CN118187917A - Combined tunnel lining structure and construction method - Google Patents

Abstract

The invention relates to the technical field of tunnel construction and provides a combined tunnel lining structure and a construction method thereof, wherein the lining structure comprises six arc-shaped blocks, namely a bottom block, two side lower blocks, two side upper blocks and a top block, wherein the two side lower blocks are respectively arranged at two ends of the bottom block, the two side upper blocks are respectively arranged at two ends of the top block, and the six blocks are sequentially spliced together to form an annular lining structure; wherein each block all is formed with first concatenation face and second concatenation face along the both ends in hoop, and the contained angle between first concatenation face and the second concatenation face is 60 ~ 150, is formed with the bolt hole in first concatenation face and second concatenation face department, and arbitrary first concatenation face is in the same place with adjacent second concatenation face butt in the hoop, and the first concatenation face and the bolt hole on the second concatenation face that the butt is in the same place are relative. The combined tunnel lining structure can quickly form an annular supporting structure during construction, the workload of assembly is greatly reduced, and the aim of shortening the working procedure time and achieving the whole construction period control is fulfilled.

Description

Combined tunnel lining structure and construction method

Technical Field

The present invention relates to the technical field of tunnel construction, and in particular to a combined tunnel lining structure and a construction method.

Background technique

During the construction of open TBM, collapse of weak surrounding rock and rock burst of hard rock are often encountered. The current conventional construction response method is to use steel arch frame (density) + steel bar support measures. However, for the operators, this still has the problem of partially exposed face. At the same time, there is a certain design space for strengthening the strength of the support structure. In order to make the open TBM more adaptable, further ensure construction safety, and minimize the collapse of weak surrounding rock and TBM shutdown caused by rock burst of hard rock, the design and use ideas of combined tunnel lining structure have been derived.

In traditional open TBM tunnels, when steel pipe segments are used for support, this type of steel pipe segment is usually composed of (6 to 8) segments spliced into a ring shape, with staggered assembly in the longitudinal direction, and the appearance is mainly a quadrilateral rectangular structure. The installation method of the open TBM segment is longitudinal insertion. When assembling the last segment, it is easy to fail to assemble the segment due to insufficient space caused by local deformation of the steel structure. In addition, the traditional quadrilateral segment needs to complete the assembly of all the segments in each ring before the next TBM excavation process can be carried out. The assembly is relatively complicated, the workload is large, and it is easy to increase the overall construction period.

Summary of the invention

The object of the present invention is to provide a combined tunnel lining structure and construction method, which can quickly form an annular support structure during construction, and the workload of assembly is greatly reduced, which is conducive to shortening the process time and achieving the purpose of overall construction period control.

In order to achieve the above-mentioned purpose, in a first aspect, the present invention provides a combined tunnel lining structure, comprising a bottom block, two side lower blocks, two side upper blocks and a top block, a total of six arc-shaped blocks, the bottom block is arranged at the bottom of the tunnel, the two side lower blocks are arranged at the two ends of the bottom block, the top block is arranged at the top of the tunnel, and the two side upper blocks are arranged at the two ends of the top block, and the six blocks are sequentially spliced together to form an annular lining structure; wherein each of the blocks is provided with a first splicing surface and a second splicing surface at both ends along the annular direction, the angle between the first splicing surface and the second splicing surface is 60°-150°, and bolt holes are formed at the first splicing surface and the second splicing surface, and any first splicing surface is abutted against the second splicing surface adjacent to the annular direction, and the abutted first splicing surfaces are opposite to the bolt holes on the second splicing surfaces.

Preferably, the front and rear ends of the bottom block are formed with raised portions and/or recessed portions of the same shape.

Preferably, the bottom block comprises a shell formed by splicing steel plates and concrete filled therein; a hoisting hole matching the assembling machine is reserved at the upper end of the bottom block.

Preferably, the side lower block comprises a skeleton structure and a steel mesh arranged on the outer arc surface; the skeleton structure comprises I-beams arranged along the circumferential direction and channel steels arranged along the outer periphery of the block and along the longitudinal direction of the tunnel.

Preferably, the upper side block includes a skeleton structure and a steel plate and a steel mesh arranged on the outer arc surface, and the steel plate is located above the steel mesh; the skeleton structure includes I-beams arranged along the circumference and channel steels arranged along the outer periphery of the block and along the longitudinal direction of the tunnel.

Preferably, the top block comprises a skeleton structure and a steel plate arranged on the outer arc surface; the skeleton structure comprises I-beams arranged along the circumferential direction and channel steels arranged along the outer periphery of the block and along the longitudinal direction of the tunnel.

Preferably, it further comprises: an inverted arch block, the bottom surface of which is a curved surface identical to that of the bottom block, and the top surface of which is a flat surface.

In order to achieve the above object, in a second aspect, the present invention provides a construction method of a combined tunnel lining structure, which is used to construct the combined tunnel lining structure as described above in a tunnel, comprising the following steps:

Step S1, fixing and installing a bottom block at a preset position at the bottom of the tunnel, wherein the tail end of the bottom block is fixed to a previously constructed supporting structure;

Step S2, installing side lower blocks at both ends of the bottom block along the annular direction, wherein the first splicing surface of the side lower block is bolted together with the second splicing surface of the bottom block, or the second splicing surface of the side lower block is bolted together with the first splicing surface of the bottom block;

Step S3, installing the side upper block on the upper ends of the two side lower blocks, wherein the second splicing surface of the side upper block is bolted together with the first splicing surface of the side lower block, or the first splicing surface of the side upper block is bolted together with the second splicing surface of the side lower block;

Step S4, installing a top block on the top of the tunnel, wherein the first joint surface of the top block is bolted to the second joint surface of the side upper block, or the second joint surface of the top block is bolted to the first joint surface of the side upper block, thereby completing the construction of a single-ring lining structure.

Preferably, it also includes:

Step S5: in the next excavation process, as the TBM excavates forward, three installation positions of the blocks will appear first, and then the corresponding blocks will be assembled at the positions to achieve the purpose of longitudinal extension of the combined tunnel lining structure;

Step S6: As the TBM continues to advance, step S5 is repeated until the construction of the combined tunnel lining structure is completed.

Preferably, bolt holes are provided at both ends of each block along the longitudinal direction of the tunnel, and the construction method further comprises: bolting two adjacent blocks along the longitudinal direction of the tunnel together.

According to the above description and practice, in the combined tunnel lining structure described in the present invention, each block is hexagonal, and staggered assembly is adopted when assembling into a ring. The installation space of the last block in a single ring is in an outward eight-shaped shape open to one end. Even if the blocks in the ring are deformed to a certain extent, the last block can be easily inserted to form a ring structure, which can avoid the situation where the conventional quadrilateral steel pipe segment cannot be installed due to local deformation. In addition, when the combined tunnel lining structure continues to be constructed forward, the number of single assembly blocks is three, which is easy to assemble and convenient for construction. It is easy to position and relatively accurate during assembly. The longitudinal bolts and annular bolts are relatively easy to install. The assembly construction stress is small and the longitudinal compaction is good.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the three-dimensional structure of a combined tunnel lining structure according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a three-dimensional structure of a plurality of combined tunnel lining structures assembled together according to an embodiment of the present invention.

FIG3 is a schematic diagram of the three-dimensional structure of a bottom block in a combined tunnel lining structure according to an embodiment of the present invention.

FIG. 4 is a schematic diagram of the three-dimensional structure of a side lower block in a combined tunnel lining structure according to an embodiment of the present invention.

FIG. 5 is a schematic diagram of the three-dimensional structure of the upper side block in the combined tunnel lining structure according to an embodiment of the present invention.

FIG. 6 is a schematic diagram of the three-dimensional structure of a top block in a combined tunnel lining structure according to an embodiment of the present invention.

FIG. 7 is a top view of a top block in a combined tunnel lining structure according to an embodiment of the present invention.

FIG8 is a flow chart of a construction method of a combined tunnel lining structure according to an embodiment of the present invention.

The reference numerals in the figure are:

11. Bottom block 12. Lower side block 13. Upper side block

14. Top block 15. Invert block 21. First joint surface

22. Second joint surface 31. Raised portion 32. Concave portion

41. Shell 42. Concrete 51. I-beam

52. Channel steel 53. Steel mesh 54. Steel plate

Detailed ways

The exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the disclosure will be more comprehensive and complete and fully convey the concepts of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

In addition, the accompanying drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and thus their repeated descriptions will be omitted. It should be noted that in the present disclosure, the terms "including", "configured with", and "set in" are used to express the meaning of open-ended inclusion, and mean that in addition to the listed elements/components/etc., there may be other elements/components/etc.; the terms "first", "second", etc. are only used as marks, and are not restrictions on the number or order of their objects; the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

Unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" 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, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

In this embodiment, a combined tunnel lining structure is disclosed, which can take into account the advantages of traditional segment through-seam splicing and staggered splicing when splicing and installing in the tunnel, while avoiding the disadvantages of both to a certain extent. Please refer to Figures 1 to 7. The combined tunnel lining structure in this embodiment mainly includes a bottom block 11 located at the bottom of the tunnel, two side lower blocks 12 located on both sides of the lower part of the tunnel, two side upper blocks 13 located on both sides of the upper part of the tunnel, and a top block 14 located at the top of the tunnel, a total of six blocks. The six blocks are spliced together in sequence to form an annular lining structure, wherein the two side lower blocks 12 are respectively arranged at the two ends of the bottom block 11, and the two side upper blocks 13 are respectively arranged at the two ends of the top block 14.

In the six blocks, each block is provided with a first splicing surface 21 and a second splicing surface 22 at both ends along the circumferential direction, and the angle between adjacent first splicing surfaces 21 and second splicing surfaces 22 on each block is 60°-150°. Bolt holes are formed at the positions of the first splicing surfaces 21 and the second splicing surfaces 22 of each block, which are used to bolt two circumferentially adjacent blocks together. In addition, bolt holes are also provided at both ends of each block along the longitudinal direction, that is, along the longitudinal direction of the tunnel, and two adjacent blocks along the longitudinal direction can be bolted together. It should be noted that it is a prior art to connect adjacent blocks together by bolts, and the specific setting shape of the bolt holes will not be repeated here.

Among the six blocks, any first splicing surface 21 abuts against the second splicing surface 22 adjacent to the circumferential direction, and the lengths of the abutting first splicing surface 21 and the second splicing surface 22 are the same. In other words, the six blocks are not completely on the same loop along the circumferential direction, but are staggered to a certain extent. In conjunction with Figure 2, taking the splicing surface at the right end of one of the bottom blocks 11 as an example, the first splicing surface 21 abuts against the second splicing surface 22 of the side lower block 12 on the left side, of the two side lower blocks 12 on the right side; the second splicing surface 22 abuts against the first splicing surface 21 of the side lower block 12 on the right side, of the two side lower blocks 12 on the right side, of the side lower block 12 on the right side.

That is, in actual application, one end of a bottom block 11 will be connected to two adjacent side lower blocks 12, and the entire bottom block 11 will be connected to four adjacent side lower blocks 12. For other side lower blocks 12, side upper blocks 13 and top blocks 14, any block that is not at both ends in the longitudinal direction will be connected to four adjacent blocks. Finally, the assembly effect as shown in Figure 2 is achieved, in which the installation seam along the longitudinal direction is a continuous bending structure, which is different from the installation seam formed by traditional through-seam splicing and staggered seam splicing. The longitudinal direction here is the length direction of the tunnel.

In addition, Fig. 2 also shows an inverted arch block 15 located above the bottom block 11. The inverted arch block 15 can be prefabricated and directly installed at the bottom of the combined tunnel lining structure to complete the installation process of the inverted arch block. Specifically, the bottom surface of the inverted arch block 15 is a curved surface identical to the bottom block 11, and the top surface is a plane. The two ends of the inverted arch block 15 are reserved with holes for planting reinforcement for the later secondary lining, which is convenient for the construction of the secondary lining. Connectors are reserved at appropriate positions on the outer sides of the two ends of the inverted arch block 15 so that the inverted arch block and the secondary lining of the later tunnel form an integral body.

With the above-mentioned blocks and the continuously bent installation seams, only the positioning of the first bottom block 11 at the starting position is relatively complicated during assembly, while the positioning of the remaining blocks is easy and accurate during assembly, the longitudinal bolts and the annular bolts are easy to install, the assembly construction stress is small, and the longitudinal compaction is good. Finally, multiple lining structures are spliced together to form a support structure with good integrity and a flat and stable annular surface in the tunnel.

In this embodiment, the front and rear ends of the bottom block 11 are formed with protrusions 31 and/or recesses 32 of the same shape, which are relative to the tunneling direction, so that the two adjacent bottom blocks 11 can be quickly aligned and connected together, thereby improving the assembly speed. As shown in FIG3 , a recess 32 is provided at the front end of the bottom block 11, and a protrusion 31 is provided at the rear end, and the shapes of the protrusion 31 and the recess 32 are the same. After the first bottom block 11 is positioned, the protrusion 31 of the subsequent bottom block 11 can be inserted into the recess 32 at its front end, so that the positioning of the subsequent bottom block 11 can be quickly achieved, and then the adjacent side lower block 12 can be quickly positioned between the side ends of the two bottom blocks 11, which can further improve the assembly efficiency of the combined tunnel lining structure. In other embodiments, the front end of the bottom block 11 can also be provided with a plurality of recesses 32 and/or protrusions 31, and the corresponding protrusions 31 and/or recesses 32 are provided at the rear end, so that the two adjacent bottom blocks 11 can be quickly and tightly connected.

Furthermore, in this embodiment, the bottom block 11 includes a shell 41 formed by splicing steel plates and concrete 42 filled therein. The upper end of the shell 41 is open to fill the interior with concrete 42. The bottom block 11 of this structural form has a certain strength before installation in the tunnel, will not be significantly deformed during transportation and installation, and can provide relatively stable support for adjacent blocks, ensuring that the splicing operation can be completed smoothly.

A hoisting hole matching the assembling machine is reserved at the upper end of the bottom block 11, so the bottom block 11 can be installed with TBM equipment, which can further improve the assembly efficiency. Bolt holes for splicing with adjacent blocks are provided on the side of the bottom block 11. Each block is connected by bolts, which can not only increase the installation speed, but also facilitate later maintenance. In other embodiments, the connection between each block is not limited to bolt connection. Other existing connection methods, such as clamping, welding, etc., can be applied to the connection between each block as long as a stable ring structure can be formed.

In this embodiment, the side lower block 12 includes a skeleton structure and a steel mesh 53 arranged on the outer arc surface. The skeleton structure can provide the main support for the lining structure, and the steel mesh 53 can improve its own bonding with the subsequent concrete. In addition, compared with the prefabricated concrete block as a single pipe segment, this type of side lower block 12 has a certain strength and is also easy to transport and install due to its light weight. Specifically, the skeleton structure includes an I-beam 51 arranged along the circumference of the block and a channel steel 52 arranged along the outer periphery of the block and along the longitudinal direction of the tunnel. Among them, the I-beam 51 serves as the main supporting structure, and the channel steel 52 serves as a stiffening rib. The side lower block 12 of this structural form can also be applied to the auxiliary thrust system of the TBM to provide support for the hydraulic rod along the longitudinal direction of the tunnel.

Similarly, in this embodiment, the upper side block 13 includes a skeleton structure and a steel plate 54 and a steel mesh 53 arranged on the outer arc surface, and the steel plate 54 thereon is located above the steel mesh 53. The top block 14 includes a skeleton structure and a steel plate 54 arranged on the outer arc surface. The skeleton structures on the two blocks also include an I-beam 51 arranged along the circumference and a channel steel 52 arranged along the outer periphery of the block and along the longitudinal direction of the tunnel, and can achieve the above-mentioned effects.

The steel plate 54 is provided on the outer periphery of the top block 14 and the upper part of the outer periphery of the side upper block 13 instead of the steel mesh 53. On the one hand, it can prevent the phenomenon of rockfall in the tunnel. On the other hand, the upper part of the support structure formed by this lining structure in the tunnel does not need to be sprayed and mixed later, and only the area with the steel mesh 53 needs to be sprayed and mixed, which can simplify the construction procedures and improve the construction efficiency. In addition, it can also avoid the problem of concrete falling due to instability during top spraying.

The combined tunnel lining structure disclosed in the present invention is further described below with a specific embodiment. In this embodiment, the shell 41 of the bottom block 11 is welded from a 12 mm thick steel plate, with an outer diameter of 4.4 m and an inner diameter of 4.0 m. The welded steel shell 41 is filled with C30 plain concrete, and a hoisting hole is reserved in the middle part in combination with the structure of the assembly machine, and bolt holes for the side lower block 12 are reserved on both sides.

One end of the two side lower blocks 12 is bolted to the bottom block 11, and the other end is bolted to the side upper block 13. In the skeleton structure of the side lower block 12, the main support is made of I14 I-steel, and the reinforcing rib is made of [14 channel steel bent and welded. The outer arc surface of its skeleton structure is welded with φ10@100*100 steel mesh. The lower ends of the two side upper blocks 13 are bolted to the side lower block 12, and the upper end of the side upper block 13 is bolted to the top block 14. In the skeleton structure of the side upper block 13, the main support is made of I14 I-steel, and the reinforcing rib is made of [14 channel steel bent and welded. The lower 1/2 area of the outer arc surface of its skeleton structure is welded with φ10@100*100 steel mesh, and the upper 1/2 area of the outer arc surface of the skeleton is welded with a 10mm thick steel plate. The top block 14 is bolted to the side upper block 13 on both sides. The main support of the skeleton structure of the top block 14 is made of I14 I-beam, and the reinforcing rib is made of [14 channel steel bent and welded. The entire area of the outer arc surface of the skeleton structure is welded firmly with a 10mm thick steel plate.

In this embodiment, except for the bottom block 11, the other blocks are in a hexagonal structure as a whole, and the two sides of the front and rear ends are parallel and have the same length along the circumferential direction. The two ends along the circumferential direction are the first splicing surface 21 and the second splicing surface 22 of the same length, and the angle between the two is 120°, which can form the above-mentioned continuous bending installation seam. On this basis, the bottom block 11 is also provided with a recessed portion 32 and a raised portion 31 at the front and rear ends, respectively, to facilitate the connection of two adjacent bottom blocks 11 together.

It should be noted that, in this embodiment, each block is provided with a structure that is a combination of a steel plate 54 and concrete 42, or a structure that is a combination of a steel skeleton, a steel mesh 53, and later concrete, or a structure that is a combination of a steel skeleton and a steel plate 54, so as to achieve different specific effects at different locations. In other embodiments, each block may also be a prefabricated concrete component, as long as the structural setting of the first splicing surface 21 and the second splicing surface 22 is met, a continuously bent construction joint can be achieved, and the corresponding technical effect can be achieved.

A single-ring combined tunnel lining structure is given above. In another embodiment, a plurality of the above-mentioned single-ring combined tunnel lining structures can be spliced together longitudinally to form a combined tunnel lining structure of a larger length, which can be used as a temporary or permanent supporting structure in the tunnel.

In this embodiment, a construction method of a combined tunnel lining structure is also disclosed, which is used to construct the above-mentioned combined tunnel lining structure in a tunnel, and specifically includes the following steps:

Step S1, a bottom block 11 is fixedly installed at a preset position at the bottom of the tunnel. Specifically, the tail end of the bottom block 11 is fixed to a previously constructed support structure. For example, the previous support structure is poured reinforced concrete, and after the bottom block 11 is positioned, it is welded to the steel bars in the previous support structure.

Step S2, installing the side lower blocks 12 at both ends of the bottom block 11 along the circumferential direction, wherein the first splicing surface 21 of the side lower block 12 is bolted together with the second splicing surface 22 of the bottom block 11, or the second splicing surface 22 of the side lower block 12 is bolted together with the first splicing surface 21 of the bottom block 11. In these two installation methods, the side lower blocks 12 are respectively located in the rear half and the front half of the bottom block 11, and can be installed according to actual needs.

Step S3, installing the upper side block 13 at the upper ends of the two lower side blocks 12, wherein the second splicing surface 22 of the upper side block 13 is bolted together with the first splicing surface 21 of the lower side block 12, or the first splicing surface 21 of the upper side block 13 is bolted together with the second splicing surface 22 of the lower side block 12. Under these two installation methods, the upper side block 13 is respectively located in the front half and the rear half of the lower side block 12, and can be installed specifically according to actual needs. The best option is that the upper side block 13 and the bottom block 11 are on the same loop line, that is, the lower side block 12 is simultaneously located in the front half or the rear half of the bottom block 11 and the upper side block 13. In this case, it is convenient to construct and install the ring lining structure.

Step S4, installing the top block 14 at the top of the tunnel, wherein the first joint surface 21 of the top block 14 is bolted to the second joint surface 22 of the side upper block 13, or the second joint surface 22 of the top block 14 is bolted to the first joint surface 21 of the side upper block 13, and the single ring lining structure is completed. Under these two installation methods, the top block 14 is respectively located in the rear half and the front half of the side upper block 13. The best option is to make the top block 14 and the side lower block 12 on the same loop line, that is, the side upper block 13 is simultaneously located in the front half or the rear half of the top block 14 and the side lower block 12, in which case, it is convenient to construct and install the ring lining structure.

The construction method of a single-ring lining structure is given above. Usually, a lining structure of a certain length is constructed in a tunnel. Therefore, the construction method of the combined tunnel lining structure also includes step S5 and step S6.

Step S5, in the next excavation process, as the TBM advances forward, for example, after excavating 0.9m, the installation positions of the three blocks will first appear (i.e., the parts of the single-ring lining structure that are recessed backward along the longitudinal direction), and then the corresponding blocks will be assembled at this position to achieve the purpose of longitudinal extension of the combined tunnel lining structure.

Step S6: As the TBM continues to advance, the step S5 is repeated until the construction of the combined tunnel lining structure is completed. For example, in the process of excavating an open tunnel, the above-mentioned lining structure is constructed for sections with poor geological environment (such as soft bedrock that is easy to collapse, or hard bedrock that is easy to rock burst). When the tunnel is excavated forward to a good geological environment, the construction of the lining mechanism can be stopped. In addition, bolt holes are set at both ends of each block along the longitudinal direction of the tunnel. During the construction process, when the tunnel is continuously advanced in the longitudinal direction, two adjacent blocks along the longitudinal direction of the tunnel are also bolted together.

In addition, in step S6, after the lining structure with a preset number of rings is constructed, the spraying operation is performed on the part of the lining structure where the steel mesh 53 is provided. The preset number of rings needs to be determined according to the actual construction scene and construction equipment. First, there needs to be enough area to be sprayed for spraying. If the area to be sprayed is small, the spraying will easily affect other operation procedures in the adjacent area. Second, the equipment to be sprayed needs to be moved to the area to be sprayed as the excavation progresses. For example, when TBM equipment is used for tunnel excavation, the spraying equipment is in a relatively backward position. Therefore, the spraying can only be performed when the spraying equipment reaches the lining structure as the tunnel continues to be excavated.

In addition, it should be noted that the installation of the invert block 15 is after the single-ring lining structure is formed into a ring. The specific time can be carried out according to actual needs. It can be carried out before the spraying and mixing operation or after the spraying and mixing operation to meet the needs of the construction operation.

The combined tunnel lining structure adopts staggered assembly, and each block is roughly in the form of a hexagon. When it is assembled into a ring, the installation space of the last block is in an outward eight-shaped shape that is open to one end. Even if the blocks in the ring are deformed to a certain extent, the last block can be easily inserted to form a ring structure. In contrast, if the conventional quadrilateral steel pipe segment is locally deformed, it is difficult for the last block to be inserted into the installation space. Therefore, the combined tunnel lining structure can avoid the situation where the conventional quadrilateral steel pipe segment cannot be installed due to local deformation. The combined tunnel lining structure has three blocks for assembly at a time, which is easy to assemble and convenient for construction. It is easy to position during assembly, and the positioning is relatively accurate. The longitudinal bolts and annular bolts are relatively easy to install, the assembly construction stress is small, and the longitudinal compaction is better. At the same time, the bottom block in the present application is composed of steel plate and concrete, which has a high compressive strength and can provide local propulsion reaction force for the TBM to meet the excavation requirements.

In addition, the combined tunnel lining structure and its construction method are particularly suitable for the tunnel excavation process of an open TBM, for situations where poor geological sections are encountered during the excavation process. For example, when encountering soft bedrock that is prone to collapse, or hard bedrock that is prone to rock bursts, the above-mentioned combined tunnel lining structure can be constructed in this section to replace the reinforced concrete support structure, and support can be quickly formed in this section to avoid collapse and rock bursts. Moreover, the combined tunnel lining structure itself has a high compressive strength in the longitudinal direction, and can provide a support point for the auxiliary propulsion system of the TBM equipment for excavation. During the tunnel excavation process, the support shoe in the main propulsion system does not need to be tightly pressed against the inner wall of the lining structure, but only relies on the oil cylinder in the auxiliary propulsion system to be tightly pressed against the front end face of the lining structure to achieve forward excavation. While ensuring normal excavation, the main body of the combined tunnel lining structure will not be damaged.

It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the present invention, and any reference numerals in the claims should not be considered as limiting the claims to which they relate.

Claims (10)

1. A combined tunnel lining structure, characterized in that it comprises a bottom block, two side lower blocks, two side upper blocks and a top block, a total of six arc-shaped blocks, wherein the bottom block is arranged at the bottom of the tunnel, the two side lower blocks are arranged at both ends of the bottom block, the top block is arranged at the top of the tunnel, the two side upper blocks are arranged at both ends of the top block, and the six blocks are sequentially spliced together to form an annular lining structure; wherein Each of the blocks is provided with a first splicing surface and a second splicing surface at both ends along the annular direction, the angle between the first splicing surface and the second splicing surface is 60°-150°, bolt holes are formed on the first splicing surface and the second splicing surface, any of the first splicing surfaces is abutted against the second splicing surface adjacent to the annular direction, and the abutted first splicing surfaces are opposite to the bolt holes on the second splicing surfaces. 2. The combined tunnel lining structure according to claim 1, characterized in that: The front and rear ends of the bottom block are formed with raised parts and/or recessed parts of the same shape. 3. The combined tunnel lining structure according to claim 1, characterized in that: The bottom block comprises a shell formed by splicing steel plates and concrete filled therein; a hoisting hole matching the assembling machine is reserved at the upper end of the bottom block. 4. The combined tunnel lining structure according to claim 1, characterized in that: The side lower block includes a skeleton structure and a steel mesh arranged on the outer arc surface; The skeleton structure includes I-beams arranged along the circumferential direction and channel steels arranged along the outer periphery of the block and along the longitudinal direction of the tunnel. 5. The combined tunnel lining structure according to claim 4, characterized in that: The side upper block includes a skeleton structure and a steel plate and a steel mesh arranged on the outer arc surface, wherein the steel plate is located above the steel mesh; The skeleton structure includes I-beams arranged along the circumferential direction and channel steels arranged along the outer periphery of the block and along the longitudinal direction of the tunnel. 6. The combined tunnel lining structure according to claim 1, characterized in that: The top block includes a skeleton structure and a steel plate arranged on the outer arc surface; The skeleton structure includes I-beams arranged along the circumferential direction and channel steels arranged along the outer periphery of the block and along the longitudinal direction of the tunnel. 7. The combined tunnel lining structure according to claim 1, further comprising: The inverted arch block has a bottom surface which is the same arc surface as the bottom block, and a top surface which is a plane. 8. A construction method of a combined tunnel lining structure, used for constructing the combined tunnel lining structure as claimed in any one of claims 1 to 7 in a tunnel, characterized in that it comprises the following steps: Step S1, fixing and installing a bottom block at a preset position at the bottom of the tunnel, wherein the tail end of the bottom block is fixed to a previously constructed supporting structure; Step S2, installing side lower blocks at both ends of the bottom block along the annular direction, wherein the first splicing surface of the side lower block is bolted together with the second splicing surface of the bottom block, or the second splicing surface of the side lower block is bolted together with the first splicing surface of the bottom block; Step S3, installing the side upper block on the upper ends of the two side lower blocks, wherein the second splicing surface of the side upper block is bolted together with the first splicing surface of the side lower block, or the first splicing surface of the side upper block is bolted together with the second splicing surface of the side lower block; Step S4, installing a top block on the top of the tunnel, wherein the first joint surface of the top block is bolted to the second joint surface of the side upper block, or the second joint surface of the top block is bolted to the first joint surface of the side upper block, thereby completing the construction of a single-ring lining structure. 9. The construction method of the combined tunnel lining structure according to claim 8, further comprising: Step S5: in the next excavation process, as the TBM excavates forward, three installation positions of the blocks will appear first, and then the corresponding blocks will be assembled at the positions to achieve the purpose of longitudinal extension of the combined tunnel lining structure; Step S6: As the TBM continues to advance, step S5 is repeated until the construction of the combined tunnel lining structure is completed. 10. The construction method of the combined tunnel lining structure according to claim 9, characterized in that: Bolt holes are arranged at both ends of each block along the longitudinal direction of the tunnel, and the construction method further comprises: bolting two adjacent blocks along the longitudinal direction of the tunnel together.