Multi - level yielding steel arch limiter and construction method

Abstract

The present invention provides a multi-stage yielding steel arch limiter and a construction method. A plurality of steel arches form an annular steel arch frame, and adjacent steel arches are connected by a limiter. The limiter includes a pressure element steel column and a pressure-receiving element steel cylinder. The pressure element steel column is sleeved inside the pressure-receiving element steel cylinder. Sand is placed between the inside of the pressure-receiving element steel cylinder and the pressure element steel column. A pressure relief hole is provided on one side of the bottom of the pressure-receiving element steel cylinder. A deformation member is provided inside the pressure-receiving element steel cylinder. The deformation member is arranged on one side of the pressure relief hole and covers the pressure relief hole. A strain gauge is arranged at the bottom of the deformation member. When the pressure element steel column is compressed, the deformation member is deformed to expose the pressure relief hole, and the sand leaks out from the pressure-receiving element steel cylinder to relieve the pressure. Using sand material as the bearing main body and cooperating with a rubber deformation member, a stable automatic pressure relief system is set by utilizing the fluidity of the sand and the deformation characteristics of the rubber, so that while the limiter arch frame maintains a certain support resistance to the surrounding rock, the original rock stress is slowly and stably released.

Description

Technical Field

[0001] The present invention relates to the field of steel arch construction, and particularly to a multi-stage pressure-relieving steel arch limiter and a construction method thereof. Background Art

[0002] During the tunnel excavation construction process, affected by factors such as geological structure and burial depth, high in-situ stress soft rock large deformation often occurs, causing a series of engineering accidents, which has always been a key technical problem concerned in engineering construction. In order to solve the problems of large deformation and fragmentation of soft rock tunnels under high in-situ stress conditions, the "combination of release and resistance" support method of using pressure relief to release the high in-situ stress of the original rock has been proposed in engineering. Currently, the commonly used construction techniques mainly include double-layer primary support arch frame support. Among them, the first arch frame with small stiffness releases part of the stress after deforming to failure with the surrounding rock, and the second arch frame with large stiffness supports the deformed surrounding rock and the first arch frame to form a support system. However, this method still has certain defects. Due to the characteristics of more construction procedures of the double-layer arch frame itself, more complex construction environment (large and fast deformation of the surrounding rock), and higher requirements for on-site organization of man, machine, and materials, it is easy to cause the second arch frame to be unable to be constructed in time, and the surrounding rock collapses without effective support when the first arch frame structure fails.

[0003] The patent "Double-layer Arch Frame Support Construction System for Highway Soft Rock Tunnels and Its Construction Method" (CN110397455B) strengthens the double-layer arch frame to improve the support capacity, but does not solve the problem of the first arch frame having a high risk of collapse due to fast deformation.

[0004] In the patent "Initial Support Structure for Loess Tunnels Based on a Limiter" (CN209067236U), a limiter is invented to release the stress of the surrounding rock on the arch frame to protect the arch frame structure and finally make the arch frame and the surrounding rock form a stress balance. However, the deformation of the limiting steel plate in the invention only has the deformation ability of a conventional steel plate. On the one hand, it does not have the characteristics of directional and pressure control. In a high in-situ stress complex environment, the arc-shaped arch frame is prone to invade the free face; at the same time, the internal stress of the steel plate changes complexly during the deformation process and the stress transfer outward is not obvious, which is easy to cause the steel plate to break under load. For extremely high in-situ stress tunnel soft rock deformation, directional and pressure control characteristics are still required.

[0005] Therefore, aiming at the problems of difficult control of the construction timing of the current double-layer arch frame and high safety risks in the process connection, it is urgent to design a device with the characteristics of large stiffness, simple structure, stable deformation, and stress informationization, which can be easily installed on the arch frame, so that it slowly deforms and unloads in a high in-situ stress environment while maintaining the integrity of the structure, provides a construction opportunity while extending the pressure relief cycle, and retains the arch frame structure to maintain a safe construction environment, and solves the construction problems of the above double-layer arch frame support. Summary of the Invention

[0006] The main object of the present invention is to provide a multi - level yielding steel arch limiter and a construction method, which solve the problems that the double - layer arch itself has more construction processes, a more complex construction environment, and higher requirements for on - site construction organization of man, machine, and materials. These characteristics easily lead to the inability to construct the second - layer arch in time, and when the first - layer arch structure is damaged, the surrounding rock has no effective support, resulting in a collapse accident.

[0007] To solve the above - mentioned technical problems, the technical solution adopted by the present invention is: a multi - level yielding steel arch limiter. Multiple steel arches form an annular steel arch frame, and adjacent steel arches are connected by limiters. The limiter includes a pressure - element steel column and a pressure - receiving element steel cylinder. The pressure - element steel column is sleeved inside the pressure - receiving element steel cylinder. Sand is placed between the inside of the pressure - receiving element steel cylinder and the pressure - element steel column. A pressure - relief hole is provided on one side of the bottom of the pressure - receiving element steel cylinder. A deformation member is provided inside the pressure - receiving element steel cylinder. The deformation member is arranged on one side of the pressure - relief hole and covers the pressure - relief hole. A strain gauge is provided at the bottom of the deformation member.

[0008] When the pressure - element steel column is pressurized, the deformation member deforms to expose the pressure - relief hole, and the sand leaks out of the pressure - receiving element steel cylinder to relieve pressure.

[0009] In a preferred embodiment, the material of the deformation member is made of rubber or silicone.

[0010] In a preferred embodiment, the deformation member is a column - shaped deformation block. The column - shaped deformation block is a cylindrical structure. The diameter of the cylinder is larger than the diameter of the pressure - relief hole. The bottom of the cylindrical structure is connected to a rectangular - shaped mounting seat.

[0011] In a preferred embodiment, an arc - shaped transition structure is provided between the two sides of the cylinder of the column - shaped deformation block and the mounting seat.

[0012] In a preferred embodiment, a pressure - receiving groove is provided at the bottom of the pressure - receiving element steel cylinder. The strain gauge is arranged at the bottom of the pressure - receiving groove. And the mounting seat at the bottom of the column - shaped deformation block is arranged above the strain gauge and is also arranged inside the pressure - receiving groove.

[0013] In a preferred embodiment, a second folded plate is provided at one end of the column - shaped deformation block. A positioning groove is provided at the bottom of the pressure - receiving element steel cylinder. The turning part at the end of the second folded plate is stuck inside the positioning groove.

[0014] In a preferred embodiment, the deformation member is a rectangular deformation block. Arc - shaped chamfered surfaces are provided on both sides of the rectangular deformation block. One end of the rectangular deformation block abuts against the pressure - relief hole of the pressure - receiving element steel cylinder. The other end is provided with an arc - shaped inclined chamfered surface, and a first folded plate is provided at the end of the arc - shaped inclined chamfered surface and is bent downward.

[0015] In a preferred embodiment, the downward - bent end of the first folded plate is stuck inside the pressure - receiving groove. The lower surface of the rectangular deformation block is arranged inside the pressure - receiving groove, and the strain gauge is arranged between the lower surface of the rectangular deformation block and the bottom of the pressure - receiving groove.

[0016] In a preferred embodiment, ear plates are provided on both sides of the rectangular deformation block, and deformation avoidance grooves are provided on both sides of the pressure-receiving groove. The ear plates on both sides of the rectangular deformation block cover the deformation avoidance grooves, and the area at the root of the lower surface of the ear plate forms a squeezing deformation area, and the squeezing deformation area deforms and extends inside the deformation avoidance groove.

[0017] The method includes:

[0018] S1. Select the parameters of the deformation component by using a pressure test, determine the reserved deformation amount and the sand filling height, and check the overall integrity and specifications of the positioner;

[0019] S2. Before installing the steel arch, align the high-strength bolt holes and then install the two components of the positioner on the steel arch by using high-strength bolts;

[0020] S3. Align the strain gauge with the lower surface of the deformation component and install them at the pressure relief hole position of the pressure-receiving component steel cylinder. The data line of the strain gauge passes through the wire hole of the pressure-receiving component steel cylinder and is connected to an external plug;

[0021] S4. Then fill a certain height of loose sand inside the pressure-receiving component steel cylinder. The deformation component closes the pressure relief hole to prevent the sand from leaking. Sleeve the pressure component steel column inside the pressure-receiving component steel cylinder, and the end face of the pressure component steel column abuts against the sand to form a positioner;

[0022] S5. After temporarily fixing the components by using spot welding of steel bars, install the steel arch by using conventional techniques. At least two symmetrically arranged positioners are installed on the formed steel arch. Knock off the spot-welded steel bars and then initially spray concrete. On-site, use materials such as geotextiles and plastics to protect the pressure relief holes and external plugs from being damaged;

[0023] S6. After the installation of the positioner is completed, monitor the internal stress of the steel arch by using the external plug during the construction process, and perform in-tunnel monitoring and measurement work well. When the deformation of the first-layer steel arch reaches the reserved deformation amount, that is, the sand in the cylinder leaks out completely and the positioner enters the constant resistance stage, construct the second-layer steel arch to form a double-layer arch initial support system. The second-layer steel arch is provided with observation ports at the positions where the positioners are installed on the first-layer steel arch.

[0024] S7. Insert the pressure component steel column into the pressure-receiving component steel cylinder to a certain depth to fix the deformation direction. At the same time, gradually increase the pressure of the pressure component steel column to compact the sand to achieve slow and directional deformation, which is the pressure increase and deformation stage;

[0025] S8. After the stress in the pressure-receiving component steel cylinder is concentrated to a certain degree, the deformation component is compressed and deformed to expose the pressure relief hole and the sand leaks out for unloading, which is the constant pressure deformation stage. Until the sand leaks out completely, the pressure component steel column is inserted to the bottom of the pressure-receiving component steel cylinder, and finally, it serves as the constant resistance stage of the arch frame to connect the next process.

[0026] The present invention provides a multi-stage yielding steel arch limiter and a construction method. The design of the present invention divides the conventional yielding process into multi-stage yielding, and at the same time uses the mortise and tenon relationship of components to control the deformation direction of the arch, which can effectively achieve the goals of directional stability and slow and continuous pressure relief under high in-situ stress conditions, eliminate construction safety hazards during the support process, and has the characteristics of simplicity, high efficiency, safety and practicality.

[0027] The limiter with a mortise and tenon structure limits the deformation direction of the arch, avoids the deformation invading the free face under complex stress conditions, and at the same time makes the limiter fit tightly after yielding is completed as a firm connection point of the arch.

[0028] After the sand inside the limiter runs out, the yielding function of the device is completed. After the pressing element and the pressed element of the limiter fit tightly, it serves as the connection structure of the arch, retaining the initial support bearing capacity of the arch for the surrounding rock.

[0029] Using sand material as the pressure-bearing main body, cooperating with rubber deformation parts, and setting up a stable automatic pressure relief system by using the fluidity of sand and the deformation characteristics of rubber, so that while the limiter arch has a certain support resistance to the surrounding rock, the in-situ stress is slowly and stably released. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below in conjunction with the drawings and embodiments:

[0031] Figure 1 is a schematic diagram of the installation of the steel arch and the limiter of the present invention;

[0032] Figure 2 is a structural diagram of the limiter installed on the steel arch of the present invention;

[0033] Figure 3 is a structural diagram of the deformation part inside the limiter of the present invention under pressure and discharging sand;

[0034] Figure 4 is a structural diagram of the deformation part inside the limiter of the present invention in the constant pressure stage;

[0035] Figure 5 is a structural diagram of the limiter of the present invention in the constant resistance stage;

[0036] Figure 6 is a main view sectional structural diagram of the limiter of the present invention;

[0037] Figure 7 is a main view structural diagram of the deformation part inside the limiter of the present invention under pressure and discharging sand

[0038] Figure 8 is a main view sectional structural diagram of the deformation part inside the limiter of the present invention in the constant pressure stage;

[0039] Figure 9 is a structural diagram of the internal installation of the preferred rectangular deformation block of the present invention;

[0040] Figure 10 is the disassembled structure diagram of the rectangular deformation block of the present invention;

[0041] Figure 11 is the left-view sectional structure diagram of the rectangular deformation block of the present invention;

[0042] Figure 12 is the cross-sectional installation structure diagram of the rectangular deformation block of the present invention;

[0043] Figure 13 is the lower surface structure diagram of the rectangular deformation block of the present invention;

[0044] Figure 14 is the installation structure diagram of the preferred cylindrical deformation block of the present invention;

[0045] Figure 15 is the disassembled installation structure diagram of the cylindrical deformation block of the present invention;

[0046] Figure 16 is the cross-sectional installation structure diagram of the cylindrical deformation block of the present invention;

[0047] Figure 17 is the left-view sectional structure diagram of the cylindrical deformation block of the present invention.

[0048] In the figure: steel arch frame 1; limiter 2; pressure element steel column 201; pressure-receiving element steel cylinder 202; pressure relief hole 203; positioning groove 204; pressure-receiving groove 205; deformation avoidance groove 206; observation port 3; inner arch frame 4; deformation part 5; strain gauge 6; external plug 7; sand 8; rectangular deformation block 9; ear plate 901; first folding plate 902; extrusion deformation area 903; cylindrical deformation block 10; second folding plate 1001; mounting seat 1002. Specific embodiments

[0049] Example 1

[0050] As Figures 1 - 17As shown in the figure, a multi-stage yielding steel arch limiter. A plurality of steel arches form an annular steel arch frame 1, and adjacent steel arches are connected by a limiter 2. The limiter 2 includes a pressing element steel column 201 and a pressed element steel cylinder 202. The pressing element steel column 201 is sleeved inside the pressed element steel cylinder 202. Sand 8 is placed between the inside of the pressed element steel cylinder 202 and the pressing element steel column 201. One side of the bottom of the pressed element steel cylinder 202 is provided with a pressure relief hole 203. A deformable member 5 is provided inside the pressed element steel cylinder 202. The deformable member 5 is arranged on one side of the pressure relief hole 203. The deformable member 5 covers the pressure relief hole 203. A strain gauge 6 is arranged at the bottom of the deformable member 5. When the pressing element steel column 201 is pressed, the deformable member 5 deforms to expose the pressure relief hole 203, and the sand 8 leaks out from the pressed element steel cylinder 202 to relieve pressure. The material of the deformable member 5 is made of rubber or silicone. Design a limiter 2 composed of mortise and tenon structure elements, and use the mortise and tenon relationship between the elements to control the deformation direction of the arch frame; utilize the material characteristics of sand, the compaction and leakage of the sand 8 in the limiter 2 provide the deformation space of the limiter; arrange a deformable member 5 for closing the pressure relief hole inside the limiter 2, and use the characteristics of the rubber material deformable member being compressed and deformed and the fluidity of sand to form a pressure relief switch with a specific threshold pressure; adopt a limiter 2 with high stiffness to ensure that the bearing capacity of the arch frame structure is retained after the limiter 2 deforms to the final value; utilize the pressure relief hole 203, the deformable member 5 to install the strain gauge 6 and fine cable to monitor the internal stress of the arch frame to guide safe construction.

[0051] The limiter 2 described above is made of steel material and is divided into two structures: a pressing element and a pressed element. Among them, the pressing element is a solid cylinder with a steel plate, and bolt holes are opened at the four corners of the steel plate; the pressed element is a hollow cylinder with a steel plate, bolt holes are opened at the four corners of the steel plate, and a deformable member and a pressure relief hole are arranged inside the cylinder.

[0052] The combination of the solid cylinder of the pressing element and the hollow cylinder of the pressed element is a mortise and tenon structure. The outer diameter of the solid cylinder is the same as the inner diameter of the hollow cylinder, and they are tightly connected to form the limiter 2.

[0053] The pressure relief hole is a small hole on one side of the wall of the pressed element cylinder. A deformable member is arranged on one side inside the cylinder to block it and prevent the sand material inside the cylinder from flowing out. After the deformable member 5 is compressed by force and exposes the pressure relief hole, the sand material can flow out through the pressure relief hole.

[0054] The deformable member 2 is a rubber material element with a strain gauge at the bottom, which is fixed to one side of the bottom of the pressed element cylinder near the pressure relief hole. The strain gauge of the deformable member is connected to an external plug 7 through a fine cable passing through the pressure relief hole. After connecting to a monitoring instrument, the change in the resistance of the strain gauge can be displayed, thereby converting it into pressure data; when the rubber of the deformable member blocking the pressure relief hole 203 is subjected to a pressure exceeding a certain threshold, the pressure relief hole is exposed to allow the sand to flow out for pressure relief, and when the stress decreases, it expands again to close the pressure relief hole to retain the support resistance of the limiter arch frame.

[0055] After the sand flow inside the limiter is exhausted, the pressure relief function of the device is completed. After the pressing element of the limiter 2 and the pressed element are tightly fitted, they serve as the connection structure of the arch support, retaining the initial support bearing capacity of the arch support for the surrounding rock.

[0056] The deformation member 5 shown in the invention is mainly made of rubber, and a strain gauge 6 is also provided at the bottom of the deformation member 5. The strain gauge 6 is mainly used to transmit stress signals, and the stress value can be displayed by connecting a monitoring instrument through a thin cable and an external plug 7. Rubber mainly uses its compressive deformation ability as a pressure relief control switch. Initially, the rubber closes the pressure relief hole 203. When the stress exceeds the threshold value (the rubber size can be determined by a pressure test before construction as the designed stress threshold value), the pressure relief hole 203 is opened to discharge the sand 8 to release the pressure, giving the surrounding rock a certain deformation space. When the stress is released below the threshold value, the rubber deforms and recovers to continue closing the pressure relief hole 203, giving the surrounding rock a certain resistance to slow down its deformation rate. After repeated pressure relief until the sand 8 is exhausted, the stress monitoring ability can still be retained. The deformation member 5 described in the present invention is mainly used to transmit stress data and form constant-pressure deformation. Using the threshold value set by the deformation member 5, the surrounding rock deforms under a certain support force condition, reducing the deformation rate of the surrounding rock. For the real-time monitoring of special sections of the tunnel, it can ensure the safety of the construction environment while using the data to guide the next step of tunnel construction.

[0057] Embodiment 2

[0058] As Figures 14 - 17 shown, the specific structure of the deformation member in the preferred solution of this scheme is a columnar deformation block 10. The deformation member 5 is a columnar deformation block 10. The columnar deformation block 10 is a cylinder structure, and the diameter of the cylinder is larger than the diameter of the pressure relief hole 203. The bottom of the cylinder structure is connected to the mounting seat 1002 with a rectangular structure. The cylinder-shaped deformation block structure has a good deformation effect. The deformation block is mainly made of rubber. The steel column 201 of the pressing element compresses the sand 8. The pressing force of the sand 8 compresses the columnar deformation block 10 of the cylinder structure from the circumference. The columnar deformation block 10 is compressed and shrunk, exposing the pressure relief hole 203. Among them, the application range of the columnar deformation block 10 is wider and the compressive deformation is more uniform.

[0059] In the preferred solution, an arc transition structure is provided between the two sides of the cylinder of the columnar deformation block 10 and the mounting seat 1002. As Figure 15 shown, the arc transition structure between the columnar deformation block 10 and the mounting seat 1002 of the bottom plate prevents uneven compression. When the upper surface of the columnar deformation block 10 is compressed, the connection position between the columnar deformation block 10 and the mounting seat 1002 can better disperse the pressure, and the arc transition structure can evenly disperse the pressure.

[0060] In the preferred embodiment, a pressure groove 205 is provided at the bottom of the pressure element steel cylinder 202, a strain gauge 6 is provided at the bottom of the pressure groove 205, and a mounting seat 1002 at the bottom of the columnar deformation block 10 is provided above the strain gauge 6, and the mounting seat 1002 is also provided inside the pressure groove 205. The columnar deformation block 10 is installed inside the pressure groove 205, which can prevent the columnar deformation block 10 from deviating when under pressure, and plays a role in fixing the bottom of the columnar deformation block 10.

[0061] In the preferred embodiment, a bent second folded plate 1001 is provided at one end of the columnar deformation block 10, a positioning groove 204 is provided at the bottom of the pressure-bearing element steel cylinder 202, and the turning part of the end of the second folded plate 1001 is stuck inside the positioning groove 204. The second folded plate 1001 of the columnar deformation block 10 is stuck inside the positioning groove 204 to prevent the columnar deformation block 10 from being squeezed out from the pressure relief hole 203 when the columnar deformation block 10 is compressed and deformed, and is used to fix the axial position of the entire columnar deformation block 10.

[0062] Example 3

[0063] like Figures 9 - 13 As shown, the specific structure of the deformation member of the preferred embodiment of the present invention is a rectangular deformation block 9, and the deformation member 5 is a rectangular deformation block 9. Circular arc chamfered surfaces are provided on both sides of the rectangular deformation block 9. One end of the rectangular deformation block 9 abuts against the pressure relief hole 203 of the pressure element steel cylinder 202, and the other end is provided with a circular arc inclined chamfered surface, and the end of the circular arc inclined chamfered surface is provided with a first folding plate 902 bent downward. The rectangular deformation block 9 has a flattened structure, and the upper surface of the rectangular deformation block 9 is the main pressure-bearing area. The tail and both sides are designed with circular arcs in order to make the pressure in all directions more uniform, so that the deformation of the rectangular deformation block 9 is more uniform, and there will be no compression deformation in the middle and warping at the end. The rectangular deformation block 9 is mainly used in the construction field of the rectangular deformation block 9 with relatively high pressure, and the rectangular deformation block 9 is more stable.

[0064] In the preferred embodiment, the downwardly bent end of the first folded plate 902 is stuck inside the pressure groove 205, the lower surface of the rectangular deformation block 9 is arranged inside the pressure groove 205, and the strain gauge 6 is arranged between the lower surface of the rectangular deformation block 9 and the bottom of the pressure groove 205. The end of the first folded plate 902 is stuck inside the pressure groove 205 to prevent the rectangular deformation block 9 from being squeezed out from the pressure relief hole 203 when it is compressed and deformed, and is used to fix the axial position of the entire rectangular deformation block 9.

[0065] In the preferred embodiment, the rectangular deformation block 9 is provided with ear plates 901 on both sides, and the pressure groove 205 is provided with deformation avoidance grooves 206 on both sides. The ear plates 901 on both sides of the rectangular deformation block 9 cover the deformation avoidance grooves 206, and the root area of the lower surface of the ear plates 901 forms an extrusion deformation area 903, and the extrusion deformation area 903 deforms and stretches inside the deformation avoidance groove 206. Figure 10Or the structure described in 12, when the rectangular deformation block 9 is stressed and deformed, in order to better relieve pressure, the extrusion deformation area 903 on the lower surface of the rectangular deformation block 9 will be compressed and filled inside the deformation relief groove 206. In order to prevent the deformation relief groove 206 from being filled with sand, the ear plate 901 is used to cover the entire deformation relief groove 206, serving the purpose of protecting the entire deformation relief groove 206.

[0066] Embodiment 4

[0067] Further described in combination with Embodiment 1, as Figures 1 - 17 Shown in the structure, a limiter 2 composed of a compression element steel column 201 and a compression element steel cylinder 202 is designed. A directional deformation channel is formed by the mortise and tenon relationship between the elements. A multi-stage pressure relief system is composed of the sand 8, the deformation member 5, and the pressure relief hole 203 inside the compression element steel cylinder 202, and the concentrated stress inside the limiter 2 is transferred by the leakage of the sand 8. At the same time, a pressure control switch is composed of the deformation member 5 and the pressure relief hole 203 to ensure the continuous and stable support resistance of the arch support to the surrounding rock. Finally, after the elements are closed, the limiter 2 can be used as a connection point with high stiffness, retaining the bearing capacity of the steel arch support 1. The design of the present invention uses high-strength bolts, compression element steel plates, and compression element steel plates to facilitate the connection of the steel arch support 1, and divides the conventional pressure relief process into multi-stage pressure relief: sand compaction stage, constant pressure unloading stage, and arch support constant resistance stage. At the same time, the mortise and tenon relationship of the elements is used to control the deformation direction of the arch support, which can effectively achieve the goals of directional stability and slow and continuous pressure relief under high in-situ stress conditions, eliminate construction safety hazards during the support process, and has the characteristics of simplicity, high efficiency, safety, and practicality.

[0068] Select the parameters of the deformation member 5 using a pressure test, and determine the reserved deformation amount, the height of the filled sand 8, and check the overall integrity and specifications of the limiter 2.

[0069] Before installing the steel arch support 1, align the high-strength bolt holes and then install the limiter 2 as a whole on the steel arch support 1 using high-strength bolts.

[0070] Align the strain gauge 6 with the lower surface of the deformation member 5 and install them at the position of the pressure relief hole 203 of the compression element steel cylinder 202. The data line of the strain gauge 6 passes through the wire hole of the compression element steel cylinder 202 and is connected to the external plug 7.

[0071] Then fill a certain height of loose sand 8 inside the compression element steel cylinder 202. The deformation member 5 closes the pressure relief hole 203 to prevent the sand 8 from leaking. The compression element steel column 201 is sleeved inside the compression element steel cylinder 202, and the end face of the compression element steel column 201 abuts against the sand 8 to form the limiter 2.

[0072] After temporarily fixing the components by spot welding of steel bars, install the steel arch frame 1 using conventional techniques. At least two limiters 2 are symmetrically installed on the steel arch frame 1 formed by the steel arch. After knocking off the spot-welded steel bars, initially spray concrete. On-site, use materials such as geotextiles and plastics to protect the pressure relief holes 203 and the external plug 7 from being damaged.

[0073] After the installation of the limiter 2 is completed, during the construction process, use the external plug 7 to monitor the internal stress of the steel arch frame 1, and do a good job in the in-tunnel monitoring and measurement work. When the first-layer steel arch frame deforms to the reserved deformation amount, that is, when the sand in the cylinder is exhausted and the limiter enters the constant resistance stage, construct the second-layer steel arch frame to form a double-layer arch frame primary support system. The second-layer steel arch frame has an observation port 3 at the position where the limiter 2 is installed on the first-layer steel arch frame.

[0074] Insert the steel column 201 of the pressure element into the steel cylinder 202 of the pressure element to a certain depth to fix the deformation direction. At the same time, gradually increase the pressure on the steel column 201 of the pressure element to compact the sand 8 to achieve slow and directional deformation, which is the pressure increase and deformation stage;

[0075] After the internal stress in the steel cylinder 202 of the pressure element is concentrated to a certain extent, the deformation part 5 is compressed and deformed to expose the pressure relief hole 203 to discharge the sand 8 for unloading, which is the constant pressure deformation stage. Until the sand 8 is completely discharged, the steel column 201 of the pressure element is inserted into the bottom of the steel cylinder 202 of the pressure element, and finally serves as the constant resistance stage of the arch frame to connect the next process.

[0076] The above embodiments are only the preferred technical solutions of the present invention and should not be regarded as limitations on the present invention. The protection scope of the present invention should be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, the equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A multi-level yielding steel arch limiter, characterized in that: multiple The steel arches form a circular steel arch frame (1). Adjacent steel arches are connected by a stopper (2). The stopper (2) includes a pressing element steel column (201) and a pressed element steel cylinder (202). The pressing element steel column (201) is sleeved inside the pressed element steel cylinder (202). Sand (8) is placed between the inside of the pressed element steel cylinder (202) and the pressing element steel column (201). A pressure relief hole (203) is provided on one side of the bottom of the pressed element steel cylinder (202). A deformable member (5) is provided inside the pressed element steel cylinder (202). The deformable member (5) is arranged on one side of the pressure relief hole (203) and covers the pressure relief hole (203). A strain gauge (6) is provided at the bottom of the deformable member (5). When the pressing element steel column (201) is pressed, the deformable member (5) deforms to expose the pressure relief hole (203), and the sand (8) leaks out of the pressed element steel cylinder (202) to relieve pressure. The deformable member (5) is made of rubber or silicone. The deformable member (5) is a columnar deformation block (10). The columnar deformation block (10) is of a cylindrical structure. The diameter of the cylinder is larger than the diameter of the pressure relief hole (203). The bottom of the cylindrical structure is connected to a mounting seat (1002) of a rectangular structure.

2. The multi-stage yielding steel arch limiter according to claim 1, wherein: Arc-shaped transition structures are provided between both sides of the cylinder of the columnar deformation block (10) and the mounting seat (1002).

3. The multi-stage yielding steel arch limiter according to claim 1, wherein: A pressed groove (205) is provided at the bottom of the pressed element steel cylinder (202). The strain gauge (6) is arranged at the bottom of the pressed groove (205). The mounting seat (1002) at the bottom of the columnar deformation block (10) is arranged above the strain gauge (6), and the mounting seat (1002) is also arranged inside the pressed groove (205).

4. The multi-stage yielding steel arch limiter according to claim 1, wherein: A bent second folding plate (1001) is provided at one end of the columnar deformation block (10). A positioning groove (204) is provided at the bottom of the pressed element steel cylinder (202). The turning part at the end of the second folding plate (1001) is stuck inside the positioning groove (204).

5. The multi-stage yielding steel arch limiter according to claim 1, characterized in that: deformation The deformable member (5) is a rectangular deformation block (9). Arc-shaped chamfered surfaces are provided on both sides of the rectangular deformation block (9). One end of the rectangular deformation block (9) abuts against the pressure relief hole (203) of the pressed element steel cylinder (202). The other end is provided with an arc-shaped inclined chamfered surface, and a first folding plate (902) bent downward is provided at the end of the arc-shaped inclined chamfered surface.

6. The multi-stage yielding steel arch limiter according to claim 5, characterized in that: The downwardly bent end of the first folding plate (902) is stuck inside the positioning groove (204). The lower surface of the rectangular deformation block (9) is arranged inside the pressed groove (205), and the strain gauge (6) is arranged between the lower surface of the rectangular deformation block (9) and the bottom of the pressed groove (205).

7. The multi - stage yielding steel arch support stopper according to claim 5, characterized in that: Ear plates (901) are provided on both sides of the rectangular deformation block (9). Deformation avoidance grooves (206) are provided on both sides of the pressed groove (205). The ear plates (901) on both sides of the rectangular deformation block (9) cover the deformation avoidance grooves (206). An extrusion deformation area (903) is formed in the area at the root of the lower surface of the ear plate (901), and the extrusion deformation area (903) deforms and extends inside the deformation avoidance groove (206).

8. The adjustment method of a multi-stage yielding steel arch limiter according to any one of claims 1-7, characterized in that: The method includes: S1. Select the parameters of the deformable member (5) by using a pressure test, determine the reserved deformation amount and the height of the filled sand (8), and check the overall integrity and specifications of the stopper (2). S2. Before installing the steel arch (1), align the high-strength bolt holes and then use high-strength bolts to install the two components of the position limiter (2) onto the steel arch (1). S3. Align the lower surfaces of the strain gauge (6) and the deformation part (5) and install them at the position of the pressure relief hole (203) of the pressure-bearing element steel cylinder (202). The data line of the strain gauge (6) passes through the wire hole of the pressure-bearing element steel cylinder (202) and is connected to the external plug (7). S4. Then fill a certain height of loose sand (8) inside the pressure-bearing element steel cylinder (202). The deformation part (5) closes the pressure relief hole (203) to prevent the sand (8) from leaking. Sleeve the pressure-bearing element steel column (201) inside the pressure-bearing element steel cylinder (202), and the end face of the pressure-bearing element steel column (201) abuts against the sand (8) to form the position limiter (2). S5. After temporarily fixing the components by spot welding with steel bars, install the steel arch (1) using the conventional process. At least two symmetrically installed position limiters (2) are installed on the steel arch formed by the steel arch (1). Knock off the spot-welded steel bars and then initially spray concrete. On-site, use materials such as geotextiles and plastics to protect the pressure relief hole (203) and the external plug (7) from being damaged. S6. After the installation of the position limiter (2) is completed, during the construction process, use the external plug (7) to monitor the internal stress of the steel arch (1) and perform in-tunnel monitoring and measurement work well. When the first-layer steel arch deforms to the reserved deformation amount, that is, when the sand in the cylinder has leaked out completely and the position limiter enters the constant resistance stage, construct the second-layer steel arch to form a double-layer arch initial support system. The second-layer steel arch has an observation port (3) opened at the position where the position limiter (2) is installed on the first-layer steel arch. S7. Insert the pressure-bearing element steel column (201) into the pressure-bearing element steel cylinder (202) to a certain depth to fix the deformation direction. At the same time, gradually increase the pressure of the pressure-bearing element steel column (201) to compact the sand (8) to achieve slow and directional deformation, which is the pressure increase and deformation stage. S8. After the internal stress of the pressure-bearing element steel cylinder (202) is concentrated to a certain extent, the deformation part (5) is compressed and deformed to expose the pressure relief hole (203) and the sand (8) leaks out for unloading, which is the constant pressure deformation stage. Until the sand (8) has leaked out completely, the pressure-bearing element steel column (201) is inserted into the bottom of the pressure-bearing element steel cylinder (202), and finally, it serves as the connection to the next process in the constant resistance stage of the arch frame.

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