the present invention also includes a vertical mechanical loading device 2 for applying vertical force to the test segment 10. The vertical mechanical loading device 2 is located above the test segment 10 and contacts the upper end of the test segment 10.

[0023] The horizontal mechanical loading device 1 and the vertical mechanical loading device 2 are used to apply working loads to the segments. The control console and power drive system are used to accurately introduce the bending moment and axial force of the segments, simulating the actual stress state of the segment structure in a water and soil load environment.

[0024] Furthermore, the horizontal mechanical loading device 1 includes a left loading beam 11, a right loading beam 12, a left segment support seat 13, a right segment support seat 14, a first power drive device 16 and a transverse pull rod 15. The left segment support seat 13 and the right segment support seat 14 are respectively located on the left and right sides of the test segment 10, and are used to contact and support the two sides of the test segment 10 respectively. The left segment support seat 13 is connected to the left loading beam 11, and the right segment support seat 14 is connected to the first power drive device 16. The first power drive device 16 is connected to the right loading beam 12, and is used to apply horizontal force to the test segment 10. The left end of the transverse tie rod 15 is connected to the left loading beam 11, and the right end of the transverse tie rod 15 is connected to the right loading beam 12; the vertical mechanical loading device 2 includes an upper loading beam 21, a base 22, a loading head 23, and a vertical tie rod 24. The loading head 23 is located above the test tube segment 10 and contacts the top of the test tube segment 10. The loading head 23 is connected to the second power drive device 25, and the second power drive device 25 is connected to the upper loading beam 21 for applying vertical force to the test tube segment 10. The upper end of the vertical tie rod 24 is connected to the upper loading beam 21, and the lower end of the vertical tie rod 24 is connected to the base 22.

[0025] Furthermore, there are at least two transverse tie rods 15 and at least two vertical tie rods 24.

[0026] The horizontal tie rod 15 pulls the left loading beam 11 and the right loading beam 12 together to provide a reaction force when loading. The vertical tie rod 24 pulls the upper loading beam 21 and the base 22 together to provide a reaction force when loading.

[0027] The horizontal pull rod 15 and the vertical pull rod 24 can be high-strength force transmission threaded pull rods, which are threadedly connected to the nuts after passing through the loading beam or base 22. The high-strength force transmission threaded pull rods and the loading beam or base 22 can be threadedly connected.

[0028] Furthermore, the left loading beam 11 and the right loading beam 12 are fixed on the base 22 .

[0029] Furthermore, the left segment support seat 13 and the right segment support seat 14 both include a seat body and a support plate for supporting the test segment 10. The support plate is arranged obliquely on the seat body. The support plate on the left segment support seat 13 and the support plate on the right segment support seat 14 are arranged opposite to each other, and the distance between the upper ends of the two support plates is greater than the distance between the lower ends of the two support plates.

[0030] Furthermore, a horizontal pressure sensor is provided between the right segment support seat 14 and the first power drive device 16; a vertical pressure sensor is provided between the loading head 23 and the second power drive device 25. The horizontal pressure sensor and the vertical pressure sensor are respectively connected to the input end of the console, and the output end of the console is connected to the power drive system. The power drive system is used to control the first power drive device 16 and the second power drive device 25 to achieve the adjustment of the pressure applied to the test segment 10.

[0031] The first power drive device 16 and the second power drive device 25 of the present invention use hydraulic jacks, but are not limited to hydraulic jacks.

[0032] Furthermore, a cathode stainless steel mesh is placed in the pressurized corrosion water tank 3, and the cathode stainless steel mesh is electrically connected to the cathode of the steady-current DC power supply 6 through the conductive wire 7, and the steel bars of the test pipe segment 10 are electrically connected to the anode of the steady-current DC power supply 6 through the conductive wire 7.

[0033] Furthermore, the pressurized corrosion water tank 3 includes four side walls and a tank top. The four side walls and the tank top enclose the top of the test tube segment 10 to form a sealed pressurized corrosion water tank 3. Rubber sealing pads 5 are respectively provided between the four side walls and the top of the test tube segment 10. A pressurized port is provided on the tank wall or the tank top of the pressurized corrosion water tank 3, and the pressurized port is connected to the pressurizing equipment through a pipeline.

[0034] Furthermore, the pressure detection device is used to detect the pressure within the pressurized corrosion tank 3 and display or transmit the pressure value to the console; the pressurizing device is connected to the console. In this embodiment, the pressure detection device is a pressure gauge 9, and the pressurizing device is a pressurizing pump 4. Of course, the pressure detection device of the present invention is not limited to the pressure gauge 9. The pressurizing device of the present invention is not limited to the pressurizing pump 4.

[0035] The apparatus for testing accelerated corrosion and degradation of load-bearing shield tunnel segments under high water pressure of the present invention also includes a segment stress and strain testing system 8, which is used to measure stress and strain, deformation, steel bar corrosion, and crack development of the test segment 10. The segment stress and strain testing system 8 of the present invention can utilize existing segment stress and strain testing systems and will not be described in detail here.

[0036] In order to control the mechanical loading in real time, the following steps can be taken:

[0037] Set the horizontal target pressure P to be applied in the console h And vertical target pressure P v and the set value m, the console controls the power drive system to apply pressure;

[0038] The vertical pressure sensor and the horizontal pressure sensor input the measured horizontal pressure P1 and vertical pressure P2 to the control console respectively, and the control console makes the following judgment: when P1-P h <0 and When the console controls the output end of the first power drive device 16 to continue to approach the pipe segment, When the value reaches m, the pressure is reduced. h <0 and When P1=P h Stop; when P2-P v <0 and When P2-P v <0 and When P2=P v Stop; when P1=P h , P2=P v Afterwards, the control console controls the relative positions of the output ends of the first power drive device 16 and the second power drive device 25 and the pipe segments to remain constant, and the test is carried out at the target pressures Ph and Pv.

[0039] In this embodiment, m is 0.5%. Of course, the value of m can be adjusted as needed. m (e.g., 0.5%) is a value that facilitates the controller to determine the pressure difference. When the difference between the actual pressure and the set pressure is greater than m (e.g., 0.5%), pressurization continues. When the difference is less than m (e.g., 0.5%), pressurization is increased slowly to prevent the pressure from exceeding the set value too quickly.

[0040] When using the present invention for testing, first, the values ​​of bending moment, axial force, water pressure, etc. that need to be applied are set through the console; then, the power drive system drives the mechanical loading device to apply a working load to the pipe segment, so as to achieve the precise introduction of the pipe segment bending moment and axial force, and simulate the real stress state of the pipe segment structure in the water and soil load environment; at the same time, the pressure pump 4 applies pressure to the pressurized corrosion water tank 3, and the pressure value is read through the pressure gauge 9, and the cathode stainless steel mesh and the corrosive solution in the pressurized corrosion water tank 3 are powered by the steady-current DC power supply 6 to accelerate the corrosion of the pipe segment structure; the stress and strain, deformation, steel corrosion state, crack occurrence and development, etc. of the pipe segment specimen are tested through the force performance test system.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A test device for accelerated corrosion degradation of load-bearing shield tunnel segments under high water pressure, characterized in that: It comprises a high water pressure accelerated corrosion degradation device and a horizontal mechanical loading device for applying horizontal force to the test tube segment. The two sides of the test tube segment are respectively supported on the horizontal mechanical loading device, and the two sides of the test tube segment are respectively in contact with the horizontal mechanical loading device. The high water pressure accelerated corrosion degradation device comprises a pressurized corrosion water tank and a pressurizing device. The pressurized corrosion water tank is arranged at the upper end of the test tube segment. The pressurizing device is connected to the pressurized corrosion water tank and is used to apply pressure to the pressurized corrosion water tank and read the pressure value through the pressure detection device; the pressure detection device is used to detect the pressure value in the pressurized corrosion water tank and display or transmit it to the console; It also includes a vertical mechanical loading device for applying vertical force to the test segment. The vertical mechanical loading device is located above the test segment and contacts the upper end of the test segment.

2. The accelerated corrosion degradation test device for load-bearing shield tunnel segments under high water pressure as claimed in claim 1, characterized in that: The horizontal mechanical loading device includes a left loading beam, a right loading beam, a left segment support seat, a right segment support seat, a first power drive device and a transverse pull rod. The left segment support seat and the right segment support seat are respectively located on the left and right sides of the test segment and are used to contact and support the two sides of the test segment respectively. The left segment support seat is connected to the left loading beam, and the right segment support seat is connected to the first power drive device. The first power drive device is connected to the right loading beam and is used to apply horizontal force to the test segment. The left end of the transverse pull rod is connected to the left loading beam, and the right end of the transverse pull rod is connected to the right loading beam. The vertical mechanical loading device includes an upper loading beam, a base, a loading head and a vertical pull rod. The loading head is located above the test segment and contacts the top of the test segment. The loading head is connected to the second power drive device, and the second power drive device is connected to the upper loading beam and is used to apply vertical force to the test segment. The upper end of the vertical pull rod is connected to the upper loading beam, and the lower end of the vertical pull rod is connected to the base.

3. The accelerated corrosion degradation test device for load-bearing shield tunnel segments under high water pressure as claimed in claim 2, characterized in that: The left loading beam and the right loading beam are fixed on the base.

4. The accelerated corrosion degradation test device for load-bearing shield tunnel segments under high water pressure as claimed in claim 2, characterized in that: The left segment support seat and the right segment support seat both include a seat body and a support plate for supporting the test segment. The support plate is obliquely arranged on the seat body. The support plate on the left segment support seat is arranged opposite to the support plate on the right segment support seat. The distance between the upper ends of the two support plates is greater than the distance between the lower ends of the two support plates.

5. The accelerated corrosion degradation test device for load-bearing shield tunnel segments under high water pressure as claimed in claim 2, characterized in that: A horizontal pressure sensor is provided between the right segment support seat and the first power drive device; a vertical pressure sensor is provided between the loading head and the second power drive device, the horizontal pressure sensor and the vertical pressure sensor are respectively connected to the input end of the console, and the output end of the console is connected to the power drive system, and the power drive system is used to control the first power drive device and the second power drive device to achieve the adjustment of the pressure applied to the test segment; The first power driving device and the second power driving device adopt hydraulic jacks.

6. The accelerated corrosion degradation test device for load-bearing shield tunnel segments under high water pressure as claimed in claim 1, characterized in that: A cathode stainless steel mesh is placed in the pressurized corrosion water tank, and the cathode stainless steel mesh is electrically connected to the cathode of the steady-current DC power supply through a conductive wire, and the steel bars of the test segment are electrically connected to the anode of the steady-current DC power supply through a conductive wire.

7. The accelerated corrosion degradation test device for load-bearing shield tunnel segments under high water pressure as claimed in claim 1, characterized in that: The pressurized corrosion water tank includes four side tank walls and a tank top. The four side tank walls and the tank top enclose the top of the test tube segment to form a sealed pressurized corrosion water tank. Sealing gaskets are respectively arranged between the four side tank walls and the top of the test tube segment. A pressurization port is arranged on the tank wall or the tank top of the pressurized corrosion water tank, and the pressurization port is connected to the pressurization equipment through a pipeline.

8. The accelerated corrosion degradation test device for load-bearing shield tunnel segments under high water pressure as claimed in claim 1, characterized in that: The pressure detection device adopts a pressure gauge, and the pressurizing device adopts a pressurizing pump.

9. The accelerated corrosion degradation test device for load-bearing shield tunnel segments under high water pressure as claimed in claim 1, characterized in that: It also includes a stress performance testing system, which is used to test the stress and strain, deformation, steel corrosion status, and crack occurrence and development of the test pipe segment.

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