TBM split mounting type circular tunnel parking strip structure and construction method thereof

Abstract

The invention discloses a TBM assembled circular tunnel parking strip structure and a construction method thereof.The TBM assembled circular tunnel parking strip structure comprises an expanding and digging hole formed in one side of a tunnel main hole, the section of the expanding and digging hole is circular, the axis of the expanding and digging hole is parallel to the axis of the tunnel main hole, and the section of the expanding and digging hole intersects with the section of the tunnel main hole; an expanding excavation supporting structure is arranged outside the intersection section of the expanding excavation hole, and the expanding excavation supporting structure is in rigid connection with the splicing pipe pieces outside the intersection section of the tunnel main hole. The expanding excavation hole with the round section is formed in one side of the tunnel main hole, the section of the expanding excavation hole intersects with the section of the tunnel main hole to form the double-round parking strip structure, the expanding excavation supporting structure is arranged to be in rigid connection with the tunnel main hole splicing pipe pieces, and the parking strip structure can meet the requirement for stress of a complex structure and also can be used for supporting the tunnel main hole. And the construction of the parking strip in the TBM assembly type circular tunnel can be effectively solved, so that a solution is provided for the operation safety of the long and large tunnel.

Description

Technical Field

[0001] The invention relates to the technical field of TBM assembled tunnel construction, and in particular to a TBM assembled circular tunnel parking strip structure and a construction method thereof. Background Art

[0002] As the length of highway tunnels increases, tunnel construction technology and tunnel ventilation technology are facing great challenges. At present, more and more highway mountain tunnels are more than 20 kilometers long. There are major technical problems in the construction of these tunnels, such as long construction period and difficult ventilation. The full-section rock tunnel boring machine (TBM) has the characteristics of fast construction and good safety performance, and has become one of the options for solving the construction of such ultra-long tunnels. The shield TBM adopts fully prefabricated assembled segment lining, with a high degree of prefabrication and factory production, and controllable quality.

[0003] For the common two-lane highway tunnels, in order to meet the driving clearance requirements, the outer diameter of the TBM circular tunnel needs to be about 12-13m. However, in order to meet the operational safety issues of long and large tunnels, a parking strip needs to be designed every 750m or so, that is, it is widened by about 3-3.5m outside the driving clearance. TBM tunnels are one of the ways to set up parking strips by expanding the parking strip after assembling the segments. However, since the length of the parking strip is about 50m, the force after the expansion and excavation of the parking strip is extremely complex, resulting in the expansion process and the structural design after the expansion being one of the difficulties currently existing. Summary of the invention

[0004] The purpose of the present invention is to provide a parking strip structure and a construction method for a TBM assembled circular tunnel, in view of the structural design and construction difficulties faced by the expansion of the parking strip after assembling the pipe segments in the TBM assembled circular tunnel, which can not only meet the stress of the complex structure after the expansion, but also meet the function of the parking strip, thereby effectively solving the parking strip construction problem of the TBM tunnel.

[0005] The present invention is achieved through the following technical solutions:

[0006] In the first aspect, the present invention provides a TBM assembled circular tunnel parking strip structure, including an expanded hole arranged on one side of the tunnel main hole, the cross-section of the expanded hole is circular, the axis of the expanded hole is parallel to the axis of the tunnel main hole, the cross-section of the expanded hole intersects with the cross-section of the tunnel main hole, the expanded hole is formed by dismantling part of the assembled pipe segments close to the parking strip side after TBM construction of the tunnel main hole and then expanding and excavating, an expanded support structure is arranged in the expanded hole, and the expanded support structure is rigidly connected with the assembled pipe segments retained in the tunnel main hole.

[0007] As a preferred embodiment of the present invention, the expansion support structure includes initial support, secondary lining, and a beam-column support system arranged between two intersections formed by the inner contour of the expansion hole and the main tunnel, and the beam-column support system is connected to the secondary lining and assembled pipe segments.

[0008] As a preferred embodiment of the present invention, the beam-column support system includes a top beam, a bottom beam and a plurality of columns, the top beam and the bottom beam are respectively arranged at the upper and lower intersection areas of the expanded hole and the main tunnel hole, and the top beam and the bottom beam both extend along the axis direction of the main tunnel hole, the plurality of columns are arranged at intervals along the axis direction of the main tunnel hole, and the upper and lower ends of the plurality of columns are respectively connected to the top beam and the bottom beam.

[0009] As a preferred solution of the present invention, the top beam and the bottom beam are rigidly connected to the secondary lining and the assembled segments.

[0010] As a preferred solution of the present invention, the spacing of the plurality of columns along the axis of the tunnel main hole is determined to be no less than 10m, and the spacing of the columns at both ends is determined to meet the needs of vehicles turning in and out of the parking strip.

[0011] As a preferred solution of the present invention, the cross-sectional radius of the expanded hole is smaller than the cross-sectional radius of the main hole of the tunnel.

[0012] As a preferred embodiment of the present invention, the assembled pipe segments use steel-concrete composite pipe segments within the parking strip.

[0013] As a preferred solution of the present invention, the assembled pipe segments are assembled using box-type steel pipe segments. According to the difference in tunnel diameter, 8-10 blocks can be assembled into a ring, and adjacent steel pipe segment blocks are connected by bolts.

[0014] As a preferred solution of the present invention, the steel pipe segments are connected by welding through a plurality of steel plates to form a box-type structure, and steel bar holes and pouring ports are reserved.

[0015] In a second aspect, the present invention provides a construction method of a TBM assembled circular tunnel parking strip structure as described in the first aspect, comprising the following steps:

[0016] Step 1: Before the parking strip is expanded, temporary support is first provided inside the assembled segments of the main tunnel with steel sections, and then grouting is performed to reinforce the rock mass outside the segments through the grouting holes reserved on the assembled segments;

[0017] Step 2: After grouting reinforcement, the segments within the excavation range are gradually removed in blocks and rings, and excavation construction is carried out. After the excavation construction reaches the contour position, initial support construction is carried out;

[0018] Step 3: When the length of the expanded hole reaches the span of the column, the top beam, bottom beam and column structure are constructed, and the unremoved segments are connected to the top beam and bottom beam with steel bars;

[0019] Step 4: Carry out secondary lining construction and use steel bars to connect the secondary lining with the top beam and bottom beam;

[0020] Step 5. Repeat steps 2 to 4 until the expansion construction of the entire parking strip is completed.

[0021] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0022] The TBM assembled circular tunnel parking strip structure of the present invention forms a double circular parking strip structure by arranging an expanded hole with a circular cross section on one side of the tunnel main hole, and the cross section of the expanded hole intersects with the cross section of the tunnel main hole, and a beam-column support system is constructed between the upper and lower areas where the expanded hole intersects with the tunnel main hole through a top beam, a bottom beam and a plurality of columns, and the beam-column support system is connected with the secondary lining of the expanded hole and the unremoved pipe segments of the tunnel main hole to form an integral force-bearing structure; the parking strip structure can meet the stress of a complex structure and the function of a parking strip, and can effectively solve the construction of a parking strip in a TBM assembled circular tunnel, thereby providing a solution for the safety of long and large tunnel operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0024] Figure 1 It is a schematic diagram of the inner contour of the TBM assembled circular tunnel parking strip structure in the present invention;

[0025] Figure 2 It is a schematic cross-sectional view of the TBM assembled circular tunnel parking strip structure in the present invention;

[0026] Figure 3 It is a schematic plan view of the TBM assembled circular tunnel parking strip structure in the present invention;

[0027] Figure 4 It is a block layout diagram of the assembled pipe segments of the main tunnel of the present invention;

[0028] Figure 5 It is a schematic plan view of the assembled pipe segments of the main tunnel of the present invention;

[0029] Figure 6 for Figure 5 AA section diagram in;

[0030] Figure 7 for Figure 5 BB cross-section diagram in;

[0031] Figure 8 for Figure 5 Schematic diagram of CC cross section;

[0032] Fig. 9 It is a schematic diagram of temporary support inside the main tunnel of the tunnel, external grouting reinforcement and dismantling of assembled pipe segments during construction of the present invention;

[0033] Fig.10 It is a schematic diagram of the excavation construction and initial support of the excavated hole in the present invention;

[0034] Fig.11 It is a schematic diagram of the construction of the top beam, bottom beam, column and secondary lining in the present invention.

[0035] Marks and corresponding parts names in the attached drawings:

[0036] 1-main tunnel, 2-expanded tunnel, 3-assembled segments, 31-back plate, 32-circumferential end plate, 33-longitudinal end plate, 34-longitudinal rib plate, 35-circumferential rib plate, 4-initial support, 5-secondary lining, 6-top beam, 7-bottom beam, 8-column, 9-temporary steel support, 10-box culvert, 11-road slab. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0039] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0040] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0041] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0042] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0043] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces), unless otherwise clearly and specifically defined.

[0044] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0045] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like 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 or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0046] At present, in order to ensure the operational safety of long and large highway tunnels, a parking strip needs to be designed every 750 meters, that is, it is widened by about 3-3.5 meters outside the driving limit. When the traditional drilling and blasting method is used to construct tunnels, the parking strip is constructed synchronously with the main tunnel, and it is not necessary to expand the side after the main tunnel is formed. With the continuous application of TBM, highway tunnels are gradually constructed by TBM. Since the shield TBM uses a fully prefabricated assembled segment lining, expanding the parking strip after assembling the segments in the TBM tunnel is one of the ways to set up the parking strip.

[0047] However, since the parking strip is about 50m long, the stress on the parking strip after excavation is extremely complex, especially at the junction of the excavation section and the main tunnel, which is prone to form a weak area, resulting in the excavation process and the structural design after excavation being one of the existing difficulties. In order to solve the structural design and construction process of the excavation parking strip of the assembled segment lining of a long circular tunnel, the applicant has conducted in-depth research and, based on the actual stress characteristics of the excavation, has proposed a design and construction scheme for the structure of the excavation parking strip of the assembled segment lining circular tunnel constructed by TBM method.

[0048] Example 1

[0049] Please refer to Figures 1 to 8 A TBM assembled circular tunnel parking strip structure provided in an embodiment of the present application comprises an expanded hole 2 arranged on one side of a tunnel main hole 1, the cross-section of the expanded hole 2 is circular, the axis of the expanded hole 2 is parallel to the axis of the tunnel main hole 1, the cross-section of the expanded hole 2 intersects with the cross-section of the tunnel main hole 1, the expanded hole 2 is formed by expanding the tunnel main hole 2 after TBM construction by removing part of the assembled pipe segments 3 close to the parking strip side, an expanded support structure is arranged in the expanded hole 2, and the expanded support structure is rigidly connected to the assembled pipe segments 3 retained in the tunnel main hole 1.

[0050] The circular excavated hole 2 in the embodiment of the present application intersects with the tunnel main hole 1 to form a double circular parking strip structure. At this time, the inner contour formed by the tunnel main hole 1 and the excavated hole 2 is as shown in FIG. Figure 1 As shown. Since the expansion construction is carried out to one side after removing part of the assembled segments 3 in the main tunnel 1, a weak area is easily formed at the intersection of the inner contours of the main tunnel 1 and the expanded tunnel 2. At the same time, the present application sets an expansion support structure for the expanded tunnel 2, and forms a rigid connection between the expansion support structure and the assembled segments 3 that have not been removed from the main tunnel 1, so that the support structure of the expanded tunnel 2 and the assembled segments of the main tunnel 1 form an integral force-bearing structure. The parking strip structure can meet the stress of the complex structure and the function of the parking strip, and can effectively solve the construction of the parking strip in the TBM assembled circular tunnel, thereby providing a solution for the safety of long and large tunnel operations.

[0051] According to some embodiments of the present application, the expansion support structure includes initial support 4, secondary lining 5, and a beam-column support system arranged between two intersection positions formed by the inner contour of the expansion hole 2 and the main tunnel 1, and the beam-column support system is rigidly connected to the secondary lining 5 and the assembled pipe segments 3.

[0052] Since the main tunnel 1 and the expanded tunnel 2 are both circular, the intersection area between the two is removed, and the inner contours of the main tunnel 1 and the expanded tunnel 2 are roughly C-shaped and the openings are opposite. Since the intersection of the inner contours of the main tunnel 1 and the expanded tunnel 2 forms a weak point, the present application constructs a beam-column support system in the above-mentioned weak area, and rigidly connects the beam-column support system with the secondary lining 4 of the expanded tunnel 2 and the assembled pipe segments 3 of the main tunnel 1 that have not been removed, thereby forming an integral force-bearing structure, so as to jointly bear the surrounding rock excavation stress, thereby meeting the force requirements of the complex structure.

[0053] According to some embodiments of the present application, the beam-column support system includes a top beam 6, a bottom beam 7 and a plurality of columns 8, the top beam 6 and the bottom beam 7 are respectively arranged at the upper and lower intersection areas of the expanded tunnel 2 and the tunnel main tunnel 1, and the top beam 6 and the bottom beam 7 both extend along the axial direction of the tunnel main tunnel 1, the plurality of columns 8 are arranged at intervals along the axial direction of the tunnel main tunnel 1, and the upper and lower ends of the plurality of columns 8 are rigidly connected to the top beam 6 and the bottom beam 7, respectively.

[0054] According to the structure of the tunnel main tunnel 1 and the expanded tunnel 2 in the present application, the inner contours of the tunnel main tunnel 1 and the expanded tunnel 2 are actually divided into two upper and lower intersecting areas, and the two intersecting areas extend along the axial direction of the tunnel respectively. Therefore, the present application respectively sets a top beam 6 and a bottom beam 7 extending along the axial direction of the tunnel in the above-mentioned two intersecting areas, and arranges a plurality of vertical columns 8 between the top beam 6 and the bottom beam 7 to jointly form a beam-column support system, and the secondary lining 5 of the expanded tunnel 2 and the assembled pipe segments 3 of the tunnel main tunnel 1 that have not been removed are rigidly connected to the top beam 6 and the bottom beam 7 respectively, thereby forming a force transmission system to support the intersection area of ​​the tunnel main tunnel 1 and the expanded tunnel 2, thereby meeting the extremely complex stress conditions after the expansion of the parking strip.

[0055] According to some embodiments of the present application, the top beam 6 and the bottom beam 7 are rigidly connected to the secondary lining 5 and the assembled pipe segments 3. Specifically, when the secondary lining 5 is constructed by expanding the hole 2, the two ends of the circumferential steel bars are anchored to a certain depth inside the top beam 6 and the bottom beam 7; the two assembled pipe segments adjacent to the top beam 6 and the bottom beam 7 in the main tunnel 1 of the tunnel are connected to the internal steel bars of the top beam 6 and the bottom beam 7 by implanting steel bars, so that the secondary lining 5, the assembled pipe segments 3 and the beam-column support system form an integral force-bearing structure together.

[0056] According to some embodiments of the present application, the arrangement spacing of the multiple columns 8 along the axial direction of the tunnel main hole 1 is determined to be no less than 10m, and the spacing of the columns 8 located at both ends is determined according to the needs of vehicles turning in and out of the parking strip.

[0057] According to some embodiments of the present application, the cross-sectional radius of the expanded hole 2 is smaller than the cross-sectional radius of the main tunnel hole 1. Taking a two-lane highway tunnel as an example, the inner contour radius of the main tunnel hole 1 is about 5.50m, and the radius of the expanded hole 2 with a double-circle structure of the parking strip is 4.5m. Of course, it is understandable that the radius of the expanded hole 2 can be adjusted to be larger than the radius of the main tunnel hole 1 according to the design width of the parking strip. As for the axial height of the expanded hole 2 and the main tunnel hole 1, it can be designed according to actual conditions, that is, the axis of the expanded hole 2 can be higher, lower, or equal to the axis of the main tunnel hole 1.

[0058] According to some embodiments of the present application, the assembled segments 3 are steel-concrete composite segments within the parking strip, that is, the assembled segments 3 are steel shell concrete structures. It should be noted that the assembled segments used in the main tunnel outside the parking strip are similar to the conventional shield segments, that is, prefabricated reinforced concrete segments are used.

[0059] According to some embodiments of the present application, the assembled pipe segments 3 are assembled using box-shaped steel pipe segments, and according to the difference in tunnel diameter, 8-10 segments can be assembled into a ring. Figure 4 As shown, the assembled pipe segment 3 includes a standard block B, an adjacent block L and a capping block F. When assembling into a ring, adjacent steel pipe segments are connected by bolts. The pipe segments between adjacent rings are also connected by bolts. When the parking strip is expanded, the corresponding pipe segment blocks in the main tunnel 1 can be removed according to the expansion area.

[0060] According to some embodiments of the present application, the steel pipe segments are connected by welding multiple steel plates to form a box-type structure, and steel bar holes and pouring ports are reserved on the steel pipe segments according to actual conditions.

[0061] like Figure 5-Figure 8As shown, the steel pipe segment includes a back plate 31, an annular end plate 32, a longitudinal end plate 33, a longitudinal rib plate 34 and annular rib plates 35, wherein the back plate 31 is located outside the pipe segment, and after assembly, the back plate 31 contacts the tunnel wall; the longitudinal end plates 33 are arranged along the longitudinal direction of the tunnel, and the two longitudinal end plates 33 are located on the opposite sides of the back plate 31; the annular end plates 32 are arranged along the annular direction of the tunnel, and the two annular end plates 32 are located on the other two sides of the back plate 31; the two longitudinal end plates 33 and the two annular end plates 32 are jointly enclosed around the back plate 31, thereby forming a box-type structure. There are multiple longitudinal rib plates 34 parallel to the longitudinal end plates 33, and there are multiple annular rib plates 35 parallel to the annular end plates 32, that is, multiple longitudinal rib plates 34 and annular rib plates 35 are distributed in a cross shape in the above-mentioned box-type structure, dividing the interior of the box-type structure into multiple rectangular areas. The back plate 31, the annular end plate 32, the longitudinal end plate 33, the longitudinal ribs 34 and the annular ribs 35 are connected by welding to form the entire steel pipe segment.

[0062] It should be noted that the side of the steel pipe segment opposite to the back plate 31 is an open structure, that is, the side of the steel pipe segment is not closed with a steel plate, that is, when the segments of the main tunnel 1 are assembled, the inside of the steel pipe segment is actually a plurality of cavities, and concrete can be poured inside the steel pipe segment by supporting a formwork in the later stage. The inside of the steel pipe segment is an open structure, which can save the amount of steel plate and reduce the cost of the steel pipe segment on the premise of meeting the strength of the supporting structure of the steel pipe segment. The longitudinal end plate 33 and the longitudinal rib plate 34 of the steel pipe segment are opened with holes, and steel bar holes and square openings are reserved to facilitate the later insertion of steel bars and concrete pouring to form a steel concrete segment.

[0063] Example 2

[0064] Please refer to Figures 1 to 11 The construction method of a TBM assembled circular tunnel parking strip structure as described in Example 1 provided in the embodiments of the present application comprises the following steps:

[0065] Step 1: Before the parking strip is expanded, a temporary steel support 9 is set up inside the assembled segment 3 of the main tunnel 1, and then the rock mass outside the segment is reinforced by grouting through the grouting holes reserved on the assembled segment 3;

[0066] Step 2: After grouting reinforcement, the assembled segments 3 within the excavation range are gradually removed in blocks and rings, and excavation construction is carried out. After the excavation construction reaches the contour position, initial support 4 construction is carried out;

[0067] Step 3: When the length of the expanded hole 2 reaches the span of the column 8, the top beam 6, the bottom beam 7 and the column 8 are constructed, and the assembled pipe segments 3 that have not been removed are connected to the top beam 6 and the bottom beam 7 with steel bars;

[0068] Step 4: construct the secondary lining 5 and connect the secondary lining 5 with the top beam 6 and the bottom beam 7 using steel bars;

[0069] Step 5. Repeat steps 2 to 4 until the expansion construction of the entire parking strip is completed.

[0070] According to some embodiments of the present application, in step 1, when constructing the steel temporary support 9 inside the assembled segments 3 of the main tunnel 1, the inner formwork used for pouring concrete inside the steel segments later can be considered together. When performing grouting reinforcement, the vertical center plane of the main tunnel 1 is used as a reference, and the area on the side of the vertical center plane facing the expanded hole 2 must be grouting reinforced, that is, the grouting reinforcement area is a 180° fan-shaped area to reinforce the rock mass in the expanded excavation area.

[0071] According to some embodiments of the present application, in step 2, only one ring of steel pipe segments can be removed each time. After the ring of steel pipe segments is removed, the parking strip expansion construction can be carried out. When the excavation reaches the contour position, initial support 4 is carried out, and then the next ring of steel pipe segments is removed, and the construction is cyclically repeated.

[0072] According to some embodiments of the present application, in step three, after removing the multi-ring steel pipe segments, when the length of the expansion along the axial direction of the tunnel reaches the distance between two adjacent columns 8, the construction of the top beam 6, bottom beam 7 and columns 8 of this section can be carried out. During construction, steel bars should be inserted into the adjacent steel pipe segments and connected to the steel bars of the top beam 6 and bottom beam 7 by anchoring. When the top beam 6 and bottom beam 7 are constructed, concrete can be poured into the assembled pipe segments 3 retained in the main tunnel 1 of the tunnel to form a whole with the concrete of the top beam 6 and bottom beam 7. Of course, concrete can also be poured separately according to specific circumstances.

[0073] According to some embodiments of the present application, in step 4, after a section of beam-column support structure is constructed, the secondary lining 5 should be constructed in time, and steel bars are used to connect the secondary lining 5 with the constructed top beam 6 and bottom beam 7. Specifically, steel bars can be reserved in advance during the construction of the top beam 6 and bottom beam 7 so as to be anchored and connected with them during the construction of the secondary lining 5.

[0074] According to some embodiments of the present application, after the expansion and excavation construction of the entire parking strip is completed, the steel temporary support 9 in the main tunnel 1 is removed, and the internal structure of the tunnel is constructed. Since the main tunnel 1 and the expansion hole 2 are both circular, and the cross-section of the actual highway tunnel is horseshoe-shaped, it is usually necessary to backfill the bottom area of ​​the tunnel with concrete, but this construction is more concrete-consuming and the construction efficiency is also low. Therefore, the present application lays a box culvert 10 in the tunnel, and lays a road panel 11 on the box culvert 10, and then directly paves the asphalt pavement on the road panel 11 in the later stage. Since the box culvert 10 and the road panel 11 can be prefabricated in the factory, it can reduce costs and improve construction efficiency. At the same time, the box culvert 10 can also be used as a channel for tunnel drainage, wiring, etc.

[0075] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A TBM assembled circular tunnel parking strip structure, It is characterized in that It includes an expanded hole arranged on one side of the main tunnel hole, the cross-section of the expanded hole is circular, the axis of the expanded hole is parallel to the axis of the main tunnel hole, the cross-section of the expanded hole intersects with the cross-section of the main tunnel hole, the expanded hole is formed by dismantling part of the assembled pipe segments close to the parking strip after TBM construction of the main tunnel hole, and an expanded hole support structure is arranged in the expanded hole, and the expanded hole support structure is rigidly connected with the assembled pipe segments retained in the main tunnel hole.

2. The TBM assembled circular tunnel parking strip structure according to claim 1, It is characterized in that The expansion support structure includes initial support, secondary lining, and a beam-column support system arranged between two intersections formed by the expansion hole and the inner contour of the main tunnel. The beam-column support system is connected to the secondary lining and the assembled pipe segments.

3. The TBM assembled circular tunnel parking strip structure according to claim 2, It is characterized in that The beam-column support system includes a top beam, a bottom beam and a plurality of columns. The top beam and the bottom beam are respectively arranged at the upper and lower intersection areas of the expanded tunnel and the main tunnel, and the top beam and the bottom beam both extend along the axis direction of the main tunnel. The plurality of columns are arranged at intervals along the axis direction of the main tunnel, and the upper and lower ends of the plurality of columns are respectively connected to the top beam and the bottom beam.

4. The TBM assembled circular tunnel parking strip structure according to claim 3, It is characterized in that The top beam and the bottom beam are rigidly connected with the secondary lining and the assembled pipe segments.

5. The TBM assembled circular tunnel parking strip structure according to claim 3, It is characterized in that The arrangement spacing of the plurality of columns along the axis of the tunnel main hole is determined to be no less than 10m, and the spacing of the columns at both ends is determined to meet the needs of vehicles turning in and out of the parking strip.

6. The TBM assembled circular tunnel parking strip structure according to any one of claims 1 to 5, It is characterized in that The cross-sectional radius of the expanded hole is smaller than the cross-sectional radius of the main hole of the tunnel.

7. The TBM assembled circular tunnel parking strip structure according to any one of claims 1 to 5, It is characterized in that The assembled pipe segments adopt steel-concrete composite pipe segments within the parking strip.

8. The TBM assembled circular tunnel parking strip structure according to claim 7, It is characterized in that The assembled pipe segments are assembled using box-type steel pipe segments, and can be assembled into a ring by dividing them into 8-10 blocks according to the difference in tunnel diameters. Adjacent steel pipe segment blocks are connected by bolts.

9. The TBM assembled circular tunnel parking strip structure according to claim 8, It is characterized in that The steel pipe segments are connected by welding through a plurality of steel plates to form a box-type structure, and steel bar holes and pouring ports are reserved.

10. A construction method for a TBM assembled circular tunnel parking strip structure as claimed in any one of claims 3 to 5, It is characterized in that The following steps are involved: Step 1: Before the parking strip is expanded, temporary support is first provided inside the assembled segments of the main tunnel with steel sections, and then grouting is performed to reinforce the rock mass outside the segments through the grouting holes reserved on the assembled segments; Step 2: After grouting reinforcement, the segments within the excavation range are gradually removed in blocks and rings, and excavation construction is carried out. After the excavation construction reaches the contour position, initial support construction is carried out; Step 3: When the length of the expanded hole reaches the span of the column, the top beam, bottom beam and column structure are constructed, and the unremoved segments are connected to the top beam and bottom beam with steel bars; Step 4: Carry out secondary lining construction and use steel bars to connect the secondary lining with the top beam and bottom beam; Step 5. Repeat steps 2 to 4 until the expansion construction of the entire parking strip is completed.

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