Hierarchical thread multi-stage yielding steel arch and design method

Abstract

The application discloses a hierarchical thread multi-stage yielding steel arch and a design method, the steel arch is composed of a plurality of steel arch assemblies, two adjacent steel arch assemblies are connected through hierarchical thread multi-stage yielding devices, the hierarchical thread multi-stage yielding device is composed of a multi-stage yielding device upper assembly and a multi-stage yielding device lower assembly which cooperate 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 an 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 a multi-stage yielding damper, 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 hierarchical thread multi-stage yielding device can self-adapt to large deformation of different surrounding rocks according to different geological conditions or surrounding rock deformation, and can protect the steel arch and the tunnel.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of efficient support of tunnels and control of large deformation of soft rock, and in particular to a stepped thread multi-stage yielding steel arch and a design method. BACKGROUND

[0002] In tunnel excavation, when the tunnel passes through a fault fracture zone or soft surrounding rock, etc., the problem of large deformation of the surrounding rock caused by extrusion will occur. The pressure of the surrounding rock caused by large deformation will cause serious damage to the support in the tunnel, affecting the construction progress, and in severe cases, leading to the destruction of the tunnel and even threatening the safety of construction personnel.

[0003] Existing research shows that yielding support is an effective technical measure to deal with the problem of large deformation of the surrounding rock caused by extrusion. In the prior art, the steel arch device for inhibiting large deformation of a tunnel disclosed in Publication No. CN214997711 U sets an adapter device between the steel arches, and the adapter device is composed of a box body, a top plate, a yielding rod, a steel arch adapter plate and a spring. A plurality of yielding rods are arranged on the top plates at both ends of the box body, and a spring is nested on the yielding rod. One end of the spring is connected with the yielding rod, and the other end is connected with the top plate. The deformation of the adapter device is used to replace the deformation of the steel arch, thereby reducing the stress on the steel arch and protecting the steel arch. The steel arch connecting component for plug-in type spherical hinge type quantifiable yielding and the use method disclosed in Patent ZL 201910995638.6 set a connecting component between two steel arches, and 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 thread part is arranged on the inner wall of the sleeve near the closed end, and a one-way clamping part is arranged on the inner wall of the open end of the sleeve. By inserting the connecting rod into the sleeve, the internal thread of the sleeve and the spherical end are extruded and sheared to generate resistance, thereby realizing yielding deformation. However, the existing technology has the following problems: (1) In fact, different geological conditions have different surrounding rock deformations, and the steel arch lacks the setting of self-adaptation to different surrounding rocks; (2) The large deformation of the surrounding rock is divided into several stages, and the steel arch lacks real-time self-adjustment and matching of the yielding deformation setting of each stage of the surrounding rock deformation; (3) The traditional yielding connecting rod is not firmly connected with the steel arch, and cannot effectively ensure the stability of the steel arch; and (4) The yielding device is arranged between the steel arches, and the yielding deformation amount is limited. SUMMARY

[0004] The present application aims at providing a hierarchical thread multi-stage yielding steel arch based on the above-mentioned prior art, which is composed of a plurality of steel arch components, and adjacent two steel arch components are connected by a hierarchical thread multi-stage yielding device, which is composed of a multi-stage yielding device upper component and a multi-stage yielding device lower component, and the multi-stage yielding device upper component and the multi-stage yielding device lower component are installed on the upper steel arch component and the lower steel arch component respectively.

[0005] The present application aims at providing a hierarchical thread multi-stage yielding steel arch based on the above-mentioned prior art, which is composed of a plurality of steel arch components, and adjacent two steel arch components are connected by a hierarchical thread multi-stage yielding device, which is composed of a multi-stage yielding device upper component and a multi-stage yielding device lower component, and the multi-stage yielding device upper component and the multi-stage yielding device lower component are installed on the upper steel arch component and the lower steel arch component respectively.

[0006] A hierarchical thread multi-stage yielding steel arch, which is composed of a plurality of steel arch components, the steel arch component is an I-beam structure, adjacent two steel arch components are connected by a hierarchical thread multi-stage yielding device, the adjacent two steel arch components are an upper steel arch component and a lower steel arch component respectively, the hierarchical thread multi-stage yielding device is composed of a multi-stage yielding device upper component and a multi-stage yielding device lower component which cooperate with each other, the multi-stage yielding device upper component and the multi-stage yielding device lower component are installed on the upper steel arch component and the lower steel arch component respectively; the multi-stage yielding device upper component comprises a sleeve, a connecting rod and a spherical end, the sleeve is a rectangular structure with a cover on the upper part which is assembled by an upper end plate and four side plates, the connecting rod is provided with a plurality of connecting rods, 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 component comprises a lower end plate and a multi-stage yielding damper, a plurality of through holes are formed on the lower end plate, and one multi-stage yielding damper is installed in each through hole, the multi-stage yielding device lower component and the lower steel arch component are installed in the sleeve, and the connecting rod and the spherical end are installed in the multi-stage yielding damper.

[0007] The multi-stage yielding damper comprises a damping cylinder and a bottom end plate, the damping cylinder is internally provided with a plurality of hierarchical threads, the inner diameter of each hierarchical thread decreases from top to bottom, and the bottom end plate is arranged at the bottom end of the damping cylinder and used for closing the bottom end of the damping cylinder.

[0008] The top of the damping cylinder is provided with a one-way clamping buckle.

[0009] The one-way clamping buckle is composed of a plurality of arc-shaped rotating plates, the arc-shaped rotating plates are arranged along the inner circumferences of the opening ends of the damping cylinder, the outer sides of the arc-shaped rotating plates are connected with the damping cylinder through rotatable members, and the inner sides of the arc-shaped rotating plates form a hole through which the connecting rod passes.

[0010] The inner wall of the side plate of the sleeve facing the wing plate of the steel arch frame assembly is provided with multiple parallel sliding grooves, and multiple self-rotating ball bearings are spaced apart in the sliding grooves.

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

[0012] The upper end plate of the upper component of the multi-stage pressure relief 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 relief device and the connecting plate of the lower steel arch frame component, are all connected by bolts.

[0013] The upper component and the lower component of the multi-stage pressure relief device are respectively mounted on the upper steel arch frame assembly and the lower steel arch frame assembly via connecting cylinders. The connecting cylinder is provided with an I-shaped groove that mates with the steel arch frame assembly. The two connecting cylinders are the upper connecting cylinder and the lower connecting cylinder. The upper connecting cylinder is connected to the upper end plate of the upper component of the multi-stage pressure relief device, and the lower connecting cylinder is connected to the lower end plate of the lower component of the multi-stage pressure relief device.

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

[0015] Let the radius of the spherical end be r; the multi-stage pressure relief device with graded threads has n multi-stage pressure relief dampers, each multi-stage pressure relief damper has m graded threads, each stage of the thread has k threads, and the inner diameter of the damping cylinder of each multi-stage pressure relief damper is R; the width W of the i-th graded thread. i The height is H i At the same time, it is required that H is satisfied. i <R,H i If +r>R, to ensure the stiffness of the i-th grade thread, the thread tip angle must be no less than 60°. Then the spherical end shears the i-th grade thread width w i and height h i They are respectively:

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

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

[0018] In the formula, i = 1, 2, ..., m;

[0019] If the shear strength of the graded thread is τ, then the i-th graded thread can provide a shear force F.i For:

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

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

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

[0023] The advantages of the present application are:

[0024] (1) The spherical end abuts and shears the first hierarchical thread, when the steel arch deforms to a certain critical value, the spherical end abuts and shears the second hierarchical thread, automatically starting the secondary deformation, and the spherical end abuts and shears the third hierarchical thread, automatically starting the tertiary deformation, realizing multi-stage pressure relief of large deformation of the steel arch;

[0025] (2) The hierarchical thread can adapt to different surrounding rocks according to different geological conditions or surrounding rock deformation, protecting the steel arch;

[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 itself, preventing the steel arch from being twisted and crushed;

[0027] (4) The hierarchical thread multi-stage pressure relief device is integrally arranged with the steel arch, which can realize fast connection between the steel arches, and the formed steel arch is firm and reliable, which can speed up the initial support construction efficiency, ensure the support time, effectively control the tunnel deformation, and ensure the safety of tunnel construction;

[0028] (5) The butt joint cylinder of the hierarchical thread multi-stage pressure relief device can realize fast connection between the steel arches, and the formed steel arch is firm and reliable, which can speed up the initial support construction efficiency, ensure the support time, effectively control the tunnel deformation, and ensure the safety of tunnel construction;

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

[0030] (7) The multi-stage pressure relief damper is arranged at the lower part of the lower end plate of the steel arch, when the deformation of the multi-stage pressure relief damper reaches the limit, the upper end plate and the lower end plate of the steel arch can be completely attached, which can fully utilize the small space between the steel arches, increase the deformation amount of the steel arch, and at the same time, can enhance the stability of the steel arch;

[0031] (8) Based on the graded thread design theory, the dimensions and materials of each component of the graded pressure relief device can be designed according to the actual large deformation requirements of the tunnel. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the steel arch frame in Embodiment 1 of the present invention;

[0033] Figure 2 for Figure 1 Sectional view of AA in the middle;

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

[0035] Figure 4 This is a schematic cross-sectional view of the components of the multi-stage pressure relief device in Embodiment 1 of the present invention;

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

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

[0038] Figure 7 This is a schematic diagram of the steel arch frame in Embodiment 2 of the present invention;

[0039] Figure 8 for Figure 7 Cross-sectional view of the middle section (BB);

[0040] Figure 9 This is a schematic diagram of the graded thread multi-stage pressure relief device in Embodiment 2 of the present invention;

[0041] Figure 10 This is a schematic diagram of the components of the multi-stage pressure relief device in Embodiment 2 of the present invention;

[0042] Figure 11 This is a schematic cross-sectional view of the components of the multi-stage pressure relief device in Embodiment 2 of the present invention;

[0043] Figure 12 for Figure 10 CC section view;

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

[0045] Figure 14 This is a schematic cross-sectional view of the lower component of the multi-stage pressure relief device in Embodiment 2 of the present invention;

[0046] Figure 15 This is a schematic diagram of the upper steel arch frame assembly in Embodiment 2 of the present invention;

[0047] Figure 16 Figure 2 is a schematic diagram of the lower steel arch assembly in the embodiment 2 of the present application;

[0048] Figure 17 Figure 3 is a schematic diagram of the steel arch in the embodiment 3 of the present application;

[0049] Figure 18 Figure 4 is a schematic diagram of the steel arch in the embodiment 4 of the present application; Figure 17 Figure 5 is a cross-sectional view along the line D-D in Figure 4;

[0050] Figure 19 Figure 6 is a schematic diagram of the stepped thread multi-stage yielding device in the embodiment 3 of the present application;

[0051] Figure 20 Figure 7 is a schematic diagram of the upper assembly of the multi-stage yielding device in the embodiment 3 of the present application;

[0052] Figure 21 Figure 8 is a cross-sectional view along the line E-E in Figure 7;

[0053] Figure 22 Figure 9 is a schematic diagram of the lower assembly of the multi-stage yielding device in the embodiment 3 of the present application; Figure 20

[0054] Figure 10 is a cross-sectional view along the line F-F in Figure 9; Figure 23

[0055] Figure 11 is a schematic diagram of the stepped thread multi-stage yielding device in the embodiment 4 of the present application; Figure 24

[0056] Figure 12 is a schematic diagram of the stepped thread multi-stage yielding device in the embodiment 5 of the present application; Figure 25 Figure 13 is a schematic diagram of the stepped thread multi-stage yielding device in the embodiment 6 of the present application;

[0057] Figure 26 Figure 14 is a schematic diagram of the relationship between the multi-stage yielding displacement and the load of the stepped thread multi-stage yielding device in the embodiment 3 of the present application;

[0058] As shown in Figure 1, the symbols in the figure represent: Figures 1-26

[0059] a. steel arch;

[0060] 1. stepped thread multi-stage yielding device, 2. steel arch assembly;

[0061] 11. upper assembly of the multi-stage yielding device, 12. lower assembly of the multi-stage yielding device;

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

[0063] ​121. Lower end plate; 122. Through hole; 123. Multi-stage pressure damper; 124. Damping cylinder; 125. Bottom sealing end plate; 126. First stage thread; 127. Second stage thread; 128. Third stage thread; 129. One-way snap-fit.

[0064] 21. Upper steel arch frame assembly, 22. Lower steel arch frame assembly, 23. Connecting plate, 24. Bolt, 25. Nut. Detailed Implementation

[0065] The features and other related features of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments, so as to facilitate understanding by those skilled in the art:

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

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

[0068] The upper component 11 of the multi-stage pressure relief 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, assembled from an upper end plate 112 and four side plates 113. The sleeve 111 is connected to the upper steel arch frame assembly 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 located inside the sleeve 111. The spherical end 115 is connected to the lower end of the connecting rod 114. The four spherical ends 115 are located on both sides of the web of the upper steel arch frame assembly 21.

[0069] The lower assembly 12 of the multi-stage pressure relief device comprises a lower end plate 121 and multi-stage pressure relief dampers 123. The lower end plate 121 is installed on the lower steel arch assembly 22. The cross-sectional size of the lower assembly 12 (the lower end plate 121), the cross-sectional size of the lower steel arch assembly 22, and the cross-sectional size of the inside of the sleeve 111 correspond to each other. The lower assembly 12 and the lower steel arch assembly 22 are both installed inside the sleeve 111 and move along the extension direction of the inside of the sleeve 111. Four through holes 122 are formed in the lower end plate 121. One multi-stage pressure relief damper 123 is welded or threadedly connected and installed in each through hole 122. The positions and numbers of the spherical end heads 115 of the upper assembly 11 correspond to the positions and numbers of the multi-stage pressure relief dampers 123 of the lower assembly 12, respectively. The four multi-stage pressure relief dampers 123 are located on both sides of the web of the lower steel arch assembly 22, respectively. The multi-stage pressure relief damper 123 comprises a damping cylinder 124 and a bottom sealing end plate 125. The damping cylinder 124 is internally provided with multi-stage threads. The inner diameter of each stage of threads decreases from top to bottom. In this embodiment, the multi-stage threads are three-stage threads. The three-stage threads comprise a first sub-stage thread 126, a second sub-stage thread 127, and a third sub-stage thread 128 arranged from top to bottom. The inner diameter of the first sub-stage thread 126 is larger than that of the second sub-stage thread 127. The inner diameter of the second sub-stage thread 127 is larger than that of the third sub-stage thread 128. The bottom sealing end plate 125 is arranged at the bottom end of the damping cylinder 124 and is used to seal 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 relief damper 123. In addition, the top of the damping cylinder 124 is provided with a one-way clamping buckle 129. The one-way clamping buckle 129 can limit the spherical end head 115 and prevent the spherical end head 115 from moving out of the damping cylinder 124. The one-way clamping buckle 129 is composed of a plurality of arc-shaped rotating plates. The arc-shaped rotating plates are arranged along the inner periphery of the opening end of the damping cylinder 124. In this embodiment, there are four arc-shaped rotating plates. The outer side of each arc-shaped rotating plate is connected to the damping cylinder 124 through a rotatable piece (a torsional spring can be used). A hole through which the connecting rod 114 passes is formed between the inner sides of the four arc-shaped rotating plates. In the normal state, the arc-shaped rotating plates are in a horizontal state. When the arc-shaped rotating plates are subjected to a downward force, the arc-shaped rotating plates rotate downward. When the downward force disappears, the arc-shaped rotating plates rotate back to the horizontal state. When the arc-shaped rotating plates are subjected to an upward force, the arc-shaped rotating plates remain in the horizontal state and do not rotate upward.

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

[0071] When the spherical end head 115 presses the one-way snap buckle 129 downward, the arc-shaped rotating plate rotates downward, so that the spherical end head 115 enters the damping cylinder 124, when the spherical end head 115 completely enters the damping cylinder 124, the arc-shaped rotating plate rotates to the horizontal state, the connecting rod 114 is located in the hole formed between the inner side of the arc-shaped rotating plate, the one-way snap buckle 129 can limit the spherical end head 115, prevent the spherical end head 115 from separating from the damping cylinder 124, and the hole formed between the inner side of the arc-shaped rotating plate guides the connecting rod 114. When the spherical end head 115 abuts and shears the first stepped thread 126, when the steel arch a deforms to a certain critical value, the spherical end head 115 abuts and shears the second stepped thread 127, and automatically starts the secondary deformation, and the spherical end head 115 abuts and shears the third stepped thread 128, and automatically starts the tertiary deformation, realizing the multi-stage pressure relief of the large deformation of the steel arch a. When the multi-stage pressure relief damper 123 deforms to the limit, the upper end plate 112 and the lower end plate 121 can be completely attached, the small space between the steel arch a can be fully utilized, the deformation amount of the steel arch a is increased, and the stability of the steel arch a is enhanced.

[0072] As shown in Figures 25-26 , the design method of the stepped thread multi-stage pressure relief device 1 is as follows:

[0073] Suppose the radius of the spherical end head is r; the stepped 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 stepped threads, each stepped 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 W i of the i-th stepped thread is H i , and it is required to satisfy H i <R, H i +r>R, in order to ensure the stiffness of the i-th stepped thread, it is required that the thread top angle is not less than 60°, then The width w i and the height h i of the spherical end head shearing the i-th stepped thread are respectively:

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

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

[0076] In the formula, i=1, 2, …, m;

[0077] The shear strength of the stepped thread is τ, and the i-th stepped thread can provide shear force F i :

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

[0079] The hierarchical thread multi-stage pressure relief device can provide vertical force as:

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

[0081] In the Figure 25 , F n is the vertical force received by the connecting rod, in Figure 26 , s is the deformation value of the steel arch, nF1 is the vertical force that the first hierarchical thread can provide, s1 is the maximum deformation value of the steel arch when the spherical end is located in the first hierarchical thread, nF2 is the vertical force that the second hierarchical thread can provide, s2 is the maximum deformation value of the steel arch when the spherical end is located in the second hierarchical thread, nF m is the vertical force that the mth hierarchical thread can provide, s m is the maximum deformation value of the steel arch when the spherical end is located in the mth hierarchical thread.

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

[0083] (1) The spherical end abuts and shears the first hierarchical thread, when the deformation of the steel arch reaches a certain critical value, the spherical end abuts and shears the second hierarchical thread, automatically starting the secondary deformation, and the spherical end abuts and shears the third hierarchical thread, automatically starting the tertiary deformation, realizing multi-stage pressure relief of large deformation of the steel arch;

[0084] (2) According to different geological conditions or surrounding rock deformation, the hierarchical thread can adapt to different surrounding rocks, protecting the steel arch;

[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 itself, preventing the steel arch from being twisted and crushed;

[0086] (4) The hierarchical thread multi-stage pressure relief device is integrally arranged with the steel arch, can realize rapid connection between the steel arches, and forms a firm and reliable steel arch, speeds up the initial support construction efficiency, ensures the support opportunity, effectively controls the tunnel deformation, and ensures the safety of tunnel construction;

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

[0088] (6) The multi-stage pressure damper is set at the lower part of the lower end plate of the steel arch frame. When the deformation of the multi-stage pressure 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) Based on the graded thread design theory, the dimensions and materials 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: As Figures 7-16 As shown, this embodiment relates to a graded threaded multi-stage pressure relief steel arch frame. Except for the different connection method between the graded threaded multi-stage pressure relief device 1 and the steel arch frame assembly 2, and the fact that the side plate 113 is provided with a friction reduction device, the other structures of the steel arch frame a in this embodiment are the same as those of the steel arch frame a in embodiment 1, so they will not be described again here.

[0091] Specifically, the upper end plate 112 of the upper component 11 of the multi-stage pressure relief device and the connecting plate 23 of the upper steel arch frame component 21, as well as the lower end plate 121 of the lower component 12 of the multi-stage pressure relief device and the connecting plate 23 of the lower steel arch frame component 22, are all connected by bolts. The connecting plate 23 of the lower steel arch frame component 22 has a mounting hole for placing the multi-stage pressure relief damper 123 (damping cylinder 124). The upper end plate 112 of the upper component 11, the connecting plate 23 of the upper steel arch frame component 21, the lower end plate 121 of the lower component 12 of the multi-stage pressure relief device, and the connecting plate 23 of the lower steel arch frame component 22 all have four bolt holes arranged in an array. The bolt structure consists of bolts 24 and nuts 25.

[0092] The inner wall of the side plates 113 of the sleeve 111, which are located on the two flanges facing the steel arch frame assembly 2, is provided with multiple parallel sliding grooves 116. Multiple self-rotating ball bearings 117 are spaced apart within each sliding groove 116. That is, the ball bearings 117 cannot move vertically along the sliding groove 116, but can rotate. The ball bearings 117 arranged on the side plates 113 of the sleeve 111 reduce the friction between the sleeve 111 and the lower steel arch frame assembly 22.

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

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

[0095] Specifically, the upper assembly 11 and the lower assembly 12 of the multi-stage yielding device are respectively installed on the upper steel arch assembly 21 and the lower steel arch assembly 22 through the butt cylinders 118, the butt cylinders 118 are provided with the I-shaped grooves 119 matched with the steel arch assemblies 2, the steel arch assemblies 2 can be inserted into the I-shaped grooves 119 of the butt cylinders 118 to complete the quick connection between the steel arch assemblies 2 and the multi-stage yielding device 1, the two butt cylinders 118 are respectively the upper butt cylinder and the lower butt cylinder, the upper butt cylinder is connected with the upper end plate 112 of the upper assembly 11 of the multi-stage yielding device, and the lower butt cylinder is connected with the lower end plate 121 of the lower assembly 12 of the multi-stage yielding device.

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

[0097] The working method and the design method of the multi-stage yielding device 1 in the embodiment are the same as those of the multi-stage yielding device 1 in the embodiment 1, and thus will not be described here.

[0098] Although the above embodiments have been described in detail with reference to the accompanying drawings for the purpose of the conception and embodiments of the present application, those skilled in the art can recognize that various improvements and changes can be made to the present application without departing from the scope defined by the claims, and thus will not be described here.

Claims

1. A stepped threaded multi-stage yield steel arch characterized in that: The steel arch is composed of a plurality of steel arch assemblies, the steel arch assembly is an I-shaped steel structure, two adjacent steel arch assemblies are connected by a hierarchical thread multi-stage yielding device, the two adjacent steel arch assemblies are an upper steel arch assembly and a lower steel arch assembly, the hierarchical thread multi-stage yielding device is composed of a multi-stage yielding device upper assembly and a multi-stage yielding device lower assembly, the multi-stage yielding device upper assembly and the multi-stage yielding device lower assembly are respectively installed on the upper steel arch assembly and the lower steel arch assembly; the multi-stage yielding device upper assembly comprises a sleeve, a connecting rod and a spherical end, the sleeve is a rectangular structure with a cover and is assembled from an upper end plate and four side plates, the connecting rod is provided in plurality, 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 a multi-stage yielding damper, 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 multi-stage yielding device lower assembly and the lower steel arch assembly are both installed in the sleeve, and the connecting rod and the spherical end are both installed in the multi-stage yielding damper.

2. A hierarchical threaded multi-stage yield steel arch as claimed in claim 1, characterized in that: The multi-stage yielding damper comprises a damping cylinder and a bottom sealing end plate, a plurality of hierarchical threads are arranged in the damping cylinder, the inner diameter of each hierarchical thread decreases from top to bottom, and the bottom sealing end plate is arranged at the bottom end of the damping cylinder and used for sealing the bottom end of the damping cylinder.

3. A stepped threaded multi-step yield steel arch as claimed in claim 2, wherein: The top of the damping cylinder is provided with a one-way clamping buckle.

4. A stepped threaded multi-step yield steel arch as claimed in claim 3, wherein: The one-way clamping buckle is composed of a plurality of arc-shaped rotating plates, the arc-shaped rotating plates are arranged along the inner circumferential surface of the opening end of the damping cylinder, the outer side of each arc-shaped rotating plate is connected with the damping cylinder through a rotatable piece, and a hole allowing the connecting rod to pass through is formed between the inner sides of the arc-shaped rotating plates.

5. A hierarchical threaded multi-stage yield steel arch as claimed in claim 1, characterized in that: The inner walls of the side plates of the sleeve facing the steel arch assemblies are provided with a plurality of sliding grooves arranged side by side, and a plurality of self-rotating balls are arranged in the sliding grooves at intervals.

6. A hierarchical threaded multi-level yield steel arch as defined in claim 1, wherein: The sleeve is connected with the upper steel arch assembly through the upper end plate, and the lower end plate is installed on the lower steel arch assembly.

7. A hierarchical threaded multi-level yield steel arch as defined in claim 1, wherein: The upper end plate of the multi-stage yielding device upper assembly and the connecting plate of the upper steel arch assembly are connected through a bolt structure, and the lower end plate of the multi-stage yielding device lower assembly and the connecting plate of the lower steel arch assembly are also connected through a bolt structure.

8. A hierarchical threaded multi-level yield steel arch as defined in claim 1, wherein: The multi-stage yielding device upper assembly and the multi-stage yielding device lower assembly are respectively installed on the upper steel arch assembly and the lower steel arch assembly through butt cylinders, the butt cylinders are provided with I-shaped grooves matched with the steel arch assemblies, the two butt cylinders are an upper butt cylinder and a lower butt cylinder, the upper butt cylinder is connected with the upper end plate of the multi-stage yielding device upper assembly, and the lower butt cylinder is connected with the lower end plate of the multi-stage yielding device lower assembly.

9. The method for designing a hierarchical thread multi-stage yield arch according to any one of claims 1-8, characterized in that: The design method comprises the following steps: The radius of the spherical head is r; the stepped thread multi-stage pressure releasing device is provided with n multi-stage pressure releasing dampers, each of which is provided with m stepped threads, each stepped thread is provided with k threads, and the inner diameter of each multi-stage pressure releasing damper is R; the width of the ith stepped thread is W i , and the height is H i ; meanwhile, the requirements of H i <R, H i +r>R are met, in order to ensure the stiffness of the ith stepped thread, the thread top angle is required to be not less than 60°, so that The width w i and the height h i of the spherical head shearing the ith stepped thread are respectively: w i = W i (r + H i -R) / H i ; h i = r + H i -R; In the formula, i = 1, 2, …, m; The shear strength of the stepped thread is τ, and the i-th stepped thread can provide a shear force F i is: F i = 2πr x w i x τ = 2πrτW i (r + H i - R) / H i ; The hierarchical thread multi-stage yielding device can provide a vertical force of: F = n x F i = 2nπrτW i (r + H i -R) / H i .

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