Nonlinear continuous yielding steel arch and design method

Abstract

The invention discloses a non-linear continuous yielding steel arch and a design method, the steel arch is composed of a plurality of steel arch assemblies, and every two adjacent steel arch assemblies are connected through a non-linear continuous yielding device; the nonlinear continuous yielding device upper assembly comprises a sleeve, a connecting rod and a truncated cone end, a plurality of sliding grooves are formed in the inner walls of two side plates facing wing plates of the steel arch assembly, a plurality of balls are arranged in the sliding grooves at intervals, the connecting rod is installed on an upper end plate, and the truncated cone end is connected with the lower end of the connecting rod. The nonlinear continuous yielding device lower assembly comprises a lower end plate and nonlinear continuous yielding dampers, the lower end plate is installed on the lower steel arch assembly, a plurality of through holes are formed in the lower end plate, and one nonlinear continuous yielding damper is installed in each through hole. The non-linear continuous yielding damper has the advantages that the truncated cone end extrudes and rubs the truncated cone wall of the non-linear continuous yielding damper, non-linear continuous yielding deformation is achieved, the non-linear continuous yielding damper is adaptive to continuous 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 nonlinear continuous yielding steel arch frame and a design method. 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 purpose of the present invention is to provide a nonlinear continuous pressure-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 nonlinear continuous pressure-yielding device. The nonlinear continuous pressure-yielding device is composed of a nonlinear continuous pressure-yielding device upper component and a nonlinear continuous pressure-yielding device lower component that cooperate with each other. The nonlinear continuous pressure-yielding deformation is achieved by the cooperation between the truncated cone end of the nonlinear continuous pressure-yielding device upper component and the nonlinear continuous pressure-yielding device lower component, and the parameters of the nonlinear continuous pressure-yielding device are designed; the friction between the sleeve and the steel arch frame component can be reduced by the balls arranged on the sleeve of the nonlinear continuous pressure-yielding device upper component; the nonlinear continuous pressure-yielding device upper component and the nonlinear continuous pressure-yielding device lower component are both connected to the steel arch frame component through a docking sleeve, thereby achieving a quick connection between the steel arch frame component and the nonlinear continuous pressure-yielding device.

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

[0006] A nonlinear continuous pressure-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 nonlinear continuous pressure-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 nonlinear continuous pressure-yielding device is composed of a nonlinear continuous pressure-yielding device upper component and a nonlinear continuous pressure-yielding device lower component that cooperate with each other, the nonlinear continuous pressure-yielding device upper component and the nonlinear continuous pressure-yielding device lower component are respectively installed on the upper steel arch frame component and the lower steel arch frame component; the nonlinear continuous pressure-yielding device upper component includes a sleeve, a connecting rod and a truncated cone end, the sleeve is a rectangular structure with a cover on the upper part assembled from an upper end plate and four side plates, and two facing The inner wall of the side plate of the wing plate of the steel arch frame assembly is provided with a plurality of parallel sliding grooves, and a plurality of rotatable balls are arranged at intervals in the sliding grooves. A plurality of connecting rods are provided, and the connecting rod is mounted on the upper end plate and located in the sleeve. The truncated cone end head is connected to the lower end of the connecting rod, and the outer diameter of the truncated cone end head gradually decreases from top to bottom. The lower component of the nonlinear continuous pressure-releasing device includes a lower end plate and a nonlinear continuous pressure-releasing damper. The lower end plate is mounted on the lower steel arch frame assembly, and a plurality of through holes are opened on the lower end plate, and a nonlinear continuous pressure-releasing damper is installed in each of the through holes. The lower component of the nonlinear continuous pressure-releasing device and the lower steel arch frame assembly are both mounted in the sleeve, and the connecting rod and the truncated cone end head are both mounted in the nonlinear continuous pressure-releasing damper.

[0007] The nonlinear continuous pressure-yielding damper comprises a damping cylinder and a bottom-sealed end plate. A truncated cone wall is provided inside the damping cylinder. The inner diameter of the truncated cone wall gradually decreases from top to bottom. The bottom-sealed end plate is provided 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 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.

[0011] The upper end plate of the upper component of the nonlinear continuous 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 nonlinear continuous pressure-releasing device and the connecting plate of the lower steel arch frame component are both connected by bolt structures.

[0012] The nonlinear continuous pressure-releasing device upper component and the nonlinear continuous 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. 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 nonlinear continuous pressure-releasing device upper component, and the lower docking tube is connected to the lower end plate of the nonlinear continuous pressure-releasing device lower component.

[0013] A design method for a nonlinear continuous yielding steel arch, the design method comprising the following steps:

[0014] The nonlinear continuous pressure-yielding device is provided with n nonlinear continuous pressure-yielding dampers, the outer radius of the damping cylinder is R, the upper radius of the truncated cone wall is r1, the lower radius is r2, the height of the truncated cone wall is H, the upper annular thickness of the truncated cone wall is w1, the lower annular thickness is w2, and the angle between the truncated cone wall and the horizontal plane is α; the upper radius of the truncated cone end is r3, the lower radius is r4, and the height of the truncated cone end is h; w4 is the diameter of the connecting rod, h1 is the distance between the upper part of the truncated cone end and the upper part of the truncated cone wall when the truncated cone end is in the initial position, the initial position here means that the truncated cone end is just in full contact with the truncated cone wall, and s is the extrusion travel distance of the truncated cone end; a coordinate system is established, with the center point of the upper part of the truncated cone end when the truncated cone end is in the initial position as the origin, the central axis of the truncated cone end as the y-axis, and the horizontal direction perpendicular to the y-axis as the x-axis;

[0015] From the force analysis of the truncated cone wall, it can be seen that the pressure distribution applied by the truncated cone end to the truncated cone wall is p(y), and the friction coefficient of the truncated cone wall is u, then the friction force distribution f(y) is:

[0016] f(y)=up(y) Formula 1;

[0017] From the force analysis of the truncated cone wall, it can be seen that the vertical force distribution N(y) and radial pressure distribution Fr(y) generated by the pressure distribution p(y) and the friction force distribution f(y) on the truncated cone wall are respectively:

[0018] N(y)=N p(y) +N f(y) =p(y)×cosα+f(y)×sinα Formula 2;

[0019] Fr(y)=Fr p(y) +Fr f(y) =p(y)×sinα+f(y)×cosα Formula 3;

[0020] When the end of the truncated cone slides to y, the annular strain and annular stress generated by the truncated cone wall at coordinate y are:

[0021] ε θr(y) (y) = Δr(y) / r(y) Formula 4;

[0022] σ θr(y) (y) = Eε θr(y) (y) Formula 5;

[0023] Wherein, Δr(y) is the radial radius expansion of the damping cylinder when the truncated cone end slides to y, Δr(y)=ycotα; r(y) is the radius change function of the truncated cone end; E is the elastic modulus of the damping cylinder material;

[0024] According to the stress analysis theory of pressure vessels, the hoop stress generated by the truncated cone wall at coordinate y has the following relationship:

[0025]

[0026] Wherein, Δw(y) is the thickness variation function of the truncated cone wall in the contact area between the truncated cone end and the truncated cone wall, Δw(y)=w1+y cotα;

[0027] Substituting equation 3 into equation 6, the hoop stress generated by the truncated cone wall at coordinate y is:

[0028]

[0029] Combining equations 4, 5, and 7, we can get:

[0030]

[0031] When the truncated cone tip slides s, the pressure distribution p(y) and the friction force distribution f(y) generate a vertical force F on the truncated cone wall. i (s) is:

[0032]

[0033] Substituting equations 1, 2 and 8 into equation 9, when the truncated cone tip slides for s, a single nonlinear continuous damper generates a vertical force F i (s) is:

[0034]

[0035] The vertical force that the nonlinear continuous pressure-yielding device can provide is:

[0036]

[0037] When the truncated cone end slides along the damping cylinder by a distance s, the deformation of the damping cylinder is s. z for:

[0038]

[0039] Where A1(y)=π{R 2 -[r1-(y+h1)cotα] 2}, A2(y)=π[R 2 -(r1-ycotα) 2 ];

[0040] Then the total deformation S of the steel arch is:

[0041] S=s+s z Formula 13.

[0042] The advantages of the present invention are:

[0043] (1) The truncated cone end squeezes and rubs the truncated cone wall of the nonlinear continuous yielding damper to achieve nonlinear continuous yielding deformation;

[0044] (2) The truncated cone wall can adapt to different surrounding rocks according to different geological conditions or surrounding rock deformation to protect the steel arch frame;

[0045] (3) When the surrounding rock pressure or deformation is large, the nonlinear continuous pressure relief device can reduce the deformation of the steel arch frame itself and prevent the steel arch frame from twisting and crushing;

[0046] (4) The nonlinear continuous 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.

[0047] (5) The butt joint of the nonlinear continuous pressure relief device can realize the rapid connection between the steel arch frames, and the formed steel arch frames are 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;

[0048] (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-releasing device. At the same time, when the pressure-releasing device is deformed, the balls arranged on the side plates of the sleeve can reduce the friction between the sleeve and the steel arch frame;

[0049] (7) The nonlinear continuous pressure-yielding damper is arranged at the lower part of the lower end plate of the steel arch frame. When the deformation of the nonlinear continuous 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.

[0050] (8) Through the truncated cone wall design theory, the dimensions and materials of the components of the nonlinear continuous yielding device can be designed according to the actual large deformation requirements of the tunnel, and the yielding deformation can also be calculated. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 Schematic diagram of the steel arch frame in Example 1 of the present invention;

[0052] Figure 2 for Figure 1 Middle AA section;

[0053] Figure 3 Schematic diagram of a nonlinear continuous pressure relief device in Example 1 of the present invention;

[0054] Figure 4 Schematic diagram of the cross section of the upper component of the nonlinear continuous pressure-releasing device in Example 1 of the present invention;

[0055] Figure 5 for Figure 4 Middle BB section;

[0056] Figure 6 It is a cross-sectional schematic diagram of the lower component of the nonlinear continuous pressure relief device in Example 1 of the present invention;

[0057] Figure 7 for Figure 6 Enlarged view of middle b;

[0058] Figure 8 Schematic diagram of the steel arch frame in Example 2 of the present invention;

[0059] Fig. 9 for Figure 8 Middle CC section;

[0060] Fig.10 Schematic diagram of a nonlinear continuous pressure relief device in Example 2 of the present invention;

[0061] Fig.11 This is a schematic diagram of the upper components of the nonlinear continuous pressure-yielding device in Example 2 of the present invention;

[0062] Fig.12 Schematic diagram of the cross section of the upper component of the nonlinear continuous pressure-yielding device in Example 2 of the present invention;

[0063] Fig.13 for Fig.11 Middle DD section;

[0064] Fig.14 This is a schematic diagram of the lower component of the nonlinear continuous pressure relief device in Example 2 of the present invention;

[0065] Fig.15 It is a cross-sectional schematic diagram of the lower component of the nonlinear continuous pressure relief device in Example 2 of the present invention;

[0066] Fig.16 This is a schematic diagram of the upper steel arch assembly in Example 2 of the present invention;

[0067] Fig.17 This is a schematic diagram of the lower steel arch assembly in Example 2 of the present invention;

[0068] Fig.18 Schematic diagram of the steel arch frame in Example 3 of the present invention;

[0069] Fig.19 for Fig.18 Middle EE section;

[0070] Fig. 20 Schematic diagram of a nonlinear continuous pressure relief device in Example 3 of the present invention;

[0071] Fig.21 This is a schematic diagram of the upper components of the nonlinear continuous pressure-yielding device in Example 3 of the present invention;

[0072] Fig. 22 Schematic diagram of the cross section of the upper component of the nonlinear continuous pressure-yielding device in Example 3 of the present invention;

[0073] Fig.23 for Fig.21 Middle FF section;

[0074] Fig.24 This is a schematic diagram of the lower component of the nonlinear continuous pressure relief device in Example 3 of the present invention;

[0075] Fig.25 Schematic cross-sectional view of the lower component of the nonlinear continuous pressure relief device in Example 3 of the present invention;

[0076] Fig.26 It is a geometric relationship diagram between the nonlinear continuous pressure-yielding damper and the truncated cone end of the present invention;

[0077] Fig. 27 Schematic diagram of the force on the truncated cone wall of the present invention (I);

[0078] Fig.28 This is a schematic diagram of the force on the truncated cone wall of the present invention (II);

[0079] Fig.29 It is a schematic diagram of the relationship between the nonlinear continuous yield displacement and the load of the present invention;

[0080] like Figures 1 to 29 As shown, the marks in the figure represent respectively:

[0081] a.Steel arch frame;

[0082] 1. Non-linear continuous pressure relief device, 2. Steel arch assembly;

[0083] 11. Upper component of nonlinear continuous pressure-yielding device, 12. Lower component of nonlinear continuous pressure-yielding device;

[0084] 111. sleeve, 112. upper end plate, 113. side plate, 114. connecting rod, 115. truncated cone end, 116. slide groove, 117. ball bearing, 118. docking sleeve, 119. I-shaped groove;

[0085] 121. lower end plate, 122. through hole, 123. nonlinear continuous pressure-yielding damper, 124. damping cylinder, 125. bottom end plate, 126. truncated cone wall, 127. one-way snap buckle;

[0086] 21. Upper steel arch frame assembly, 22. Lower steel arch frame assembly, 23. Connecting plate, 24. Bolts, 25. Nuts. DETAILED DESCRIPTION

[0087] 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:

[0088] Example 1: Figures 1 to 7 As shown, this embodiment relates to a nonlinear continuous pressure-yielding 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 nonlinear continuous pressure-yielding 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.

[0089] like Figures 1 to 7 As shown, the nonlinear continuous pressure-yielding device 1 is composed of a nonlinear continuous pressure-yielding device upper component 11 and a nonlinear continuous pressure-yielding device lower component 12 that cooperate with each other. The nonlinear continuous pressure-yielding device upper component 11 and the nonlinear continuous pressure-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.

[0090] The upper assembly 11 of the nonlinear continuous pressure relief device includes a sleeve 111, a connecting rod 114 and a truncated cone 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 inner walls of the two side plates 113 facing the wing plates of the steel arch frame assembly 2 in the sleeve 111 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 be rotated along the vertical direction of the slide grooves 116. The sleeve 111 is connected to the upper steel arch 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 are located in the sleeve 111. The truncated cone end head 115 is connected to the lower end of the connecting rod 114. The outer diameter of the truncated cone end head 115 gradually decreases from top to bottom. The four truncated cone end heads 115 are respectively located on both sides of the web of the upper steel arch assembly 21.

[0091] The nonlinear continuous pressure-releasing device lower component 12 includes a lower end plate 121 and a nonlinear continuous pressure-releasing damper 123. The lower end plate 121 is installed on the lower steel arch component 22. The cross-sectional size of the nonlinear continuous pressure-releasing device lower component 12 (lower end plate 121) and the cross-sectional size of the lower steel arch component 22 correspond to the cross-sectional size inside the sleeve 111. The nonlinear continuous pressure-releasing device lower component 12 and the lower steel arch component 22 are both installed inside the sleeve 111 and extend along the inner portion of the sleeve 111. The lower end plate 121 is provided with four through holes 122, and a nonlinear continuous pressure-yielding damper 123 is welded or threadedly installed in each through hole 122. The position and quantity of the truncated cone end 115 of the upper component 11 of the nonlinear continuous pressure-yielding device respectively correspond to the position and quantity of the nonlinear continuous pressure-yielding damper 123 of the lower component 12 of the nonlinear continuous pressure-yielding device. The four nonlinear continuous pressure-yielding dampers 123 are respectively located on both sides of the web of the lower steel arch frame component 22 in pairs. The nonlinear continuous pressure-yielding damper 123 includes a damping cylinder 124 and a bottom end plate 125. A truncated cone wall 126 is provided inside the damping cylinder 124. The inner diameter of the truncated cone wall 126 gradually decreases from top to bottom. The bottom end plate 125 is provided 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 truncated cone end head 115 are both installed in the damping cylinder 124 of the nonlinear continuous pressure-yielding damper 123. In addition, a one-way snap-fit ​​buckle 127 is provided at the top of the damping cylinder 124. The one-way snap-fit ​​buckle 127 can limit the truncated cone end 115 to prevent the truncated cone end 115 from moving outside the damping cylinder 124. The one-way snap-fit ​​buckle 127 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.

[0092] like Figures 1 to 7 As shown, the working method of the nonlinear continuous pressure-yielding device 1 is as follows:

[0093] When the truncated cone end 115 presses the one-way snap buckle 127 downward, the arc-shaped rotating plate rotates downward, so that the truncated cone end 115 enters the damping cylinder 124. When the truncated cone 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 127 can limit the truncated cone end 115 to prevent the truncated cone 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 truncated cone end 115 presses the truncated cone wall 126 of the friction nonlinear continuous yielding damper 123 to achieve nonlinear continuous yielding deformation. When the deformation of the nonlinear continuous yield damper 123 reaches the limit, the upper end plate 112 and the lower end plate 121 can be completely fitted, and the small space between the steel arches a can be fully utilized to increase the deformation space of the steel arches a and enhance the stability of the steel arches a. In this process, the ball bearings 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.

[0094] like Figures 26 to 29 As shown, the design method steps of the nonlinear continuous pressure-yielding device 1 are as follows:

[0095] The nonlinear continuous pressure-yielding device is provided with n nonlinear continuous pressure-yielding dampers, the outer radius of the damping cylinder is R, the upper radius of the truncated cone wall is r1, the lower radius is r2, the height of the truncated cone wall is H, the upper annular thickness of the truncated cone wall is w1, the lower annular thickness is w2, and the angle between the truncated cone wall and the horizontal plane is α; the upper radius of the truncated cone end is r3, the lower radius is r4, and the height of the truncated cone end is h; w4 is the diameter of the connecting rod, h1 is the distance between the upper part of the truncated cone end and the upper part of the truncated cone wall when the truncated cone end is in the initial position, the initial position here means that the truncated cone end is just in full contact with the truncated cone wall, and s is the extrusion travel distance of the truncated cone end; a coordinate system is established, with the center point of the upper part of the truncated cone end when the truncated cone end is in the initial position as the origin, the central axis of the truncated cone end as the y-axis, and the horizontal direction perpendicular to the y-axis as the x-axis; F n is the vertical force on the connecting rod, F i (s) is the vertical force that a single nonlinear continuous yielding damper can provide;

[0096] like Fig. 27 As shown in the figure, from the force analysis of the truncated cone wall, it can be seen that the pressure distribution applied by the end of the truncated cone to the truncated cone wall is p(y), and the friction coefficient of the truncated cone wall is u, then the friction force distribution f(y) is:

[0097] f(y)=up(y) Formula 1;

[0098] like Fig.28As shown in the figure, from the force analysis of the truncated cone wall, it can be seen that the vertical force distribution N(y) and radial pressure distribution Fr(y) generated by the pressure distribution p(y) and the friction force distribution f(y) on the truncated cone wall are respectively:

[0099] N(y)=N p(y) +N f(y) =p(y)×cosα+f(y)×sinα Formula 2;

[0100] Fr(y)=Fr p(y) +Fr f(y) =p(y)×sinα+f(y)×cosα Formula 3;

[0101] When the end of the truncated cone slides to y, the annular strain and annular stress generated by the truncated cone wall at coordinate y are:

[0102] ε θr(y) (y) = Δr(y) / r(y) Formula 4;

[0103] σ θr(y) (y) = Eε θr(y) (y) Formula 5;

[0104] Wherein, △r(y) is the radial radius expansion of the damping tube when the truncated cone end slides to y, △r(y) = y cotα; r(y) is the radius change function of the truncated cone end, and E is the elastic modulus of the damping tube material;

[0105] According to the stress analysis theory of pressure vessels, the hoop stress generated by the truncated cone wall at coordinate y has the following relationship:

[0106]

[0107] Where △w(y) is the thickness variation function of the truncated cone wall in the contact area between the truncated cone end and the truncated cone wall, △w( y ) = w1 + ycotα;

[0108] Substituting equation 3 into equation 6, we can obtain the hoop stress generated by the truncated cone wall at coordinate y:

[0109]

[0110] Combining equations 4, 5, and 7, we can get:

[0111]

[0112] When the end of the truncated cone slides s, the pressure distribution p(y) and the friction force distribution f(y) generate a vertical force F on the truncated cone wall. i (s) is:

[0113]

[0114] Substituting equations 1, 2, and 8 into equation 9, when the truncated cone tip slides s, the single nonlinear continuous damper generates a vertical force F i (s) is:

[0115]

[0116] The vertical force that the nonlinear continuous pressure-yielding device can provide is:

[0117]

[0118] When the truncated cone end slides along the damping cylinder, the deformation of the damping cylinder is s. z for:

[0119]

[0120] Where A1(y)=π{R 2 -[r1-(y+h1)cotα] 2}, A2(y)=π[R 2 -(r1-ycotα) 2 ];

[0121] The total deformation S of the steel arch (nonlinear continuous yielding deformation) is:

[0122] S=s+s z Formula 13.

[0123] exist Fig.29 In the equation, nF1(s1) is the vertical force that the first truncated cone wall can provide, s1 is the maximum deformation of the steel arch when the end of the truncated cone is located in the first truncated cone wall, nF2(s2) is the vertical force that the second truncated cone wall can provide, s2 is the maximum deformation of the steel arch when the end of the truncated cone is located in the second truncated cone wall, nF m (s m ) is the vertical force that the mth segment of the truncated cone wall can provide, s m It is the maximum deformation of the steel arch when the end of the truncated cone is located inside the wall of the mth section of the truncated cone.

[0124] The beneficial technical effects of this embodiment are:

[0125] (1) The truncated cone end squeezes and rubs the truncated cone wall of the nonlinear continuous yielding damper to achieve nonlinear continuous yielding deformation;

[0126] (2) The truncated cone wall can adapt to different surrounding rocks according to different geological conditions or surrounding rock deformation to protect the steel arch frame;

[0127] (3) When the surrounding rock pressure or deformation is large, the nonlinear continuous pressure relief device can reduce the deformation of the steel arch frame itself and prevent the steel arch frame from twisting and crushing;

[0128] (4) The nonlinear continuous 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.

[0129] (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-releasing device. At the same time, when the pressure-releasing device is deformed, the balls arranged on the side plates of the sleeve can reduce the friction between the sleeve and the steel arch frame;

[0130] (6) The nonlinear continuous pressure-yielding damper is arranged at the lower part of the lower end plate of the steel arch frame. When the deformation of the nonlinear continuous 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.

[0131] (7) Through the truncated cone wall design theory, the dimensions and materials of the components of the nonlinear continuous pressure-yielding device can be designed according to the actual large deformation requirements of the tunnel, and the pressure-yielding deformation can also be calculated.

[0132] Example 2: Figures 8 to 17 As shown, this embodiment relates to a nonlinear continuous pressure-yielding steel arch frame. Unless the connection method between the linear continuous pressure-yielding device 1 and the steel arch frame assembly 2 is different, 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.

[0133] Specifically, the upper end plate 112 of the upper component 11 of the nonlinear continuous pressure-yielding device and the connecting plate 23 of the upper steel arch component 21, as well as the lower end plate 121 of the lower component 12 of the nonlinear continuous pressure-yielding device and the connecting plate 23 of the lower steel arch component 22 are connected by a bolt structure. Among them, the connecting plate 23 of the lower steel arch component 22 is provided with a placement hole for placing the nonlinear continuous pressure-yielding damper 123 (damping cylinder 124), and the upper end plate 112 of the upper component 11 of the nonlinear continuous pressure-yielding device, the connecting plate 23 of the upper steel arch component 21, the lower end plate 121 of the lower component 12 of the nonlinear continuous pressure-yielding device, and the connecting plate 23 of the lower steel arch component 22 are all provided with 4 screw holes, which are arranged in an array, and the bolt structure is composed of bolts 24 and nuts 25.

[0134] The working method and design method of the nonlinear continuous pressure-releasing device 1 in this embodiment are the same as those of the nonlinear continuous pressure-releasing device 1 in Embodiment 1, and therefore will not be described in detail herein.

[0135] Example 3: Figures 18 to 25 As shown, this embodiment relates to a nonlinear continuous pressure-yielding steel arch frame. Unless the connection method between the linear continuous pressure-yielding device 1 and the steel arch frame assembly 2 is different, 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.

[0136] Specifically, the nonlinear continuous pressure-releasing device upper component 11 and the nonlinear continuous 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 nonlinear continuous 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 nonlinear continuous pressure-releasing device upper component 11, and the lower docking tube is connected to the lower end plate 121 of the nonlinear continuous pressure-releasing device lower component 12.

[0137] The working method and design method of the nonlinear continuous pressure-releasing device 1 in this embodiment are the same as those of the nonlinear continuous pressure-releasing device 1 in Embodiment 1, and therefore will not be described in detail herein.

[0138] 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 nonlinear continuous yielding steel arch, 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 nonlinear continuous pressure-yielding device, and the two adjacent steel arch frame components are respectively an upper steel arch frame component and a lower steel arch frame component. The nonlinear continuous pressure-yielding device is composed of a nonlinear continuous pressure-yielding device upper component and a nonlinear continuous pressure-yielding device lower component that cooperate with each other. The nonlinear continuous pressure-yielding device upper component and the nonlinear continuous pressure-yielding device lower component are respectively installed on the upper steel arch frame component and the lower steel arch frame component; the nonlinear continuous pressure-yielding device upper component includes a sleeve, a connecting rod and a truncated cone end head. The sleeve is a rectangular structure with a cover on the upper part assembled from an upper end plate and four side plates. Two of the sleeves face the steel arch frame components. The inner wall of the side plate of the wing plate of the component is provided with a plurality of parallel sliding grooves, and a plurality of rotatable balls are arranged at intervals in the sliding grooves. The connecting rod is provided with a plurality of connecting rods, and the connecting rod is installed on the upper end plate and is located in the sleeve. The truncated cone end head is connected to the lower end of the connecting rod, and the outer diameter of the truncated cone end head gradually decreases from top to bottom. The lower component of the nonlinear continuous pressure-releasing device includes a lower end plate and a nonlinear continuous pressure-releasing damper. The lower end plate is installed on the lower steel arch frame component, and a plurality of through holes are opened on the lower end plate, and a nonlinear continuous pressure-releasing damper is installed in each of the through holes. The lower component of the nonlinear continuous pressure-releasing device and the lower steel arch frame component are both installed in the sleeve, and the connecting rod and the truncated cone end head are both installed in the nonlinear continuous pressure-releasing damper.

2. The nonlinear continuous yield steel arch according to claim 1, characterized in that: The nonlinear continuous pressure-yielding damper comprises a damping cylinder and a bottom-sealed end plate. A truncated cone wall is provided inside the damping cylinder. The inner diameter of the truncated cone wall gradually decreases from top to bottom. The bottom-sealed end plate is provided at the bottom end of the damping cylinder and is used to close the bottom end of the damping cylinder.

3. The nonlinear continuous yield steel arch according to claim 2, characterized in that: A one-way snap buckle is provided on the top of the damping cylinder.

4. The nonlinear continuous yield steel arch according to 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 nonlinear continuous yield steel arch 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.

6. The nonlinear continuous yield steel arch according to claim 1, characterized in that: The upper end plate of the upper component of the nonlinear continuous 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 nonlinear continuous pressure-releasing device and the connecting plate of the lower steel arch frame component are both connected by bolt structures.

7. The nonlinear continuous yield steel arch according to claim 1, characterized in that: The nonlinear continuous pressure-releasing device upper component and the nonlinear continuous 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. 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 nonlinear continuous pressure-releasing device upper component, and the lower docking tube is connected to the lower end plate of the nonlinear continuous pressure-releasing device lower component.

8. A design method for a nonlinear continuous yield steel arch according to any one of claims 1 to 7, characterized in that: The design method comprises the following steps: The nonlinear continuous pressure-yielding device is provided with n nonlinear continuous pressure-yielding dampers, the outer radius of the damping cylinder is R, the upper radius of the truncated cone wall is r1, the lower radius is r2, the height of the truncated cone wall is H, the upper annular thickness of the truncated cone wall is w1, the lower annular thickness is w2, and the angle between the truncated cone wall and the horizontal plane is α; the upper radius of the truncated cone end is r3, the lower radius is r4, and the height of the truncated cone end is h; w4 is the diameter of the connecting rod, h1 is the distance between the upper part of the truncated cone end and the upper part of the truncated cone wall when the truncated cone end is in the initial position, the initial position here means that the truncated cone end is just in full contact with the truncated cone wall, and s is the extrusion travel distance of the truncated cone end; a coordinate system is established, with the center point of the upper part of the truncated cone end when the truncated cone end is in the initial position as the origin, the central axis of the truncated cone end as the y-axis, and the horizontal direction perpendicular to the y-axis as the x-axis; From the force analysis of the truncated cone wall, it can be seen that the pressure distribution applied by the truncated cone end to the truncated cone wall is p(y), and the friction coefficient of the truncated cone wall is u, then the friction force distribution f(y) is: f(y)=up(y) Formula 1; From the force analysis of the truncated cone wall, it can be seen that the vertical force distribution N(y) and radial pressure distribution Fr(y) generated by the pressure distribution p(y) and the friction force distribution f(y) on the truncated cone wall are respectively: N(y) = N p(y) + N f(y) = p(y)×cosα + f(y)×sinα Equation 2; Fr(y) = Fr p(y) + Fr f(y) = p(y) × sinα + f(y) × cosα Equation 3; When the end of the truncated cone slides to y, the annular strain and annular stress generated by the truncated cone wall at coordinate y are: ε θr(y) (y)=Δr(y) / r(y) = 4; σ θr(y) (y) = Eε θr(y) (y), Equation 5; Wherein, Δr(y) is the radial radius expansion of the damping cylinder when the truncated cone end slides to y, Δr(y)=ycotα; r(y) is the radius change function of the truncated cone end; E is the elastic modulus of the damping cylinder material; According to the stress analysis theory of pressure vessels, the hoop stress generated by the truncated cone wall at coordinate y has the following relationship: Wherein, Δw(y) is the thickness variation function of the truncated cone wall in the contact area between the truncated cone end and the truncated cone wall, Δw(y)=w1+ycotα; Substituting equation 3 into equation 6, the hoop stress generated by the truncated cone wall at coordinate y is: Combining equations 4, 5, and 7, we can get: When the truncated cone tip slides s, the pressure distribution p(y) and the friction force distribution f(y) generate a vertical force F on the truncated cone wall. i (s) is: Substituting equations 1, 2 and 8 into equation 9, when the truncated cone tip slides for s, a single nonlinear continuous damper generates a vertical force F i (s) is: The vertical force that the nonlinear continuous pressure-yielding device can provide is: When the truncated cone end slides along the damping cylinder by a distance s, the deformation of the damping cylinder is s. z for: where \(A1(y)=\pi\{R 2 - [r1 - (y + h1)\cot\alpha] 2 \}\), \(A2(y)=\pi[R 2 - (r1 - y\cot\alpha) 2 ; Then the total deformation S of the steel arch is: S=s+s z Formula 13.

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