Graded thread multi-stage yielding steel arch and design method

Abstract

The invention discloses a graded thread multi-stage yielding steel arch and a design method, the steel arch is composed of a plurality of steel arch assemblies, every two adjacent steel arch assemblies are connected through a graded thread multi-stage yielding device, and the graded thread multi-stage yielding device is composed of a multi-stage yielding device upper assembly and a multi-stage yielding device lower assembly which are matched with each other; the multi-stage yielding device upper assembly comprises a sleeve, a connecting rod and a spherical end, the connecting rod is installed on the upper end plate and located in the sleeve, the spherical end is connected with the lower end of the connecting rod, the multi-stage yielding device lower assembly comprises a lower end plate and multi-stage yielding dampers, a plurality of through holes are formed in the lower end plate, and one multi-stage yielding damper is installed in each through hole. The yielding damper has the advantages that according to different geological conditions or surrounding rock deformation, the graded threads in the yielding damper designed through stress analysis can adapt to large deformation of different surrounding rocks, and the safety of a steel arch and a tunnel is protected.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel efficient support and soft rock large deformation control, in particular to a graded thread multi-stage yielding steel arch frame and a design method thereof. Background Art

[0002] During tunnel excavation, when the tunnel passes through fault fracture zones or soft surrounding rocks, large deformation of the surrounding rock will occur. The surrounding rock pressure caused by large deformation will cause serious damage to the support inside the tunnel, affect the construction progress, and in severe cases cause the destruction of the tunnel, and even threaten the lives of construction workers.

[0003] Existing research shows that yield support is an effective technical measure to deal with the problem of large deformation caused by surrounding rock compression. In the prior art, the "Steel Arch Frame Device for Suppressing Large Deformation of Tunnel" with publication number CN214997711 U sets a connection device between steel arch frames, and the connection device consists of a box body, a top plate, a yield rod, a steel arch frame connection plate and a spring. A plurality of yield rods are arranged on the top plates at both ends of the box body, and springs are nested on the yield rods. One end of the spring is connected to the yield rod, and the other end is connected to the top plate. The deformation of the steel arch frame is replaced by the deformation of the connection device, thereby reducing the stress on the steel arch frame and protecting the steel arch frame. Patent ZL 201910995638.6 "A plug-in ball-jointed steel arch frame connecting component with quantifiable pressure relief and its use method" sets a connecting component between two steel arch frames. The connecting component includes a connecting rod and a sleeve. The connecting rod includes a spherical end at one end, a threaded end at the other end and a rod body in the middle; the sleeve is a cylindrical structure with one end closed and the other end open. An internal threaded portion is provided on the inner wall of the sleeve near the closed end, and a one-way clamping portion is provided on the inner wall of the open end of the sleeve. By inserting the connecting rod into the sleeve, the threads in the cylinder and the spherical end are squeezed and sheared to generate resistance, thereby achieving deformation and pressure relief. However, the existing technology has the following problems: (1) In fact, the geological conditions are different and the deformation of the surrounding rock is also different, and the steel arch frame lacks a setting to adapt to different surrounding rocks; (2) The large deformation of the surrounding rock is divided into multiple stages, and the steel arch frame lacks a setting for real-time self-adjustment to match the various stages of surrounding rock deformation; (3) The traditional yielding connecting rod is not firmly connected to the steel arch frame, and the stability of the steel arch frame cannot be effectively guaranteed; (4) The yielding device is placed between the steel arch frames, and the yielding deformation is limited. Summary of the invention

[0004] The object of the present invention is to provide a graded thread multi-stage yielding steel arch frame and a design method based on the above-mentioned deficiencies of the prior art. The steel arch frame is composed of a plurality of steel arch frame components, and two adjacent steel arch frame components are connected by a graded thread multi-stage yielding device. The graded thread multi-stage yielding device is composed of a multi-stage yielding device upper component and a multi-stage yielding device lower component that cooperate with each other. The multi-stage yielding of the steel arch frame with large deformation is achieved through the cooperation between the spherical end of the multi-stage yielding device upper component and the multi-stage yielding damper of the multi-stage yielding device lower component, and the parameters of the graded thread multi-stage yielding device are designed.

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] A graded thread multi-stage yielding steel arch frame, the steel arch frame is composed of a plurality of steel arch frame components, the steel arch frame components are I-beam structures, two adjacent steel arch frame components are connected by a graded thread multi-stage yielding device, the two adjacent steel arch frame components are respectively an upper steel arch frame component and a lower steel arch frame component, the graded thread multi-stage yielding device is composed of a multi-stage yielding device upper component and a multi-stage yielding device lower component that cooperate with each other, the multi-stage yielding device upper component and the multi-stage yielding device lower component are respectively installed on the upper steel arch frame component and the lower steel arch frame component; the multi-stage yielding device upper component includes a sleeve The sleeve is a rectangular structure with a cover on the upper part which is assembled from an upper end plate and four side plates. The connecting rods are provided with a plurality of connecting rods which are mounted on the upper end plate and located in the sleeve. The spherical end is connected to the lower end of the connecting rod. The lower component of the multi-stage pressure-relieving device comprises a lower end plate and a multi-stage pressure-relieving damper. The lower end plate is provided with a plurality of through holes, and each of the through holes is provided with a multi-stage pressure-relieving damper. The lower component of the multi-stage pressure-relieving device and the lower steel arch frame component are both mounted in the sleeve, and the connecting rod and the spherical end are both mounted in the multi-stage pressure-relieving damper.

[0007] The multi-stage pressure-releasing damper comprises a damping cylinder and a bottom end plate. The damping cylinder is provided with a multi-stage thread inside. The inner diameter of each stage of the multi-stage thread decreases from top to bottom. The bottom end plate is arranged at the bottom end of the damping cylinder and is used to close the bottom end of the damping cylinder.

[0008] A one-way snap buckle is provided on the top of the damping cylinder.

[0009] The one-way snap buckle is composed of a plurality of arc-shaped rotating plates, which are arranged along the inner circumference of the opening end of the damping cylinder. The outer sides of each of the arc-shaped rotating plates are connected to the damping cylinder through a rotatable part, and a hole allowing the connecting rod to pass through is formed between the inner sides of the plurality of arc-shaped rotating plates.

[0010] The inner walls of the two side plates in the sleeve that are arranged facing the wing plates of the steel arch frame assembly are provided with a plurality of parallel sliding grooves, and a plurality of rotatable balls are arranged at intervals in the sliding grooves.

[0011] The sleeve is connected to the upper steel arch assembly through the upper end plate, and the lower end plate is installed on the lower steel arch assembly.

[0012] The upper end plate of the upper component of the multi-stage pressure-releasing device and the connecting plate of the upper steel arch frame component, as well as the lower end plate of the lower component of the multi-stage pressure-releasing device and the connecting plate of the lower steel arch frame component are both connected by a bolt structure.

[0013] The multi-stage pressure-releasing device upper component and the multi-stage pressure-releasing device lower component are respectively installed on the upper steel arch frame component and the lower steel arch frame component through docking tubes, and the docking tubes are provided with I-shaped grooves that match the steel arch frame components. The two docking tubes are an upper docking tube and a lower docking tube respectively. The upper docking tube is connected to the upper end plate of the multi-stage pressure-releasing device upper component, and the lower docking tube is connected to the lower end plate of the multi-stage pressure-releasing device lower component.

[0014] A design method for a graded thread multi-stage yield steel arch frame, the design method comprising the following steps:

[0015] Assume that the radius of the spherical end is r; the graded thread multi-stage pressure relief device is provided with n multi-stage pressure relief dampers, each multi-stage pressure relief damper is provided with m graded threads, each graded thread is provided with k threads, and the inner diameter of the damping cylinder of each multi-stage pressure relief damper is R; the width of the i-th graded thread is W i , height is H i , and also requires that H i <R,H i +r>R, in order to ensure the i-th grade thread stiffness, the thread top angle is required to be no less than 60°, then Then the spherical end shears the i-th grade thread width w i and height h i They are:

[0016] w i =W i (r+H i -R) / H i ;

[0017] h i =r+H i -R;

[0018] Wherein, i = 1, 2, ..., m;

[0019] The shear strength of the graded thread is τ, then the i-th graded thread can provide a shear force Fi for:

[0020] F i =2πr×w i ×τ=2πrτW i (r+H i -R) / H i ;

[0021] Then the vertical force that the graded thread multi-stage pressure relief device can provide is:

[0022] F=n×F i =2nπrτW i (r+H i -R) / H i .

[0023] The advantages of the present invention are:

[0024] (1) The spherical end abuts and shears the first graded thread. When the deformation of the steel arch frame reaches a certain critical value, the spherical end abuts and shears the second graded thread, automatically starting the second grade deformation, and the spherical end abuts and shears the third graded thread, automatically starting the third grade deformation, thereby realizing multi-stage pressure relief for large deformation of the steel arch frame;

[0025] (2) The steel arch can be protected by adaptively adapting to different surrounding rocks through graded threads according to different geological conditions or surrounding rock deformation;

[0026] (3) When the surrounding rock pressure or deformation is large, the multi-stage pressure relief device can reduce the deformation of the steel arch frame itself and prevent the steel arch frame from twisting and crushing;

[0027] (4) The graded thread multi-stage pressure relief device is integrated with the steel arch frame, which can realize the rapid connection between the steel arch frames. The formed steel arch frame is firm and reliable, which speeds up the efficiency of the initial support construction, ensures the timing of support, effectively controls the deformation of the tunnel, and ensures the safety of tunnel construction;

[0028] (5) The butt-jointed tube of the graded thread multi-stage pressure relief device can realize the rapid connection between the steel arch frames, and the formed steel arch frame is firm and reliable, which speeds up the efficiency of the initial support construction, ensures the timing of support, effectively controls the deformation of the tunnel, and ensures the safety of tunnel construction;

[0029] (6) The steel arch frame is inserted into the sleeve and multiple connecting rods are inserted into the damping cylinder, which can not only guide the deformation direction of the steel arch frame, but also increase the overall stability between the steel arch frame and the pressure relief device;

[0030] (7) The multi-stage pressure-yielding damper is arranged at the lower part of the lower end plate of the steel arch frame. When the deformation of the multi-stage pressure-yielding damper reaches the limit, the upper end plate and the lower end plate of the steel arch frame can be completely fitted together, which can make full use of the small space between the steel arch frames, increase the deformation of the steel arch frame, and enhance the stability of the steel arch frame;

[0031] (8) Through the theory of graded thread design, the size and material of each component of the graded pressure relief device can be designed according to the actual large deformation requirements of the tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of the steel arch frame in Example 1 of the present invention;

[0033] Figure 2 for Figure 1 Middle AA section;

[0034] Figure 3 This is a schematic diagram of a graded thread multi-stage pressure relief device in Example 1 of the present invention;

[0035] Figure 4 It is a cross-sectional schematic diagram of the upper component of the multi-stage pressure relief device in Example 1 of the present invention;

[0036] Figure 5 This is a cross-sectional schematic diagram of the lower component of the multi-stage pressure relief device in Example 1 of the present invention;

[0037] Figure 6 for Figure 5 Enlarged view of middle b;

[0038] Figure 7 Schematic diagram of the steel arch frame in Example 2 of the present invention;

[0039] Figure 8 for Figure 7 Middle BB section;

[0040] Fig. 9 Schematic diagram of a graded thread multi-stage pressure relief device in Example 2 of the present invention;

[0041] Fig.10 This is a schematic diagram of the upper components of the multi-stage pressure relief device in Example 2 of the present invention;

[0042] Fig.11 It is a cross-sectional schematic diagram of the upper component of the multi-stage pressure relief device in Example 2 of the present invention;

[0043] Fig.12 for Fig.10 Middle CC section;

[0044] Fig.13 This is a schematic diagram of the lower component of the multi-stage pressure relief device in Example 2 of the present invention;

[0045] Fig.14 It is a cross-sectional schematic diagram of the lower component of the multi-stage pressure relief device in Example 2 of the present invention;

[0046] Fig.15 This is a schematic diagram of the upper steel arch assembly in Example 2 of the present invention;

[0047] Fig.16 This is a schematic diagram of the lower steel arch assembly in Example 2 of the present invention;

[0048] Fig.17 Schematic diagram of the steel arch frame in Example 3 of the present invention;

[0049] Fig.18 for Fig.17 Middle DD section;

[0050] Fig.19 Schematic diagram of a graded thread multi-stage pressure relief device in Example 3 of the present invention;

[0051] Fig. 20 This is a schematic diagram of the upper components of the multi-stage pressure relief device in Example 3 of the present invention;

[0052] Fig.21 It is a cross-sectional schematic diagram of the upper component of the multi-stage pressure-releasing device in Example 3 of the present invention;

[0053] Fig. 22 for Fig. 20 Middle EE section;

[0054] Fig.23 This is a schematic diagram of the lower component of the multi-stage pressure relief device in Example 3 of the present invention;

[0055] Fig.24 It is a cross-sectional schematic diagram of the lower component of the multi-stage pressure relief device in Example 3 of the present invention;

[0056] Fig.25 This is a schematic diagram of the force of the graded thread of the present invention;

[0057] Fig.26 This is a schematic diagram of the relationship between the multi-stage yield displacement and load of the graded thread of the present invention;

[0058] like Figures 1 to 26 As shown, the marks in the figure represent respectively:

[0059] a.Steel arch frame;

[0060] 1. Multi-stage pressure relief device with graded threads, 2. Steel arch assembly;

[0061] 11. Upper assembly of multi-stage pressure-releasing device, 12. Lower assembly of multi-stage pressure-releasing device;

[0062] 111. sleeve, 112. upper end plate, 113. side plate, 114. connecting rod, 115. spherical end, 116. slide groove, 117. ball bearing, 118. docking sleeve, 119. I-shaped groove;

[0063] 121. lower end plate, 122. through hole, 123. multi-stage pressure-releasing damper, 124. damping cylinder, 125. bottom end plate, 126. first graded thread, 127. second graded thread, 128. third graded thread, 129. one-way snap buckle;

[0064] 21. Upper steel arch frame assembly, 22. Lower steel arch frame assembly, 23. Connecting plate, 24. Bolts, 25. Nuts. DETAILED DESCRIPTION

[0065] The features of the present invention and other related features are further described in detail below through embodiments in conjunction with the accompanying drawings to facilitate understanding by those skilled in the art:

[0066] Example 1: Figures 1 to 6 As shown, this embodiment relates to a graded threaded multi-stage pressure-relieving steel arch frame, which is composed of multiple steel arch frame components 2. The steel arch frame components 2 are I-beam structures. Two adjacent steel arch frame components 2 are connected by a graded threaded multi-stage pressure-relieving device 1. The two adjacent steel arch frame components 2 are an upper steel arch frame component 21 and a lower steel arch frame component 22 respectively.

[0067] like Figures 1 to 6 As shown, the graded thread multi-stage yielding device 1 is composed of a multi-stage yielding device upper component 11 and a multi-stage yielding device lower component 12 that cooperate with each other. The multi-stage yielding device upper component 11 and the multi-stage yielding device lower component 12 are respectively installed on the upper steel arch frame component 21 and the lower steel arch frame component 22 by welding.

[0068] The upper component 11 of the multi-stage pressure-releasing device includes a sleeve 111, a connecting rod 114 and a spherical end 115. The sleeve 111 is a rectangular structure with a cover on the upper part, which is assembled from an upper end plate 112 and four side plates 113. The sleeve 111 is connected to the upper steel arch frame component 21 through the upper end plate 112. There are four connecting rods 114, which are arranged in an array. The connecting rods 114 are installed on the upper end plate 112 and are located in the sleeve 111. The spherical end 115 is connected to the lower end of the connecting rod 114. The four spherical ends 115 are respectively located on both sides of the web of the upper steel arch frame component 21.

[0069] The multi-stage pressure relief device lower component 12 includes a lower end plate 121 and a multi-stage pressure relief damper 123. The lower end plate 121 is installed on the lower steel arch component 22. The cross-sectional size of the multi-stage pressure relief device lower component 12 (lower end plate 121), the cross-sectional size of the lower steel arch component 22 and the cross-sectional size of the inside of the sleeve 111 correspond. The multi-stage pressure relief device lower component 12 and the lower steel arch component 22 are both installed inside the sleeve 111 and along the inside of the sleeve 111. The lower end plate 121 is provided with four through holes 122, and a multi-stage pressure-releasing damper 123 is welded or threadedly installed in each through hole 122. The position and quantity of the spherical end 115 of the multi-stage pressure-releasing device upper component 11 respectively correspond to the position and quantity of the multi-stage pressure-releasing dampers 123 of the multi-stage pressure-releasing device lower component 12, and the four multi-stage pressure-releasing dampers 123 are respectively located on both sides of the web of the lower steel arch frame component 22. The multi-stage pressure-yielding damper 123 includes a damping cylinder 124 and a bottom end plate 125. The damping cylinder 124 is provided with a multi-stage thread inside. The inner diameter of each stage of the multi-stage thread decreases from top to bottom. In this embodiment, the multi-stage thread is a three-stage thread. The three-stage thread includes a first graded thread 126, a second graded thread 127 and a third graded thread 128 arranged from top to bottom. The inner diameter of the first graded thread 126 is greater than the inner diameter of the second graded thread 127, and the inner diameter of the second graded thread 127 is greater than the third graded thread 128. The bottom end plate 125 is arranged at the bottom end of the damping cylinder 124 and is used to close the bottom end of the damping cylinder 124. The connecting rod 114 and the spherical end head 115 are both installed in the damping cylinder 124 of the multi-stage pressure-yielding damper 123. In addition, a one-way snap buckle 129 is provided at the top of the damping cylinder 124. The one-way snap buckle 129 can limit the spherical end 115 to prevent the spherical end 115 from moving outside the damping cylinder 124. The one-way snap buckle 129 is composed of a plurality of arc-shaped rotating plates, and the arc-shaped rotating plates are arranged along the inner circumference of the open end of the damping cylinder 124. In this embodiment, there are four arc-shaped rotating plates, and the outer sides of each arc-shaped rotating plate are connected to the damping cylinder 124 through a rotatable member (a torsion spring can be selected), and a hole is formed between the inner sides of the four arc-shaped rotating plates to allow the connecting rod 114 to pass through. Under normal conditions, the arc-shaped rotating plate is in a horizontal state. When the arc-shaped rotating plate is subjected to a downward force, the arc-shaped rotating plate rotates downward. When the downward force disappears, the arc-shaped rotating plate rotates back to a horizontal state, and when the arc-shaped rotating plate is subjected to an upward force, it is still in a horizontal state and will not rotate upward.

[0070] like Figures 1 to 6 As shown, the working method of the graded thread multi-stage pressure relief device 1 is as follows:

[0071] When the spherical end 115 presses the one-way snap buckle 129 downward, the arc-shaped rotating plate rotates downward, so that the spherical end 115 enters the damping cylinder 124. When the spherical end 115 completely enters the damping cylinder 124, the arc-shaped rotating plate rotates back to a horizontal state, and the connecting rod 114 is located in the hole formed between the inner sides of the arc-shaped rotating plate. The one-way snap buckle 129 can limit the spherical end 115 to prevent the spherical end 115 from being separated from the damping cylinder 124, and the hole formed between the inner sides of the arc-shaped rotating plate guides the connecting rod 114. The spherical end 115 abuts and shears the first graded thread 126. When the deformation of the steel arch frame a reaches a certain critical value, the spherical end 115 abuts and shears the second graded thread 127, automatically starting the second-stage deformation, and the spherical end 115 abuts and shears the third graded thread 128, automatically starting the third-stage deformation, and realizing multi-stage pressure relief of large deformation of the steel arch frame a. When the deformation of the multi-stage pressure damper 123 reaches the limit, the upper end plate 112 and the lower end plate 121 can be completely fitted together, and the small space between the steel arch frames a can be fully utilized to increase the deformation of the steel arch frames a and enhance the stability of the steel arch frames a.

[0072] like Figures 25-26 As shown, the design method steps of the graded thread multi-stage pressure relief device 1 are as follows:

[0073] Assume that the radius of the spherical end is r; the multi-stage pressure relief device with graded threads is provided with n multi-stage pressure relief dampers, each multi-stage pressure relief damper is provided with m graded threads, each graded thread is provided with k threads, and the inner diameter of the damping cylinder of each multi-stage pressure relief damper is R; the width of the i-th graded thread is W i , height H i , and also requires that H i <R,H i +r>R, in order to ensure the i-th grade thread stiffness, the thread top angle is required to be no less than 60°, then The spherical end shear thread width w of the i-th grade i and height h i They are:

[0074] w i =W i (r+H i -R) / H i ;

[0075] h i =r+H i -R;

[0076] Wherein, i = 1, 2, ..., m;

[0077] The shear strength of the graded thread is τ, then the i-th graded thread can provide a shear force F i for:

[0078] Fi =2πr×w i ×τ=2πrτW i (r+H i -R) / H i ;

[0079] The vertical force that the graded thread multi-stage pressure relief device can provide is:

[0080] F=n×F i =2nπrτW i (r+H i -R) / H i .

[0081] exist Fig.25 Medium, F n is the vertical force on the connecting rod. Fig.26 In the formula, s is the deformation value of the steel arch, nF1 is the vertical force that the first grade thread can provide, s1 is the maximum deformation value of the steel arch when the spherical end is located in the first grade thread, nF2 is the vertical force that the second grade thread can provide, s2 is the maximum deformation value of the steel arch when the spherical end is located in the second grade thread, nF m is the vertical force that the mth grade thread can provide, s m It is the maximum deformation value of the steel arch when the spherical end is located in the mth grade thread.

[0082] The beneficial technical effects of this embodiment are:

[0083] (1) The spherical end abuts and shears the first graded thread. When the deformation of the steel arch frame reaches a certain critical value, the spherical end abuts and shears the second graded thread, automatically starting the second grade deformation, and the spherical end abuts and shears the third graded thread, automatically starting the third grade deformation, thereby realizing multi-stage pressure relief for large deformation of the steel arch frame;

[0084] (2) The steel arch can be protected by adaptively adapting to different surrounding rocks through graded threads according to different geological conditions or surrounding rock deformation;

[0085] (3) When the surrounding rock pressure or deformation is large, the multi-stage pressure relief device can reduce the deformation of the steel arch frame itself and prevent the steel arch frame from twisting and crushing;

[0086] (4) The graded thread multi-stage pressure relief device is integrated with the steel arch frame, which can realize the rapid connection between the steel arch frames. The formed steel arch frame is firm and reliable, which speeds up the efficiency of the initial support construction, ensures the timing of support, effectively controls the deformation of the tunnel, and ensures the safety of tunnel construction;

[0087] (5) The steel arch frame is inserted into the sleeve and multiple connecting rods are inserted into the damping cylinder, which can not only guide the deformation direction of the steel arch frame, but also increase the overall stability between the steel arch frame and the pressure relief device;

[0088] (6) The multi-stage pressure-yielding damper is arranged at the lower part of the lower end plate of the steel arch frame. When the deformation of the multi-stage pressure-yielding damper reaches the limit, the upper end plate and the lower end plate of the steel arch frame can be completely fitted together, which can make full use of the small space between the steel arch frames, increase the deformation of the steel arch frame, and enhance the stability of the steel arch frame;

[0089] (7) Through the theory of graded thread design, the size and material of each component of the graded pressure relief device can be designed according to the actual large deformation requirements of the tunnel.

[0090] Example 2: Figures 7 to 16 As shown, this embodiment relates to a graded thread multi-stage pressure-relieving steel arch frame. Except that the connection method between the graded thread multi-stage pressure-relieving device 1 and the steel arch frame assembly 2 is different, and a friction reduction device is provided on the side plate 113, the other structures of the steel arch frame a in this embodiment are the same as the steel arch frame a in Example 1, so they will not be repeated here.

[0091] Specifically, the upper end plate 112 of the multi-stage pressure-releasing device upper assembly 11 and the connecting plate 23 of the upper steel arch assembly 21, as well as the lower end plate 121 of the multi-stage pressure-releasing device lower assembly 12 and the connecting plate 23 of the lower steel arch assembly 22 are connected by a bolt structure. Among them, the connecting plate 23 of the lower steel arch assembly 22 is provided with a placement hole for placing the multi-stage pressure-releasing damper 123 (damping cylinder 124), and the upper end plate 112 of the multi-stage pressure-releasing device upper assembly 11, the connecting plate 23 of the upper steel arch assembly 21, the lower end plate 121 of the multi-stage pressure-releasing device lower assembly 12 and the connecting plate 23 of the lower steel arch assembly 22 are provided with 4 screw holes, which are arranged in an array, and the bolt structure is composed of bolts 24 and nuts 25.

[0092] The inner walls of the two side plates 113 of the sleeve 111 facing the wing plates of the steel arch assembly 2 are provided with a plurality of parallel slide grooves 116, and a plurality of self-rotating balls 117 are arranged at intervals in the slide grooves 116, that is, the balls 117 cannot move along the vertical direction of the slide grooves 116, but can rotate. The balls 117 arranged on the side plates 113 of the sleeve 111 can reduce the friction between the sleeve 111 and the lower steel arch assembly 22.

[0093] The working method and design method of the graded thread multi-stage pressure-releasing device 1 in this embodiment are the same as the working method and design method of the graded thread multi-stage pressure-releasing device 1 in Example 1, so they will not be repeated here.

[0094] Example 3: Figures 17 to 24 As shown, this embodiment relates to a graded thread multi-stage pressure-relieving steel arch frame. Except that the connection method between the graded thread multi-stage pressure-relieving device 1 and the steel arch frame assembly 2 is different, and a friction reduction device is provided on the side plate 113, the other structures of the steel arch frame a in this embodiment are the same as the steel arch frame a in Example 1, so they will not be repeated here.

[0095] Specifically, the multi-stage pressure-releasing device upper component 11 and the multi-stage pressure-releasing device lower component 12 are respectively installed on the upper steel arch frame component 21 and the lower steel arch frame component 22 through the docking tube 118. The docking tube 118 is provided with an I-shaped groove 119 that matches the steel arch frame component 2. The steel arch frame component 2 can be inserted into the I-shaped groove 119 of the docking tube 118 to complete the quick connection between the steel arch frame component 2 and the graded threaded multi-stage pressure-releasing device 1. The two docking tubes 118 are respectively an upper docking tube and a lower docking tube. The upper docking tube is connected to the upper end plate 112 of the multi-stage pressure-releasing device upper component 11, and the lower docking tube is connected to the lower end plate 121 of the multi-stage pressure-releasing device lower component 12.

[0096] The inner walls of the two side plates 113 of the sleeve 111 facing the wing plates of the steel arch assembly 2 are provided with a plurality of parallel slide grooves 116, and a plurality of self-rotating balls 117 are arranged at intervals in the slide grooves 116, that is, the balls 117 cannot move along the vertical direction of the slide grooves 116, but can rotate. The balls 117 arranged on the side plates 113 of the sleeve 111 can reduce the friction between the sleeve 111 and the lower steel arch assembly 22.

[0097] The working method and design method of the graded thread multi-stage pressure-releasing device 1 in this embodiment are the same as the working method and design method of the graded thread multi-stage pressure-releasing device 1 in Example 1, so they will not be repeated here.

[0098] Although the above embodiments have described in detail the concepts and embodiments of the present invention with reference to the accompanying drawings, ordinary technicians in this field can recognize that various improvements and changes can still be made to the present invention without departing from the scope of the claims, so they are not described one by one here.

Claims

1. A graded thread multi-stage yield steel arch frame, characterized in that: The steel arch frame is composed of a plurality of steel arch frame components, and the steel arch frame components are I-beam structures. Two adjacent steel arch frame components are connected by a graded thread multi-stage pressure-releasing device. The two adjacent steel arch frame components are an upper steel arch frame component and a lower steel arch frame component, respectively. The graded thread multi-stage pressure-releasing device is composed of a multi-stage pressure-releasing device upper component and a multi-stage pressure-releasing device lower component that cooperate with each other. The multi-stage pressure-releasing device upper component and the multi-stage pressure-releasing device lower component are respectively installed on the upper steel arch frame component and the lower steel arch frame component; the multi-stage pressure-releasing device upper component includes a sleeve, a connecting rod and a spherical The end head is a rectangular structure with a cover on the upper part which is assembled from an upper end plate and four side plates. There are multiple connecting rods, which are installed on the upper end plate and located in the sleeve. The spherical end head is connected to the lower end of the connecting rod. The lower component of the multi-stage pressure-relieving device includes a lower end plate and a multi-stage pressure-relieving damper. The lower end plate is provided with multiple through holes, and each of the through holes is equipped with a multi-stage pressure-relieving damper. The lower component of the multi-stage pressure-relieving device and the lower steel arch frame component are both installed in the sleeve, and the connecting rod and the spherical end head are both installed in the multi-stage pressure-relieving damper.

2. A graded thread multi-stage yield steel arch as claimed in claim 1, characterized in that: The multi-stage pressure-releasing damper comprises a damping cylinder and a bottom end plate. The damping cylinder is provided with a multi-stage thread inside. The inner diameter of each stage of the multi-stage thread decreases from top to bottom. The bottom end plate is arranged at the bottom end of the damping cylinder and is used to close the bottom end of the damping cylinder.

3. A graded thread multi-stage yield steel arch as claimed in claim 2, characterized in that: A one-way snap buckle is provided on the top of the damping cylinder.

4. A graded thread multi-stage yield steel arch as claimed in claim 3, characterized in that: The one-way snap buckle is composed of a plurality of arc-shaped rotating plates, which are arranged along the inner circumference of the opening end of the damping cylinder. The outer sides of each of the arc-shaped rotating plates are connected to the damping cylinder through a rotatable part, and a hole allowing the connecting rod to pass through is formed between the inner sides of the plurality of arc-shaped rotating plates.

5. The graded thread multi-stage yield steel arch frame according to claim 1, characterized in that: The inner walls of the two side plates in the sleeve that are arranged facing the wing plates of the steel arch frame assembly are provided with a plurality of parallel sliding grooves, and a plurality of rotatable balls are arranged at intervals in the sliding grooves.

6. The graded thread multi-stage yield steel arch frame according to claim 1, characterized in that: The sleeve is connected to the upper steel arch assembly through the upper end plate, and the lower end plate is installed on the lower steel arch assembly.

7. The graded thread multi-stage yield steel arch frame according to claim 1, characterized in that: The upper end plate of the upper component of the multi-stage pressure-releasing device and the connecting plate of the upper steel arch frame component, as well as the lower end plate of the lower component of the multi-stage pressure-releasing device and the connecting plate of the lower steel arch frame component are both connected by a bolt structure.

8. The graded thread multi-stage yield steel arch frame according to claim 1, characterized in that: The multi-stage pressure-releasing device upper component and the multi-stage pressure-releasing device lower component are respectively installed on the upper steel arch frame component and the lower steel arch frame component through docking tubes, and the docking tubes are provided with I-shaped grooves that match the steel arch frame components. The two docking tubes are an upper docking tube and a lower docking tube respectively. The upper docking tube is connected to the upper end plate of the multi-stage pressure-releasing device upper component, and the lower docking tube is connected to the lower end plate of the multi-stage pressure-releasing device lower component.

9. A method for designing a graded thread multi-stage yield steel arch as claimed in any one of claims 1 to 8, characterized in that: The design method comprises the following steps: Assume that the radius of the spherical end is r; the graded thread multi-stage pressure relief device is provided with n multi-stage pressure relief dampers, each multi-stage pressure relief damper is provided with m graded threads, each graded thread is provided with k threads, and the inner diameter of the damping cylinder of each multi-stage pressure relief damper is R; the width of the i-th graded thread is W i , height is H i , and also requires that H i <R,H i +r>R, in order to ensure the i-th grade thread stiffness, the thread top angle is required to be no less than 60°, then Then the spherical end shears the i-th grade thread width w i and height h i They are: w i =W i (r+H i -R) / H i ; h i =r+H i -R; Wherein, i = 1, 2, ..., m; The shear strength of the graded thread is τ, then the i-th graded thread can provide a shear force F i for: F i =2πr×w i ×τ=2πrτW i (r+H i -R) / H i ; Then the vertical force that the graded thread multi-stage pressure relief device can provide is: F=n×F i =2nπrτW i (r+H i -R) / H i 。

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