CN116752995A

CN116752995A - A construction method for the collapse of the top of the shield tail of an open TBM full-section tunnel boring machine

Info

Publication number: CN116752995A
Application number: CN202310878491.9A
Authority: CN
Inventors: 李亚隆; 毛锦波; 张斌斌; 安佩娟; 赵红刚; 曾煜; 陈永刚; 于海涛
Original assignee: CCCC SHEC Dong Meng Engineering Co Ltd
Current assignee: CCCC SHEC Dong Meng Engineering Co Ltd
Priority date: 2023-07-18
Filing date: 2023-07-18
Publication date: 2023-09-15
Anticipated expiration: 2043-07-18
Also published as: CN116752995B

Abstract

The invention provides a construction method for the collapse of the top of the shield tail of an open-type TBM full-section tunnel boring machine. It analyzes the surrounding rock conditions on the tunnel face in front of the cutterhead through advance drilling, thereby adjusting the tunneling support parameters. Corresponding support methods are adopted for the collapse cavity formed by the collapse of the shield tail during the excavation process. At the same time, for strata with serious collapse and blockage, long strips of steel plates are closely arranged on the previous steel arch to play the role of steel bar rows, allowing the open TBM without steel bar rows to quickly and safely pass through complex strata such as fold belts, thus making the TBM Safely and quickly pass through long-distance fold belts, thereby improving excavation efficiency, reducing construction safety risks and damage to mechanical equipment caused by falling blocks and collapse. The collapse of the upper part of the support shoe caused the collapse cavity to adopt the technical measure of "strong support and then filling", and the collapse of the support shoe The cavity adopts the technical measures of “first temporary filling, then permanent filling” to ensure safe and efficient excavation of the open TBM.

Description

Construction method for collapse of shield tail top of open TBM full-face heading machine

Technical Field

The application belongs to the technical field of TBM construction of long and large tunnels, and particularly relates to a construction method for collapse of the top of the shield tail of an open TBM full-face heading machine.

Background

The open TBM has been widely used in mountain long tunnel construction, the construction technology is mature day by day, especially aiming at hard strata with good stability of II, III, IV and V, the advantage of rapid tunneling can be fully developed, but the TBM usually passes through a fold belt in the tunneling process, and the top of a shield usually accompanies collapse blocks and forms collapse cavities with different sizes in the tunneling process due to soft surrounding rock, broken rock and crack development, thereby endangering the construction safety and damaging mechanical equipment; collapse occurs at the support shoe, so that the support shoe cannot be uniformly stressed, the support shoe is slipped and cannot be tunneled, and the support shoe can smoothly pass through after temporary support; meanwhile, the collapsed slag falls to the bottom of the shield, a large amount of manpower is required to be input for slag removal, and the tunneling period is delayed.

Especially in the two lithology cross transition stages, the rock is in an embedded block structure, the integrity is poor, the stability is poor, the collapse is more serious, and the rapid tunneling of the TBM is influenced. Especially for the open type TBM without the reinforcement bar supporting function, the safety risk is greater during tunneling.

Disclosure of Invention

The application provides a construction method for collapsing the top of the shield tail of an open TBM full-face tunneling machine, which solves the problems that the TBM has no reinforcement bar function but has the functions of die casting and opening and passes through a fold belt, adopts a corresponding supporting mode through a collapse cavity formed by collapsing the shield tail in the tunneling process, and simultaneously densely arranges strip-shaped steel plates on a steel arch frame of the last truss for a stratum with serious collapse and collapse block so as to play the role of reinforcement bar, thereby realizing the rapid and safe passage of the open TBM without reinforcement bar through complex strata such as the fold belt and the like, ensuring that the TBM safely and rapidly passes through the long-distance fold belt, further improving tunneling efficiency, reducing construction safety risks and damage of collapse block collapse to mechanical equipment.

The application is realized by the following technical scheme:

a construction method for collapse of the top of the shield tail of an open TBM full-face heading machine comprises the following specific contents:

the collapse cavity depth caused by the collapse of the upper part of the supporting shoe is detected, and different strong supporting treatment measures are corresponding to different depths and positions, and the method is as follows:

i: when the collapse cavity depth H formed in the tunneling process within the range above the top of the shield tail support boot is less than 0.5m, the disposal measure of the collapse cavity is as follows:

removing slag in a collapse cavity after finishing the N-th cyclic tunneling, performing primary injection concrete sealing on exposed surrounding rock of the collapse cavity by an L1-zone emergency spraying and mixing system, laying reinforcing steel meshes, installing an N-th cyclic steel arch, firmly welding the N-th cyclic steel arch and the N-1-th cyclic steel arch in a staggered manner by adopting a circumferential connecting rib, spraying concrete to a designed intrados by adopting a wet spraying and mixing zone, wherein the circumferential connecting rib spacing between the N-th cyclic steel arch and the N-1-th cyclic steel arch is B, the B is less than or equal to 100cm, and the spacing L between the N-th cyclic steel arch and the N-1-th cyclic steel arch is equal to the per-cyclic tunneling stroke L' of an open TBM;

II: when the depth of a collapse cavity formed by collapse in the tunneling process within the range above the top of the shield tail support boot is more than or equal to 0.5m and less than or equal to H and less than 2m, the treatment measures are as follows:

s1: clearing slag in the collapse cavity after the Nth circulation is separated from the shield tail, and performing primary injection concrete sealing on exposed surrounding rock of the collapse cavity of the Nth circulation by using an L1 area emergency spraying and mixing system, laying N layers of dense reinforcing steel meshes, installing an Nth circulation type steel arch, and replacing connecting ribs between the Nth circulation type steel arch and the N-1 th circulation type steel arch by adopting strip-shaped steel members, wherein N is more than or equal to 2. The length of the strip steel member is equal to the spacing between the Nth circulating steel arch and the N-1 th circulating steel arch, and the strip steel member can be HW steel or channel steel. The annular distance between the section steel arches is B, and B is less than or equal to 80cm;

s2: the grouting guide pipe and the ventilation pipe are arranged in the Nth circulating collapse cavity in a quincuncial manner and welded with the Nth circulating steel arch frame, the distance between the grouting guide pipe and the ventilation pipe and the surrounding rock surface at the top of the collapse cavity is B, wherein B is less than or equal to 10cm, and the grouting guide pipe and the ventilation pipe have grouting and ventilation functions;

s3: blocking the grouting guide pipe and the tail part of the vent pipe, and supporting sprayed concrete for the Nth cyclic collapse cavity by an L1 area emergency spray mixing system, wherein the thickness of the sprayed concrete is more than or equal to 10cm;

s4: along with the forward tunneling of the open TBM, after the Nth cyclic collapse cavity is supported to a wet spraying machine of a spraying and mixing area, connecting a sprayed concrete pipeline, carrying out layered backfilling on concrete in the Nth cyclic collapse cavity to the top of the collapse cavity through a grouting guide pipe, and then spraying the concrete to an intrados surface by adopting the wet spraying machine of the spraying and mixing area, wherein the layered backfilling sequence of the concrete is from two sides to the middle and from the bottom to the high;

s5: detecting compactness by adopting monitoring equipment, judging whether grouting plugging is needed according to a monitoring result, and continuously monitoring and measuring;

III: when the collapse cavity depth H is more than 2m in the tunneling process in the range above the top of the shield tail support boot and the shield tail surrounding rock is continuously collapsed and blocked in the tunneling process, the treatment measures are as follows:

s1: the steel mesh is replaced by a strip steel plate, the strip steel plate is welded in a closely-distributed mode in the circumferential direction of the outer wing plate of the Nth circulating steel arch after the installation of the Nth circulating steel arch is completed, the dimension of the strip steel plate is L multiplied by B multiplied by h (longitudinal multiplied by circumferential multiplied by thickness), wherein L is equal to the tunneling stroke of the open type TBM, B is determined by the outer arc degree of the steel arch, h is less than or equal to 8mm, one end of the length direction of the strip steel plate is welded at the outer wing plate of the Nth circulating steel arch, one end of the strip steel plate extends into the inner side of the open type TBM shield and is tightly attached to the outer wing plate of the Nth+1 circulating steel arch which is pre-installed on the inner side of the shield.

The circumferential radian range of the welding of the end part of the strip steel plate is determined according to the collapse degree of surrounding rock separated from the shield tail;

s2: when the open TBM is used for tunneling forward for the (N+1) -th cycle, the strip steel plate and the pre-installed (N+1) -th cycle steel arch are slowly separated from the inner side of the shield, stone falling from the tail of the shield is intercepted, after the (N+1) -th cycle tunneling is completed, the arch frame assembling machine is used for tightly supporting the (N+1) -th cycle steel arch to be tightly attached to surrounding rocks with the strip steel plate, the strip steel plate is firmly welded with the outer edge of the arch frame, and the (N+2) -th cycle steel plate, the (N+n) -th cycle steel plate and the steel arch frame are sequentially completed, and 1/2 of the outer wing plate of the (N+n) -th cycle steel arch frame is welded with the end part of the strip steel plate;

s3: after S2 is finished, a plurality of strip steel members are adopted between the n+n cycle steel arch and the N cycle steel arch to be firmly welded, wherein the strip steel members can be HW steel or channel steel, and the distance B is less than or equal to 60cm;

s4: punching holes at the positions of the strip steel plates in the (n+n) th cycle and the (N) th cycle, installing grouting guide pipes and ventilation pipes, wherein the grouting guide pipes and the ventilation pipes are arranged in a quincuncial shape and welded with the profile steel arch, the distance between the grouting guide pipes and the ventilation pipes and the surrounding rock surface at the top of the collapse cavity is B, wherein B is less than or equal to 10cm, and the grouting guide pipes and the ventilation pipes have grouting and exhaust functions;

s5: along with tunneling of an open TBM, after an Nth circulation collapse cavity support and an n+n circulation collapse cavity support are connected to a wet spraying machine in a spraying and mixing area, concrete is filled in the Nth circulation collapse cavity and the n+n circulation collapse cavity in a layered manner through a grouting conduit, concrete is sprayed to an intrados surface by the wet spraying machine in the spraying and mixing area, the layered concrete filling sequence is from two sides to the middle and from the bottom to the high, the layered concrete filling height is at least higher than the highest point N of a profile steel arch, wherein N is a natural number which is not zero, and the residual space of the collapse cavity is filled with light materials;

s6: and the N-th cycle and the N+n-th cycle collapse cavity support the sprayed concrete to the designed intrados.

IV: when the two side support boot parts collapse, the disposal measures are as follows:

when the cavity collapse depth H is smaller than 0.5m, dense reinforcing steel meshes are laid at intervals in the cavity collapse, the L1 area emergency spraying and mixing system sprays concrete to the designed intrados layer by layer, and the strength of the sprayed concrete is early strength concrete;

when the cavity collapse depth H is more than or equal to 0.5m, temporarily filling the cavity collapse position by adopting sand bags and sleepers, laying strip steel plates with L multiplied by B multiplied by H (longitudinal multiplied by circumferential multiplied by thickness) on the surface, and spraying concrete to the designed intrados layer by layer at the wet spraying machine from the cavity collapse to the spraying and mixing area after the supporting boots at the two sides pass safely.

Preferably, the construction steps of the reinforcing mesh sheet are as follows:

s1, steel components such as a reinforcing mesh sheet, connecting ribs and the like are processed and formed in a reinforcing yard in a centralized manner, and an MSV multifunctional rubber-tyred vehicle is transported to a material lifting platform by an open TBM (tunnel boring machine) rear supporting trolley;

s2, starting a material lifting platform, lifting steel members such as a reinforcing mesh sheet and connecting ribs to a rotary crane on the top of the L1 girder, lifting the rotary crane to the girder, and manually transporting to a designated area for installation;

s3, overlapping and welding one end of the Nth circulating reinforcing steel bar net sheet with one end of the N-1 th circulating reinforcing steel bar net sheet, wherein the overlapping length of the reinforcing steel bar net sheet is more than or equal to 30 times of the diameter of the reinforcing steel bar;

s4, assembling an nth circulating steel arch by an arch assembling machine, and rounding and tightly attaching a steel bar net sheet to a rock surface;

the supporting shoe and the reinforcing steel mesh below the bottom of the supporting shoe are installed before the wet spraying machine in the spraying and mixing area sprays concrete after the supporting shoe passes through the position.

Preferably, the section steel arch is installed as follows:

s1, intensively processing a section steel arch in a reinforced bar yard, transporting an MSV multifunctional rubber-tyred vehicle to an inverted arch crane through an open TBM (tunnel boring machine) rear supporting trolley, transporting to a service beam through the inverted arch crane, and transporting to an arch frame assembling machine through the service beam;

s2, the section steel arch frame is formed by splicing N section steel, connecting plates are arranged at the ends of the N section steel and the N+1 section steel, the N section steel and the N+1 section steel are connected into a whole through M bolts, an arch frame splicing machine grabbing head grabs the N section steel and rotates to vacate the installation position of the N+1 section steel, then the N+1 section steel is installed and rotated, the N+n section steel is installed in sequence, wherein M is more than or equal to 4, and N is a natural number which is not zero;

s3, the assembled section steel arch is moved to a designated position by the tightening device, the circle is tightened to be tightly attached to the rock face, the reinforcing ribs are installed, the nuts of the connecting plates are tightened, and joints of the section steel arch in the Nth cycle and the (n+1) th cycle are staggered by at least 50%;

s4, installing the annular connecting ribs among the Nth cycle, the N+1 th cycle and the N+n th cycle, and installing the supporting shoe and the connecting rib at the bottom of the supporting shoe before the wet spraying machine in the spraying and mixing area sprays concrete after the supporting shoe passes.

Preferably, the grouting plugging step comprises the following steps:

s1, forward prefabricating an overhead arch block in a centralized manner in a prefabricating field, conveying the overhead arch block to an inverted arch crane by adopting an MSV multifunctional rubber tire vehicle through an open TBM and a matched trolley, and installing a water stop strip on the Nth inverted arch block before conveying;

s2, cleaning an N-th inverted arch block installation area, installing cushion blocks, and installing the inverted arch crane to a designated position in a rotary manner after lifting;

s3, installing bolts between the N block and the N-1 inverted arch block and screwing the bolts;

s4, connecting a grouting pipeline to perform grouting plugging;

the installation of the upward arch blocks and the construction of the steel mesh and the section steel arch are not interfered with each other, and the upward arch blocks and the section steel arch can be independently carried out.

Compared with the prior art, the application has the following advantages and beneficial effects:

1. three strong supporting modes and supporting modes when the two side supporting shoe parts collapse cavities are provided for the open TBM to penetrate through the fold zone collapse stratum, the three strong supporting modes and the supporting modes are flexibly adopted according to the condition of the shield tail collapse and collapse block and the size of the collapse cavity, and the risk of initial supporting deformation and even collapse of the collapse block-collapse stratum due to insufficient initial supporting strength is reduced.

2. Aiming at the open TBM without the reinforcement bar function or with insufficient reinforcement bar strength to resist the pressure of collapse slag, the method has the advantages that the strip steel plates are densely arranged and welded at the outer wing plates of the upper steel arch frame, the strip steel plates move backwards to block the collapse slag at the top of the shield along with the tunneling of the open TBM, the construction is safe and reliable, the safety risk is low, the damage of the collapse slag to personnel and equipment in the tunneling process is avoided, and the tunneling efficiency of the open TBM in a corrugated belt is improved.

3. For the small space in the matched trolley behind the open TBM, the general vehicle cannot be freely taken out, and the material transportation of the open TBM such as a profile steel arch, a steel bar net sheet, an overhead arch block and the like in the tunneling process is completed by adopting an MSV multifunctional rubber-tyred vehicle. The MSV multifunctional rubber-tyred vehicle has the double-head driving function, can be freely moved, is convenient and quick, is not limited by clearance of a rear matched trolley, and provides reliable material transportation guarantee for tunneling of an open TBM.

Drawings

The accompanying drawings, which are included to provide a further understanding of embodiments of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application. In the drawings:

FIG. 1 is a flow chart of the present application;

FIG. 2 is a schematic illustration of an open TBM in accordance with an embodiment of the present application;

FIG. 3 is an enlarged view of A in a schematic view of an open TBM in accordance with an embodiment of the present application;

FIG. 4 is an enlarged view of B in a schematic view of an open TBM in accordance with an embodiment of the present application;

FIG. 5 is an enlarged view of C in a schematic view of an open TBM in accordance with an embodiment of the present application;

FIG. 6 is a schematic illustration of an open TBM jumbolter in accordance with an embodiment of the present application;

FIG. 7 is a schematic view of left and right side strut shoes of an open TBM in accordance with an embodiment of the present application;

FIG. 8 is a schematic diagram of an MSV multi-functional cart in accordance with an embodiment of the present application;

FIG. 9 is a cross-sectional view I of a continuous belt conveyor arrangement in accordance with an embodiment of the present application;

FIG. 10 is a cross-sectional view II of a continuous belt conveyor arrangement in accordance with an embodiment of the present application;

FIG. 11 is a schematic view of a 0.5 m-2 m support of a collapsed cavity in an embodiment of the application;

FIG. 12 is a schematic view of a collapsed cavity with a depth of 2m and above in an embodiment of the application.

In the figure: the hydraulic system comprises a 1-cutter head, a 2-shield, a 3-arch frame assembling machine, a 4-jumbolter, a 5-emergency spraying and mixing system, a 6-supporting shoe, a 7-rear support, an 8-upward arch block, a 9-inverted arch crane, a 10-rotary crane, an 11-material lifting platform, a 12-spraying and mixing area wet spraying machine, a No. 13-No. 1 trolley main control room, a 14-concrete conveying pump, a 15-concrete tank, a 16-concrete tank crane, a 17-MSV multifunctional rubber-tire vehicle, an 18-continuous belt conveyor, a 19-concrete layered backfilling machine, a 20-grouting guide pipe, a 21-ventilation pipe, a 22-sprayed concrete, a 23-shaped steel arch frame, a 24-reinforcing steel mesh, 25-bar steel members, 25-connecting ribs, 26-bar steel plates, 27-lightweight materials and 28-service beams.

Detailed Description

For the purpose of making apparent the objects, technical solutions and advantages of the present application, the present application will be further described in detail with reference to the following examples and the accompanying drawings, wherein the exemplary embodiments of the present application and the descriptions thereof are for illustrating the present application only and are not to be construed as limiting the present application. It should be noted that the present application is already in a practical development and use stage.

1-12, a construction method for collapsing the top of the shield tail of an open TBM full-face heading machine comprises the following steps:

Preferably, the section steel arch is installed as follows:

s3, installing the annular connecting ribs among the Nth cycle, the N+1 th cycle and the N+n th cycle, and installing the supporting shoe and the connecting rib at the bottom of the supporting shoe before the wet spraying machine in the spraying and mixing area sprays concrete after the supporting shoe passes.

Preferably, the grouting plugging step comprises the following steps:

s4, connecting a grouting pipeline to perform grouting plugging;

Examples

As shown in fig. 2 to 12, a 22.13 km-level extra-long tunnel is arranged in Xinjiang, a 3 hole and 4 shaft design scheme is adopted in the high-cold high-altitude area, an open TBM (tunnel boring machine) method is adopted in the middle pilot tunnel, the excavation diameter is 8430mm, the total machine length is 285m, and the device has the functions of pressure injection and open excavation, so that the design of a steel bar row is canceled by lengthening the shield 2 to 10 m.

And (5) tunneling the tunnel with an open TBM at the outlet end for 10.801km, and sequentially passing through the apoplexy granite spot, the marble sandy slate and the granite. The belt 3576m is influenced by the medium mountain folds, mainly a marble sand inclusion paper board, the harder rock is in a block mosaic structure, collapse is encountered 54 times in the process, and the collapse occurs on the top of the two-side supporting boots 6, wherein the maximum collapse cavity is 13m multiplied by 7.3m multiplied by 6m (longitudinal multiplied by circumferential multiplied by depth), meanwhile, light micro-blocking is accompanied, and the collapse cavity is treated for 7 days.

The open TBM in the embodiment comprises a cutter head 1, a shield 2, an arch centering assembly machine 3, an anchor rod drilling machine 4, an emergency spraying and mixing system 5, a supporting shoe 6, a rear support 7, an arch centering block 8, an inverted arch crane 9, a rotary crane 10, a material lifting platform 11, a spraying and mixing area wet spraying machine 12, a No. 1 trolley main control room 13, a concrete conveying pump 14, a concrete tank 15, a concrete tank crane 16, an MSV multifunctional rubber-tyred vehicle 17, a continuous belt conveyor 18, a concrete layering backfill 19, a grouting guide pipe 20, a ventilation pipe 21, a sprayed concrete 22, a section steel arch 23, a steel mesh 24, a strip steel member 25, a connecting rib 25, a strip steel plate 26, a lightweight material 27 and a service beam 28.

The present example is one of the 54 collapses with the largest collapse occurring at the top of the two side support shoes 6, the collapse cavity being 13m x 7.3m x 6m (longitudinal x circumferential x depth) with light micro-jamming.

At this time, the depth of the collapse cavity exceeds 2m, so that a third strong supporting mode is used, and the steps are as follows:

s1: after the installation of the Nth circulating steel arch 23 is completed, the steel bar 26 is welded on the outer wing plate of the Nth circulating steel arch 23 in a circumferential close-packed manner, the size of the steel bar 26 is L multiplied by B multiplied by h (longitudinal multiplied by circumferential multiplied by thickness), wherein L is equal to the tunneling stroke of the open TBM, B is determined by the outer arc of the steel arch 23, h is less than or equal to 8mm, one end of the length direction of the steel bar 26 is welded at the outer wing plate of the Nth circulating steel arch 23, and one end of the steel bar is stretched into the inner side of the open TBM shield 2 and is tightly attached to the outer wing plate of the N+1th circulating steel arch 23 pre-installed on the inner side of the shield 2.

The circumferential radian range of the welding of the end part of the strip steel plate 26 is determined according to the collapse degree of surrounding rock separated from the shield tail;

s2: when the open TBM is used for tunneling forward for the (N+1) -th cycle, the strip steel plate 26 and the pre-installed (N+1) -th cycle steel arch 23 slowly fall out of the inner side of the shield 2, stone falling from the shield tail is intercepted, after the (N+1) -th cycle tunneling is completed, the arch centering assembling machine 3 supports the (N+1) -th cycle steel arch 23 to tightly cling to surrounding rocks with the strip steel plate 26, the strip steel plate 26 is firmly welded with the outer edge of the arch, and the (N+2) -th cycle steel plate 26 and the (N+n) -th cycle steel arch 23 are sequentially completed, and 1/2 of the outer wing plate of the (N+n) -th cycle steel arch 23 is welded with the end part of the strip steel plate 26;

s3: after S2 is finished, a plurality of strip steel members 25 are adopted between the n+n circulating type steel arch 23 and the N circulating type steel arch 23 to be firmly welded, wherein the strip steel members 25 can be HW type steel or channel steel, and the interval B is less than or equal to 60cm;

s4: punching the position of the (n+n) th circulation and (N) th circulation strip steel plate 26, and installing a grouting guide pipe 20 and a vent pipe 21, wherein the quincuncial arrangement of the grouting guide pipe 20 and the vent pipe 21 is welded with a profile steel arch 23, the distance between the grouting guide pipe 20 and the vent pipe 21 and the surrounding rock surface at the top of the collapse cavity is B, wherein B is less than or equal to 10cm, and the grouting guide pipe 20 and the vent pipe 21 have grouting and exhaust functions;

s5: along with tunneling of an open TBM, after an Nth cyclic collapse cavity support and an n+n cyclic collapse cavity support are connected to a wet spraying machine 12 in a spraying and mixing area, a sprayed concrete 22 pipeline is connected to perform concrete layered backfilling 19 on the Nth cyclic collapse cavity and the n+n cyclic collapse cavity through a grouting conduit 20, then the wet spraying machine 12 in the spraying and mixing area is adopted to spray concrete 22 to an intrados surface, the concrete layered backfilling 19 is sequentially from two sides to the middle and from the bottom to the high, the height of the concrete layered backfilling 19 is at least higher than the highest point N of a profile steel arch 23, wherein N is a natural number which is not zero, and the residual space of the collapse cavity is filled with a light material 27;

s6: the nth and n+nth cycles collapse to support the sprayed concrete 22 to the designed intrados, and the continuous belt conveyor 18 is suspended above the roof of the hole by a mortar anchor rod matched with a guide chain.

The construction steps of the reinforcing mesh 24 are as follows:

s1, steel components such as a reinforcing mesh 24 and connecting ribs 25 are processed and formed in a reinforcing yard in a centralized mode, and the MSV multifunctional rubber-tyred vehicle 17 is transported to the material lifting platform 11 through an open TBM and a matched trolley.

S2, starting the material lifting platform 11, lifting steel members such as the reinforcing mesh 24 and the connecting ribs 25 to the rotary crane 10 on the top of the L1 girder, lifting the rotary crane 10 to the girder, and manually transporting to a designated area for installation.

S3, overlapping and welding one end of the Nth circulating reinforcing steel bar mesh 24 with one end of the N-1 th circulating reinforcing steel bar mesh 24. The overlap length of the reinforcing mesh 24 is more than or equal to 30 times of the diameter of the reinforcing.

S4, assembling the nth circulating steel arch 23 by the arch assembling machine 3, and rounding the steel mesh 24 to be tightly attached to the rock surface.

The shoe 6 and the reinforcing mesh 24 below the bottom of the shoe 6 are installed before the wet spraying machine 12 in the spraying and mixing area sprays the concrete 22 after the shoe 6 passes through the position.

The installation steps of the section steel arch 23 are as follows:

s1, intensively processing the section steel arch 23 in a reinforced bar yard, transporting the MSV multifunctional rubber-tyred vehicle 17 to an inverted arch crane 9 through an open TBM and a matched trolley, transporting to a service beam 28 through the inverted arch crane 9, and transporting to an arch assembly machine 3 through the service beam 28.

S2, the section steel arch 23 is formed by splicing N section steel, connecting plates are arranged at the ends of the N section and the N+1 section, the N section steel and the N section steel are connected into a whole through M bolts, the arch centering splicing machine 3 grabs the N section steel and rotates to vacate the installation position of the N+1 section steel, then the N+1 section steel is installed and rotated, and the N+n section steel is installed in sequence. Wherein M is more than or equal to 4, and N is a natural number which is not zero.

S3, the assembled section steel arch 23 is moved to a designated position by the tightening device, the circle is tightened to be tightly attached to the rock face, the reinforcing ribs are arranged, and the connecting plate nuts are tightened. The joints of the Nth circulation and the (n+1) th circulation type steel arches 23 are staggered by at least 50 percent.

S4, installing the annular connecting ribs 25 among the Nth cycle, the N+1th cycle and the N+n th cycle. The supporting shoe 6 and the connecting ribs 25 at the bottom of the supporting shoe 6 are arranged before the wet spraying machine 12 in the spraying and mixing area sprays the concrete 22 after the supporting shoe 6 passes

The grouting plugging steps are as follows:

s1, performing centralized forward prefabrication on the inverted arch blocks 8 in a prefabrication field, and conveying the inverted arch blocks to an inverted arch crane 9 by adopting an MSV multifunctional rubber-tyred vehicle 17 through an open TBM rear supporting trolley. The Nth inverted arch block 8 is provided with a water stop strip before transportation.

S2, cleaning an installation area of the N inverted arch block 8, and installing cushion blocks. The inverted arch crane 9 is lifted and mounted to a designated position by rotation.

S3, installing bolts between the N th block and the N-1 th inverted arch block 8 and screwing.

S4, connecting a grouting pipeline to perform grouting plugging.

The installation of the inverted arch block 8 and the construction of the reinforcing mesh 24, the section steel arch 23, the system anchor rod and the sprayed concrete 22 are not interfered with each other, and can be independently carried out.

Finally, under the method of the application, the time for treating the collapse cavity is 7 days, thereby reducing the falling of the collapse stone and the damage to mechanical equipment, improving the tunneling efficiency and improving the safety degree. The foregoing description of the embodiments has been provided for the purpose of illustrating the general principles of the application, and is not meant to limit the scope of the application, but to limit the application to the particular embodiments, and any modifications, equivalents, improvements, etc. that fall within the spirit and principles of the application are intended to be included within the scope of the application.

Claims

1. The construction method for the collapse of the top of the shield tail of the open TBM full-face heading machine is characterized by comprising the following steps of:

the collapse cavity depth caused by the collapse of the upper part of the supporting shoe (6) is detected, and different strong supporting treatment measures are corresponding to different depths and positions, and the method specifically comprises the following steps:

i: when the collapse cavity depth H formed in the tunneling process is less than 0.5m within the range above the top of the shield tail support boot (6), the disposal measure of the collapse cavity is as follows:

removing slag in a collapse cavity after the Nth cyclic tunneling is finished, performing primary injection concrete (22) sealing on exposed surrounding rock of the Nth cyclic collapse cavity by an L1 area emergency injection mixing system (5), laying a reinforcing steel mesh (24), installing an Nth cyclic steel arch (23), firmly welding the Nth cyclic steel arch (23) and the N-1 cyclic steel arch (23) in a staggered manner by adopting a circumferential connecting rib (25), injecting concrete (22) to a designed intrados surface by adopting an injection mixing area wet injection machine (12), wherein the circumferential connecting rib (25) between the Nth cyclic steel arch (23) and the N-1 cyclic steel arch (23) is B, the distance L between the Nth cyclic steel arch (23) and the N-1 cyclic steel arch (23) is less than or equal to the open TBM per cyclic tunneling stroke L';

II: when the collapse cavity depth formed in the tunneling process within the range above the top of the shield tail support boot (6) is more than or equal to 0.5m and less than or equal to H < 2m, the treatment measures are as follows:

s1: cleaning slag in a collapse cavity after an Nth circulation is separated from the shield tail, performing primary injection concrete (22) sealing on exposed surrounding rock of the Nth circulation collapse cavity by an L1 area emergency spraying and mixing system (5), laying N layers of dense reinforcing steel meshes (24), installing an Nth circulation type steel arch frame (23), and replacing connecting ribs (25) between the Nth circulation type steel arch frame (23) and the N-1 th circulation type steel arch frame (23) by strip type steel members (25), wherein N is more than or equal to 2, the length of each strip type steel member (25) is equal to the spacing between the Nth circulation type steel arch frame (23) and the N-1 th circulation type steel arch frame (23), the strip type steel members (25) are HW type steel or channel steel, the circumferential spacing between the type steel arch frames (23) is B, and B is less than or equal to 80cm;

s2: the grouting guide pipe (20) and the vent pipe (21) are arranged in the Nth circulating collapse cavity, the quincuncial arrangement of the grouting guide pipe (20) and the vent pipe (21) is welded with the Nth circulating steel arch (23), the distance between the grouting guide pipe (20) and the vent pipe (21) and the top surrounding rock surface of the collapse cavity is B, wherein B is less than or equal to 10cm, and the grouting guide pipe (20) and the vent pipe (21) have grouting and ventilation functions;

s3: blocking the tail parts of the grouting guide pipe (20) and the vent pipe (21), and supporting sprayed concrete (22) on the Nth circulating collapse cavity by an emergency spraying and mixing system (5) in the L1 area, wherein the thickness of the sprayed concrete (22) is more than or equal to 10cm;

s4: along with the forward tunneling of the open TBM, after the Nth cyclic collapse cavity is supported to a wet spraying machine (12) in a spraying and mixing area, connecting a sprayed concrete (22) pipeline, carrying out concrete layered backfilling (19) on the Nth cyclic collapse cavity to the top of the collapse cavity through a grouting conduit (20), and then spraying concrete (22) to an intrados surface by adopting the wet spraying machine (12) in the spraying and mixing area, wherein the concrete layered backfilling (19) is sequentially carried out from two sides to the middle and from the bottom to the high;

III: when the collapse cavity depth H is more than 2m in the tunneling process within the range above the top of the shield tail support boot (6), and the shield tail surrounding rock continuously collapses and blocks in the tunneling process, the treatment measures are as follows:

s1: the method comprises the steps that a bar-shaped steel plate (26) is adopted to replace a reinforcing mesh (24), after the installation of an Nth circulating steel arch (23) is completed, the bar-shaped steel plate (26) is welded on the outer wing plate of the Nth circulating steel arch (23) in a circumferential and close arrangement mode, the dimension of the bar-shaped steel plate (26) is L multiplied by B multiplied by h, the longitudinal direction multiplied by the thickness of the bar-shaped steel plate is multiplied by X, L is equal to the tunneling stroke of an open TBM, B is determined by the outer arc degree of the steel arch (23), h is less than or equal to 8mm, one end of the length direction of the bar-shaped steel plate (26) is welded at the outer wing plate of the Nth circulating steel arch (23), and one end of the bar-shaped steel plate extends into the inner side of an open TBM shield (2) and is clung to the outer wing plate of the Nth+1th circulating steel arch which is pre-installed on the inner side of the shield;

the circumferential radian range of the end part of the strip steel plate (26) is determined according to the collapse degree of surrounding rock separated from the shield tail;

s2: when the open TBM is used for tunneling forward for the (N+1) th cycle, a strip steel plate (26) and a pre-installed (N+1) th cycle steel arch slowly deviate from the inner side of a shield (2), stone falling from the tail of the shield is intercepted, after the (N+1) th cycle tunneling is completed, an arch centering assembling machine is used for tightly supporting the (N+1) th cycle steel arch to be tightly attached to surrounding rocks with the strip steel plate, the strip steel plate is firmly welded with the outer edge of the arch centering, an (N+2) th ring, the (N+n) th cycle steel plate (26) and the steel arch (23) are sequentially completed, and 1/2 of an outer wing plate of the (N+n) th cycle steel arch (23) is welded with the end part of the strip steel plate (26);

s3: after S2 is finished, a plurality of strip steel members (25) are adopted between the (n+n) th circulating steel arch (23) and the (N) th circulating steel arch (23) for firm welding, the strip steel members (25) are HW steel or channel steel, and the distance B is less than or equal to 60cm;

s4: punching the part of an (n+n) th circulation and an (N) th circulation strip steel plate (26), installing a grouting guide pipe (20) and a vent pipe (21), wherein the quincuncial arrangement of the grouting guide pipe (20) and the vent pipe (21) is welded with a profile steel arch (23), the distance between the grouting guide pipe (20) and the vent pipe (21) and the top surrounding rock surface of a collapse cavity is B, wherein B is less than or equal to 10cm, and the grouting guide pipe (20) and the vent pipe (21) have grouting and exhausting functions;

s5: along with tunneling of an open TBM, after an Nth cyclic collapse cavity support and an N+n cyclic collapse cavity support are connected to a wet spraying machine (12) in a spraying mixing area, a sprayed concrete (22) pipeline is connected to perform concrete layered backfilling (19) on the Nth cyclic collapse cavity and the N+n cyclic collapse cavity through a grouting guide pipe (20), then the wet spraying machine (12) in the spraying mixing area is adopted to spray concrete (22) to an intrados surface, the concrete layered backfilling (19) is sequentially carried out from two sides to the middle and from the bottom to the top, the height of the concrete layered backfilling (19) is at least higher than the highest point N of a profile steel arch (23), wherein N is a natural number which is not zero, and the residual space of the collapse cavity is filled with a light material (27);

s6: the Nth cycle and the n+n cycle collapse cavity support the sprayed concrete (22) to the designed intrados;

IV: when the two side support boots (6) collapse, the disposal measures are as follows:

when the cavity collapse depth H is smaller than 0.5m, dense reinforcing steel meshes (24) are laid at intervals in the cavity collapse, the L1 area emergency spraying and mixing system (5) sprays concrete (22) to the designed intrados in a layered mode, and the strength of the sprayed concrete (22) is early-strength concrete;

when the cavity collapse depth H is more than or equal to 0.5m, sand bags and sleepers are adopted for temporary filling at the cavity collapse position, LXB Xh and strip steel plates (26) with longitudinal Xannular X thickness are laid on the surfaces, after the supporting shoes (6) on two sides safely pass through, concrete (22) is sprayed to the designed intrados at the position of a wet spraying machine (12) from the cavity collapse position to the spraying and mixing area.

2. The construction method for the top collapse of the shield tail of the open TBM full-face heading machine according to claim 1, wherein the construction steps of the reinforcing mesh (24) are as follows:

s1, steel components such as a reinforcing mesh (24) and connecting ribs (25) are processed and formed in a centralized manner in a reinforcing yard, and an MSV multifunctional rubber-tyred vehicle (17) is transported to a material lifting platform (11) through an open TBM and a matched trolley;

s2, starting a material lifting platform (11), lifting steel members such as a reinforcing mesh (24) and connecting ribs (25) to a rotary crane (10) on the top of the L1 main beam, lifting the rotary crane (10) to the main beam, and manually transporting to a designated area for installation;

s3, overlapping and welding one end of the Nth circulating reinforcing steel bar mesh (24) with one end of the N-1 th circulating reinforcing steel bar mesh (24), wherein the overlapping length of the reinforcing steel bar mesh (24) is more than or equal to 30 times of the diameter of the reinforcing steel bar;

s4, assembling an Nth circulating steel arch (23) by an arch assembling machine (3), and rounding and tightly attaching a steel mesh (24) to a rock surface;

the supporting shoe (6) and the reinforcing steel mesh (24) below the bottom of the supporting shoe (6) are installed before the wet spraying machine (12) in the spraying and mixing area sprays concrete (22) after the supporting shoe (6) passes through the position.

3. The construction method for the top collapse of the shield tail of the open TBM full-face heading machine according to claim 1, wherein the step of installing the section steel arch (23) is as follows:

s1, intensively processing a section steel arch (23) in a reinforced bar yard, transporting an MSV multifunctional rubber-tyred vehicle (17) to an inverted arch crane (9) through an open TBM and a matched trolley, transporting to a service beam (28) through the inverted arch crane (9), and then transporting to an arch erection machine (3) through the service beam (28);

s2, the section steel arch frame (23) is formed by splicing N section steel, connecting plates are arranged at the ends of the N section steel and the N+1 section steel, the N section steel and the N+1 section steel are connected into a whole through M bolts, an arch frame splicing machine (3) grabs the N section steel and rotates to vacate the installation position of the N+1 section steel, then the N+1 section steel is installed and rotated, the N+n section steel is installed in sequence, wherein M is more than or equal to 4, and N is a natural number which is not zero;

s3, the assembled section steel arch (23) is moved to a designated position by the tightening device, the circle is tightened to be clung to the rock face, the reinforcing ribs are arranged, the nuts of the connecting plates are tightened, and joints of the section steel arch (23) of the Nth cycle and the (n+1) th cycle are staggered by at least 50%;

s4, installing the annular connecting ribs (25) among the Nth cycle, the N+1 th cycle and the N+n th cycle, and installing the supporting shoe (6) and the connecting ribs (25) at the bottom of the supporting shoe (6) before the spraying concrete (22) is sprayed by the wet spraying machine (12) in the spraying and mixing area after the supporting shoe (6) passes.

4. The construction method for the top collapse of the shield tail of the open TBM full-face heading machine according to claim 1, wherein the grouting and plugging steps are as follows:

s1, performing centralized forward prefabrication on inverted arch blocks (8) in a prefabrication field, conveying the inverted arch blocks (8) to an inverted arch crane (9) by adopting an MSV multifunctional rubber-tyred vehicle (17) through an open TBM and a matched trolley, wherein water stop bars are arranged on the Nth inverted arch blocks (8) before conveying;

s2, cleaning an installation area of an N-th inverted arch block (8), installing cushion blocks, and lifting and installing the inverted arch crane (9) to a designated position through rotation;

s3, installing bolts between the N block and the N-1 inverted arch block (8) and screwing the bolts;

s4, connecting a grouting pipeline to perform grouting plugging;

the installation of the upward arch blocks (8) and the construction of the reinforcing mesh (24) and the section steel arch (23) are not interfered with each other, and can be independently carried out.