Inverted arch structure and construction method thereof

Abstract

The application 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 and a supporting mechanism; the top surface of the arch body is symmetrically provided with a plurality of sleeper grooves; a steel rail is arranged in the sleeper groove; a track vehicle mounted on the steel rail is used for synchronously conveying materials in the process of tunnel excavation construction; the supporting mechanism is symmetrically arranged on the bottom side of the arch body and located on both sides of the tunnel extension direction; the supporting mechanism is used for adjusting the angle between the arch body and a steel arch frame, so that the arch body is matched with a main hole wall; the application further provides a construction method of the inverted arch structure; by adopting the combined mode of prefabricated inverted arches and cast-in-place inverted arches, the tunnel cost can be significantly reduced, the construction speed is improved, the construction quality is controllable, and the construction precision and efficiency are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel inverted arch construction, in particular to an inverted arch structure and a construction method thereof. BACKGROUND

[0002] In order to meet the needs of long tunnel construction, TBM flat guide assisted main hole construction method is often used in modern road and bridge construction. The TBM method has the obvious advantage of fast construction speed.

[0003] There are currently two methods: one is that the main hole is fully penetrated by flat guide, and then the cast-in-place inverted arch and the flat guide pavement are laid, and then the auxiliary main hole construction is carried out, and the flat guide adopts full cast-in-place inverted arch; the second is that the TBM flat guide is excavated and the prefabricated inverted arch is constructed, and generally, in order to form a trackless transport channel for auxiliary construction vehicles as soon as possible, a full prefabricated inverted arch structure is used.

[0004] However, the first method of using full cast-in-place inverted arch has low overall cost, but the construction quality is difficult to control, and in order to ensure the rapid transportation of materials in front of the TBM construction, a "reinforced stirrup" pavement structure needs to be used in the tunnel, which will cause inconvenience in the tunnel and poor appearance of the construction site; the on-site construction of the "reinforced stirrup" pavement is complex, and the stirrup needs to be removed during the construction of the cast-in-place inverted arch, which is complicated and wastes a lot of resources; and the cast-in-place inverted arch cannot be constructed immediately after the tunnel face, which also causes the lining to be unable to be closed in time, and will affect the safety of the structure in the case of adverse geological sections (such as large deformation).

[0005] The second method of using full prefabricated inverted arch has fast construction speed, but high cost and high installation precision requirement, and slow construction speed; the full prefabricated inverted arch needs to be transported from outside the tunnel to the rail vehicle in the TBM tunneling section by trackless vehicle, which greatly limits the speed and capacity of transportation.

[0006] In addition, both methods cannot make the auxiliary construction of the main hole and the TBM construction synchronous, which leads to significant defects. SUMMARY

[0007] Therefore, the present application aims to solve the technical problems existing in the two existing TBM tunnel construction technologies.

[0008] The first purpose of the present application is to provide an inverted arch structure, which comprises:

[0009] an arch body, a plurality of rail slot are symmetrically arranged on the top surface of the arch body; a steel rail is arranged in the rail slot, so that a track vehicle installed on the steel rail can synchronously transport materials during tunnel excavation construction;

[0010] Supporting mechanisms symmetrically arranged on the bottom side of the arch body and located on both sides of the tunnel extension direction, the supporting mechanisms being adapted to adjust the angle between the arch body and the steel arch frame so as to make the arch body fit the main hole wall.

[0011] Further, the supporting mechanisms comprise:

[0012] Support blocks with bottom surfaces consistent with the bottom surface curvature of the arch body and fixed on the arch body with the bottom surfaces flush;

[0013] Adjusting mechanisms for adjusting the fit of the support blocks to the main hole wall.

[0014] Further, the adjusting mechanisms comprise a screw rod, a first pad block, a first clamping sleeve, a second pad block and a locking nut.

[0015] The top surface of the support block is downwardly provided with a through cavity hole, the upper end of the cavity hole is provided with a first cavity and the lower end is provided with a second cavity, the first cavity and the second cavity are concentrically arranged with the cavity hole and form a limiting step, the inner periphery of the first cavity is provided with a first limiting groove and the inner periphery of the second cavity is provided with a third limiting groove.

[0016] The two ends of the screw rod are respectively provided with a first thread and a second thread.

[0017] The outer periphery of the first pad block is provided with a first limiting key and the inner periphery is symmetrically provided with two second limiting grooves, the first pad block is adapted to be arranged in the first cavity, and the first limiting key is matched with the first limiting groove.

[0018] The outer periphery of the first clamping sleeve is symmetrically provided with two second limiting keys, the first clamping sleeve is a reverse conical structure and the lower end periphery is uniformly provided with a plurality of first clamping gaps, the first clamping sleeve is arranged in the first pad block, the second limiting keys are arranged in the second limiting grooves, and the first clamping sleeve is made of an elastic deformation material.

[0019] The outer periphery of the second pad block is symmetrically provided with two third limiting keys, the second pad block is internally provided with a threaded hole and the second thread of the screw rod is matched, the second pad block is adapted to be arranged in the second cavity, and the third limiting keys are matched with the third limiting grooves.

[0020] The first thread of the screw rod penetrates the locking nut, and the locking nut is arranged above the first clamping sleeve; when the locking nut is tightened, the top surface of the first clamping sleeve is in contact with the locking nut.

[0021] The screw rod penetrates the locking nut, the first clamping sleeve, the first pad block, the cavity hole and the second pad block in sequence from top to bottom.

[0022] Further, the upper end of the screw rod is detachably provided with a crowbar, and the periphery of the locking nut is provided with a jack hole suitable for the crowbar.

[0023] Further, the limiting plates are symmetrically arranged on the top surface of the arch body and located at both ends along the vertical direction of the tunnel, and the limiting plates are clamped in the steel arch.

[0024] Further, the arc-shaped bottom surface of the arch body is provided with a first groove, and the two ends of the first groove respectively extend to the corresponding side between the limiting plates; the bottom surface of the support block is provided with a second groove penetrating along the vertical direction of the tunnel, and the curvature and depth of the second groove are consistent with those of the first groove.

[0025] Further, the lower side of the support block is provided with a third cavity, and a clamping block is fitted in the third cavity; the top surface of the clamping block is rotationally connected with the lower end of the screw rod, and an opening formed in the lower end of the clamping block is correspondingly arranged with the second groove.

[0026] Further, the top surface of the arch body is provided with a drainage groove, the bottom of the drainage groove is lower than the bottom of the sleeper groove, the sleeper groove is connected from the bottom by a plurality of through first drainage holes, and the first drainage holes are connected with the drainage groove.

[0027] Further, the arch body is symmetrically provided with a through cavity along the tunnel extension direction, and a drainage ditch is arranged in the middle of the arch body; a second drainage hole is downwardly formed in the top surface of the arch body and is connected with the upper side of the drainage ditch; a plurality of through holes are downwardly formed in the top surface of the arch body and are arranged between the two sleeper grooves or between the sleeper grooves and the drainage groove.

[0028] The second object of the present application is to provide a construction method of the inverted arch structure, based on the inverted arch structure, the construction method comprises the steps of:

[0029] Step S1: hoisting the prefabricated arch body into the main hole excavated, and uniformly and intervally laying the arch body on the inverted arch base in the main hole;

[0030] Step S2: after aligning the arch body, laying a steel rail for material transportation in the sleeper groove of the arch body;

[0031] Step S3: adjusting the angle between the arch body and the steel arch through the supporting mechanism, so that the arch body is matched with the wall of the main hole;

[0032] Step S4: making a cast-in-place inverted arch between the prefabricated arch bodies.

[0033] Compared with the prior art, the present application has the following beneficial effects:

[0034] The inverted arch structure obtained by the above design, during construction, the prefabricated arch bodies are uniformly and spacedly arranged on the inverted arch bases in the main hole after excavation, steel rails are laid on the prefabricated arch bodies, the material transportation demand of TBM construction is met, and the auxiliary construction of the main hole and the TBM itself can be realized simultaneously without shifting to rail transportation by trackless rubber-tyred vehicles; and the supporting mechanism is symmetrically arranged on the bottom side of the arch body and at both sides in the extension direction of the tunnel, so that the supporting mechanism can be used to adjust the angle between the arch body and the steel arch frame, so that the arch body is matched with the main hole wall; finally, the cast-in-situ inverted arch is filled between the prefabricated arch bodies. The construction speed of the prefabricated arch body is fast, and the quality is controllable, the cast-in-situ inverted arch filled in the middle avoids the piece-by-piece connection of the full-prefabricated inverted arch and the steel frame under the inverted arch, and the cooperation of the two can greatly reduce the construction difficulty and cost, and improve the construction speed and precision. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation to the scope, and other related drawings can also be obtained by those skilled in the art without creative labor.

[0036] Figure 1 is a schematic diagram of the inverted arch structure provided in the embodiment of the present application;

[0037] Figure 2 is a schematic diagram of the inverted arch structure provided in the embodiment of the present application;

[0038] Figure 3 is a schematic diagram of the inverted arch structure provided in the embodiment of the present application from another perspective;

[0039] Figure 4 is a schematic diagram of the inverted arch structure provided in the embodiment of the present application; Figure 2 is a schematic diagram of the enlarged structure at A in FIG. 8;

[0040] Figure 5 is a schematic diagram of the supporting mechanism structure provided in the embodiment of the present application;

[0041] Figure 6 is a schematic diagram of the supporting block, the second pad block, the clamping block and the second groove structure provided in the embodiment of the present application;

[0042] Figure 7 is a schematic diagram of the supporting mechanism explosion structure provided in the embodiment of the present application;

[0043] Figure 8 is a schematic diagram of the first pad block and the first clamping sleeve structure provided in the embodiment of the present application;

[0044] Figure 9 A second cushion block structure schematic diagram provided in the embodiments of the present application;

[0045] Figure 10 A support block structure schematic diagram provided in the embodiments of the present application;

[0046] Figure 11 A second groove, cavity hole, second limiting slot and third cavity structure schematic diagram provided in the embodiments of the present application;

[0047] Figure 12 A support block cross-sectional structure schematic diagram provided in the embodiments of the present application.

[0048] Explanation of reference signs:

[0049] 10 - arch body; 11 - sleeper slot; 111 - first drainage hole; 12 - drainage slot; 13 - through cavity; 14 - drainage ditch; 141 - second drainage hole; 15 - through hole; 17 - first groove;

[0050] 20 - limiting plate;

[0051] 30 - supporting mechanism;

[0052] 31 - support block; 311 - second groove; 312 - cavity hole; 313 - first cavity; 3131 - first limiting slot; 314 - second cavity; 3141 - third limiting slot; 315 - third cavity;

[0053] 32 - adjusting mechanism; 321 - screw rod; 3211 - first thread; 3212 - second thread; 3213 - crowbar; 322 - first clamping sleeve; 3221 - second limiting key; 3222 - first clamping gap; 323 - first cushion block; 3231 - first limiting key; 3232 - second limiting slot; 324 - second cushion block; 3241 - third limiting key; 325 - locking nut; 3251 - jack;

[0054] 33 - clamping block. DETAILED DESCRIPTION

[0055] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings.

[0056] In the description of the present application, it is to be noted that the terms "arrangement", "installation", "connection", "linkage" should be understood in a broad sense unless otherwise specifically defined and limited, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection; can be directly connected, or indirectly connected through intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0057] In the description of the present application, the description of the terms "embodiment", "one embodiment" and "one implementation" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or implementation are included in at least one embodiment or implementation of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or implementation. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or implementations in a suitable manner. Based on the implementation in the present application, all other implementations obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0058] Please refer to Figures 1-12 As shown in the drawings, the embodiment of the present application provides an inverted arch structure, which comprises an arch body 10 and a supporting mechanism 30, wherein:

[0059] The top surface of the arch body 10 is symmetrically provided with a plurality of sleeper grooves 11 along the tunneling direction, and a steel rail is arranged in the sleeper groove 11, and a rail car is installed on the steel rail, so that the rail car on the steel rail can synchronously transport materials outward during the tunneling construction process.

[0060] The supporting mechanism 30 is symmetrically arranged on the bottom side of the arch body 10, and the supporting mechanism 30 is located on both sides of the tunnel extension direction of the arch body 10, so that the supporting mechanism 30 can be used to adjust the angle between the arch body 10 and the steel arch frame, so that the arch body 10 is matched with the main hole wall.

[0061] Specifically, during construction, the prefabricated arch body 10 is uniformly and spacedly arranged on the inverted arch base in the main hole which is excavated, and when the prefabricated arch body 10 is erected, the matching degree between the arch body 10 and the main hole wall is adjusted through the supporting mechanism 30; the sleeper groove 11 is arranged on the prefabricated arch body 10, and the steel rail is laid on the sleeper groove 11, which is used for material transportation requirement in the TBM construction process, so that it is not necessary to be transferred to the rail transportation through the trackless rubber-tyred vehicle, and the auxiliary construction main hole and the TBM itself construction can be realized synchronously.

[0062] It needs to be explained that the Chinese full name of TBM (abbreviation of Tunnel Boring Machine) is tunnel boring machine, which is a large engineering mechanical equipment specially used for tunnel excavation in rock stratum. It integrates mechanical, electronic, hydraulic, laser, control and other technologies, and can realize parallel and continuous operation of construction processes such as tunneling, supporting and slagging.

[0063] As a preferred mode of the embodiment, the number of sleeper grooves 11 is set to two, and of course the number and position of the sleeper grooves 11 can be adaptively adjusted according to the actual construction situation, and the application does not make any restrictive description on the number and position of the sleeper grooves 11.

[0064] Specifically, please refer to Figure 7 In an embodiment of the application, the supporting mechanism 30 includes a support block 31 and an adjusting mechanism 32, wherein:

[0065] The bottom surface of the support block 31 is consistent with the bottom surface of the arch body 10, and the bottom surface of the support block 31 is flush and fixed on the arch body 10.

[0066] The adjusting mechanism 32 is used to adjust the fit of the support block 31 and the main hole wall (not shown in the figure).

[0067] Therefore, since the bottom surface of the support block 31 is consistent with the bottom surface of the arch body 10, the fit of the support block 31 and the arch body 10 with the main hole wall is consistent; the adjusting mechanism 32 is used to adjust the angle of the support block 31, and the adjusting mechanism 32 in the embodiment can be extended and fixed relative to the support block 31.

[0068] It can be understood that as long as the guide rail structure, screw structure and jack structure with similar functions can be used as the adjusting mechanism 32.

[0069] Please refer to Figures 5-12 In an embodiment of the application, the adjusting mechanism 32 includes a screw 321, a first sleeve 322, a first pad 323, a second pad 324 and a locking nut 325, wherein:

[0070] The screw 321 is provided with a first thread 3211 and a second thread 3212 at both ends respectively.

[0071] The support block 31 is provided with a through cavity 312 on the top surface downward, a first cavity 313 is provided on the upper end of the cavity 312, and a second cavity 314 is provided on the lower end of the cavity 312, the first cavity 313 and the second cavity 314 are concentrically arranged with the cavity 312 and form a limiting step, the first limiting groove 3131 is arranged on the inner wall of the first cavity 313, and the third limiting groove 3141 is arranged on the inner wall of the second cavity 314.

[0072] The outer periphery of the first cushion block 323 is provided with a first limiting key 3231 and two second limiting grooves 3232 are symmetrically arranged on the inner periphery; the first cushion block 323 is adapted to the first cavity 313, and the first limiting key 3231 is matched with the first limiting groove 3131.

[0073] The outer periphery of the first clamping sleeve 322 is symmetrically provided with two second limiting keys 3221, and the first clamping sleeve 322 is preferably provided in a reverse conical structure in this embodiment, and a plurality of first clamping gaps 3222 are uniformly arranged on the lower end periphery; the first clamping sleeve 322 is arranged in the first cushion block 323, and the second limiting key 3221 is arranged in the second limiting groove 3232.

[0074] It can be understood that the first clamping sleeve 322 is made of an elastically deformable material.

[0075] The outer periphery of the second cushion block 324 is symmetrically provided with two third limiting keys 3241, and the second cushion block 324 is provided with a threaded hole and the second thread 3212 of the screw rod 321 is matched; the second cushion block 324 is adapted to the second cavity 314, and the third limiting key 3241 is matched with the third limiting groove 3141.

[0076] The first thread 3211 of the screw rod 321 penetrates the locking nut 325, and the locking nut 325 is arranged above the first clamping sleeve 322; when the locking nut 325 is tightened, it is in contact with the top surface of the first clamping sleeve 322;

[0077] The screw rod 321 penetrates the locking nut 325, the first clamping sleeve 322, the first cushion block 323, the cavity hole 312 and the second cushion block 324 from top to bottom.

[0078] Specifically, since the screw rod 321 penetrates the locking nut 325, the first clamping sleeve 322, the first cushion block 323, the cavity hole 312 of the support block 31 and the second cushion block 324 from top to bottom, the entire adjusting mechanism 32 can be installed on the support block 31; wherein the first limiting key 3231 arranged on the outer periphery of the first cushion block 323 is matched with the shape of the first limiting groove 3131 arranged on the inner periphery of the first cavity 313, when the first limiting key 3231 is inserted into the first limiting groove 3131, the first cushion block 323 can be limited in the rotation direction around the shaft in the first cavity 313, in addition, the first cavity 313 and the cavity hole 312 are concentrically arranged as circular holes, and the inner diameter of the first cavity 313 is greater than that of the cavity hole 312, so that a limiting step is formed at the junction of the first cavity 313 and the cavity hole 312, which can vertically limit the first cushion block 323.

[0079] Thus, through the action of the second limiting groove 3232 and the second limiting key 3221, the first clamp 322 is restricted from rotating around the axis, so that during the process of adjusting the fit of the arch 10, the first pad 323 and the first clamp 322 do not rotate with the screw 321, and also prevent the screw 321 from continuing to rotate after clamping, which would cause the adjustment mechanism 32 to loosen.

[0080] In addition, since the first clamping sleeve 322 has an inverted conical structure and several first clamping gaps 3222 are evenly provided on the lower circumference of the first clamping sleeve 322, and the first clamping gaps 3222 and the second limit key 3221 are evenly spaced, when the locking nut 325 is tightened, the first clamping sleeve 322 is deformed by the downward pressure of the conical outer circumference to clamp the screw 321.

[0081] Similarly, two third limiting keys 3241 are symmetrically arranged on the outer periphery of the second pad 324, and the second thread 3212 of the screw 321 is engaged with the threaded through hole of the second pad 324. The third limiting key 3241 arranged on the outer periphery of the second pad 324 is adapted to the shape of the third limiting groove 3141 arranged on the inner periphery of the second cavity 314, so as to realize the extension and retraction adjustment of the screw 321.

[0082] The second cavity 314 opened at the lower end of the cavity 312 is adapted to the shape of the second pad 324. The third limiting groove 3141 provided on the inner circumference of the second cavity 314 is adapted to the shape of the third limiting key 3241. Due to the cooperation of the third limiting groove 3141 and the third limiting key 3241, the second pad 324 is fixed during the rotation adjustment process, making the rotation adjustment more effective.

[0083] In some other embodiments, the cross-sections of the first pad 323 and the second pad 324 may also be square, circular, or other shapes.

[0084] like Figure 7 As shown, in another embodiment of the present invention, a pry bar 3213 is detachably provided at the upper end of the screw 321, and an insertion hole 3251 suitable for the pry bar 3213 is provided on the periphery of the locking nut 325.

[0085] Therefore, a pry bar 3213 is separately provided at the upper end of the screw 321, which can both increase the lever arm to rotate the screw 321 and be used for tightening the locking nut 325.

[0086] Please see Figure 3 , 4 As shown, in one embodiment of the present invention, the arch structure further includes a limiting plate 20, which is symmetrically arranged on the top surface of the arch 10 and located at both ends perpendicular to the tunnel extension direction. The limiting plate 20 is snapped into the steel arch frame.

[0087] As a preferred mode of the embodiment, the limiting plates 20 are symmetrically arranged in pairs at the upper two ends of the arch body 10, so that the two ends of the arch body 10 can be aligned with the connecting plates at the connecting positions of the steel arch frames of the side walls and the inverted arches.

[0088] As shown in FIGS. 1, 2 and 3, in one embodiment of the present application, the bottom surface of the arch body 10 is provided with a first groove 17, and the bottom surface of the support block 31 is provided with a second groove 311 penetrating in the direction perpendicular to the extension direction of the tunnel. Figure 2 Figure 6 As shown in FIGS. 1, 2 and 3, in one embodiment of the present application, the bottom surface of the arch body 10 is provided with a first groove 17, and the bottom surface of the support block 31 is provided with a second groove 311 penetrating in the direction perpendicular to the extension direction of the tunnel.

[0089] The advantage of such an arrangement is that the first groove 17 and the main hole steel arch frame are limited by the limiting plate 20, which facilitates the fitting and limiting of the first groove 17 and the main hole steel arch frame. When the steel arch frame is placed in the first groove 17, the outer arc side of the arch body 10 can be fitted with the main hole inverted arch wall and the steel arch frame, which facilitates the secondary lining construction.

[0090] It can be understood that in the embodiment, the number of the first grooves 17 is one, and in some other embodiments, the number of the first grooves 17 can be correspondingly set according to the number of the steel arch frames spanned by the arch body 10 during construction.

[0091] As shown in FIGS. 1, 2 and 3, in one embodiment of the present application, the bottom surface of the arch body 10 is provided with a first groove 17, and the bottom surface of the support block 31 is provided with a second groove 311 penetrating in the direction perpendicular to the extension direction of the tunnel. Figure 7 11 As shown in FIGS. 1, 2 and 3, in one embodiment of the present application, the bottom surface of the arch body 10 is provided with a first groove 17, and the bottom surface of the support block 31 is provided with a second groove 311 penetrating in the direction perpendicular to the extension direction of the tunnel.

[0092] During the implementation process, since the clamping block 33 is rotationally connected with the screw rod 321, when the screw rod 321 is rotated, the clamping block 33 is driven to move in the third cavity 315, so that the clamping block 33 abuts against the steel arch frame. The notch at the bottom end of the clamping block 33 is correspondingly arranged with the second groove 311, so that the clamping block 33 can be clamped on the steel arch frame, and the adjustment of the arch body 10 is more stable.

[0093] As shown in FIGS. 1, 2 and 3, in one embodiment of the present application, the bottom surface of the arch body 10 is provided with a first groove 17, and the bottom surface of the support block 31 is provided with a second groove 311 penetrating in the direction perpendicular to the extension direction of the tunnel. Figure 3 Figure 4 As shown in FIGS. 1, 2 and 3, in one embodiment of the present application, the bottom surface of the arch body 10 is provided with a first groove 17, and the bottom surface of the support block 31 is provided with a second groove 311 penetrating in the direction perpendicular to the extension direction of the tunnel.

[0094] Therefore, since the first drainage hole 111 connects the bottom of the sleeper groove 11 and the drainage groove 12, and the depth of the drainage groove 12 is greater than that of the sleeper groove 11, the drainage of the sleeper groove 11 is facilitated.​​​

[0095] As shown in Figure 3 、 Figure 4 In one embodiment of the present application, the arch body 10 is symmetrically provided with a through cavity 13 along the tunnel extension direction. The through cavity 13 can not only ensure the strength of the arch body 10, but also make the arch body 10 lightweight, facilitating hoisting and paving.

[0096] Preferably, the through cavity 13 in the embodiment is provided in a semicircular structure. In some other embodiments, the cross-sectional shape of the through cavity 13 can also be circular, square, elliptical, etc. The embodiment does not limit the shape of the through cavity 13, and can meet the lightweight requirement of the arch body. In addition, the number of the through cavity 13 can also be adjusted according to actual needs.

[0097] In one embodiment of the present application, the middle part of the arch body 10 is provided with a drainage ditch 14, and the top surface of the arch body 10 is downwardly provided with a second drainage hole 141, which is in communication with the drainage ditch 14.

[0098] Thus, by providing the drainage ditch 14 in the middle part of the arch body 10 along the tunnel extension direction, preferably, the drainage ditch 14 is provided between the two through cavities 13 close to the center of the arch body 10, the upper side of the drainage ditch 14 is provided with the second drainage hole 141, the drainage ditch 14 is communicated to the upper side of the arch body 10 through the second drainage hole 141, and the second drainage hole 141 can be provided for inserting a drainage pipe, so that the drainage ditch 14 can be used for main hole drainage.

[0099] It can be understood that one or more second drainage holes 141 can be provided on a single arch body 10 according to the drainage needs, and the number of the second drainage hole 141 is not limited in the embodiment.

[0100] As shown in Figure 3 、 Figure 4 In one embodiment of the present application, a plurality of through holes 15 are downwardly provided on the top surface of the arch body 10, and the through holes 15 are located between the two sleeper grooves 11 or between the sleeper grooves 11 and the drainage grooves 12. The through holes 15 are used for communicating the through cavities 13, and can be used for grouting and vibrating during construction. Thus, it is convenient to fill the through cavities 13 when filling the inverted arch, and the overall inverted arch filling construction is completed. It should be noted that the setting position of the through hole 15 needs to avoid the sleeper groove 11 and the drainage groove 12.

[0101] As shown in Figure 3 、 Figure 4 In one embodiment of the present application, the outer contour of the limiting plate 20 is in an arc structure, which can adapt to the curvature of the side wall.

[0102] The specific working implementation process of the inverted arch structure is as follows:

[0103] During construction, the prefabricated arch bodies 10 are evenly and spacedly arranged on the inverted arch bases in the main hole after excavation, and rails are laid on the prefabricated arch bodies 10 to meet the material transportation requirements of TBM construction.

[0104] The sleeper groove 11 is drained through the first drainage hole 111 and the drainage groove 12, the through cavity 13 can lighten the arch body 10 to facilitate hoisting and paving under the premise of ensuring the strength of the arch body 10, the second drainage hole 141 can be used for inserting a drainage pipe, the drainage ditch 14 can be used for main hole drainage, and the through hole 15 can be used for grouting and vibrating to facilitate filling the through cavity 13 when filling the inverted arch, and the overall inverted arch filling construction is completed.

[0105] By adjusting the fit degree of the supporting mechanism 30 and the steel arch frame, and adjusting the fit degree of the arch body 10 and the steel arch frame and the main hole wall, the locking nut 325 can be screwed up to a certain extent, the screw rod 321 is rotated by the crowbar 3213, the clamping block 33 is driven to move in the third cavity 315, and the clamping block 33 is tightly clamped on the steel arch frame. The gap on the outside of the clamping block 33 can be clamped on the steel arch frame, and the limiting structure (the first limiting key 3231, the first limiting groove 3131, the second limiting groove 3232, the second limiting key 3221, the third limiting key 3241 and the third limiting groove 3141) arranged on the first pad 323, the first clamping sleeve 322 and the second pad 324 can prevent the screw rod 321 from rotating.

[0106] After adjustment, the crowbar 3213 is removed from the top end of the screw rod 321 and inserted into the insertion hole 3251 on the side of the locking nut 325, the locking nut 325 is tightened by rotating, the first clamping sleeve 322 is tightly clamped in the first pad 323 and the first cavity 313, and the first clamping sleeve 322 will be tightened due to the existence of the first clamping gap 3222 under the action of pressure, thereby locking the screw rod 321 to prevent it from rotating, and the clamping block 33 is stably clamped on the steel arch frame, thereby achieving the purpose of adjusting the fit degree of the arch body 10 on the steel arch frame and the main hole inverted arch wall by the supporting block 31.

[0107] The inverted arch structure is beneficial to the overall structural stability of the arch body 10 after paving, thereby ensuring the overall stability of the main hole inverted arch structure, and facilitating the secondary lining construction; the prefabricated arch body 10 is used for cast-in-place inverted arch between the prefabricated arch bodies 10, the construction speed of the prefabricated arch body 10 is fast, and the quality is controllable, the cast-in-place inverted arch filled in the middle avoids the connection of the full prefabricated inverted arch and the steel frame under the inverted arch, and the cooperation of the two can greatly reduce the construction difficulty and cost, and improve the construction speed and precision.

[0108] The above is only a preferred embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An inverted arch structure, characterized in that, include: An arch (10) has several sleeper grooves (11) symmetrically opened on its top surface; rails are placed in the sleeper grooves (11) to facilitate the synchronous transport of materials by a railcar installed on the rails during tunnel excavation. Support mechanism (30) is symmetrically arranged on the bottom side of the arch (10) and located on both sides of the tunnel extension direction. The support mechanism (30) is adapted to adjust the angle between the arch (10) and the steel arch frame so that the arch (10) fits into the main tunnel wall. The support mechanism (30) includes a support block (31) and an adjustment mechanism (32). The bottom curvature of the support block (31) is consistent with the bottom curvature of the arch (10), and the bottom surface is flush with the arch (10) and fixed on the arch (10). The adjustment mechanism (32) is used to adjust the fit between the support block (31) and the main tunnel wall. The adjustment mechanism (32) includes a screw (321), a first pad (323), a first sleeve (322), a second pad (324), and a locking nut (325); The support block (31) has a through cavity (312) on its top surface facing downwards. The cavity (312) has a first cavity (313) at its upper end and a second cavity (314) at its lower end. The first cavity (313), the second cavity (314) and the cavity (312) are concentrically arranged and form a limiting step. The first cavity (313) has a first limiting groove (3131) on its inner circumference, and the second cavity (314) has a third limiting groove (3141) on its inner circumference. The screw (321) is provided with a first thread (3211) and a second thread (3212) at both ends. The first pad (323) has a first limiting key (3231) on its outer periphery and two second limiting grooves (3232) symmetrically opened on its inner periphery; the first pad (323) is adapted to the first cavity (313), and the first limiting key (3231) cooperates with the first limiting groove (3131); The first sleeve (322) has two second limiting keys (3221) symmetrically arranged on its outer periphery. The first sleeve (322) has an inverted conical structure and a plurality of first clamping gaps (3222) are evenly opened on its lower periphery. The first sleeve (322) is disposed in the first pad (323). The second limiting keys (3221) are disposed in the second limiting groove (3232). The first sleeve (322) is made of elastic deformable material. The second pad (324) has two third limiting keys (3241) symmetrically arranged on its outer periphery. The second pad (324) has a threaded through hole and the second thread (3212) of the screw (321) is engaged. The second pad (324) is adapted to the second cavity (314), and the third limiting key (3241) is engaged with the third limiting groove (3141). The first thread (3211) of the screw (321) passes through the locking nut (325), and the locking nut (325) is disposed above the first sleeve (322); when the locking nut (325) is tightened, it contacts the top surface of the first sleeve (322); The screw (321) passes through the locking nut (325), the first sleeve (322), the first pad (323), the cavity (312) and the second pad (324) from top to bottom.

2. The inverted arch structure according to claim 1, characterized in that, The upper end of the screw (321) is detachably provided with a pry bar (3213), and the locking nut (325) has an insertion hole (3251) on its periphery suitable for the pry bar (3213).

3. The inverted arch structure according to claim 1, characterized in that, It also includes a limiting plate (20), which is symmetrically arranged on the top surface of the arch (10) and located at both ends perpendicular to the tunnel extension direction. The limiting plate (20) is snapped into the steel arch frame.

4. The inverted arch structure according to claim 3, characterized in that, The arch (10) has a first groove (17) on its arc-shaped bottom surface, and the two ends of the first groove (17) extend to the corresponding side limit plates (20); the bottom surface of the support block (31) has a second groove (311) that runs through the tunnel perpendicular to the tunnel extension direction, and the second groove (311) and the first groove (17) have the same arc and depth.

5. The inverted arch structure according to claim 4, characterized in that, The support block (31) has a third cavity (315) on its lower side. A locking block (33) is fitted inside the third cavity (315). The top surface of the locking block (33) is rotatably connected to the lower end of the screw (321). The notch at the lower end of the locking block (33) is correspondingly provided with the second groove (311).

6. The inverted arch structure according to claim 1, characterized in that, The top surface of the arch (10) is provided with a drainage groove (12), the bottom of the drainage groove (12) is lower than the bottom of the sleeper groove (11), and the sleeper groove (11) is connected from the bottom by a number of through first drainage holes (111), and the first drainage holes (111) are connected to the drainage groove (12).

7. The inverted arch structure according to claim 6, characterized in that, The arch (10) is symmetrically provided with through cavities (13) along the tunnel extension direction, and a drainage ditch (14) is provided in the middle of the arch (10); a second drainage hole (141) is provided on the top surface of the arch (10) facing downwards, and the second drainage hole (141) is connected to the upper side of the drainage ditch (14); a number of through holes (15) are provided on the top surface of the arch (10) facing downwards, and the through holes (15) are provided between the two sleeper grooves (11) or between the sleeper groove (11) and the drainage ditch (12).

8. A construction method for an inverted arch structure, based on the inverted arch structure according to any one of claims 1-7, characterized in that, The construction method includes the following steps. Step S1: Hoist the prefabricated arch (10) into the excavated main tunnel and lay the arch (10) evenly at intervals on the inverted arch base in the main tunnel; Step S2: After locating and aligning the arch (10), lay the steel rails for material transportation in the sleeper groove (11) of the arch (10); Step S3: Adjust the angle between the arch (10) and the steel arch frame by means of the support mechanism (30) so that the arch (10) fits into the main tunnel wall; Step S4: Construct a cast-in-place inverted arch between the precast arches (10).

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