阅读说明：本技术 公路隧道二衬顶推施工方法 (Two-lining pushing construction method for highway tunnel ) 是由 李长俊 郑云辉 邓小欢 孙飞 郑国平 郑蓉军 于 2021-09-07 设计创作，主要内容包括：本申请公开一种隧道二衬顶推施工方法。包括准备步骤、拼装步骤、铺设步骤、顶推步骤、退回步骤、重复步骤以及连接步骤。在洞门处安装顶推装置；在所述顶推装置上对预制管片进行拼装以形成所述衬砌环；沿隧道的延伸方向铺设底座和底梁；顶推装置工作,顶推所述顶推装置上的所述衬砌环,以使得所述衬砌环沿所述底座向隧道内前进预设距离；在完成顶推步骤后,所述顶推装置退回预设距离,且在所述顶推装置上拼装另一个所述衬砌环,并使得所述顶推装置上的衬砌环抵顶所述隧道内的所述衬砌；重复若干次所述铺设步骤、顶推步骤以及退回步骤。本申请提出的洞外拼装再顶推施作公路隧道二衬的方式,远比常规洞内预制拼装方式简易灵活,具有良好的应用前景。(The application discloses a tunnel secondary lining pushing construction method. The method comprises a preparation step, an assembling step, a laying step, a pushing step, a returning step, a repeating step and a connecting step. Installing a pushing device at the tunnel door; assembling prefabricated pipe pieces on the pushing device to form the lining ring; laying a base and a bottom beam along the extending direction of the tunnel; pushing the lining ring on the pushing device by the pushing device to enable the lining ring to advance a preset distance into the tunnel along the base; after the pushing step is completed, the pushing device retracts for a preset distance, another lining ring is assembled on the pushing device, and the lining ring on the pushing device abuts against the lining in the tunnel; and repeating the laying step, the pushing step and the withdrawing step for a plurality of times. The mode of assembling outside the tunnel and then pushing to apply as the secondary lining of the highway tunnel is far simpler and more flexible than the conventional mode of prefabricating and assembling inside the tunnel, and has good application prospect.)

1. A two-lining pushing construction method for a road tunnel is characterized by comprising the following steps:

a preparation step, installing a pushing device at a tunnel portal, wherein the pushing device is used for assembling and pushing the lining ring;

assembling prefabricated pipe pieces on the pushing device to form the lining ring;

a laying step, wherein primary support and waterproof layer construction are carried out on the tunnel, and after the primary support and waterproof layer construction is finished, a base and a bottom beam are laid along the extending direction of the tunnel, wherein the base is used for being connected with the lining ring in a sliding manner;

pushing, namely working a pushing device to push the lining ring on the pushing device so as to enable the lining ring to advance a preset distance into the tunnel along the base;

a retracting step, after the pushing step is finished, retracting the pushing device for a preset distance, assembling another lining ring on the pushing device, and enabling the lining ring on the pushing device to abut against the lining ring in the tunnel;

repeating the laying step, the pushing step and the withdrawing step for a plurality of times so that the plurality of lining rings complete the support of the tunnel in the extending direction of the tunnel;

and a connecting step, namely connecting the lining rings with the base, connecting a plurality of lining rings in sequence, and performing backfill grouting.

2. The road tunnel secondary lining jacking construction method according to claim 1,

the two-lining pushing construction method for the highway tunnel comprises a one-way pushing method, wherein the one-way pushing method comprises the following steps:

in the preparation step, the number of the thrusters is one;

in the pushing step, the pushing device pushes the lining ring from one side of the tunnel to the other side of the tunnel.

3. The road tunnel secondary lining jacking construction method according to claim 1,

the two-lining pushing construction method for the road tunnel comprises a two-way pushing method, wherein the two-way pushing method comprises the following steps:

in the preparation step, the number of the thrusters is two, and the thrusters are respectively positioned at two sides of the tunnel;

in the pushing step, the two pushing devices push the corresponding lining rings from one side of the tunnel to the center of the tunnel.

4. The road tunnel secondary lining jacking construction method according to claim 1,

the two-lining jacking construction method for the highway tunnel comprises an intermediate jacking method, wherein the intermediate jacking method comprises the following steps:

a step of assembling relay, in which after the pushing step is completed, the pushing device returns to a preset distance, and a relay is assembled on the pushing device and is abutted against the lining ring in the tunnel, wherein the relay is used for pushing the lining ring in the tunnel;

and a dismantling step, namely dismantling the relay when the relay pushes the corresponding lining ring to a target position.

5. The road tunnel secondary lining jacking construction method according to claim 4,

the relay room comprises a first top iron, a second top iron and a relay jack group;

the sections of the first top iron and the second top iron are the same as the section of the lining ring and are used for abutting against the lining ring respectively;

the relay jack group comprises a plurality of jacks, the jacks are connected with the first top iron and the second top iron, and the jacks are used for jacking the lining ring jacked by the top iron and the first top iron.

6. The road tunnel secondary lining jacking construction method according to any one of claims 1 to 5,

the pushing device comprises a workbench, a pushing jack group, a pushing top iron and a two-lining splicing support;

the working platform is cast in place at the portal, the pushing jack group is fixed on the surface of the working platform, and the pushing top iron is fixed at an execution end of the pushing jack group;

the two-lining assembling support is arranged at the portal and comprises an assembling surface, and the assembling surface is used for supporting the lining ring so as to assemble the lining ring on the two-lining assembling support.

7. The road tunnel secondary lining jacking construction method according to any one of claims 1 to 5,

a duct piece slot extending along the extending direction of the tunnel is formed in the base, the duct piece slot is in sliding fit with the lining ring, a bolt hole is formed in the duct piece slot, and the bolt hole is used for connecting the lining ring through a bolt;

the base is provided with a plurality of ground locking anchor holes, and the ground locking anchor holes are used for inserting ground locking anchor rods of the base so that the base is fixed on the ground;

the base is formed with a sill jack for fastening with the sill.

8. The road tunnel secondary lining jacking construction method according to any one of claims 1 to 5,

in the laying step, when the supporting construction is carried out, the inner surface profiles of the primary support and the waterproof layer are larger than the outer surface profile of the lining ring.

9. The road tunnel secondary lining jacking construction method according to any one of claims 1 to 5,

and the lining rings comprise a plurality of prefabricated pipe pieces, and each ring is connected between every two adjacent prefabricated pipe pieces in the lining ring and between every two adjacent prefabricated pipe pieces in the lining ring by bolts and water stop rubber.

Technical Field

The application relates to the technical field of tunnel construction, in particular to a two-lining pushing construction method for a highway tunnel.

Background

The vast width of Chinese breadth, numerous mountains and tunnels, the number of established tunnels is in the world leaderboard. According to statistics, the number of the road tunnels in China is 19067 in 2019, the road tunnels are increased by 7.5% on the same scale, and the total length of the tunnels reaches 1896.66 kilometers. The new Olympic method has become the most common construction method in mountain highway tunnel construction by virtue of the unique advantages of better geological adaptability, high economic benefit and strong flexibility.

The two liners are used as important parts of a tunnel structure, defects such as cavities behind walls, cracking of the two liners and the like easily occur in conventional trolley vertical mold cast-in-place construction, processes such as formwork erecting, water stop belt arranging, vibrating, maintaining and the like are complex, and construction progress is slow. In view of this, the two linings can be constructed by adopting a prefabrication technology, and the construction quality and the construction efficiency are greatly improved by factory prefabrication and field assembly.

At present, the tunnel prefabrication at home and abroad is mainly a circular shield/TBM segment tunnel, and a construction mode of assembling and forming a ring in a segment tunnel is adopted. Non-circular tunnel prefabrication is only seen in a few foreign railway tunnels with small cross sections, and an in-tunnel splicing construction mode is also adopted. And the prefabricated lining form of the small section such as a railway tunnel, a conventional pipe jacking and the like is different, the prefabricated technology of the section of the mountain highway tunnel is difficult to realize under the prior art condition, and the prefabricated case of the mountain tunnel at home and abroad is almost not available, and the difficulty is mainly reflected in the following points:

(1) the excavation section of the road tunnel is large and is not a circular section, and the design and assembly of the prefabricated secondary lining can not simply apply the shield/TBM segment prefabrication technology and the small-section railway tunnel prefabrication technology;

(2) the cross section shape parameters of the highway tunnel are variable, if in-tunnel prefabrication and assembly are adopted, corresponding prefabrication and assembly equipment is nonstandard, special development is needed, the difficulty is high, and the cost is too high;

(3) the assembly space in the tunnel of the highway tunnel is limited, and if the tunnel is prefabricated and assembled, the assembly precision requirement is high, and the construction process is complex.

Disclosure of Invention

The application provides a two-lining pushing construction method for a road tunnel, which has the following advantages: 1. compared with the conventional trolley vertical mould cast-in-place secondary lining, the prefabricated secondary lining has high construction quality and high assembling speed. 2. The method is different from the in-tunnel prefabrication and assembly mode adopted by the conventional circular shield tunnel and the small-section railway tunnel, the mode of assembling outside the tunnel and then pushing to construct a second lining is avoided, the problems that when the large-section non-circular highway tunnel adopts in-tunnel prefabrication and assembly, the assembly precision requirement is high, special assembly equipment needs to be independently developed, and the construction difficulty is large are solved, the difficult problem of large-section non-circular highway tunnel lining prefabrication is effectively solved, the blank of a highway tunnel second lining prefabrication technology is filled, and the method has a good engineering application prospect.

The invention provides a two-lining pushing construction method for a highway tunnel, which comprises the following steps of:

a preparation step, installing a pushing device at a tunnel portal, wherein the pushing device is used for assembling and pushing the lining ring;

assembling prefabricated pipe pieces on a pushing device to form a lining ring;

a laying step, wherein primary support and waterproof layer construction are carried out on the tunnel, and after the primary support and waterproof layer construction is finished, a base and a bottom beam are laid along the extending direction of the tunnel, wherein the base is used for being connected with the lining ring in a sliding manner;

pushing, namely working a pushing device to push the lining ring on the pushing device so that the lining ring advances a preset distance into the tunnel along the base;

a retracting step, after the pushing step is finished, retracting the pushing device by a preset distance, assembling another lining ring on the pushing device, and enabling the lining ring on the pushing device to abut against the lining ring in the tunnel;

repeating the step, namely repeating the laying step, the pushing step and the returning step for a plurality of times so that the plurality of lining rings complete the support of the tunnel in the extending direction of the tunnel;

and a connecting step, connecting the lining rings with the base, connecting the lining rings in sequence, and performing backfill grouting.

In the implementation process, a new factory prefabrication process is combined, a related construction method of primary support of a new Olympic method is reserved, the traditional method of cast-in-place of a second lining construction site is abandoned, lining ring duct pieces are assembled on the factory prefabrication site and continuously pushed into a segmented lining ring to enter the tunnel, the advantages of simple top pushing method process and low cost can be fully exerted, the second measurement construction efficiency of the new Olympic tunnel is improved, the working environment is improved, and finally a brand-new road tunnel second lining tunnel pushing construction method is formed.

In an optional embodiment, the two-lining jacking construction method for the road tunnel comprises a one-way jacking method, and the one-way jacking method comprises the following steps:

in the preparation step, the number of the thrusters is one;

in the pushing step, the pushing device pushes the lining ring from one side of the tunnel to the other side of the tunnel.

In an optional embodiment, the two-lining jacking construction method for the road tunnel comprises a two-way jacking method, and the two-way jacking method comprises the following steps:

in the preparation step, the number of the thrusters is two, and the thrusters are respectively positioned at two sides of the tunnel;

in the pushing step, two pushing devices push the corresponding lining rings from one side of the tunnel to the center of the tunnel.

In an optional implementation manner, the two-lining jacking construction method for the road tunnel includes an inter-junction jacking method, and the inter-junction jacking method includes:

a step of assembling the relay, in which after the pushing step is completed, the pushing device returns to a preset distance, the relay is assembled on the pushing device, the relay on the pushing device is enabled to abut against a lining ring in the tunnel, and the relay is used for pushing the lining ring in the tunnel;

and a dismantling step, namely dismantling the relay when the relay pushes the corresponding lining ring to a target position.

In an alternative embodiment, the relay room comprises a first top iron, a second top iron and a relay jack group;

the sections of the first top iron and the second top iron are the same as the sections of the lining rings and are used for abutting against the lining rings respectively;

the relay jack group comprises a plurality of jacks, the jacks are connected with first top iron and second top iron, and the jacks are used for lining rings which are abutted against the top iron and the first top iron.

In an optional embodiment, the pushing device comprises a workbench, a pushing jack group, a pushing top iron and a two-lining splicing bracket;

the working platform is cast in place at the portal, the pushing jack group is fixed on the surface of the working platform, and the pushing iron is fixed at the execution end of the pushing jack group;

the two-lining assembling support is arranged at the portal and comprises an assembling surface, and the assembling surface is used for supporting the lining ring so as to assemble the lining ring on the two-lining assembling support.

In an optional embodiment, the base is provided with a duct piece slot extending along the extending direction of the tunnel, the duct piece slot is in sliding fit with the lining ring, and the duct piece slot is provided with a bolt hole for connecting the lining ring through a bolt;

the base is provided with a plurality of ground locking anchor holes, and the ground locking anchor holes are used for inserting ground locking anchor rods of the base so that the base is fixed on the ground;

the base is formed with a sill jack for fastening with a sill.

In an alternative embodiment, in the laying step, the inner surface profile of the primary backing and the waterproof layer is greater than the outer surface profile of the lining ring when the supporting construction is performed.

In an optional embodiment, two adjacent lining rings are spliced in a staggered manner, each lining ring comprises a plurality of prefabricated pipe pieces, and bolts and water stop rubbers are adopted for connecting the adjacent prefabricated pipe pieces in each lining ring and the prefabricated pipe pieces of the adjacent lining rings.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

FIG. 1 is a schematic view of a pushing device in the present embodiment;

FIG. 2 is a schematic view of a lining ring according to the present embodiment;

FIG. 3 is a schematic diagram of a tube sheet set in the present embodiment;

FIG. 4 is an enlarged view taken at IV in FIG. 3;

FIG. 5 is a perspective view of the base and bottom beams of the present embodiment;

fig. 6-15 are schematic process diagrams of a one-way jacking method adopted by the road tunnel secondary lining jacking construction method in the embodiment;

fig. 16 is a schematic diagram of a bidirectional pushing method adopted in the road tunnel secondary lining pushing construction method in this embodiment;

FIG. 17 is a diagram illustrating an exemplary relay in the present embodiment;

fig. 18 to fig. 22 are schematic process diagrams of the road tunnel secondary lining pushing construction method adopting the inter-junction pushing method in this embodiment.

Icon: 10-a workbench; 11-a jacking jack group; 12-pushing top iron; 13-two lining assembling support;

20-lining the ring; 22-prefabricating a pipe piece; 23-a bolt; 24-water stop rubber; 25-reserving a hole in the prestressed steel bar; 20 a-a first segment lining ring; 20 b-a second segment lining ring; 20 c-a third segmented lining ring;

30-a base; 31-bottom beam; 32-segment slots; 33-bolt holes; 34-a ground locking anchor hole; 35-locking ground anchor rod; 37-bottom beam socket;

40-relay; 41-first top iron; 42-second top iron; 43-relay jack group; 40 a-first section inter-relay; 40 b-second section inter-relay;

50-prestressed steel bars.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the embodiments of the present application, it is to be understood that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like, refer to the orientation or positional relationship as shown in the drawings, or as conventionally placed in use of the product of the application, or as conventionally understood by those skilled in the art, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and therefore should not be considered as limiting the present application.

In the description of the embodiments of the present application, it should also be noted that, unless otherwise explicitly stated or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

The technical solution in the present application will be described below with reference to the accompanying drawings.

The embodiment provides a jacking construction method for a two-lining of a highway tunnel, which can solve the problem of high difficulty in construction of the two-lining of the tunnel in the prior art.

The two-lining jacking construction method for the road tunnel comprises the following steps: the method comprises the steps of preparation, assembly, laying, pushing, returning, repeating and connecting.

A preparation step, installing a pushing device at the portal, wherein the pushing device is used for assembling and pushing the lining ring 20; according to the actual situation of the ground outside the tunnel portal, the ground at the tunnel portal is leveled, and a pushing device is installed at a proper position of the tunnel portal. Referring to fig. 1, fig. 1 is a schematic view of a pushing device in this embodiment. The pushing device comprises a workbench 10, a pushing jack group 11, a pushing iron block 12 and a two-lining splicing support 13. The working platform 10 is cast in situ at a portal, the pushing jack group 11 is fixed on the surface of the working platform 10, and the pushing iron 12 is fixed at the execution end of the pushing jack group 11. The two-lining assembling support 13 is arranged at the portal, the two-lining assembling support 13 comprises an assembling surface, and the assembling surface is used for supporting the lining ring 20 so as to assemble the lining ring 20 on the two-lining assembling support 13. The working table 10 is used as a back wall, and the anti-overturning, anti-sliding and anti-pressure bearing capacity checking calculation needs to be carried out, and when the pushing jack group 11 (comprising a plurality of jacks) is arranged, the maximum jacking force of the pushing jack group 11 is determined according to the calculation. The two-lining assembling support 13 is a special rigid frame, the shape of the assembling surface at the upper part is consistent with the shape of the inner ring of the two linings, and the two-lining assembling support 13 is strictly prohibited from invading the tunnel building clearance.

An assembling step, assembling the prefabricated pipe pieces 22 on a pushing device to form a lining ring 20; the lining ring 20 means that the lining is divided into a plurality of ring lining rings 20 (or a plurality of sections of lining rings 20), and after the construction is completed, a plurality of lining rings 20 are connected with each other to form a complete lining. Referring to fig. 2, fig. 2 is a schematic view of a lining ring 20 in the present embodiment. The lining ring 20 comprises a plurality of prefabricated pipe pieces 22, and adjacent prefabricated pipe pieces 22 are connected through bolts 23 and water-stop rubber 24. The prefabricated segment 22 is that constructors divide the lining ring 20 into a plurality of segments according to actual demands and prefabricate in advance, and when the prefabricated segment is actually used, the prefabricated segment is assembled on the two lining assembling templates, so that the process difficulty and the precision requirement are low compared with the existing in-tunnel assembling process. Referring to fig. 3 and 4, fig. 3 is a schematic view of a two-ring lining ring according to the present embodiment, and fig. 4 is an enlarged view of the portion iv in fig. 3. The adjacent lining rings 20 are spliced by staggered joints along the pushing direction of the lining rings 20. Because the lining rings 20 are supported on the two-lining form, the bolts 23 between the plurality of prefabricated pipe segments 22 are located on the outer surface of the prefabricated pipe segments 22. The labeled "a" to "E" in fig. 2 indicate that a and B denote standard block segments, respectively; c and D represent adjacent block segments; and E represents a capping block segment, and it is to be noted that a prestressed steel bar preformed hole 25 is formed in the lining ring 20.

A laying step, wherein primary support and waterproof layer construction are carried out on the tunnel, after the primary support and waterproof layer construction is finished, a base 30 and a bottom beam 31 are laid along the extending direction of the tunnel, and the base 30 is used for being connected with the lining ring 20 in a sliding mode; referring to fig. 5, fig. 5 is a perspective view of the base 30 and the bottom beam 31 in this embodiment. The base 30 is formed with the section of jurisdiction slot 32 that extends along the tunnel extending direction, and section of jurisdiction slot 32 and lining ring 20 sliding fit, section of jurisdiction slot 32 are formed with bolt hole 33, and bolt hole 33 is used for pushing away when target in place at lining ring 20, connects lining ring 20 and base 30 through bolt 23. The base 30 is formed with a plurality of ground locking anchor holes 34, and the ground locking anchor holes 34 are used for inserting ground locking anchors 35 of the base 30 so that the base 30 is fixed to the ground. The base 30 is formed with a sill insertion opening 37, and the sill insertion opening 37 is adapted to be fastened to the sill 31. The base 30 is connected with the base 30 by connecting tenons at both sides of the base 30, that is, by a concave-convex structure. When the supporting construction is carried out, the inner surface profiles of the primary support and the waterproof layer are larger than the outer surface profile of the lining ring.

A pushing step, in which a pushing device works to push the lining ring 20 on the pushing device so that the lining ring 20 advances a preset distance into the tunnel along the base 30; the predetermined distance may comprise the length of a section of the lining ring 20.

A retracting step, after the pushing step is finished, retracting the pushing device for a preset distance, assembling another lining ring 20 on the pushing device, and enabling the lining ring 20 on the pushing device to abut against the lining ring 20 in the tunnel; the lining ring 20 which is newly assembled is abutted to the last lining ring 20 which is assembled and pushes the lining ring 20 entering the tunnel, so that when the pushing jack group 11 pushes the lining ring 20 in the tunnel again, the new lining ring 20 and the lining ring 20 in the tunnel are pushed for a preset distance continuously.

Repeating the step, namely repeating the laying step, the pushing step and the returning step for a plurality of times so that the plurality of lining rings 20 complete the support of the tunnel in the extending direction of the tunnel; the tunnel is braced between the tunnel entrance and the tunnel exit by a number of lining rings 20 by repeating the laying step, the pushing step and the retracting step several times.

And a connecting step, connecting the lining ring 20 with the base 30, connecting a plurality of lining rings 20 in sequence to finally form a complete lining, and performing backfill grouting. The lining ring 20 and the foundation 30 are connected by bolts 23 through bolt holes 33 in the foundation 30. And after the connecting step is completed, removing the pushing device, removing the redundant base 30 bottom beam 31, tensioning the prestressed reinforcement and completing the second lining construction of the tunnel.

In some embodiments of the present application, the two-lining pushing construction method for a road tunnel includes a one-way pushing method. In the preparation step, the number of the thrusters is one; in the pushing step, the pushing means pushes the lining ring 20 from one side of the tunnel to the other side of the tunnel.

The following will describe a construction process of the unidirectional pushing method, please refer to fig. 6-15, and fig. 6-15 are schematic diagrams of a process of the unidirectional pushing method adopted by the road tunnel secondary lining pushing construction method in this embodiment.

Referring to fig. 6, a workbench 10 is cast in place at a proper position of a hole, and a jacking jack group 11, a jacking iron 12 and a two-lining splicing support 13 are installed on the workbench 10 after the completion.

As shown in fig. 7, after the primary support and the waterproof layer are completed, the foundation 30 is laid, the ground locking anchor rods 35 are arranged, the bottom beams 31 are laid, and the first section of lining ring 20a is assembled on the second lining assembling bracket 13.

As shown in fig. 8, the duct piece slot of the base 30 is cleaned, and the jacking jack set 11 is started to enter the working position.

Referring to fig. 9, the jacking jack set 11 is activated to jack the first lining ring 20a along the segment slot 32 of the base 30 by a distance equal to the length of the lining ring 20.

As shown in fig. 10, the jack sets 11 are withdrawn, the foundation 30 is laid, the ground locking anchor rods 35 are arranged, the bottom beams 31 are laid, and the second lining rings 20b are assembled on the second lining assembling support 13.

As shown in fig. 11, the duct piece slot of the base 30 is cleaned, and the jacking jack set 11 is started to enter the working position.

As shown in fig. 12, the jacking jack set 11 is started to jack the first lining ring 20a and the second lining ring 20b to advance by the distance of one lining ring 20 along the segment slot 32 on the base 30;

as shown in fig. 13, the jack sets 11 are retracted, the foundation 30 is laid, the ground locking anchor rods 35 are drilled, the bottom beams 31 are laid, and the third section of lining ring 20c is assembled on the second lining assembling support 13.

As shown in fig. 14, the subsequent pushing of each section of lining ring 20 (the third section of lining ring 20c, the fourth section of lining ring 20, the fifth section of lining ring 20, etc.) is performed according to the above steps until the first section of lining ring 20a successfully reaches the predetermined position, and the pushing is finished until the first section of lining ring 20a reaches the tunnel exit position.

As shown in fig. 15, the ground part of the working platform 10 and the related equipment are removed, the bottom beam 31 of the redundant base 30 is removed, the prestressed reinforcement (prestressed steel bar 50) is tensioned, and the second lining construction of the tunnel is completed.

In some embodiments of the present application, the two-lining pushing construction method for a road tunnel includes a two-way pushing method, and the two-way pushing method includes: in the preparation step, the number of the thrusters is two, and the thrusters are respectively positioned at two sides of the tunnel; in the pushing step, two pushing devices push the corresponding lining rings 20 from one side of the tunnel to the center of the tunnel. The following will describe a construction flow of the bidirectional pushing method, and with reference to fig. 16, fig. 16 is a schematic diagram of the bidirectional pushing method adopted in the road tunnel secondary lining pushing construction method in this embodiment.

Similar to the construction process of the unidirectional pushing method, the bidirectional pushing method is different from the unidirectional pushing method in that:

two workbenches 10 need to be cast in situ on two sides of the tunnel, and a pushing jack group 11, a pushing iron 12 and a two-lining splicing support 13 are respectively arranged. The lining rings 20 are pushed simultaneously on both sides of the tunnel. When the lining rings 20 pushed by both sides are close to each other, the bottom beams 31 of the connecting bases 30 are laid in advance to complete the butt joint. After pushing all lining rings 20, two workbenches 10 and the bottom beam 31 of the redundant base 30 need to be removed, prestressed steel bars are tensioned, and secondary lining construction of the tunnel is completed.

In some embodiments of the present application, the two-lining pushing construction method for a road tunnel includes a middle 40 pushing method, where the middle 40 pushing method includes: a step of assembling the intermediate chamber 40, wherein after the pushing step is completed, the pushing device returns to a preset distance, the intermediate chamber 40 is assembled on the pushing device, the intermediate chamber 40 on the pushing device is enabled to abut against the lining ring 20 in the tunnel, and the intermediate chamber 40 is used for pushing the lining ring 20 in the tunnel; and (4) a dismantling step, namely dismantling the intermediate chamber 40 when the intermediate chamber 40 pushes the corresponding lining ring 20 to the target position.

Referring to fig. 17, fig. 17 is a schematic diagram of the relay 40 in the embodiment. The relay bay 40 includes a first head iron 41, a second head iron 42, and a relay jack group 43. The first top iron 41 and the second top iron 42 have the same cross section as the lining ring 20 and are used to abut against the lining ring 20, respectively. The relay jack group 43 includes a plurality of jacks, the plurality of jacks connect the first top iron 41 and the second top iron 42, and the plurality of jacks are used for the lining ring 20 against which the top iron abuts against the first top iron 41.

The following will describe a construction flow of the inter-junction 40 pushing method, and with reference to fig. 18 to fig. 22, fig. 18 to fig. 22 are schematic diagrams of a process of the inter-junction 40 pushing method adopted by the road tunnel secondary lining pushing construction method in this embodiment.

Similar to the above construction process of the unidirectional pushing method, the inter-relay 40 pushing method is different from the unidirectional pushing method in that:

as shown in fig. 18, when the jacking force of the jacking jack group 11 reaches a design value, the first section of the intermediate bay 40a is placed on the second lining erection support 13, and the length of one section of the lining ring 20 is jacked.

As shown in fig. 19, when the jacking force of the jacking jack group 11 and the first-section trunk 40a reaches the design value again, the second-section trunk 40b is placed on the second lining erection support 13, and the length of one lining ring 20 section is jacked, and so on, until the first ring lining ring 20 reaches the expected position, the jacking is stopped.

As shown in fig. 20, the first section of the relay room 40a is removed, and the subsequent relay room 40 continues to be pushed in, so as to fill up the removed space.

As shown in fig. 21, the subsequent relay rooms 40 are removed, and the gap is filled by jacking until all the relay rooms 40 are removed;

as shown in fig. 22, the ground part of the working platform 10 and the related equipment are removed, the bottom beam 31 of the redundant base 30 is removed, the prestressed reinforcement is tensioned, and the construction of the second lining of the tunnel is completed.

Compared with a new Olympic method second lining construction method, the tunnel second lining jacking construction method has the following advantages and effects: concrete is not required to be cast in situ on a construction site, so that the quality of the second lining is ensured, and the construction environment is improved; need not to carry out the maintenance to the concrete, the top pushes up fastly, and the efficiency of construction is high.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.