阅读说明：本技术 浅埋粉细砂层双侧壁临时支撑跳割拆除分段回顶施工工艺 (Construction process for jumping-cutting demolishing and subsection back-jacking of double-side-wall temporary support of shallow-buried fine sand layer ) 是由 苏春生 何十美 徐少平 马天昌 饶胜斌 汤振亚 梁朋刚 李向海 刘宏宇 于 2019-11-07 设计创作，主要内容包括：本发明涉及浅埋粉细砂层双侧壁临时支撑跳割拆除分段回顶施工工艺,属于轨道交通施工工艺技术领域,包括对双侧壁6导洞、双侧壁9导洞采用跳仓法分片分区分部分段施工,临时支撑拆除,向凿除初支砼,再割除格栅拱架,通过跳割回顶的方法,调整控制拆撑长度及部位,做到快速回撑,使临时支撑不同时拆除,而是部分拆除并及时回顶受力,保证施工过程中临时支撑始终处于受力状态。本发明所公开的浅埋粉细砂层双侧壁临时支撑跳割拆除分段回顶施工工艺采用跳仓法分6~8m一段按部位由里向外拆除临时支撑,既可以保证施工安全,同时也可多个作业面施工,加快施工进度。(The invention relates to a double-side-wall temporary support jumping-cutting-dismantling segmented back-jacking construction process for a shallow-buried fine sand layer, which belongs to the technical field of rail transit construction processes and comprises the steps of carrying out segmental construction on a double-side-wall 6 pilot tunnel and a double-side-wall 9 pilot tunnel by adopting a skip cabin method, dismantling a temporary support, chiseling primary concrete, then cutting off a grid arch frame, and adjusting and controlling the dismantling length and position by a jumping-cutting back-jacking method to realize quick back-jacking so that the temporary support is not dismantled at the same time, but is partially dismantled and stressed on the back-jacking in time, thereby ensuring that the temporary support is always in a stressed state in the construction process. The construction process for the shallow-buried fine-grained sand layer double-side-wall temporary support skip-cutting dismantling subsection back-to-top adopts a skip method to dismantle the temporary supports from inside to outside in sections of 6-8 m according to positions, so that the construction safety can be ensured, meanwhile, construction of a plurality of working faces can be realized, and the construction progress is accelerated.)

1. A shallow buried fine sand layer double-side wall temporary support jumping-cutting demolition subsection back-jacking construction process is suitable for a shallow buried sand layer large-section tunnel construction process with small clear distance, multiple sections in parallel and section piece interconversion excavated by a CRD method or a double-side wall pit guiding method.

2. The shallow-buried fine sand layer double-side-wall temporary support skip-cutting demolition subsection back-jacking construction process as claimed in claim 1, which is characterized by comprising the following steps:

s1) removing the temporary supports of the double-side-wall 6 pilot tunnel;

s11), temporarily supporting and cutting the lower part, and applying a waterproof and protective layer;

locally breaking and cutting off vertical temporary supports of the D-section-H-section skip cabin of the double-side-wall 6 pilot tunnel, and reserving a part of construction steel to stretch into an inverted arch concrete filling structure during cutting so as to apply force again after constructing the inverted arch and form a supporting system; after the temporary vertical support of the double-side-wall 6 pilot tunnel is cut off, leveling the bottom surface of the inverted arch and laying a waterproof layer and a protective layer;

s12) constructing inverted arch and filling structure

Binding reinforcing steel bars, erecting a formwork and pouring an inverted arch and a filling layer of the double-side-wall 6-guide hole, reserving I-steel and an inverted arch filling concrete structure after concrete pouring to form a support back-jacking, and removing temporary supports of adjacent sections after the inverted arch concrete reaches 75% of the design;

s13) cutting off the temporary inverted arch support, and applying the temporary inverted arch support as a waterproof and side wall structure

Breaking the temporary support in the secondary lining structure of the double-side-wall 6 pilot tunnel according to the length of the inverted arch, cutting off the reinforcing steel bars, laying a waterproof layer, binding the reinforcing steel bars, and erecting a formwork to pour side wall concrete to form secondary lining structures of the side walls at two sides of the double-side-wall 6 pilot tunnel;

s14) temporarily supporting and cutting the upper part and constructing a vault two-lining structure

Breaking the vertical temporary support in the secondary lining structure of the double-side-wall 6 pilot tunnel, cutting off the working steel, laying a waterproof layer, binding reinforcing steel bars, and erecting a formwork to pour arch concrete to form a secondary lining closed structure of the double-side-wall 6 pilot tunnel;

s15) removing the residual temporary supports to finish the secondary lining work

Breaking the residual temporary supports of the double-side-wall 6 pilot tunnel to form an interval structure of the double-side-wall 6 pilot tunnel;

s2) removing the temporary supports of the double-side-wall 9 pilot tunnel;

s21) chiseling the vertical temporary support lower concrete, and applying a waterproof layer

Adopting a waterproof board to annularly lay a rear construction protective layer of the double-side-wall 9 pilot tunnel, timely jacking the original support cutoff position of the double-side-wall 9 pilot tunnel to the inverted arch protective layer of the double-side-wall 9 pilot tunnel, enabling temporary support of the double-side-wall 9 pilot tunnel to restore support, then dismantling adjacent vertical supports, cutting off construction steel, constructing a waterproof layer, and continuing to enable the vertical supports to bear force after jacking;

s22) pouring inverted arch and filling structural concrete

Binding reinforcing steel bars, erecting a formwork and pouring an inverted arch and a filling layer of the double-side-wall 9 pilot tunnel, forming a support back-jacking by the poured concrete post-construction steel and an inverted arch filling concrete structure, and breaking the temporary support of the subsequent section of the double-side-wall 9 pilot tunnel after the inverted arch concrete reaches 75% of the design;

s23) chiseling out temporary inverted arches in the side wall structure, and applying waterproof layers and structures

Breaking the temporary support in the secondary lining structure of the double-side-wall 9 pilot tunnel, cutting off the reinforcing steel bars, laying a waterproof layer, binding the reinforcing steel bars, and erecting a formwork to pour side wall concrete to form secondary lining structures of the side walls at two sides of the double-side-wall 9 pilot tunnel;

s24) chiseling vertical temporary support upper concrete and constructing a waterproof layer structure

Breaking the vertical temporary support in the secondary lining structure of the double-side-wall 9 pilot tunnel, cutting off the working steel, laying a waterproof layer, binding reinforcing steel bars, and erecting a formwork to pour arch concrete; 3-roof-separated method is adopted when the vertical support of the double-side wall 9 pilot tunnel is cut off, and the roof is returned in time after the construction of the waterproof layer;

s25) removing the residual temporary support to form a secondary lining structure

After the two liners of the double-side-wall 9 pilot hole are closed, the remaining temporary supports of the double-side-wall 9 pilot hole are sequentially broken off from top to bottom, and an interval structure of the double-side-wall 9 pilot hole is formed.

3. The jump cutting and dismantling segmented back-jacking construction process for the double-side-wall temporary supports of the shallow-buried fine-grained sand layer as claimed in claim 2, wherein in the step length of locally breaking and cutting off the vertical temporary supports in the section D to the section H in the step S11) is 6-8 m.

4. The shallow-buried fine-grained sand layer double-side-wall temporary support, skip-cutting, demolition and subsection roof-back construction process according to claim 2, characterized in that in S11), the reserved length of the cutting-off process steel is 30-50 cm.

5. The construction process for carrying out jump cutting demolition and subsection roof return on double-side temporary supports of shallow buried fine sand layers as claimed in claim 2, wherein in the step S21), when the lower ends of the vertical temporary supports are demolished, a method of reserving 3 trusses at intervals is adopted.

6. The construction process for double-side temporary supporting, jumping, cutting and demolishing a segmented back-jacking for a shallow-buried fine sand layer as claimed in claim 2, wherein in S23), 4-roof-separated method is adopted when the transverse support of the double-side 9 pilot tunnel is cut off, the back jacking is carried out in time after the waterproof layer is finished, and the adjacent transverse support can be cut off only after the back jacking is finished.

7. The construction process for performing jump cutting and demolition of the shallow buried fine sand layer double-side wall temporary support and subsection roof-back construction according to claim 2, wherein in S2), chiseling the middle partition wall support and the concrete spraying, i.e. the steel bar net, of the temporary inverted arch steel frame pieces is performed from top to bottom from top to top.

8. The shallow-buried fine sand layer double-side-wall temporary support, skip-cutting, demolition and subsection back-jacking construction process as claimed in any one of claims 1 to 7, wherein two linings of double-side-wall 6-pilot holes and double-side-wall 9-pilot holes are constructed by combining a full-hall scaffold with an arched steel pipe back-bracing support; the arched steel pipe back support bracket comprises a top back support and an arch wall back support, the arch top back support is divided into a long section and a short section, the assembling time is short, and the assembling joints of the arch frame are not on the same straight line; the arch crown back support is tangentially connected with the arch wall back support, the arch wall back support is a comb-shaped steel pipe arc frame, and a 30cm steel pipe is reserved at the bottom of the arch wall back support.

Technical Field

The invention relates to the technical field of rail transit construction processes, in particular to a construction process for removing a shallow-buried fine sand layer double-side-wall temporary support by jumping-cutting and subsection back-jacking.

Background

The crossover area of the underground railway often forms a large-span tunnel with variable sections due to functional requirements, and after the conclusion of commonly selected construction methods for construction of the domestic subway crossover area, the shallow-buried underground excavation method is considered to be the current preferred method, but because the span is large, a CRD method or a double-side-wall pilot tunnel method is often assisted to control surface subsidence caused by excavation, particularly in a weak surrounding rock stratum. If the temporary support is not detached properly, the deformation of the primary support is overlarge or the local internal force exceeds the bearing limit, so that safety accidents occur.

Disclosure of Invention

The invention provides a double-side-wall temporary support jumping-cutting demolition and subsection back-jacking construction process for a shallow-buried fine sand layer, which aims to solve the technical problems and is suitable for the construction process of a small-clear-distance and multi-section parallel tunnel excavated by a CRD (tunnel boring device) method or a double-side-wall pit guiding method and a shallow-buried sand layer large-section tunnel with mutually-converted section pieces.

The technical scheme for solving the technical problems is as follows: a construction process for removing the top of the shallow buried fine sand layer by temporary support and jump cutting for the dual-side wall includes such steps as constructing the leading holes of dual-side wall 6 and dual-side wall 9 by jump cabin method, removing the temporary support, chiseling the primary concrete, cutting the arch frame, and cutting the top back.

Further, the method specifically comprises the following steps:

s1) removing the temporary supports of the double-side-wall 6 pilot tunnel;

s11), temporarily supporting and cutting the lower part, and applying a waterproof and protective layer;

c, locally breaking and cutting off vertical temporary supports in a cabin jump mode from the section D to the section H of the double-side-wall 6 pilot tunnel, and reserving a part of construction steel to stretch into a filling concrete structure of the inverted arch during cutting so as to apply force again after the inverted arch is constructed to form a supporting system; after the temporary vertical support of the double-side-wall 6 pilot tunnel is cut off, leveling the bottom surface of the inverted arch and laying a waterproof layer and a protective layer;

s12) constructing inverted arch and filling structure

Binding reinforcing steel bars, erecting a formwork and pouring an inverted arch and a filling layer of the double-side-wall 6-guide hole, reserving I-steel and an inverted arch filling concrete structure after concrete pouring to form a support back-jacking, and removing temporary supports of adjacent sections after the inverted arch concrete reaches 75% of the design;

s13) cutting off the temporary inverted arch support, and applying the temporary inverted arch support as a waterproof and side wall structure

Breaking the temporary support in the secondary lining structure of the double-side-wall 6 pilot tunnel according to the length of the inverted arch, cutting off the reinforcing steel bars, laying a waterproof layer, binding the reinforcing steel bars, and erecting a formwork to pour side wall concrete to form secondary lining structures of the side walls at two sides of the double-side-wall 6 pilot tunnel;

s14) temporarily supporting and cutting the upper part and constructing a vault two-lining structure

Breaking the vertical temporary support in the secondary lining structure of the double-side-wall 6 pilot tunnel, cutting off the working steel, laying a waterproof layer, binding reinforcing steel bars, and erecting a formwork to pour arch concrete to form a secondary lining closed structure of the double-side-wall 6 pilot tunnel;

s15) removing the residual temporary supports to finish the secondary lining work

Breaking the residual temporary supports of the double-side-wall 6 pilot tunnel to form an interval structure of the double-side-wall 6 pilot tunnel;

s2) removing the temporary supports of the double-side-wall 9 pilot tunnel;

s21) chiseling the vertical temporary support lower concrete, and applying a waterproof layer

Adopting a waterproof board to annularly lay a rear construction protective layer of the double-side-wall 9 pilot tunnel, timely jacking the original support cutoff position of the double-side-wall 9 pilot tunnel to the inverted arch protective layer of the double-side-wall 9 pilot tunnel, enabling temporary support of the double-side-wall 9 pilot tunnel to restore support, then dismantling adjacent vertical supports, cutting off construction steel, constructing a waterproof layer, and continuing to enable the vertical supports to bear force after jacking; therefore, the pillow can be supported vertically to bear force, and the waterproof quality of the inverted arch can be guaranteed.

S22) pouring inverted arch and filling structural concrete

Binding reinforcing steel bars, erecting a formwork and pouring an inverted arch and a filling layer of the double-side-wall 9 pilot tunnel, forming a support back-jacking by the poured concrete post-construction steel and an inverted arch filling concrete structure, and breaking the temporary support of the subsequent section of the double-side-wall 9 pilot tunnel after the inverted arch concrete reaches 75% of the design;

s23) chiseling out temporary inverted arches in the side wall structure, and applying waterproof layers and structures

Breaking the temporary support in the secondary lining structure of the double-side-wall 9 pilot tunnel, cutting off the reinforcing steel bars, laying a waterproof layer, binding the reinforcing steel bars, and erecting a formwork to pour side wall concrete to form secondary lining structures of the side walls at two sides of the double-side-wall 9 pilot tunnel;

s24) chiseling vertical temporary support upper concrete and constructing a waterproof layer structure

Breaking the vertical temporary support in the secondary lining structure of the double-side-wall 9 pilot tunnel, cutting off the working steel, laying a waterproof layer, binding reinforcing steel bars, and erecting a formwork to pour arch concrete; 3-roof-separated method is adopted when the vertical support of the double-side wall 9 pilot tunnel is cut off, and the roof is returned in time after the construction of the waterproof layer;

s25) removing the residual temporary support to form a secondary lining structure

After the two liners of the double-side-wall 9 pilot hole are closed, the remaining temporary supports of the double-side-wall 9 pilot hole are sequentially broken off from top to bottom, and an interval structure of the double-side-wall 9 pilot hole is formed.

Further, in the step S11), the step length of the local breaking and intercepting vertical temporary support of the D section to the H section is 6-8 m.

Further, in the step S11), the reserved length of the H-shaped steel during cutting is 30-50 cm.

Further, in S21), when the lower end of the vertical temporary support is removed, the lower end is removed by 3-by-3 method, so as to avoid instability due to insufficient rigidity of the vertical support after all the vertical temporary support is removed.

Further, in S23), 4-by-4 method is adopted for cutting the lateral support of the double-side wall 9 pilot hole, the roof is returned in time after the waterproof layer is finished, and the adjacent lateral support can be cut off after the roof is returned. The integrity of the waterproof board can be ensured, and the waterproof quality is ensured.

Further, in S2), chiseling the middle partition wall supports and the concrete spraying, i.e., the steel mesh, of the temporary inverted arch steel frame members should be performed from top to bottom, so as to ensure that the connection of the steel frame connecting ribs is not damaged and prevent the steel frame from being unstable during chiseling.

Preferably, two linings of the double-side-wall 6 pilot tunnel and the double-side-wall 9 pilot tunnel are used as a back-support bracket by combining a full framing scaffold with an arched steel pipe; the arched steel pipe back support bracket comprises a top back support and an arch wall back support, the arch top back support is divided into a long section and a short section, the assembling time is short, the joints of the arch centering are not on the same straight line, and the integral stability of the arch centering is ensured; the vault back support and the arch wall back support are connected in a tangent mode, the arch wall back support is a comb-shaped steel pipe arc frame, a 30cm steel pipe is reserved at the bottom of the arch wall back support, the back support of an upper guide tunnel and a lower guide tunnel of the arch wall can be connected conveniently, the integral rigidity of the arc back support is guaranteed, and the smoothness of the two linings is improved.

The invention has the beneficial effects that: (1) the invention discloses a double-side-wall temporary support skip-cutting and dismantling segmented back-to-top construction process for a shallow-buried fine sand layer, which is characterized in that a skip method is adopted to dismantle temporary supports from inside to outside in sections of 6-8 m according to positions, so that the construction safety can be ensured, and meanwhile, construction of a plurality of operation surfaces can be realized, and the construction progress is accelerated; the problem of in the current lining cutting platform truck scheme because the tunnel section is big, need once only cut off interim support, can only advance to the centre from both ends moreover, the working face is few, supports temporarily in big section tunnel supports, and the atress is great, if once only all demolish, the potential safety hazard is great is solved.

(2) The construction process for the shallow-buried fine-powder sand layer double-side-wall temporary support jumping-cutting dismantling subsection back-jacking further adopts a detailed waterproof treatment measure, the temporary support dismantling is carried out through jumping-cutting back-jacking, a waterproof layer is quickly applied after a local grid Via unit is cut off and the roof is timely backed up to form a secondary support, so that the vertical support stress can be ensured, the waterproof quality of an inverted arch can be ensured, the integrity of the waterproof plate is ensured to the maximum extent, the pavement sinking is effectively controlled, and the aim of improving the waterproof quality is fulfilled.

Detailed Description

The principles and features of this invention are described below in conjunction with embodiments, which are included to explain the invention and not to limit the scope of the invention.

A construction process for removing the top of the shallow buried fine sand layer by temporary support and jump cutting for the dual-side wall includes such steps as constructing the leading holes of dual-side wall 6 and dual-side wall 9 by jump cabin method, removing the temporary support, chiseling the primary concrete, cutting the arch frame, and cutting the top back.

Further, the method specifically comprises the following steps:

s1) removing the temporary supports of the double-side-wall 6 pilot tunnel;

s11), temporarily supporting and cutting the lower part, and applying a waterproof and protective layer;

c, locally breaking and cutting off vertical temporary supports in a cabin jump mode from the section D to the section H of the double-side-wall 6 pilot tunnel, and reserving a part of construction steel to stretch into a filling concrete structure of the inverted arch during cutting so as to apply force again after the inverted arch is constructed to form a supporting system; after the temporary vertical support of the double-side-wall 6 pilot tunnel is cut off, leveling the bottom surface of the inverted arch and laying a waterproof layer and a protective layer;

s12) constructing inverted arch and filling structure

Binding reinforcing steel bars, erecting a formwork and pouring an inverted arch and a filling layer of the double-side-wall 6-guide hole, reserving I-steel and an inverted arch filling concrete structure after concrete pouring to form a support back-jacking, and removing temporary supports of adjacent sections after the inverted arch concrete reaches 75% of the design;

s13) cutting off the temporary inverted arch support, and applying the temporary inverted arch support as a waterproof and side wall structure

Breaking the temporary support in the secondary lining structure of the double-side-wall 6 pilot tunnel according to the length of the inverted arch, cutting off the reinforcing steel bars, laying a waterproof layer, binding the reinforcing steel bars, and erecting a formwork to pour side wall concrete to form secondary lining structures of the side walls at two sides of the double-side-wall 6 pilot tunnel;

s14) temporarily supporting and cutting the upper part and constructing a vault two-lining structure

Breaking the vertical temporary support in the secondary lining structure of the double-side-wall 6 pilot tunnel, cutting off the working steel, laying a waterproof layer, binding reinforcing steel bars, and erecting a formwork to pour arch concrete to form a secondary lining closed structure of the double-side-wall 6 pilot tunnel;

s15) removing the residual temporary supports to finish the secondary lining work

Breaking the residual temporary supports of the double-side-wall 6 pilot tunnel to form an interval structure of the double-side-wall 6 pilot tunnel;

s2) removing the temporary supports of the double-side-wall 9 pilot tunnel;

s21) chiseling the vertical temporary support lower concrete, and applying a waterproof layer

Adopting a waterproof board to annularly lay a rear construction protective layer of the double-side-wall 9 pilot tunnel, timely jacking the original support cutoff position of the double-side-wall 9 pilot tunnel to the inverted arch protective layer of the double-side-wall 9 pilot tunnel, enabling temporary support of the double-side-wall 9 pilot tunnel to restore support, then dismantling adjacent vertical supports, cutting off construction steel, constructing a waterproof layer, and continuing to enable the vertical supports to bear force after jacking; therefore, the pillow can be supported vertically to bear force, and the waterproof quality of the inverted arch can be guaranteed.

S22) pouring inverted arch and filling structural concrete

Binding reinforcing steel bars, erecting a formwork and pouring an inverted arch and a filling layer of the double-side-wall 9 pilot tunnel, forming a support back-jacking by the poured concrete post-construction steel and an inverted arch filling concrete structure, and breaking the temporary support of the subsequent section of the double-side-wall 9 pilot tunnel after the inverted arch concrete reaches 75% of the design;

s23) chiseling out temporary inverted arches in the side wall structure, and applying waterproof layers and structures

Breaking the temporary support in the secondary lining structure of the double-side-wall 9 pilot tunnel, cutting off the reinforcing steel bars, laying a waterproof layer, binding the reinforcing steel bars, and erecting a formwork to pour side wall concrete to form secondary lining structures of the side walls at two sides of the double-side-wall 9 pilot tunnel;

s24) chiseling vertical temporary support upper concrete and constructing a waterproof layer structure

Breaking vertical temporary supports (step length is 6-8 m) in a secondary lining structure of a double-side-wall 9 pilot tunnel, cutting off working steel, laying a waterproof layer, binding reinforcing steel bars, and erecting a formwork to pour arch concrete; 3-roof-separated method is adopted when the vertical support of the double-side wall 9 pilot tunnel is cut off, and the roof is returned in time after the construction of the waterproof layer;

s25) removing the residual temporary support to form a secondary lining structure

After the two liners of the double-side-wall 9 pilot hole are closed, the remaining temporary supports of the double-side-wall 9 pilot hole are sequentially broken off from top to bottom, and an interval structure of the double-side-wall 9 pilot hole is formed.

Preferably, in the step S11), the step length of the local breaking and intercepting vertical temporary support of the D section to the H section is 6-8 m.

Preferably, in the step S11), the reserved length of the H-shaped steel during cutting is 30-50 cm.

Preferably, in S21), when the lower end of the vertical temporary support is removed, the lower end is removed by 3-out-of-3 method, so as to avoid instability due to insufficient rigidity of the vertical support after all the vertical temporary support is removed.

Preferably, in S23), 4-by-4 method is used for cutting the lateral support of the double-side wall 9 pilot hole, and the adjacent lateral support can be cut off only after the waterproof layer is finished and the roof is returned. The integrity of the waterproof board can be ensured, and the waterproof quality is ensured.

Preferably, in S2), chiseling the middle partition wall supports and the concrete spraying, i.e., the steel mesh, of the temporary inverted arch steel frame members should be performed from top to bottom, so as to ensure that the connection of the steel frame connecting ribs is not damaged and prevent the steel frame from being unstable during chiseling.

Preferably, in S2), the removal of the temporary support of the double-side wall 9 pilot hole should also take care of the following:

1) when the temporary support is dismantled in the construction of the two lining, the cabin jump method is adopted for segmental construction, the length and the position are adjusted and controlled according to profit change, the quick support return is realized, and the construction safety is ensured.

2) And arranging deformation observation points for stress monitoring, dismantling front and rear Europe of the temporary steel frame, monitoring two sides, ensuring the stress safety of the support and controlling vault settlement. And when the vault sinks abnormally, the steel frame is temporarily stopped to be dismantled and a proper reinforcing measure is taken.

3) And (4) carrying out a dismantling test to ensure the dismantling safety and prevent the primary support instability caused by overlarge stress conversion of a stress system of the tunnel.

4) The steel frame can be dismantled in a mode of directly destroying the excavator and the loader during dismantling, so that deformation and instability of the primary support system caused by mechanical collision are prevented.

Preferably, two linings of the double-side-wall 6 pilot tunnel and the double-side-wall 9 pilot tunnel are used as a back-support bracket by combining a full framing scaffold with an arched steel pipe; the arched steel pipe back support bracket comprises a top back support and an arch wall back support, the arch top back support is divided into a long section and a short section, the assembling time is short, the joints of the arch centering are not on the same straight line, and the integral stability of the arch centering is ensured; the vault back support and the arch wall back support are connected in a tangent mode, the arch wall back support is a comb-shaped steel pipe arc frame, a 30cm steel pipe is reserved at the bottom of the arch wall back support, the back support of an upper guide tunnel and a lower guide tunnel of the arch wall can be connected conveniently, the integral rigidity of the arc back support is guaranteed, and the smoothness of the two linings is improved.

The comb-shaped steel pipe arc-shaped frame comprises a vault steel pipe arc-shaped frame and an arch wall steel pipe arc-shaped frame, the vault back support is fixed on a platform erected by square timbers of a scaffold, and the vault back support and the arch wall back support are connected in a tangent mode and are installed on a temporary inverted arch. In the concrete implementation process, the arch wall back support is firmly reinforced, the radian of the template is ensured to be smooth and firm between the upper arch wall and the lower arch wall, the arch top back support ensures that the seams are not on the same straight line, and the whole arch top back support is connected into a whole by steel pipes along the longitudinal direction of the tunnel, so that the stability of the structure is ensured.

The scheme of adopting the full framing scaffold to line the full framing scaffold can realize the sectional multipoint synchronous operation and simultaneously carry out a plurality of operation surfaces, thereby better ensuring the construction period. The arched steel pipe arc frame can solve the problems of heaviness and difficult construction of the section steel support, has the advantages of light rigidity and strength of the throw pillow support, greatly reduces the construction quantity of the full-scale support, and can effectively accelerate the construction progress.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.