Steel arch for tunnel mechanized construction

Abstract

The utility model relates to a steel arch for tunnel mechanized construction, and belongs to the technical field of tunnel construction. The steel arch comprises N steel arches, wherein N is greater than or equal to 1; each truss of steel arch frame comprises an upper step steel arch frame section, two middle step steel arch frame sections, two lower step steel arch frame sections, two inverted arch steel arch frame sections, seven first joints and two second joints. Part of components of the steel arch can be prefabricated outside a hole, the construction efficiency is effectively improved, and an arch trolley is allowed to be used for installing as many as three trusses of steel arches in one operation cycle. An existing steel arch frame structure is improved, part of arch frame sections and joints are assembled outside a hole, the steel arch frame is suitable for arch frame trolley construction, and three arch frames can be installed through one-cycle footage, so that arch frame operation procedures are simplified, potential safety hazards in arch frame installation operation can be reduced to the maximum extent, meanwhile, the construction progress can be accelerated, and the construction efficiency is improved. And the mounting precision can be ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of tunnel construction, and in particular relates to a steel arch frame for mechanized tunnel construction. Background Art

[0002] Against the backdrop of the current booming infrastructure development in my country, tunnel projects, as a vital component of the transportation network, are experiencing increasing scale and complexity, placing correspondingly higher demands on construction technology. Steel arches play a crucial role in ensuring the safety of tunnel support structures. This is especially true when the surrounding rock is weak and severely fractured, requiring timely installation as initial support to control deformation and prevent collapse.

[0003] Currently, tunnel construction often involves manually erecting steel arches, and the steel frame structure is designed to accommodate manual installation. However, traditional manual installation relies on a large number of workers, resulting in low efficiency. Furthermore, due to differences in worker skills and experience, as well as the complexity of the site environment, the quality of manually erected steel arches is often difficult to guarantee, resulting in problems such as loose connections and inaccurate positioning. Furthermore, manual installation of steel arches requires work at high altitudes or in confined spaces, making it difficult to guarantee the safety of workers and posing significant safety risks.

[0004] Therefore, how to overcome the shortcomings of the existing technology is an urgent problem to be solved in the field of tunnel steel arch construction technology. Utility Model Content

[0005] The purpose of the utility model is to solve the deficiencies of the prior art and to provide a steel arch frame for mechanized tunnel construction.

[0006] In order to achieve the above purpose, the technical solution adopted by the present utility model is as follows:

[0007] A steel arch frame for mechanized tunnel construction, comprising N steel arch frames, where N is greater than or equal to 1;

[0008] Each steel arch frame consists of an upper step steel arch frame segment, two middle step steel arch frame segments, two lower step steel arch frame segments, two inverted arch steel arch frame segments, seven first joints and two second joints;

[0009] The left and right sides of the upper step steel arch section are respectively connected to the upper end of a middle step steel arch section through a first joint;

[0010] The lower end of each middle step steel arch section is connected to the upper end of a lower step steel arch section through a first joint;

[0011] The two inverted arch steel arch frame sections are arranged symmetrically on both sides, and the two inverted arch steel arch frame sections are connected via a first joint;

[0012] The left end of the left inverted arch steel arch section is connected to the left lower step steel arch section through a first joint;

[0013] The right end of the right inverted arch steel arch section is connected to the right lower step steel arch section through a first joint;

[0014] The left lower step steel arch sections of two adjacent frames are longitudinally connected via a second joint;

[0015] The right side lower step steel arch frame sections of two adjacent frames are longitudinally connected through another second joint.

[0016] Further, preferably, the first joint includes a first connecting plate, a first angle steel, a first bolt, and a first nut;

[0017] There are two first connecting plates;

[0018] Two first angle steels are symmetrically fixedly connected to each first connecting plate;

[0019] The two first connecting plates are each provided with four through holes; the bottom surfaces of the two first connecting plates are opposite to each other, and then four first bolts are passed through the four through holes and threadedly connected with the corresponding first nuts, so that the relative positions of the two first connecting plates are fixed.

[0020] Furthermore, preferably, the lower step steel arch section includes a vertical steel arch section, a transverse steel arch section and reinforcement ribs;

[0021] The vertical steel arch section and the transverse steel arch section are connected via a third joint;

[0022] The vertical steel arch frame section and the transverse steel arch frame section are also connected by reinforcing ribs.

[0023] Further, preferably, the third joint includes a third connecting plate, a third angle steel, a third bolt and a third nut;

[0024] There are two third connecting plates;

[0025] Two third angle steels are symmetrically fixedly connected to each third connecting plate;

[0026] There are six through holes on each of the two third connecting plates; the bottom surfaces of the two first connecting plates are opposite to each other, and then six third bolts are passed through the six through holes and threadedly connected with the corresponding third nuts, so that the relative positions of the two third connecting plates are fixed.

[0027] Furthermore, preferably, a second joint is provided at the bottom end of the vertical steel arch frame section and located at the arch foot of the side wall.

[0028] Further, preferably, the second joint includes a channel steel, a second connecting plate, a second angle steel, a second bolt and a second nut;

[0029] Two second angle steels are symmetrically fixedly connected on the second connecting plate;

[0030] The bottom of the channel steel and the second connecting plate are both provided with a through hole; four third bolts pass through the four through holes and are threadedly connected with corresponding third nuts, so that the relative positions of the bottom of the channel steel and the second connecting plate are fixed.

[0031] Furthermore, it is preferred that three steel frames serve as a longitudinal cycle.

[0032] The inner sides of the upper step steel arch section and the inner sides of the middle step steel arch section of the 3 steel arches are connected by multiple evenly distributed I14 I-beams;

[0033] The inner side of the upper step steel arch section and the outer side of the middle step steel arch section of the 3 steel arch frames are connected by multiple evenly distributed first connecting steel bars;

[0034] The inner and outer sides of the lower step steel arch sections of the three steel arch frames are connected by multiple evenly distributed second connecting steel bars.

[0035] Furthermore, preferably, the I14 I-beams and the first connecting steel bars are alternately arranged from top to bottom with a circumferential spacing of 1 m;

[0036] The inner and outer sides of the lower step steel arch sections of the three steel arch frames are connected by multiple evenly distributed second connecting steel bars, and the second connecting steel bars are alternately arranged on the inner and outer sides with a circumferential spacing of 1m.

[0037] To address the urgent need for safety and efficiency in tunnel construction, this utility model has designed a steel arch system specifically for mechanized tunnel construction. This fundamentally addresses the key issues of high operational risk and low efficiency inherent in traditional manual construction, significantly improving the overall efficiency and safety of tunnel construction.

[0038] In the utility model, the three longitudinal steel arch frames form a cycle, and the upper step steel arch frame sections of each cycle are longitudinally connected, and the middle step steel arch frame sections of each cycle are longitudinally connected at the same time; that is, the inner sides of the upper step steel arch frame sections and the inner sides of the middle step steel arch frame sections of the three steel arch frames are connected by multiple evenly distributed I14 I-beams; the inner sides of the upper step steel arch frame sections and the outer sides of the middle step steel arch frame sections of the three steel arch frames are connected by multiple evenly distributed first connecting steel bars.

[0039] In the utility model, the function of the second joint is to connect the longitudinally adjacent lower step steel arch frame sections.

[0040] In order to prevent excessive deformation of sections without secondary lining, the utility model sets sinking monitoring points on the arch with a longitudinal spacing of 10m.

[0041] In the utility model, the upper step steel arch frame section and the middle step steel arch frame section of each cycle are prefabricated and connected outside the cave; and then they are assembled with the lower step steel arch frame section and the inverted arch steel arch frame section inside the cave.

[0042] Part of the components of the steel arch frame of the utility model can be prefabricated outside the tunnel, which effectively improves the construction efficiency and allows the use of an arch frame trolley to install up to three steel arch frames in one operation cycle.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The utility model provides a steel arch frame for mechanized construction of a tunnel, which improves the existing steel arch frame structure. Some arch frame sections and joints are assembled outside the tunnel, and the utility model is suitable for arch frame trolley construction. Three arch frames can be installed in one cycle of footage, thereby streamlining the arch frame operation procedure, minimizing safety hazards in the arch frame installation operation, accelerating the construction progress, and ensuring installation accuracy.

[0045] The steel arch frame structure provided by the present invention was used in a certain tunnel and mechanized construction was adopted. Compared with the traditional structural form and its erection technology, 1.5 hours can be saved for every three steel frames. A 300m test section was selected during the tunnel construction, and the total construction period saved was 36 days. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0047] Figure 1 This is a schematic diagram of the main structure of the steel arch frame used for mechanized tunnel construction in accordance with the present invention;

[0048] Figure 2 This is the longitudinal connection diagram of the steel arch frame used for mechanized tunnel construction in this utility model;

[0049] Figure 3 Schematic diagram of the main structure of the first joint;

[0050] Figure 4 Schematic diagram of the top structure of the first joint;

[0051] Figure 5 Schematic diagram of the main structure of the second joint;

[0052] Figure 6 Schematic diagram of the top structure of the second joint;

[0053] Figure 7 This is a schematic diagram of the main structure of the third joint;

[0054] Figure 8 Schematic diagram of the top structure of the third joint;

[0055] Figure 9 This is a construction procedure diagram for tunnel mechanized construction using steel arch frames;

[0056] Among them, 1. Upper step steel arch frame section; 2. First joint; 21. First nut; 22. First bolt; 23. First connecting plate; 24. First angle steel; 3. Middle step steel arch frame section; 4. Second joint; 41. Channel steel; 42. Second connecting plate; 43. Second bolt; 44. Second angle steel; 45. Second nut; 5. Lower step steel arch frame section; 51. Vertical steel arch frame section; 52. Horizontal steel arch frame section; 53. Reinforcement rib; 6. Third joint; 61. Third bolt; 62. Third connecting plate; 63. Third angle steel; 64. Third nut; 7. Inverted arch steel arch frame section; 8. I14 I-beam; 9. First connecting steel bar; 10. Second connecting steel bar. DETAILED DESCRIPTION

[0057] The present invention will be described in further detail below with reference to the embodiments.

[0058] Those skilled in the art will understand that the following examples are intended only to illustrate the present invention and should not be construed as limiting the scope of the present invention. Where specific techniques, connections, or conditions are not specified in the examples, the techniques, connections, and conditions described in literature in the art or in accordance with product specifications were used. Materials, instruments, or equipment used, where the manufacturer is not specified, are commercially available conventional products.

[0059] Those skilled in the art will understand that, unless expressly stated otherwise, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present utility model refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we say that an element is "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. The term "and / or" used herein includes any unit and all combinations of one or more associated listed items.

[0060] In the description of this utility model, unless otherwise specified, "plurality" means two or more. Terms such as "inner," "upper," and "lower" indicating positions or states are based on the positions or states shown in the accompanying drawings and are intended solely to facilitate and simplify the description of this utility model. They do not indicate or imply that the devices or components referred to must have a specific position, be constructed, or operate in a specific position. Therefore, they should not be construed as limitations on this utility model.

[0061] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "provided with" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; and direct or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances.

[0062] Those skilled in the art will understand that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art in the art to which this invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art, and will not be interpreted in an idealized or overly formal sense unless defined as such herein. Example 1

[0063] like Figure 1 As shown, a steel arch frame for mechanized tunnel construction is characterized by comprising N steel arch frames, N ≥ 1;

[0064] Each steel arch frame includes an upper step steel arch frame segment 1, two middle step steel arch frame segments 3, two lower step steel arch frame segments 5, two inverted arch steel arch frame segments 7, seven first joints 2 and two second joints 4;

[0065] The left and right sides of the upper step steel arch section 1 are respectively connected to the upper end of a middle step steel arch section 3 through a first joint 2;

[0066] The lower end of each middle step steel arch section 3 is connected to the upper end of a lower step steel arch section 5 through a first joint 2;

[0067] The two inverted arch steel arch frame sections 7 are arranged symmetrically, and the two inverted arch steel arch frame sections 7 are connected by a first joint 2;

[0068] The left end of the left inverted arch steel arch frame section 7 is connected to the left lower step steel arch frame section 5 through the first joint 2;

[0069] The right end of the right inverted arch steel arch frame section 7 is connected to the right lower step steel arch frame section 5 through the first joint 2;

[0070] The left lower step steel arch sections 5 of two adjacent frames are longitudinally connected by a second joint 4;

[0071] The right side lower step steel arch frame sections 5 of two adjacent frames are longitudinally connected through another second joint 4. Example 2

[0072] like Figure 1 and Figure 2 As shown, a steel arch frame for mechanized tunnel construction is characterized by comprising N steel arch frames, N ≥ 1;

[0073] Each steel arch frame includes an upper step steel arch frame segment 1, two middle step steel arch frame segments 3, two lower step steel arch frame segments 5, two inverted arch steel arch frame segments 7, seven first joints 2 and two second joints 4;

[0074] The left and right sides of the upper step steel arch section 1 are respectively connected to the upper end of a middle step steel arch section 3 through a first joint 2;

[0075] The lower end of each middle step steel arch section 3 is connected to the upper end of a lower step steel arch section 5 through a first joint 2;

[0076] The two inverted arch steel arch frame sections 7 are arranged symmetrically, and the two inverted arch steel arch frame sections 7 are connected by a first joint 2;

[0077] The left end of the left inverted arch steel arch frame section 7 is connected to the left lower step steel arch frame section 5 through the first joint 2;

[0078] The right end of the right inverted arch steel arch frame section 7 is connected to the right lower step steel arch frame section 5 through the first joint 2;

[0079] The left lower step steel arch sections 5 of two adjacent frames are longitudinally connected by a second joint 4;

[0080] The right lower step steel arch sections 5 of two adjacent frames are longitudinally connected by another second joint 4;

[0081] Three steel frames serve as a longitudinal loop.

[0082] The inner sides of the upper step steel arch section 1 and the middle step steel arch section 3 of the three steel arches are connected by multiple evenly distributed I14 I-beams 8;

[0083] The inner side of the upper step steel arch section 1 and the outer side of the middle step steel arch section 3 of the three steel arches are connected by multiple evenly distributed first connecting steel bars 9;

[0084] The inner and outer sides of the lower step steel arch sections 5 of the three steel arches are connected by multiple evenly distributed second connecting steel bars 10. Example 3

[0085] like Figure 1 and Figure 2 As shown, a steel arch frame for mechanized tunnel construction is characterized by comprising N steel arch frames, N ≥ 1;

[0086] Each steel arch frame includes an upper step steel arch frame segment 1, two middle step steel arch frame segments 3, two lower step steel arch frame segments 5, two inverted arch steel arch frame segments 7, seven first joints 2 and two second joints 4;

[0087] The left and right sides of the upper step steel arch section 1 are respectively connected to the upper end of a middle step steel arch section 3 through a first joint 2;

[0088] The lower end of each middle step steel arch section 3 is connected to the upper end of a lower step steel arch section 5 through a first joint 2;

[0089] The two inverted arch steel arch frame sections 7 are arranged symmetrically, and the two inverted arch steel arch frame sections 7 are connected by a first joint 2;

[0090] The left end of the left inverted arch steel arch frame section 7 is connected to the left lower step steel arch frame section 5 through the first joint 2;

[0091] The right end of the right inverted arch steel arch frame section 7 is connected to the right lower step steel arch frame section 5 through the first joint 2;

[0092] The left lower step steel arch sections 5 of two adjacent frames are longitudinally connected by a second joint 4;

[0093] The right side lower step steel arch frame sections 5 of two adjacent frames are longitudinally connected through another second joint 4.

[0094] Three steel frames serve as a longitudinal loop.

[0095] The inner sides of the upper step steel arch section 1 and the middle step steel arch section 3 of the three steel arches are connected by multiple evenly distributed I14 I-beams 8;

[0096] The inner side of the upper step steel arch section 1 and the outer side of the middle step steel arch section 3 of the three steel arches are connected by multiple evenly distributed first connecting steel bars 9;

[0097] The inner and outer sides of the lower step steel arch sections 5 of the three steel arches are connected by multiple evenly distributed second connecting steel bars 10.

[0098] I14 I-beams 8 and first connecting steel bars 9 are arranged alternately from top to bottom, with a circumferential spacing of 1m;

[0099] The inner and outer sides of the lower step steel arch sections 5 of the three steel arches are connected by a plurality of evenly distributed second connecting steel bars 10, and the second connecting steel bars 10 are alternately arranged on the inner and outer sides with a circumferential spacing of 1m. Example 4

[0100] like Figure 1 and Figures 3 to 8 As shown, a steel arch frame for mechanized tunnel construction includes N steel arch frames, where N is greater than or equal to 1;

[0101] Each steel arch frame includes an upper step steel arch frame segment 1, two middle step steel arch frame segments 3, two lower step steel arch frame segments 5, two inverted arch steel arch frame segments 7, seven first joints 2 and two second joints 4;

[0102] The left and right sides of the upper step steel arch section 1 are respectively connected to the upper end of a middle step steel arch section 3 through a first joint 2;

[0103] The lower end of each middle step steel arch section 3 is connected to the upper end of a lower step steel arch section 5 through a first joint 2;

[0104] The two inverted arch steel arch frame sections 7 are arranged symmetrically, and the two inverted arch steel arch frame sections 7 are connected by a first joint 2;

[0105] The left end of the left inverted arch steel arch frame section 7 is connected to the left lower step steel arch frame section 5 through the first joint 2;

[0106] The right end of the right inverted arch steel arch frame section 7 is connected to the right lower step steel arch frame section 5 through the first joint 2;

[0107] The left lower step steel arch sections 5 of two adjacent frames are longitudinally connected by a second joint 4;

[0108] The right side lower step steel arch frame sections 5 of two adjacent frames are longitudinally connected through another second joint 4.

[0109] The first joint 2 includes a first connecting plate 23, a first angle steel 24, a first bolt 22, and a first nut 21;

[0110] There are two first connecting plates 23;

[0111] Two first angle steels 24 are symmetrically fixedly connected to each first connecting plate 23;

[0112] The two first connecting plates 23 are each provided with four through holes; the bottom surfaces of the two first connecting plates 23 are opposite to each other, and then four first bolts 22 pass through the four through holes and are threadedly connected with the corresponding first nuts 21, so that the relative positions of the two first connecting plates 23 are fixed.

[0113] The lower step steel arch section 5 includes a vertical steel arch section 51, a transverse steel arch section 52 and a reinforcing rib 53;

[0114] The vertical steel arch section 51 and the transverse steel arch section 52 are connected via a third joint 6;

[0115] Furthermore, the vertical steel arch section 51 and the transverse steel arch section 52 are connected via reinforcing ribs 53 .

[0116] The third joint 6 includes a third connecting plate 62, a third angle steel 63, a third bolt 61 and a third nut 64;

[0117] There are two third connecting plates 62;

[0118] Two third angle steels 63 are symmetrically fixedly connected to each third connecting plate 62;

[0119] The two third connecting plates 62 are each provided with six through holes; the bottom surfaces of the two first connecting plates 23 are opposite to each other, and then six third bolts 61 pass through the six through holes and are threadedly connected with the corresponding third nuts 64, so that the relative positions of the two third connecting plates 62 are fixed.

[0120] A second joint 4 is provided at the bottom end of the vertical steel arch section 51 and located at the side wall arch foot.

[0121] The second joint 4 includes a channel steel 41, a second connecting plate 42, a second angle steel 44, a second bolt 43 and a second nut 45;

[0122] Two second angle steels 44 are symmetrically fixedly connected to the second connecting plate 42;

[0123] Four through holes are provided on the bottom of the channel steel 41 and the second connecting plate 42; four third bolts 61 pass through the four through holes and are threadedly connected with corresponding third nuts 64, so that the relative positions of the bottom of the channel steel 41 and the second connecting plate 42 are fixed. Example 5

[0124] like Figures 1 to 8 As shown, a steel arch frame for mechanized tunnel construction includes N steel arch frames, where N is greater than or equal to 1;

[0125] Each steel arch frame includes an upper step steel arch frame segment 1, two middle step steel arch frame segments 3, two lower step steel arch frame segments 5, two inverted arch steel arch frame segments 7, seven first joints 2 and two second joints 4;

[0126] The left and right sides of the upper step steel arch section 1 are respectively connected to the upper end of a middle step steel arch section 3 through a first joint 2;

[0127] The lower end of each middle step steel arch section 3 is connected to the upper end of a lower step steel arch section 5 through a first joint 2;

[0128] The two inverted arch steel arch frame sections 7 are arranged symmetrically, and the two inverted arch steel arch frame sections 7 are connected by a first joint 2;

[0129] The left end of the left inverted arch steel arch frame section 7 is connected to the left lower step steel arch frame section 5 through the first joint 2;

[0130] The right end of the right inverted arch steel arch frame section 7 is connected to the right lower step steel arch frame section 5 through the first joint 2;

[0131] The left lower step steel arch sections 5 of two adjacent frames are longitudinally connected by a second joint 4;

[0132] The right side lower step steel arch frame sections 5 of two adjacent frames are longitudinally connected through another second joint 4.

[0133] The first joint 2 includes a first connecting plate 23, a first angle steel 24, a first bolt 22, and a first nut 21;

[0134] There are two first connecting plates 23;

[0135] Two first angle steels 24 are symmetrically fixedly connected to each first connecting plate 23;

[0136] The two first connecting plates 23 are each provided with four through holes; the bottom surfaces of the two first connecting plates 23 are opposite to each other, and then four first bolts 22 pass through the four through holes and are threadedly connected with the corresponding first nuts 21, so that the relative positions of the two first connecting plates 23 are fixed.

[0137] The lower step steel arch section 5 includes a vertical steel arch section 51, a transverse steel arch section 52 and a reinforcing rib 53;

[0138] The vertical steel arch section 51 and the transverse steel arch section 52 are connected via a third joint 6;

[0139] Furthermore, the vertical steel arch section 51 and the transverse steel arch section 52 are connected via reinforcing ribs 53 .

[0140] The third joint 6 includes a third connecting plate 62, a third angle steel 63, a third bolt 61 and a third nut 64;

[0141] There are two third connecting plates 62;

[0142] Two third angle steels 63 are symmetrically fixedly connected to each third connecting plate 62;

[0143] The two third connecting plates 62 are each provided with six through holes; the bottom surfaces of the two first connecting plates 23 are opposite to each other, and then six third bolts 61 pass through the six through holes and are threadedly connected with the corresponding third nuts 64, so that the relative positions of the two third connecting plates 62 are fixed.

[0144] A second joint 4 is provided at the bottom end of the vertical steel arch section 51 and located at the side wall arch foot.

[0145] The second joint 4 includes a channel steel 41, a second connecting plate 42, a second angle steel 44, a second bolt 43 and a second nut 45;

[0146] Two second angle steels 44 are symmetrically fixedly connected to the second connecting plate 42;

[0147] Four through holes are provided on the bottom of the channel steel 41 and the second connecting plate 42; four third bolts 61 pass through the four through holes and are threadedly connected with corresponding third nuts 64, so that the relative positions of the bottom of the channel steel 41 and the second connecting plate 42 are fixed.

[0148] Three steel frames serve as a longitudinal loop.

[0149] The inner sides of the upper step steel arch section 1 and the middle step steel arch section 3 of the three steel arches are connected by multiple evenly distributed I14 I-beams 8;

[0150] The inner side of the upper step steel arch section 1 and the outer side of the middle step steel arch section 3 of the three steel arches are connected by multiple evenly distributed first connecting steel bars 9;

[0151] The inner and outer sides of the lower step steel arch sections 5 of the three steel arches are connected by multiple evenly distributed second connecting steel bars 10.

[0152] I14 I-beams 8 and first connecting steel bars 9 are arranged alternately from top to bottom, with a circumferential spacing of 1m;

[0153] The inner and outer sides of the lower step steel arch sections 5 of the three steel arches are connected by a plurality of evenly distributed second connecting steel bars 10, and the second connecting steel bars 10 are alternately arranged on the inner and outer sides with a circumferential spacing of 1m.

[0154] The present invention does not limit the parameters such as radius, central angle and arc length of the upper step steel arch frame section 1, the middle step steel arch frame section 3, the lower step steel arch frame section 5 and the inverted arch steel arch frame section 7, which can be obtained according to the contour data in the tunnel using existing methods.

[0155] The dimensions of the connecting steel plate 23 are 220 mm in length × 220 mm in width × 15 mm in thickness;

[0156] The dimensions of the first angle steel 24 are side length × side length × thickness 40 mm × 40 mm × 4 mm;

[0157] Channel steel 41 is 28a channel steel;

[0158] The dimensions of the second connecting plate 42 are 220 mm in length × 220 mm in width × 15 mm in thickness;

[0159] The dimensions of the second angle steel 44 are side length × side length × thickness 40 mm × 40 mm × 4 mm;

[0160] The dimensions of the third connecting plate 62 are 300 mm in length × 300 mm in width × 15 mm in thickness;

[0161] The dimensions of the third angle steel 63 are side length × side length × thickness 40 mm × 40 mm × 4 mm;

[0162] The first bolt 22, the second bolt 43, and the third bolt 61 are all A26 bolts;

[0163] The first nut 21 , the second nut 45 , and the third nut 64 are all A26 nuts.

[0164] The mechanized tunnel construction is carried out using the steel arch frame for mechanized tunnel construction. The specific construction method includes the following steps:

[0165] Step (1) is to first prepare for the tunnel outside and determine that the tunnel excavation cycle advance is 3 steel frame spacings; longitudinally connect the upper step steel arch frame section of each cycle, and longitudinally connect the middle step steel arch frame section of each cycle; then transport the connected structure and the lower step steel arch frame section together to the front of the tunnel face and wait for construction;

[0166] Step (2), after excavating a cycle of upper step rock and soil mass and middle step rock and soil mass I, first apply 40mm thick initial sprayed concrete to the upper step and middle step surrounding rock surface, then use the arch frame trolley installation arm to grab and lift the three connected upper step steel arch frame sections to the arch top and the middle step steel arch frame sections to the corresponding positions, and make the first joint to connect the upper step steel arch frame sections and the middle step steel arch frame sections;

[0167] Step (3): excavate the rock mass II on the left side of the lower step, spray 40mm of concrete on the surrounding rock surface on the left side of the lower step, and place the lower step steel arch frame section upright to the installation position; construct a first joint to connect the left middle step steel arch frame section and the left lower step steel arch frame section; construct a second connecting steel bar to connect the left lower step steel arch frame section in one cycle;

[0168] Step (4), constructing a second joint at the arch foot end of the steel arch frame side wall on the left side of the lower step to connect the longitudinally adjacent steel arch frames;

[0169] Step (5): excavate the rock mass III on the right side of the lower step, spray 40mm of concrete on the surrounding rock surface on the right side of the lower step, place the lower step steel arch frame section upright to the installation position, make a first joint to connect the right middle step steel arch frame section and the right lower step steel arch frame section, and make a second connecting steel bar to connect the right lower step steel arch frame section in one cycle;

[0170] Step (6), constructing a second joint at the arch foot end of the side wall of the steel arch frame on the right side of the lower step to connect the longitudinally adjacent steel arch frames;

[0171] Step (7), excavating the rock mass IV in the middle of the lower step, spraying 40 mm of concrete on the rock surface surrounding the bottom side of the lower step inverted arch, placing a circular inverted arch steel arch frame section to the designated position of the inverted arch, and constructing a first joint 2 to connect the lower step steel arch frame section and the inverted arch steel arch frame section;

[0172] Step (8), after checking the quality of steel frame installation, continue with the next cycle of excavation and arch frame installation;

[0173] Preferably, during the construction process, arch monitoring equipment can be arranged at intervals of 10m on the arch to monitor the deformation rate of the tunnel.

[0174] This construction method utilizes a two-step approach for tunnel excavation, increasing the construction step distance to provide ample operating space for the mechanized trolley. To ensure construction safety and structural stability, this method also strengthens the monitoring system during construction and incorporates necessary temporary support measures. The implementation of this construction method not only improves the efficiency of mechanized tunnel construction but also enhances safety and controllability during the construction process.

[0175] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements are intended to fall within the scope of the present invention. The scope of protection claimed in this invention is defined by the appended claims and their equivalents.

Claims

1. A steel arch frame for mechanized tunnel construction, characterized in that: Including N steel arch frames, N ≥ 1; Each steel arch frame includes an upper step steel arch frame section (1), two middle step steel arch frame sections (3), two lower step steel arch frame sections (5), two inverted arch steel arch frame sections (7), seven first joints (2) and two second joints (4); The left and right sides of the upper step steel arch section (1) are respectively connected to the upper end of a middle step steel arch section (3) via a first joint (2); The lower end of each middle step steel arch section (3) is connected to the upper end of a lower step steel arch section (5) via a first joint (2); The two inverted arch steel frame sections (7) are arranged symmetrically on both sides, and the two inverted arch steel frame sections (7) are connected via a first joint (2); The left end of the left inverted arch steel arch frame section (7) is connected to the left lower step steel arch frame section (5) via a first joint (2); The right end of the right inverted arch steel arch frame section (7) is connected to the right lower step steel arch frame section (5) via a first joint (2); The left lower step steel arch sections (5) of two adjacent frames are longitudinally connected via a second joint (4); The right lower step steel arch frame sections (5) of two adjacent frames are longitudinally connected via another second joint (4).

2. The steel arch frame for mechanized tunnel construction according to claim 1, characterized in that: The first joint (2) comprises a first connecting plate (23), a first angle steel (24), a first bolt (22), and a first nut (21); There are two first connecting plates (23); Two first angle steels (24) are symmetrically fixedly connected to each first connecting plate (23); Four through holes are provided on each of the two first connecting plates (23); the bottom surfaces of the two first connecting plates (23) are opposed to each other, and then four first bolts (22) are passed through the four through holes and threadedly connected to the corresponding first nuts (21), so that the relative positions of the two first connecting plates (23) are fixed.

3. The steel arch frame for mechanized tunnel construction according to claim 1, characterized in that: The lower step steel arch section (5) includes a vertical steel arch section (51), a transverse steel arch section (52) and reinforcement ribs (53); The vertical steel arch section (51) and the transverse steel arch section (52) are connected via a third joint (6); Furthermore, the vertical steel arch frame section (51) and the transverse steel arch frame section (52) are connected via reinforcing ribs (53).

4. The steel arch frame for mechanized tunnel construction according to claim 3, characterized in that: The third joint (6) includes a third connecting plate (62), a third angle steel (63), a third bolt (61) and a third nut (64); There are two third connecting plates (62); Two third angle steels (63) are symmetrically fixedly connected to each third connecting plate (62); Six through holes are provided on each of the two third connecting plates (62); the bottom surfaces of the two first connecting plates (23) are opposed to each other, and six third bolts (61) are passed through the six through holes and threadedly connected to corresponding third nuts (64), so that the relative positions of the two third connecting plates (62) are fixed.

5. The steel arch frame for mechanized tunnel construction according to claim 3, characterized in that: A second joint (4) is provided at the bottom end of the vertical steel arch frame section (51) and located at the side wall arch foot.

6. The steel arch frame for mechanized tunnel construction according to claim 5, characterized in that: The second joint (4) includes a channel steel (41), a second connecting plate (42), a second angle steel (44), a second bolt (43) and a second nut (45); Two second angle steels (44) are symmetrically fixedly connected to the second connecting plate (42); Four through holes are provided on the bottom of the channel steel (41) and the second connecting plate (42); four third bolts (61) pass through the four through holes and are threadedly connected to corresponding third nuts (64), so that the relative positions of the bottom of the channel steel (41) and the second connecting plate (42) are fixed.

7. The steel arch frame for mechanized tunnel construction according to claim 1, characterized in that: 3 steel frames serve as a longitudinal loop; The inner sides of the upper step steel arch frame section (1) and the middle step steel arch frame section (3) of the three steel arch frames are connected by a plurality of evenly distributed I14 I-beams (8); The inner side of the upper step steel arch frame section (1) and the outer side of the middle step steel arch frame section (3) of the three steel arch frames are connected by a plurality of evenly distributed first connecting steel bars (9); The inner and outer sides of the lower step steel arch sections (5) of the three steel arches are connected by a plurality of evenly distributed second connecting steel bars (10).

8. The steel arch frame for mechanized tunnel construction according to claim 7, characterized in that: I14 I-beams (8) and first connecting steel bars (9) are alternately arranged from top to bottom, with a circumferential spacing of 1 m; The inner and outer sides of the lower step steel arch sections (5) of the three steel arches are connected by a plurality of evenly distributed second connecting steel bars (10), and the second connecting steel bars (10) are alternately arranged on the inner and outer sides with a circumferential spacing of 1 m.

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