Inverted arch structure and construction method thereof

Abstract

The invention provides an inverted arch structure and a construction method thereof, and belongs to the technical field of tunnel inverted arch construction. The inverted arch structure comprises an arch body, a reserved steel bar connector and two positioning mechanisms. An arc-shaped through groove is formed in the arc-shaped bottom face of the arch body. The reserved steel bar connectors comprise a plurality of first steel bar connectors evenly arranged on the bottom edges of the two sides of the arch body in the length direction and a plurality of second steel bar connectors evenly arranged on the top edges of the two sides of the arch body in the width direction. The two positioning mechanisms are symmetrically arranged on the top side edge of the arch body in the length direction, each positioning mechanism is suitable for being correspondingly arranged at the end of the corresponding arc-shaped through groove, and the positioning mechanisms are suitable for adjusting the angle between the arch body and the steel arch frame so that the arc-shaped through grooves of the arch body can be clamped with the connecting plates of the steel arch frame. The invention further provides a construction method of the inverted arch structure, the mode that the prefabricated inverted arch and the cast-in-place inverted arch are combined is adopted, the tunnel manufacturing cost can be remarkably reduced, the construction speed can be increased, the controllability of the construction quality is high, and the construction precision and efficiency can be improved easily.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel invert construction, and in particular to an invert structure and a construction method thereof. Background Art

[0002] At present, during the construction of long road and bridge tunnels, when the location of the inclined shaft is restricted by protected areas, environmentally sensitive areas, etc., TBM (tunnel boring machine) horizontal guide is often used to assist the main tunnel construction in order to achieve the purpose of rapid construction.

[0003] At present, there are two main methods: cast-in-place invert or prefabricated invert to complete the closed ring, which can effectively assist the main tunnel construction. After all the horizontal guides in the main tunnel are connected, the cast-in-place invert and horizontal guide pavement are laid together; or TBM horizontal guide is used to excavate and construct prefabricated invert, so as to ensure construction continuity and construction quality.

[0004] However, for the currently used fully cast-in-place invert method, although its overall cost is low, the construction quality is difficult to control, and the appearance conditions of the construction site are poor and the on-site construction is complicated. Especially in soft rock and large deformation geological sections, the invert cannot keep up with the construction of the heading face, which also causes the lining to not be closed in time, seriously affecting the safety of the overall construction structure of the main tunnel.

[0005] Although the method of using fully prefabricated inverts has the advantage of high speed, it is also costly, requires high installation precision of the prefabricated inverts, is difficult to construct, and is inconvenient to transport within the tunnel. Summary of the invention

[0006] In view of this, in order to solve the technical problems existing in two existing TBM tunnel construction technologies, the present invention provides an invert structure and a construction method thereof. The first object of the present invention is to provide an inverted arch structure, comprising: An arch body, wherein the arc-shaped bottom surface of the arch body is provided with an arc-shaped through groove perpendicular to the extending direction of the tunnel, and both ends of the arc-shaped through groove extend to the top side of the arch body; The reserved steel bar joints include a plurality of first steel bar joints evenly arranged at the bottom edges of both sides in the length direction of the arch body and a plurality of second steel bar joints evenly arranged at the top edges of both sides in the width direction of the arch body; Two positioning mechanisms are symmetrically arranged on the top side edge in the length direction of the arch body, and each of the positioning mechanisms is suitable for being correspondingly arranged at the end of the arc-shaped through groove. The positioning mechanisms are suitable for adjusting the angle between the arch body and the steel arch frame so that the arc-shaped through groove of the arch body is engaged with the connecting plate of the steel arch frame.

[0007] Furthermore, the positioning mechanism includes: A connecting seat, fixed on the arch body; A movable block, vertically slidably connected to the connecting seat; The movable fork head is horizontally and vertically penetrated on the movable block, and the movable fork head is suitable for being adjusted to face the arc-shaped through groove.

[0008] Furthermore, the connecting seat includes: A base body is vertically fixedly connected to the top edge of the arch body close to the arc-shaped through groove; The first connecting block is fixedly connected to the upper middle portion of one side of the base body away from the arc-shaped through groove.

[0009] Furthermore, the activity block includes: A top seat body, adapted to be vertically slidably connected to the base body; A second connecting block, horizontally fixedly connected to the top side of the top seat body and located directly above the first connecting block, and an adjustable clamping hole is provided on the second connecting block; A first bolt, with a vertical thread passing through the second connection block, and a lower end of the first bolt is rotatably connected to an upper side of the first connection block; A second bolt is threadedly locked on the second connection block and is located at the open end of the adjustable clamping aperture.

[0010] Furthermore, the movable fork comprises: a third connecting block, located at a side of the base body away from the first connecting block; A third bolt, threadedly disposed in the middle of the top seat body and adapted to be rotatably connected to the middle of the third connecting block; Two guide pillars are horizontally parallel and symmetrically connected to two sides of the third connecting block, and each of the guide pillars slides through the top seat body; The two fork bodies are horizontally, parallelly and symmetrically connected to a side of the third connecting block away from the guide column.

[0011] Furthermore, each of the fork bodies comprises: A first fork arm, horizontally and symmetrically connected to two ends of the third connecting block away from the guide column; A second fork arm is horizontally parallel and symmetrically connected directly above the first fork arm; A fourth bolt is vertically threaded and penetrates the second fork arm, and a distal end of the fourth bolt is rotatably connected to the first fork arm.

[0012] Furthermore, a plurality of sleeper grooves are symmetrically provided on the top surface of the arch body along the extension direction of the tunnel; rails are placed in the sleeper grooves so as to be suitable for rail vehicles installed on the rails to synchronously transport materials during tunnel excavation construction.

[0013] Furthermore, a drainage ditch is provided on the top surface of the arch body, and the bottom of the drainage ditch is lower than the bottom of the sleeper groove; a drainage channel is provided inside the arch body, and the drainage channel is located in the middle and upper part of the arch body, and the drainage channel is connected to the upper surface of the arch body through a plurality of through holes; a hollow through cavity is provided on the arch body, and a grouting port is also provided on the arch body between the two sleeper grooves, and the grouting port passes through the through cavity.

[0014] Furthermore, the first steel bar joint comprises: A steel bar head exposed along a side perpendicular to the arch body; A connecting sleeve, threadedly connected to the outer end thread of the steel bar head; A protective sleeve is sleeved on the outside of the steel bar head and the connecting sleeve.

[0015] The second object of the present invention is to provide a construction method of an inverted arch structure. Based on the inverted arch structure described above, the construction method comprises the steps of: Step S1: hoisting the prefabricated arch body into the excavated main tunnel, and paving the arch body on the inverted arch wall at the lower part of the main tunnel at even intervals; Step S2: After the arch is aligned by the positioning mechanism, a steel rail for material transportation is laid in the sleeper groove of the arch; Step S3: arranging a steel mesh on the wall surface of the inverted arch between the arch bodies by reserving steel bar joints, and making a cast-in-place inverted arch between the arch bodies.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. An inverted arch structure obtained by the above design, the inverted arch structure is composed of an arch body, a reserved steel bar joint and two positioning mechanisms, wherein the arc bottom surface of the arch body is provided with an arc through groove perpendicular to the extension direction of the tunnel, and the two ends of the arc through groove extend to between the positioning mechanisms on the corresponding sides respectively, and the arc through groove is arranged to facilitate the arc through groove and the connecting plate of the main tunnel steel arch frame to fit and limit, when the connecting plate of the steel arch frame is placed in the arc through groove, the outer arc side of the arch body can fit the main tunnel inverted arch wall and the steel arch frame, which is convenient for secondary lining construction; the reserved steel bar joint includes a first steel bar Joints and second steel bar joints, wherein several first steel bar joints are evenly arranged at the bottom edges on both sides of the length direction of the arch body, and several second steel bar joints are evenly arranged at the top edges on both sides of the width direction of the arch body, so that it is convenient to set the steel mesh on the inverted arch wall between the prefabricated arch bodies, and to make cast-in-place inverted arches between the prefabricated arch bodies; two positioning mechanisms are symmetrically arranged at the top side edges in the length direction of the arch body, and each positioning mechanism is correspondingly arranged at the end of the arc-shaped through groove, and the positioning mechanism is used to adjust the angle between the arch body and the steel arch frame so that the arc-shaped through groove of the arch body and the connecting plate of the steel arch frame are engaged. During construction, the prefabricated arch bodies are evenly spaced on the inverted arch wall of the excavated main cave. After the prefabricated arch body is erected, the relative position between the arch body and the steel arch frame is adjusted by the positioning mechanism so that the arch body fits with the main cave wall and the steel arch frame, which is convenient for more accurate fine-tuning and limiting the paving accuracy of the arch body in the main cave of the soft rock large deformation geological section. Then, sleeper grooves are opened on the prefabricated arch, and steel rails are laid on the sleeper grooves to meet the material transportation needs during the TBM construction process. In this way, there is no need to transfer to rail transportation via trackless rubber-tyred vehicles, and the auxiliary construction of the main tunnel and the TBM's own construction can be carried out simultaneously.

[0017] 2. The invert structure can realize the integration of the advantages of prefabricated invert and cast-in-place invert, satisfy the auxiliary construction of the main tunnel, and meet the rail transportation of materials throughout the process, which is convenient for rapid closure and ring formation in soft rock and large deformation geological sections, so that the invert can be constructed closely with the face, ensuring that the lining can be closed in time, reducing the construction accuracy and difficulty, and improving the construction speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 is a schematic diagram of a three-dimensional structure of an inverted arch structure provided in an embodiment of the present invention; Figure 2 for Figure 1 A schematic diagram of the enlarged structure at A in the middle; Figure 3 for Figure 1 A schematic diagram of the enlarged structure at B in the middle; Figure 4 A schematic diagram of the structure of a positioning mechanism in one direction in an embodiment of the present invention; Figure 5 It is a schematic diagram of the structure of the positioning mechanism in another direction in an embodiment of the present invention; Figure 6 It is a schematic diagram of the exploded structure of the positioning mechanism in one direction in an embodiment of the present invention; Figure 7 It is a schematic diagram of the exploded structure of the positioning mechanism in another direction in an embodiment of the present invention; Figure 8 The figure is a schematic diagram of the exploded structure of the movable fork in the embodiment of the present invention.

[0020] Description of reference numerals: 10-arch body; 11-arc-shaped through groove; 12-drainage channel; 121-through hole; 13-sleeper groove; 14-drainage ditch; 15-through cavity; 16-grouting port; 20-reserved steel bar joint; 21-first steel bar joint; 211-steel bar head; 212-connecting sleeve; 213-protective sleeve; 22-second steel bar joint; 30- positioning mechanism; 31-connecting seat; 311-base body; 312-first connecting block; 32-movable block; 321-top seat body; 322-second connecting block; 3221-adjustable clamping hole; 323-first bolt; 324-second bolt; 33-movable fork head; 331-third connecting block; 332-third bolt; 333-guide column; 334-fork body; 3341-first fork arm; 3342-second fork arm; 3343-fourth bolt. DETAILED DESCRIPTION

[0021] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] It should be noted that, in the coordinate system X, Y, and Z provided in this article, the positive direction of the X axis represents the front, the negative direction of the X axis represents the back, the positive direction of the Y axis represents the right, the negative direction of the Y axis represents the left, the positive direction of the Z axis represents the top, and the negative direction of the Z axis represents the bottom.

[0024] In the description of this specification, the description with reference to the terms "embodiment", "one embodiment" and "one implementation method" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or implementation method are included in at least one embodiment or implementation method of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or implementation method. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or implementation methods in a suitable manner. Based on the implementation methods in the present invention, all other implementation methods obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0025] See also Figure 1-8 As shown, an embodiment of the present invention provides an inverted arch structure, which includes an arch body 10, a reserved steel bar joint 20 and two positioning mechanisms 30, wherein: The arc-shaped bottom surface of the arch body 10 is provided with an arc-shaped through groove 11 which is perpendicular to the extension direction of the tunnel, and both ends of the arc-shaped through groove 11 extend to the top side of the arch body 10, that is, both ends of the arc-shaped through groove 11 extend to between the positioning mechanisms 30 on the corresponding sides. Through the arrangement of the arc-shaped through groove 11, it is convenient for the arc-shaped through groove 11 and the connecting plate of the main tunnel steel arch frame to fit and limit. When the connecting plate of the steel arch frame is placed in the arc-shaped through groove 11, the outer arc side of the arch body 10 can fit the main tunnel inverted arch wall and the steel arch frame, which is convenient for secondary lining construction.

[0026] The reserved steel bar joints 20 include first steel bar joints 21 and second steel bar joints 22 , wherein a plurality of first steel bar joints 21 are evenly arranged at the bottom edges on both sides of the length direction of the arch body 10 , and a plurality of second steel bar joints 22 are evenly arranged at the top edges on both sides of the width direction of the arch body 10 .

[0027] The two positioning mechanisms 30 are symmetrically arranged at the top side edge in the length direction of the arch body 10, and each positioning mechanism 30 is suitable for being correspondingly arranged at the end of the arc-shaped through groove 11. The positioning mechanism 30 is suitable for adjusting the angle between the arch body 10 and the steel arch frame so that the arc-shaped through groove 11 of the arch body 10 is engaged with the connecting plate of the steel arch frame.

[0028] In the specific implementation process of this embodiment, the prefabricated arches 10 are evenly spaced and arranged on the inverted arch wall of the excavated main tunnel during construction. After the prefabricated arches 10 are erected, the relative position between the arches 10 and the steel arch frame is adjusted by the positioning mechanism 30 so that the arches 10 fit the main tunnel wall and the steel arch frame, which is convenient for more accurate fine-tuning and limiting the paving accuracy of the arches 10 in the main tunnel of the soft rock large deformation geological section. Then, rail sleeper grooves 13 are opened on the prefabricated arches 10, and steel rails are laid on the rail sleeper grooves 13 for material transportation needs during TBM construction. In this way, there is no need to transfer to rail transportation through trackless rubber-wheeled vehicles, and the auxiliary construction of the main tunnel and the TBM itself can be synchronized.

[0029] The invert structure can realize the integration of the advantages of prefabricated invert and cast-in-place invert, meet the auxiliary construction of the main tunnel, and meet the rail transportation of materials throughout the process. It is convenient for the rapid closure and ring formation in soft rock and large deformation geological sections, so that the invert can be constructed closely with the heading face, ensuring that the lining can be closed in time, reducing the construction accuracy and difficulty, and improving the construction speed.

[0030] It can be understood that, in the present embodiment, the number of the arc-shaped through grooves 11 is set to one, and in some other embodiments, the number of the arc-shaped through grooves 11 can also be set correspondingly according to the number of steel arch frames spanned by the arch body 10 during construction.

[0031] It should be noted that under certain geographical conditions, such as in soft rock and large deformation geological sections, the natural conditions of the rock, soil and rock walls are poor, and it is very easy to cause large errors when paving the prefabricated arch 10. If this error problem cannot be solved, it will seriously affect the final construction accuracy, making it difficult to ensure the construction quality and slowing down the construction speed.

[0032] In addition, TBM (abbreviation of Tunnel Boring Machine) is a large-scale engineering machinery equipment specially used for tunnel excavation in rock formations. It integrates mechanical, electronic, hydraulic, laser, control and other technologies, and can realize parallel and continuous operation of construction processes such as excavation, support, and slag discharge.

[0033] Specifically, see Figure 4 , Figure 5 As shown, in one embodiment of the present invention, the positioning mechanism 30 includes a connecting seat 31, a movable block 32 and a movable fork 33, wherein: The connecting seat 31 is fixed on the arch body 10; the movable block 32 is vertically slidably connected to the connecting seat 31; the movable fork head 33 is horizontally and vertically penetrated on the movable block 32, and the movable fork head 33 is suitable for being adjustable to face the arc-shaped through groove 11.

[0034] Specifically, the positioning mechanism 30 can make the two ends of the prefabricated arch body 10 align with the connecting plates at the connection between the side wall of the main hole and the steel arch frame, and snap the connecting plates into the arc-shaped through grooves 11 of the arch body 10 .

[0035] As a preferred mode of this embodiment, the positioning mechanisms 30 are symmetrically arranged in pairs at the two ends of the upper side of the arch body 10 so that the two ends of the arch body 10 can be aligned with the connecting plates at the connection of the steel arch frame of the side wall and the invert arch.

[0036] Specifically, see Figure 6 , Figure 7 As shown, in one embodiment of the present invention, the connection base 31 includes a base body 311 and a first connection block 312, wherein: The base body 311 is vertically fixedly connected to the top edge of the arch body 10 close to the arc-shaped through groove 11 ; the first connecting block 312 is fixedly connected to the upper middle part of one side of the base body 311 away from the arc-shaped through groove 11 .

[0037] Specifically, see Figure 6 , Figure 7 As shown, in one embodiment of the present invention, the movable block 32 includes a top seat body 321, a second connecting block 322, a first bolt 323 and a second bolt 324, wherein: The top seat body 321 is suitable for vertical sliding connection on the base body 311; the second connecting block 322 is horizontally fixedly connected to the top side of the top seat body 321 and is located directly above the first connecting block 312, and an adjustable clamping hole 3221 is provided on the second connecting block 322; the first bolt 323 is vertically threaded through the second connecting block 322, and the lower end of the first bolt 323 is rotatably connected to the upper side of the first connecting block 312; the second bolt 324 is threadedly locked on the second connecting block 322 and is located at the open end of the adjustable clamping hole 3221, so as to be suitable for adjusting the opening degree of the adjustable clamping hole 3221.

[0038] Specifically, see Figure 6 , Figure 7 As shown, in one embodiment of the present invention, the movable fork head 33 includes a third connecting block 331, a third bolt 332, two guide pillars 333 and two fork bodies 334, wherein: The third connecting block 331 is located on the side of the base body 311 away from the first connecting block 312; the third bolt 332 is threadedly penetrated into the middle of the top seat body 321 and is suitable for being rotatably connected in the third connecting block 331; the two guide pillars 333 are horizontally parallel and symmetrically connected to the two sides of the third connecting block 331, and each guide pillar 333 slides through the top seat body 321; the two fork bodies 334 are horizontally parallel and symmetrically connected to the side of the third connecting block 331 away from the guide pillar 333.

[0039] Specifically, see Figure 6 , Figure 7 As shown, in one embodiment of the present invention, each fork body 334 includes a first fork arm 3341, a second fork arm 3342 and a fourth bolt 3343, wherein: The first fork arm 3341 is horizontally symmetrically connected to the two ends of the third connecting block 331 away from the guide column 333; the second fork arm 3342 is horizontally parallel and symmetrically connected directly above the first fork arm 3341; the fourth bolt 3343 is vertically threaded on the second fork arm 3342, and the end of the fourth bolt 3343 is rotatably connected to the first fork arm 3341.

[0040] Specifically, see Figure 1 As shown, in one embodiment of the present invention, a plurality of sleeper grooves 13 are symmetrically opened on the top surface of the arch body 10 along the extension direction of the tunnel; rails are placed in the sleeper grooves 13 to be suitable for rail vehicles installed on the rails to synchronously transport materials during the tunnel excavation construction process.

[0041] In this way, since the top surface of the arch body 10 is symmetrically provided with a plurality of sleeper grooves 13 along the tunnel excavation direction, rails are placed in the sleeper grooves 13, and rail cars are installed on the rails, materials can be synchronously transported outwards through the rail cars on the rails during the tunnel excavation construction process.

[0042] As a preferred embodiment of the present invention, the number of sleeper grooves 13 is set to four. Of course, the number and position of the sleeper grooves 13 can be adaptively adjusted according to actual construction conditions. This application does not make any restrictive description on the number and position of the sleeper grooves 13.

[0043] Specifically, see Figure 1 As shown, in one embodiment of the present invention, a drainage ditch 14 is opened on the top surface of the arch body 10, and the depth of the drainage ditch 14 is greater than the depth of the sleeper groove 13, so that the water in the arch filling area can be discharged in time, and the depth of the drainage ditch 14 is greater than the depth of the sleeper groove 13, which facilitates the drainage of the sleeper groove 13.

[0044] Preferably, two drainage grooves 14 are provided in this embodiment, and the two drainage grooves 14 are respectively located outside the sleeper groove 13. It can be understood that the number of drainage grooves 14 can be adaptively adjusted according to actual needs, and this embodiment does not impose any restriction on the number of drainage grooves 14.

[0045] In another embodiment of the present invention, a drainage channel 12 is opened inside the arch body 10, and the drainage channel 12 is located in the middle and upper part of the arch body 10. The drainage channel 12 is connected to the upper surface of the arch body 10 through a plurality of through holes 121. In this way, a drainage pipe can be installed through the through holes 121 to connect the drainage channel 12, thereby achieving the purpose of drainage in the hole.

[0046] Therefore, by setting a drainage channel 12 in the middle of the arch body 10 along the extension direction of the tunnel, it is preferred that the drainage channel 12 is set above the through cavity 15 close to the center of the arch body 10, and a through hole 121 is opened on the upper side of the drainage channel 12. The drainage channel 12 is connected to the upper side of the arch body 10 through the through hole 121. The through hole 121 can be used to insert a drainage pipe, so that the drainage channel 12 can be used for drainage of the main hole.

[0047] It is understandable that one or more through holes 121 may be provided on a single arch body 10 according to drainage requirements, and this embodiment does not impose any limitation on the number of through holes 121 .

[0048] In another embodiment of the present invention, a hollow through cavity 15 is provided on the arch body 10. Under the premise of ensuring the strength of the arch body 10, the prefabricated arch body 10 can be made lightweight to facilitate material transportation.

[0049] Preferably, the through cavity 15 in this embodiment is set to an arch structure. In some other embodiments, the cross-sectional shape of the through cavity 15 can also be set to a circular, square, oval, etc. This embodiment does not impose any restrictions on the shape of the through cavity 15, and specifically meets the requirements of lightweight arch. In addition, the number of through cavities 15 can also be adjusted according to actual needs.

[0050] In another embodiment of the present invention, a grouting port 16 is provided between the two sleeper grooves 13 of the arch body 10, and the grouting port 16 passes through the through cavity 15. Grouting and vibration are performed into the prefabricated arch body 10 through the grouting port 16, so as to facilitate the filling construction of the invert.

[0051] Specifically, see Figure 1 , Figure 3 As shown, in one embodiment of the present invention, the first steel bar joint 21 includes a steel bar head 211, a connecting sleeve 212 and a protective sleeve 213, wherein: The steel bar head 211 is exposed along the side perpendicular to the arch body 10; the connecting sleeve 212 is threadedly connected to the outer end thread of the steel bar head 211; the protective sleeve 213 is sleeved on the outside of the steel bar head 211 and the connecting sleeve 212, which can effectively prevent the steel bar head 211 and the connecting sleeve 212 from rusting, and avoid rust removal taking a long time; in addition, the steel bar head 211 is also convenient for external connection of steel bars through the connecting sleeve 212, and the steel mesh is quickly and accurately made between the prefabricated arch bodies 10; it is also convenient for external connection of the steel mesh on the side wall to ensure the smooth and rapid progress of the lining construction.

[0052] The specific working process of the inverted arch structure is as follows: During construction, the prefabricated arch body 10 is transported and hoisted into the excavated main tunnel, and is evenly laid on the inverted arch wall of the main tunnel. The two ends of the arch body 10 and the connecting plate are aligned and connected with each other based on the connecting plate at the connection between the side wall and the inverted arch steel frame; The fourth bolt 3343 is screwed to separate the first fork arm 3341 and the second fork arm 3342, and the distance between the first fork arm 3341 and the second fork arm 3342 is made larger than the thickness of the steel arch connecting plate; The first bolt 323 is screwed to drive the top seat body 321 and the movable fork head 33 to rise and fall as a whole. After reaching a suitable height facing the steel arch frame connecting plate, the third bolt 332 is screwed to drive the first fork arm 3341 and the second fork arm 3342 to extend, so that the first fork arm 3341 and the second fork arm 3342 are respectively extended to the upper and lower parts of the steel arch frame connecting plate, and the first fork arm 3341 and the second fork arm 3342 are respectively pressed against the outer edge of the steel arch frame connecting plate, that is, the upper side of the first fork arm 3341 is pressed against the lower side of the steel arch frame connecting plate, and then the fourth bolt 3343 is screwed again to press the second fork arm 3342 against the upper side of the steel arch frame connecting plate, and then the first fork arm 3341 and the second fork arm 3342 are completely locked on the connecting plate of the steel arch frame by the fourth bolt 3343; The second bolt 324 is screwed to tighten the adjustable clamping hole 3221 on the second connecting block 322, and then the first bolt 323 is locked, so that the prefabricated arch body 10 can be firmly fixed on the steel arch frame, thereby minimizing the influence of the soft rock large deformation geological section on the paving accuracy of the prefabricated arch body 10, and improving the stability and accuracy of the overall construction structure; Finally, a steel mesh is made by pre-reserving steel bar joints 20, and an invert is cast between the prefabricated arches 10. A material transport track can be quickly laid on the prefabricated arches 10 to facilitate the transportation of materials into the cave. The prefabricated arches 10 can be cast in time in the soft rock large deformation section, avoiding the problems of slow construction progress and slow closure caused by the use of full cast-in-place invert construction, and the full cast-in-place invert may have structural cracks, large deformation, etc.

[0053] It is understandable that the prefabricated arch body 10 can be manufactured in advance after the initial support of the main tunnel construction, which greatly shortens the lining closure time and ensures the structural safety of the overall construction structure of the main tunnel in the soft rock with large deformation sections. In this way, the advantages of the prefabricated invert arch and the cast-in-place invert arch can be integrated, which can not only assist the main tunnel construction, but also meet the rail transportation of TBM construction materials throughout the process, and realize the rapid closure of the tunnel into a ring in the soft rock with large deformation geological sections, so that the invert arch follows the construction of the heading face closely, ensuring that the lining can be closed in time, thereby ensuring the safety of the overall construction structure of the main tunnel, and greatly improving the efficiency and convenience of material transportation, significantly reducing the construction accuracy and difficulty, and increasing the construction speed.

[0054] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An inverted arch structure, characterized in that: include: An arch body (10), wherein the arc-shaped bottom surface of the arch body (10) is provided with an arc-shaped through groove (11) perpendicular to the extension direction of the tunnel, and both ends of the arc-shaped through groove (11) extend to the top side of the arch body (10); The reserved steel bar joints (20) include a plurality of first steel bar joints (21) evenly arranged at the bottom edges of both sides in the length direction of the arch body (10) and a plurality of second steel bar joints (22) evenly arranged at the top edges of both sides in the width direction of the arch body (10); Two positioning mechanisms (30) are symmetrically arranged at the top side edge of the arch body (10) in the length direction, and each positioning mechanism (30) is suitable for being correspondingly arranged at the end of the arc-shaped through groove (11), and the positioning mechanism (30) is suitable for adjusting the angle between the arch body (10) and the steel arch frame so that the arc-shaped through groove (11) of the arch body (10) is engaged with the connecting plate of the steel arch frame.

2. The inverted arch structure according to claim 1, characterized in that: The positioning mechanism (30) comprises: A connecting seat (31) fixed on the arch body (10); The movable block (32) is vertically slidably connected to the connecting seat (31); The movable fork head (33) is horizontally and vertically penetrated on the movable block (32), and the movable fork head (33) is suitable for being adjustable to face the arc-shaped through slot (11).

3. The inverted arch structure according to claim 2, characterized in that: The connecting seat (31) comprises: A base body (311) is vertically fixedly connected to a top edge of the arch body (10) close to the arc-shaped through groove (11); The first connecting block (312) is fixedly connected to the upper middle portion of a side of the base body (311) facing away from the arc-shaped through groove (11).

4. The inverted arch structure according to claim 3, characterized in that: The activity block (32) comprises: A top seat body (321) adapted to be vertically slidably connected to the base body (311); A second connection block (322) is horizontally fixedly connected to the top side of the top seat body (321) and is located directly above the first connection block (312); an adjustable clamping hole (3221) is provided on the second connection block (322); A first bolt (323) is vertically threaded and penetrates the second connection block (322), and the lower end of the first bolt (323) is rotatably connected to the upper side of the first connection block (312); A second bolt (324) is threadedly locked on the second connection block (322) and is located at the open end of the adjustable clamping hole (3221) so as to be suitable for adjusting the opening degree of the adjustable clamping hole (3221).

5. The inverted arch structure according to claim 4, characterized in that: The movable fork (33) comprises: A third connecting block (331), located on a side of the base body (311) away from the first connecting block (312); A third bolt (332) is threadedly disposed in the middle of the top seat body (321) and is suitable for being rotatably connected to the middle of the third connecting block (331); Two guide pillars (333) are horizontally, parallelly and symmetrically connected to two sides of the third connecting block (331), and each of the guide pillars (333) slides through the top seat body (321); The two fork bodies (334) are horizontally, parallelly and symmetrically connected to a side of the third connecting block (331) facing away from the guide pillar (333).

6. The inverted arch structure according to claim 5, characterized in that: Each of the fork bodies (334) comprises: A first fork arm (3341) is horizontally and symmetrically connected to two ends of the third connecting block (331) away from the guide column (333); A second fork arm (3342) is horizontally, parallelly and symmetrically connected just above the first fork arm (3341); A fourth bolt (3343) is vertically threaded and penetrates the second fork arm (3342), and a distal end of the fourth bolt (3343) is rotatably connected to the first fork arm (3341).

7. The inverted arch structure according to claim 1, characterized in that: The top surface of the arch body (10) is symmetrically provided with a plurality of rail sleeper grooves (13) along the extension direction of the tunnel; steel rails are placed in the rail sleeper grooves (13) so as to be suitable for rail vehicles installed on the steel rails to synchronously transport materials during the tunnel excavation construction process.

8. The inverted arch structure according to claim 7, characterized in that: The top surface of the arch body (10) is provided with a drainage ditch (14), the depth of which is greater than the depth of the sleeper groove (13); a drainage channel (12) is provided inside the arch body (10), and the drainage channel (12) is located in the middle and upper part of the arch body (10), and the drainage channel (12) is connected to the upper surface of the arch body (10) through a plurality of through holes (121); a hollow through cavity (15) is provided on the arch body (10), and a grouting port (16) is provided on the arch body (10) between the two sleeper grooves (13), and the grouting port (16) passes through the through cavity (15).

9. The inverted arch structure according to claim 1, characterized in that: The first steel bar joint (21) comprises: A steel bar head (211) is exposed along a side surface perpendicular to the arch body (10); A connecting sleeve (212) threadedly connected to the outer end thread of the steel bar head (211); A protective sleeve (213) is sleeved on the outside of the steel bar head (211) and the connecting sleeve (212).

10. A construction method of an inverted arch structure, based on the inverted arch structure according to any one of claims 1 to 9, characterized in that: The construction method comprises the steps of Step S1: hoisting the prefabricated arch body (10) into the excavated main tunnel, and paving the arch body (10) at even intervals on the inverted arch wall at the lower part of the main tunnel; Step S2: after the arch body (10) is aligned accurately by the positioning mechanism (30), a steel rail for material transportation is laid in the sleeper groove (13) of the arch body (10); Step S3: a steel mesh is arranged on the wall surface of the inverted arch between the arch bodies (10) by reserving a steel bar joint (20), and a cast-in-place inverted arch is manufactured between the arch bodies (10).

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