CN112160759A - Method for starting and trial tunneling of tunnel shield crossing river - Google Patents
Method for starting and trial tunneling of tunnel shield crossing river Download PDFInfo
- Publication number
- CN112160759A CN112160759A CN202011123760.3A CN202011123760A CN112160759A CN 112160759 A CN112160759 A CN 112160759A CN 202011123760 A CN202011123760 A CN 202011123760A CN 112160759 A CN112160759 A CN 112160759A
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- shield
- steel
- tunnel
- ring
- sealing
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/06—Making by using a driving shield, i.e. advanced by pushing means bearing against the already placed lining
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/04—Lining with building materials
- E21D11/08—Lining with building materials with preformed concrete slabs
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/04—Lining with building materials
- E21D11/10—Lining with building materials with concrete cast in situ; Shuttering also lost shutterings, e.g. made of blocks, of metal plates or other equipment adapted therefor
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/001—Improving soil or rock, e.g. by freezing; Injections
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/003—Arrangement of measuring or indicating devices for use during driving of tunnels, e.g. for guiding machines
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/06—Making by using a driving shield, i.e. advanced by pushing means bearing against the already placed lining
- E21D9/0607—Making by using a driving shield, i.e. advanced by pushing means bearing against the already placed lining the shield being provided with devices for lining the tunnel, e.g. shuttering
- E21D9/0609—Making by using a driving shield, i.e. advanced by pushing means bearing against the already placed lining the shield being provided with devices for lining the tunnel, e.g. shuttering with means for applying a continuous liner, e.g. sheets of plastics, between the main concrete lining and the rock
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/06—Making by using a driving shield, i.e. advanced by pushing means bearing against the already placed lining
- E21D9/0635—Tail sealing means, e.g. used as end shuttering
Abstract
The invention discloses a method for starting and trying to drive a shield of a river-crossing tunnel, which comprises the following steps: 1) constructing an originating base and a reaction frame; 2) sealing a tunnel door and installing a rubber curtain cloth; 3) assembling a shield machine; 4) and (3) tunnel portal breaking construction: 5) starting a warehouse; 6) secondary sealing of the tunnel portal; 7) starting trial excavation construction and synchronously grouting; 8) initial trial excavation monitoring. The invention has the beneficial effects that: the invention summarizes the preparation work before the shield starting in detail to form a set of complete construction scheme before starting and tunneling, and can effectively ensure the stability and the safety of the shield starting and tunneling process.
Description
Technical Field
The invention relates to the technical field of river-crossing tunnel construction engineering, in particular to a method for starting and trying to drive a shield of a river-crossing tunnel.
Background
The river-crossing tunnel has the advantages of no restriction on shipping, no influence of weather conditions, good anti-seismic performance, high strategic significance and the like, and is generally applied to river-crossing engineering in recent years. The slurry balance shield method is one of the main construction methods of the river-crossing tunnel, and when slurry balance shield is carried out, if preparation work before shield starting is insufficient or preparation work is not arranged according to a reasonable flow, the safety and the construction progress of later construction can be directly influenced, so that the shield starting preparation work is very important.
At present, some researches related to shield starting preparation work exist in the prior art, but the above technologies are usually improved only for a certain very tiny and specific problem in the shield starting work, and from the whole shield starting work, researches for optimizing the whole process of each work in the starting preparation are not common, so that, in order to ensure the safety and the economy of construction, it is important to obtain a construction method with reasonable process arrangement from the whole shield starting preparation work.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a method for starting and trying to drive a shield of a tunnel crossing a river, which has reasonable design and complete process.
The technical scheme of the invention is as follows:
a method for starting and trying to drive a tunnel shield across a river is characterized by comprising the following steps:
1) constructing an originating base and a reaction frame;
2) sealing a tunnel door and installing a rubber curtain cloth;
3) assembling a shield machine;
4) and (3) tunnel portal breaking construction:
5) starting a warehouse;
6) secondary sealing of the tunnel portal;
7) starting trial excavation construction and synchronously grouting;
8) initial trial excavation monitoring.
The method for starting and trying to drive the shield of the tunnel across the river is characterized in that the step 1) comprises the following steps:
1.1) the originating base adopts a cast-in-place reinforced concrete structure, the originating base is an arc structure and is divided into a shield tail base and a shield body base, the originating base is longitudinally parallel to the shield center line, a gap is arranged between the shield shell and the originating base and is used for welding a track, profile steel is longitudinally embedded in the originating base, the upper part of the originating base is welded with square steel, stiffening ribs are longitudinally arranged at intervals of 10cm, the height of a welding line is not less than 8mm, the square steel is used as the track for sliding the shield shell, inserting ribs are embedded when the bottom plate of an originating well is constructed, the originating base and the bottom plate are connected into a whole, and the shearing resistance of the base; four shield machine sliding tracks are longitudinally and symmetrically arranged on the shield tail, and the included angles between the four shield machine sliding tracks and the central line of the shield machine are respectively 42 degrees and 112 degrees; 2 concrete wall supporting shield starting bases are respectively arranged on the east and west sides of the starting base, two grooves are reserved longitudinally, and an operation space is provided for assembling and welding the shield; the shield body is divided into a front body and a middle body, four shield machine sliding tracks are longitudinally and symmetrically arranged, and the included angles between the four shield machine sliding tracks and the center line of the shield machine are respectively 42 degrees and 81 degrees; when the starting bases on two sides of the shield are constructed, an I-steel is pre-embedded respectively, when the shield machine tunnels, a reaction force is caused due to the fact that a cutter head cuts soil, and the shield body can be twisted, so that a steel component is welded on the shield body, the other end of the steel component props against the I-steel pre-embedded on two sides of the base, a groove is reserved between the bases on two sides transversely to provide an operation space for assembling and welding the shield, an I-steel support is erected between a longitudinal groove and the transverse groove, and two ends of the I-steel are welded with two concrete base pre-embedded steel plates; according to the design center line of the shield, the starting base at the starting tunnel portal is lifted by 20mm, the base is not lifted by extending a length from the point to the large-mileage direction, the two points are in line to control other parts to adjust the size, and the cutter head of the shield machine is theoretically lifted by 30mm after the shield machine completely contacts the continuous wall;
1.2) the reaction frame adopts steel reaction frame, including steel ring, crossbeam and perpendicular roof beam, the steel ring is by annular upper and lower apron and web assembly welding I-shaped structure, this reaction frame adopts portal frame square frame shape structure, the portal is by two crossbeams, two perpendicular roof beams and four sloping beams assembly welding door shape structure of box structure, reaction frame back is according to the condition of well centre sill, arranges a plurality of steel pipes as the support on perpendicular roof beam.
The method for starting and trying to drive the shield of the tunnel across the river is characterized in that the step 2) comprises the following specific steps:
2.1) the pre-buried steel ring of the working well portal of the shield machine is of a circular ring plate structure, and a sealing steel ring is arranged outside the pre-buried steel ring and comprises a sealing plate, a stiffening plate, a circular ring plate, a turning plate and two curtain cloth rubber plates, wherein the whole ring surface of the sealing steel ring is vertical to the axis of the shield machine, and the stiffening plate is arranged on the inner side of the sealing plate; the sealing steel rings are assembled on the ground to form a ring, integrally hoisted, hoisted and welded on the flange face of the tunnel door in a manual matching mode, the sealing steel rings are required to be firmly welded on the two sides in a water stopping mode, the sealing steel rings are firmly fixed on the pre-buried tunnel door rings through the inner and outer stiffening plates, and in order to ensure that the sealing rings are not damaged due to stress in the process of passing through the shield well, concrete is poured at the ring bottom in the range of 60 degrees at the upper parts of the sealing steel rings for filling;
2.2) the sealing steel ring circular plate is provided with 120 bolt holes, the cord fabric rubber plate is fixed between the circular plate and the sealing steel ring by bolts, the circular plate is positioned at the inner side of the sealing plate and fixed on the portal sealing ring steel plate by double-sided welding, the circular plate is connected with the turning plate by a pin shaft, the turning plate is used as a rigid support for cord fabric rubber sealing, the sealing ring is welded on the flange surface of the pre-embedded portal steel ring before the shield starts, and the rubber cord fabric and the circular plate are fixed on the sealing steel ring by the bolts after the portal is broken; processing a steel pipe ladder on site, symmetrically welding four lifting lugs on two sides, paving a 6-point position of a cord fabric rubber plate at the center of the ladder, placing a protruding edge face at one end of rubber downwards, then paving the ladder towards two sides by taking No. 60 and No. 61 bolt holes as boundaries, folding each side in an S shape, finally arranging No. 1 and No. 120 bolt holes at the uppermost side, and making the protruding edge face at one end of the rubber downwards so that all rubber protrusions are arranged at the inner edge of the annular cord fabric rubber plate; after the curtain cloth rubber plates have installation conditions, two hanging strips with the same length and four buckles are fastened on the four processed lifting lugs, the curtain cloth is lifted by a crane and placed on the highest layer of a scaffold, a first curtain cloth rubber plate is installed firstly, installation is started from an upper bolt hole, and bolts are installed towards the inside of a foundation pit when the first curtain cloth rubber plate and the second curtain cloth rubber plate are installed, so that the bolts are conveniently fastened; firstly, inserting a steel chisel from a No. 1 bolt hole of a sealing steel ring, installing a cord fabric rubber plate on the steel chisel corresponding to the bolt hole, then installing a No. 5 bolt hole, installing No. 1 and No. 5 bolt holes on the steel chisel, then installing No. 2, 3 and No. 4 bolt holes by bolts, then drawing out the steel chisel from No. 1 and No. 5 bolt holes, installing bolts, wherein every 5 bolt holes form a group, the central line of the steel ring is taken as a standard, the left and right sides are simultaneously installed, when the first cord fabric rubber plate is installed, a hole is opened again and the position nearby the hole, a folding turning plate is not installed temporarily, and after the whole installation is finished, the installation of the position is carried: turning plates at other parts are simultaneously installed in place along with the cord fabric rubber plates, and rubber gaskets and steel gasket rubber gaskets are additionally arranged on the two sides of each turning plate and are tightly attached to the turning plates; in the installation process of the curtain cloth, the left side and the right side are required to be installed at the same time, one side is installed too fast, the other side is difficult to install, and the whole installation period is prolonged; after the installation of curtain cloth rubber slab, for preventing that the future entrance to a cave breaks the waste residue and drops and influence sealed effect on the rubber slab, lay old bamboo offset plate in the sealing ring bottom and protect curtain cloth rubber slab, arrange simultaneously that the special messenger carries out the secondary fastening to the bolt because rubber curtain cloth size is great, the curtain cloth of bottom will be laid to the entrance to a cave direction after the installation of rubber curtain cloth is accomplished, it has certain influence to build the storehouse to muddy water, for avoiding the emergence of this kind of condition, respectively at twice curtain cloth inlayer, installation one deck spring steel sheet is used for propping up the curtain cloth and is located upright state.
The method for starting and trying to drive the shield of the tunnel across the river is characterized in that the step 3) comprises the following specific steps:
3.1) determining an originating axis before assembling the shield tunneling machine, wherein the centerline vertical section of a tunnel designed in an originating section is positioned above a 45% downhill, and in order to reduce the influence of head collapse of the shield tunneling machine, a certain gradient is adjusted upwards during originating of the shield tunneling machine and the shield tunneling machine is originated in a 44% downhill;
3.2) N negative rings are arranged between the reaction frame and the positive ring, each ring of pipe piece comprises 5 standard blocks, 2 adjacent blocks and 1 top sealing block, the negative ring adopts an A-shaped concrete pipe piece, after the shield machine is debugged and reaches a starting position, the jack supporting shoes are completely retracted to the reaction frame, the assembling of the negative N rings is started, and the front end surfaces of the negative N rings are used as reference surfaces for assembling the negative N-1 rings; the negative N-2 ring can be easily formed into a ring on the reference, and the circumferential gap is uniform after the ring is formed, so that no horn mouth is required; after the negative N-1 ring is adjusted in position, the negative N-1 ring is connected with a counter-force frame in a steel pipe welding mode, a steel plate is embedded in the segment during manufacturing, and the counter-force frame is a steel counter-force frame and is directly welded with the steel pipe; the shield machine moves forwards to assemble the negative N-2 ring, the thrust of the shield machine is slowly increased from 0, the shield machine is kept to move forwards slowly, the shield machine stops moving forwards when the shortest jack stroke reaches the design distance, and the negative N-2 ring duct pieces are assembled; when the shield machine moves forwards, the attitude condition and the connection condition of the assembled duct pieces are observed, if the duct pieces are unstable, the forward movement is stopped immediately, anti-twisting blocks for preventing the shield machine from twisting are arranged on two sides of the shield machine, the anti-twisting blocks are cut off in time after dragging out of an originating base, connecting points are cut off and polished completely, and the anti-twisting blocks are prevented from damaging a tunnel portal;
3.3) after the negative N-2 rings are assembled, the shield machine starts to advance, the negative N-3 rings are assembled after a specified stroke is reached, each segment is connected block by block and ring by ring, and the negative N-4 rings, the negative N-5 rings and the negative N-6 rings are assembled in the same way;
3.4) when the duct piece is separated from the shield tail, welding of a steel plate embedded outside the duct piece needs to be carried out in time, and the rigidity of a duct piece ring is ensured; after the duct piece is separated from the shield tail, the duct piece needs to be supported in time, and the support is divided into three parts: 1) inserting a steel wedge between the duct piece and the square steel of the guide rail of the shield tunneling machine to ensure that the duct piece does not drop; the steel wedges are arranged at the joint of the segment and in the center of the segment; 2) welding an I-shaped steel support below the side of the pipe piece; 3) and welding steel supports on two sides of the shield body in the horizontal direction, and driving wood wedges between the steel supports and the duct piece to compress the duct piece after the duct piece is separated from the shield tail.
The method for starting and trying to drive the shield of the tunnel across the river is characterized in that the step 4) comprises the following specific steps:
4.1) underground continuous walls mainly affect shield starting in the tunnel portal range of shield starting, underground continuous wall chiseling construction in the tunnel portal range is arranged in the assembling and debugging period of a shield machine, the underground continuous wall chiseling construction can be carried out in the condition that the water level of end soil bodies is reduced to 2m below the arch bottom according to design requirements, the actual situation of the shield machine assembling field is considered, in order to reduce the influence of tunnel portal chiseling on shield assembling as much as possible and to start out a tunnel as soon as possible when the shield assembling is finished, the continuous wall walls in the tunnel portal range are chiselled out in three times; the first chiseling is carried out in the assembling process of the shield tunneling machine, concrete is chiseled, inner-layer steel bars of the underground continuous wall are stripped, concrete slag is arranged to be cleaned after chiseling is finished, and a temperature detecting hole is drilled in a tunnel door to detect whether temperature is frozen or not; and the second chiseling is arranged when the negative N ring pipe pieces of the shield tunneling machine are assembled, the concrete chiseling and cleaning work is completed two days before the shield is started to move forwards, and the concrete is chiseled: the third chiseling is completed within two days, when the shield machine carries out N-1 ring duct piece assembling, the residual concrete and the outside reinforcing steel bars of the underground continuous wall are chiseled, and chiseling concrete slag in the sealing ring is cleaned up, so that all chiseling and cleaning work is guaranteed to be completed before the shield machine starts;
4.2) chiseling concrete to set up a steel pipe support, wherein the support is made of seamless steel pipes, three rows are longitudinally set up, the steel pipes are connected through fasteners, a dense mesh protective net is pulled on the outer side of the support, a ballast cleaning operation platform is set up between the front of the starting base and the tunnel portal sealing steel ring, and chiseling concrete ballast is hoisted out of the foundation pit through a crane by using a hoisting bucket.
The method for starting and trying to drive the shield of the tunnel across the river is characterized in that the step 5) comprises the following specific steps:
5.1) injecting plugging materials between the rubber curtain cloth in advance before building the bin;
5.2) the storehouse building is carried out in three steps:
the first step is as follows: the slurry prepared in the slurry field is injected into the excavation surface, and the slurry liquid level of the excavation bin is kept above the central line for 3 m;
the second step is that: slowly pressurizing the air pressure bin, wherein the pressurizing is not higher than 0.1bar each time, opening a grouting hole in a sealing steel ring of a tunnel door to exhaust air, and simultaneously paying attention to the display of liquid levels in the front bin and the rear bin in the shield tunneling machine; when the slurry starts to be sprayed out from the slurry injection hole at the top, the valve of the slurry injection hole is closed; checking the liquid level in the bubble bin, if the liquid level is between-0.5 m and +0.5m at the central line, no adjustment is needed, if the liquid level is out of the range, starting a slurry circulating system, finely adjusting the liquid level to the range, and displaying the notch pressure as 0;
the third step: increasing the air pressure in the bubble chamber to 2.2bar, maintaining the pressure of 2.2bar for 15 minutes, observing whether the abnormality such as leakage exists or not, and if so, taking a leakage stopping measure; if not, slowly reducing the air pressure until the incision pressure is slowly adjusted to 0 bar;
and (3) observing the sealing condition of the tunnel portal, plugging in time, if small-scale leakage occurs, adopting cotton cloth, cotton yarn, sand bags, polyurethane and shield tail sealing grease materials to plug the front side, properly increasing the viscosity of the slurry and the high-molecular plugging slurry, if large leakage occurs, immediately stopping filling the slurry, finding out the reason, continuously filling the slurry, and during the slurry warehousing process, according to the water leakage condition of the rubber curtain cloth, passing through a grease filling hole on the sealing ring near a leakage point, and filling the slurry to plug the gap between the rubber of the curtain cloth and the shield body between the first curtain cloth and the second curtain cloth for sealing.
The method for starting and trying to drive the shield of the tunnel across the river is characterized in that the step 6) comprises the following specific steps:
6.1) the shield tunneling machine tunnels forwards, after the last steel brush of the shield tail completely enters the sealing steel ring, a zero-ring segment is installed at the sealing steel ring, and a pre-buried steel plate is installed on the rear end face of the outer side face of the zero-ring segment; after the shield tail of the shield tunneling machine completely passes through the sealing plate, the edge of the circular ring plate is welded with the embedded steel plate on the outer side of the zero-ring segment by using the sealing steel plate to form secondary sealing, so that the slurry pressure balance of the shield tunneling machine is ensured, the sealing effect is improved, the smooth implementation of synchronous grouting of the shield tunneling machine is ensured, and the welding seam of the secondary sealing is required to be continuous and not leak.
The method for starting and trying to drive the shield of the tunnel across the river is characterized in that the step 7) comprises the following specific steps:
7.1) starting trial excavation is divided into two sections: a stirring pile reinforcing section of 0-15m and an undisturbed soil section of 15-200 m;
7.2) in order to reduce and prevent settlement, in the shield tunneling process, sufficient serous fluid material is synchronously injected behind the lining segment which is separated from the shield tail as soon as possible to fill the annular building gap of the shield tail; synchronous grouting is simultaneously injected at 6 paths at the tail of the shield by adopting 3 double-piston grouting pumps of a shield machine, so that an annular gap between a duct piece and the stratum is filled in time, the stratum deformation is controlled, the duct piece structure is stabilized, the shield tunneling direction is controlled, and the self-waterproof capability of the tunnel structure is enhanced; during synchronous grouting, the pressure of grout in the stratum is required to be larger than the sum of the static water pressure and the soil pressure at the point, the grout is filled as much as possible and is not easy to split, and the grouting pressure is too high, so that the tunnel is disturbed by the grout to cause later-stage stratum settlement and tunnel self settlement, and grout leakage is easy to cause; and the grouting pressure is too low, the slurry filling speed is too low, the filling is insufficient, the deformation of the earth surface is increased, the synchronous grouting pressure is basically balanced with the muddy water pressure of the soil bin, the muddy water back-flowing or the mud front-flowing is avoided, and the synchronous grouting pressure of the engineering is set to be 0.3-0.4 MPa.
The method for starting and trying to drive the shield of the tunnel across the river is characterized in that the step 8) comprises the following specific steps:
8.1) monitoring pipeline settlement; stopping arranging pipeline settlement monitoring points on underground pipelines in a range of 30m in both sides of a tunnel and in a parallel vertical shaking-in direction, wherein the monitoring points are arranged at intervals of 10-15m in the parallel tunneling direction and at intervals of 8-10m in the vertical tunneling direction;
8.2) building monitoring; monitoring point measurement is arranged at proper positions in the wall corners, the upright columns or the middle of the outer walls of all the building structures within the range of 30m above the axis of the tunnel; if the important crossing area is locally encrypted;
8.3) monitoring the surface subsidence; in the range of 50m of the entrance and exit hole, arranging a settlement monitoring point every 4m along the axis in the tunnel advancing direction, arranging a settlement monitoring profile every 24m, in the range of 50m of the entrance and exit hole, in the tunnel advancing direction, arranging a settlement monitoring point every 6m along the axis, and arranging a settlement monitoring profile every 40 m;
8.4) monitoring tunnel deformation, wherein the distance between monitoring points is 6m within the range of 50m between a hole and a hole, and the distance between monitoring points in other areas is 12 m.
The method for starting and trial tunneling of the tunnel shield across the river is characterized in that in the step 3.2), if the distance between the front end faces of the negative N rings is larger than the sum of the total distance between the jack support shoes and the maximum distance between the jack strokes, the N rings must be spliced in an empty mode, and then the whole tunnel is moved backwards to the final position.
The invention has the beneficial effects that: the invention summarizes the preparation work before the shield starting in detail to form a set of complete construction scheme before starting tunneling, and can effectively ensure the stability and the safety of the shield starting tunneling.
Drawings
FIG. 1 is a process flow diagram of the present invention.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
As shown in fig. 1:
a method for starting and trying to drive a tunnel shield across a river is characterized by comprising the following steps:
1) constructing an originating base and a reaction frame;
1.1) the originating base adopts a cast-in-place reinforced concrete structure, the originating base is an arc structure and is divided into a shield tail base and a shield body base, the originating base is longitudinally parallel to the shield center line, a gap is arranged between the shield shell and the originating base and is used for welding a track, profile steel is longitudinally embedded in the originating base, the upper part of the originating base is welded with square steel, stiffening ribs are longitudinally arranged at intervals of 10cm, the height of a welding line is not less than 8mm, the square steel is used as the track for sliding the shield shell, inserting ribs are embedded when the bottom plate of an originating well is constructed, the originating base and the bottom plate are connected into a whole, and the shearing resistance of the base; four shield machine sliding tracks are longitudinally and symmetrically arranged on the shield tail, and the included angles between the four shield machine sliding tracks and the central line of the shield machine are respectively 42 degrees and 112 degrees; 2 concrete wall supporting shield starting bases are respectively arranged on the east and west sides of the starting base, two grooves are reserved longitudinally, and an operation space is provided for assembling and welding the shield; the shield body is divided into a front body and a middle body, four shield machine sliding tracks are longitudinally and symmetrically arranged, and the included angles between the four shield machine sliding tracks and the center line of the shield machine are respectively 42 degrees and 81 degrees; when the starting bases on two sides of the shield are constructed, an I-steel is pre-embedded respectively, when the shield machine tunnels, a reaction force is caused due to the fact that a cutter head cuts soil, and the shield body can be twisted, so that a steel component is welded on the shield body, the other end of the steel component props against the I-steel pre-embedded on two sides of the base, a groove is reserved between the bases on two sides transversely to provide an operation space for assembling and welding the shield, an I-steel support is erected between a longitudinal groove and the transverse groove, and two ends of the I-steel are welded with two concrete base pre-embedded steel plates; according to the design center line of the shield, the starting base at the starting tunnel portal is lifted by 20mm, the base is not lifted by extending a length from the point to the large-mileage direction, the two points are in line to control other parts to adjust the size, and the cutter head of the shield machine is theoretically lifted by 30mm after the shield machine completely contacts the continuous wall;
1.2) the reaction frame adopts steel reaction frame, including steel ring, crossbeam and perpendicular roof beam, the steel ring is by annular upper and lower apron and web assembly welding I-shaped structure, this reaction frame adopts portal frame square frame shape structure, the portal is by two crossbeams, two perpendicular roof beams and four sloping beams assembly welding door shape structure of box structure, reaction frame back is according to the condition of well centre sill, arranges a plurality of steel pipes as the support on perpendicular roof beam.
2) Sealing a tunnel door and installing a rubber curtain cloth;
2.1) the pre-buried steel ring of the working well portal of the shield machine is of a circular ring plate structure, and a sealing steel ring is arranged outside the pre-buried steel ring and comprises a sealing plate, a stiffening plate, a circular ring plate, a turning plate and two curtain cloth rubber plates, wherein the whole ring surface of the sealing steel ring is vertical to the axis of the shield machine, and the stiffening plate is arranged on the inner side of the sealing plate; the sealing steel rings are assembled on the ground to form a ring, integrally hoisted, hoisted and welded on the flange face of the tunnel door in a manual matching mode, the sealing steel rings are required to be firmly welded on the two sides in a water stopping mode, the sealing steel rings are firmly fixed on the pre-buried tunnel door rings through the inner and outer stiffening plates, and in order to ensure that the sealing rings are not damaged due to stress in the process of passing through the shield well, concrete is poured at the ring bottom in the range of 60 degrees at the upper parts of the sealing steel rings for filling;
2.2) the sealing steel ring circular plate is provided with 120 bolt holes (the bolt holes are symmetrically distributed clockwise in the circumferential direction from the position close to the central axis), the curtain cloth rubber plate is fixed between the circular plate and the sealing steel ring by bolts, the circular plate is positioned on the inner side of the sealing plate and is fixed on the portal sealing ring steel plate through double-sided welding, the circular plate is connected with the turning plate through a pin shaft, the turning plate is used as a rigid support for curtain cloth rubber sealing, the sealing ring is firstly welded on the flange surface of the pre-embedded portal steel ring before the shield starts, and the rubber curtain cloth and the circular plate are fixed on the sealing steel ring through the bolts after the portal is broken; processing a steel pipe ladder on site, symmetrically welding four lifting lugs on two sides, paving a 6-point position of a cord fabric rubber plate at the center of the ladder, placing a protruding edge face at one end of rubber downwards, then paving the ladder towards two sides by taking No. 60 and No. 61 bolt holes as boundaries, folding each side in an S shape, finally arranging No. 1 and No. 120 bolt holes at the uppermost side, and making the protruding edge face at one end of the rubber downwards so that all rubber protrusions are arranged at the inner edge of the annular cord fabric rubber plate; after the curtain cloth rubber plates have installation conditions, two hanging strips with the same length and four buckles are fastened on the four processed lifting lugs, the curtain cloth is lifted by a crane and placed on the highest layer of a scaffold, a first curtain cloth rubber plate is installed firstly, installation is started from an upper bolt hole, and bolts are installed towards the inside of a foundation pit when the first curtain cloth rubber plate and the second curtain cloth rubber plate are installed, so that the bolts are conveniently fastened; firstly, inserting a steel chisel from a No. 1 bolt hole of a sealing steel ring, installing a cord fabric rubber plate on the steel chisel corresponding to the bolt hole, then installing a No. 5 bolt hole, installing No. 1 and No. 5 bolt holes on the steel chisel, then installing No. 2, 3 and No. 4 bolt holes by bolts, then drawing out the steel chisel from No. 1 and No. 5 bolt holes, installing bolts, wherein every 5 bolt holes form a group, the central line of the steel ring is taken as a standard, the left and right sides are simultaneously installed, when the first cord fabric rubber plate is installed, a hole is opened again and the position nearby the hole, a folding turning plate is not installed temporarily, and after the whole installation is finished, the installation of the position is carried: turning plates at other parts are simultaneously installed in place along with the cord fabric rubber plates, and rubber gaskets and steel gasket rubber gaskets are additionally arranged on the two sides of each turning plate and are tightly attached to the turning plates; in the installation process of the curtain cloth, the left side and the right side are required to be installed at the same time, one side is installed too fast, the other side is difficult to install, and the whole installation period is prolonged; after the installation of curtain cloth rubber slab, for preventing that the future entrance to a cave breaks the waste residue and drops and influence sealed effect on the rubber slab, lay old bamboo offset plate in the sealing ring bottom and protect curtain cloth rubber slab, arrange simultaneously that the special messenger carries out the secondary fastening to the bolt because rubber curtain cloth size is great, the curtain cloth of bottom will be laid to the entrance to a cave direction after the installation of rubber curtain cloth is accomplished, it has certain influence to build the storehouse to muddy water, for avoiding the emergence of this kind of condition, respectively at twice curtain cloth inlayer, installation one deck spring steel sheet is used for propping up the curtain cloth and is located upright state.
3) Assembling a shield machine;
3.1) determining an originating axis before assembling the shield tunneling machine, wherein the centerline vertical section of a tunnel designed in an originating section is positioned above a 45% downhill, and in order to reduce the influence of head collapse of the shield tunneling machine, a certain gradient is adjusted upwards during originating of the shield tunneling machine and the shield tunneling machine is originated in a 44% downhill;
3.2) N negative rings are arranged between the reaction frame and the positive ring, each ring of pipe piece comprises 5 standard blocks, 2 adjacent blocks and 1 top sealing block, the negative ring adopts an A-shaped concrete pipe piece, after the shield machine is debugged and reaches a starting position, the jack supporting shoes are completely retracted to the reaction frame, the assembling of the negative N rings is started, and the front end surfaces of the negative N rings are used as reference surfaces for assembling the negative N-1 rings; the negative N-2 ring can be easily formed into a ring on the reference, and the circumferential gap is uniform after the ring is formed, so that no horn mouth is required; after the negative N-1 ring is adjusted in position, the negative N-1 ring is connected with a counter-force frame in a steel pipe welding mode, a steel plate is embedded in the segment during manufacturing, and the counter-force frame is a steel counter-force frame and is directly welded with the steel pipe; the shield machine moves forwards to assemble the negative N-2 ring, the thrust of the shield machine is slowly increased from 0, the shield machine is kept to move forwards slowly, when the jack stroke reaches the design distance, the shield machine stops moving forwards, and the negative N-2 ring duct pieces are assembled; when the shield machine moves forwards, the attitude condition and the connection condition of the assembled duct pieces are observed, if the duct pieces are unstable, the forward movement is stopped immediately, anti-twisting blocks for preventing the shield machine from twisting are arranged on two sides of the shield machine, the anti-twisting blocks are cut off in time after dragging out of an originating base, connecting points are cut off and polished completely, and the anti-twisting blocks are prevented from damaging a tunnel portal;
3.3) after the negative N-2 rings are assembled, the shield machine starts to advance, the negative N-3 rings are assembled after a specified stroke is reached, each segment is connected block by block and ring by ring, and the negative N-4 rings, the negative N-5 rings and the negative N-6 rings are assembled in the same way; if the distance of the front end face of the negative N ring is larger than the sum of the distance between the jack shoe and the maximum distance of the jack stroke, the negative N ring needs to be spliced in an empty mode, then the whole body moves backwards to the final position, and due to the fact that the negative N ring is spliced in an empty mode completely, the duct piece is in place in the shield tail, especially the first block is fixed by means of an external cushion block and welding completely, and therefore steel plates are embedded in the end faces of two sides of the negative N ring and are convenient to weld and fix;
3.4) when the duct piece is separated from the shield tail, welding of a steel plate embedded outside the duct piece needs to be carried out in time, and the rigidity of a duct piece ring is ensured; after the duct piece is separated from the shield tail, the duct piece needs to be supported in time, and the support is divided into three parts: 1) inserting a steel wedge between the duct piece and the square steel of the guide rail of the shield tunneling machine to ensure that the duct piece does not drop; the steel wedges are arranged at the joint of the segment and in the center of the segment; 2) welding an I-shaped steel support below the side of the pipe piece; 3) and welding steel supports on two sides of the shield body in the horizontal direction, and driving wood wedges between the steel supports and the duct piece to compress the duct piece after the duct piece is separated from the shield tail.
4) And (3) tunnel portal breaking construction:
4.1) underground continuous walls mainly affect shield starting in the tunnel portal range of shield starting, underground continuous wall chiseling construction in the tunnel portal range is arranged in the assembling and debugging period of a shield machine, the underground continuous wall chiseling construction can be carried out in the condition that the water level of end soil bodies is reduced to 2m below the arch bottom according to design requirements, the actual situation of the shield machine assembling field is considered, in order to reduce the influence of tunnel portal chiseling on shield assembling as much as possible and to start out a tunnel as soon as possible when the shield assembling is finished, the continuous wall walls in the tunnel portal range are chiselled out in three times; the first chiseling is carried out in the assembling process of the shield tunneling machine, concrete is chiseled, inner-layer steel bars of the underground continuous wall are stripped, concrete slag is arranged to be cleaned after chiseling is finished, and a temperature detecting hole is drilled in a tunnel door to detect whether temperature is frozen or not; and the second chiseling is arranged when the negative N ring pipe pieces of the shield tunneling machine are assembled, the concrete chiseling and cleaning work is completed two days before the shield is started to move forwards, and the concrete is chiseled: the third chiseling is completed within two days, when the shield machine carries out N-1 ring duct piece assembling, the residual concrete and the outside reinforcing steel bars of the underground continuous wall are chiseled, and chiseling concrete slag in the sealing ring is cleaned up, so that all chiseling and cleaning work is guaranteed to be completed before the shield machine starts;
4.2) chiseling concrete to set up a steel pipe support, wherein the support is made of seamless steel pipes, three rows are longitudinally set up, the steel pipes are connected through fasteners, a dense mesh protective net is pulled on the outer side of the support, a ballast cleaning operation platform is set up between the front of the starting base and the tunnel portal sealing steel ring, and chiseling concrete ballast is hoisted out of the foundation pit through a crane by using a hoisting bucket.
5) Starting a warehouse;
5.1) injecting plugging materials between the rubber curtain cloth in advance before building the bin;
5.2) the storehouse building is carried out in three steps:
the first step is as follows: the slurry prepared in the slurry field is injected into the excavation surface, and the slurry liquid level of the excavation bin is kept above the central line for 3 m;
the second step is that: slowly pressurizing the air pressure bin, wherein the pressurizing is not higher than 0.1bar each time, opening a grouting hole in a sealing steel ring of a tunnel door to exhaust air, and simultaneously paying attention to the display of liquid levels in the front bin and the rear bin in the shield tunneling machine; when the slurry starts to be sprayed out from the slurry injection hole at the top, the valve of the slurry injection hole is closed; checking the liquid level in the bubble bin, if the liquid level is between-0.5 m and +0.5m at the central line, no adjustment is needed, if the liquid level is out of the range, starting a slurry circulating system, finely adjusting the liquid level to the range, and displaying the notch pressure as 0;
the third step: increasing the air pressure in the bubble chamber to 2.2bar, maintaining the pressure of 2.2bar for 15 minutes, observing whether the abnormality such as leakage exists or not, and if so, taking a leakage stopping measure; if not, slowly reducing the air pressure until the incision pressure is slowly adjusted to 0 bar;
and (3) observing the sealing condition of the tunnel portal, plugging in time, if small-scale leakage occurs, adopting cotton cloth, cotton yarn, sand bags, polyurethane and shield tail sealing grease materials to plug the front side, properly increasing the viscosity of the slurry and the high-molecular plugging slurry, if large leakage occurs, immediately stopping filling the slurry, finding out the reason, continuously filling the slurry, and during the slurry warehousing process, according to the water leakage condition of the rubber curtain cloth, passing through a grease filling hole on the sealing ring near a leakage point, and filling the slurry to plug the gap between the rubber of the curtain cloth and the shield body between the first curtain cloth and the second curtain cloth for sealing.
6) Secondary sealing of the tunnel portal;
6.1) the shield tunneling machine tunnels forwards, after the last steel brush of the shield tail completely enters the sealing steel ring, a zero-ring segment is installed at the sealing steel ring, and a pre-buried steel plate is installed on the rear end face of the outer side face of the zero-ring segment; after the shield tail of the shield tunneling machine completely passes through the sealing plate, the edge of the circular ring plate is welded with the embedded steel plate on the outer side of the zero-ring segment by using the sealing steel plate to form secondary sealing, so that the slurry pressure balance of the shield tunneling machine is ensured, the sealing effect is improved, the smooth implementation of synchronous grouting of the shield tunneling machine is ensured, and the welding seam of the secondary sealing is required to be continuous and not leak.
7) Starting trial excavation construction and synchronously grouting;
7.1) starting trial excavation is divided into two sections: a stirring pile reinforcing section of 0-15m and an undisturbed soil section of 15-200 m;
7.2) in order to reduce and prevent settlement, in the shield tunneling process, sufficient serous fluid material is synchronously injected behind the lining segment which is separated from the shield tail as soon as possible to fill the annular building gap of the shield tail; synchronous grouting is simultaneously injected at 6 paths at the tail of the shield by adopting 3 double-piston grouting pumps of a shield machine, so that an annular gap between a duct piece and the stratum is filled in time, the stratum deformation is controlled, the duct piece structure is stabilized, the shield tunneling direction is controlled, and the self-waterproof capability of the tunnel structure is enhanced; during synchronous grouting, the pressure of grout in the stratum is required to be larger than the sum of the static water pressure and the soil pressure at the point, the grout is filled as much as possible and is not easy to split, and the grouting pressure is too high, so that the tunnel is disturbed by the grout to cause later-stage stratum settlement and tunnel self settlement, and grout leakage is easy to cause; and the grouting pressure is too low, the slurry filling speed is too low, the filling is insufficient, the deformation of the earth surface is increased, the synchronous grouting pressure is basically balanced with the muddy water pressure of the soil bin, the muddy water back-flowing or the mud front-flowing is avoided, and the synchronous grouting pressure of the engineering is set to be 0.3-0.4 MPa.
8) Starting trial excavation monitoring;
8.1) monitoring pipeline settlement; stopping arranging pipeline settlement monitoring points on underground pipelines in a range of 30m in both sides of a tunnel and in a parallel vertical shaking-in direction, wherein the monitoring points are arranged at intervals of 10-15m in the parallel tunneling direction and at intervals of 8-10m in the vertical tunneling direction;
8.2) building monitoring; monitoring point measurement is arranged at proper positions in the wall corners, the upright columns or the middle of the outer walls of all the building structures within the range of 30m above the axis of the tunnel; if the important crossing area is locally encrypted;
8.3) monitoring the surface subsidence; in the range of 50m of the entrance and exit hole, arranging a settlement monitoring point every 4m along the axis in the tunnel advancing direction, arranging a settlement monitoring profile every 24m, in the range of 50m of the entrance and exit hole, in the tunnel advancing direction, arranging a settlement monitoring point every 6m along the axis, and arranging a settlement monitoring profile every 40 m;
8.4) monitoring tunnel deformation, wherein the distance between monitoring points is 6m within the range of 50m between a hole and a hole, and the distance between monitoring points in other areas is 12 m.
Claims (10)
1. A method for starting and trying to drive a tunnel shield across a river is characterized by comprising the following steps:
1) constructing an originating base and a reaction frame;
2) sealing a tunnel door and installing a rubber curtain cloth;
3) assembling a shield machine;
4) and (3) tunnel portal breaking construction:
5) starting a warehouse;
6) secondary sealing of the tunnel portal;
7) starting trial excavation construction and synchronously grouting;
8) initial trial excavation monitoring.
2. The method for starting and trying to tunnel through a river tunnel shield according to claim 1, wherein the specific steps of the step 1) are as follows:
1.1) the originating base adopts a cast-in-place reinforced concrete structure, the originating base is an arc structure and is divided into a shield tail base and a shield body base, the originating base is longitudinally parallel to the shield center line, a gap is arranged between the shield shell and the originating base and is used for welding a track, profile steel is longitudinally embedded in the originating base, the upper part of the originating base is welded with square steel, stiffening ribs are longitudinally arranged at intervals of 10cm, the height of a welding line is not less than 8mm, the square steel is used as the track for sliding the shield shell, inserting ribs are embedded when the bottom plate of an originating well is constructed, the originating base and the bottom plate are connected into a whole, and the shearing resistance of the base; four shield machine sliding tracks are longitudinally and symmetrically arranged on the shield tail, 2 concrete wall supporting shield starting bases are respectively arranged on the east and west sides of the starting base, two grooves are longitudinally reserved, and an operation space is provided for shield assembly welding; the shield body is divided into a front body and a middle body, and four shield machine sliding tracks are longitudinally and symmetrically arranged; when the starting bases on two sides of the shield are constructed, an I-steel is pre-embedded respectively, when the shield machine tunnels, a reaction force is caused due to the fact that a cutter head cuts soil, and the shield body can be twisted, so that a steel component is welded on the shield body, the other end of the steel component props against the I-steel pre-embedded on two sides of the base, a groove is reserved between the bases on two sides transversely to provide an operation space for assembling and welding the shield, an I-steel support is erected between a longitudinal groove and the transverse groove, and two ends of the I-steel are welded with two concrete base pre-embedded steel plates; according to the design center line of the shield, the starting base at the starting tunnel portal is lifted by 20mm, the base is not lifted by extending a length from the point to the large-mileage direction, the two points are in line to control other parts to adjust the size, and the cutter head of the shield machine is theoretically lifted by 30mm after the shield machine completely contacts the continuous wall;
1.2) the reaction frame adopts steel reaction frame, including steel ring, crossbeam and perpendicular roof beam, the steel ring is by annular upper and lower apron and web assembly welding I-shaped structure, this reaction frame adopts portal frame square frame shape structure, the portal is by two crossbeams, two perpendicular roof beams and four sloping beams assembly welding door shape structure of box structure, reaction frame back is according to the condition of well centre sill, arranges a plurality of steel pipes as the support on perpendicular roof beam.
3. The method for starting and trying to tunnel through a river tunnel shield according to claim 1, wherein the step 2) comprises the following specific steps:
2.1) the pre-buried steel ring of the working well portal of the shield machine is of a circular ring plate structure, and a sealing steel ring is arranged outside the pre-buried steel ring and comprises a sealing plate, a stiffening plate, a circular ring plate, a turning plate and two curtain cloth rubber plates, wherein the whole ring surface of the sealing steel ring is vertical to the axis of the shield machine, and the stiffening plate is arranged on the inner side of the sealing plate; the sealing steel rings are assembled on the ground to form a ring, integrally hoisted, hoisted and welded on the flange face of the tunnel door in a manual matching mode, the sealing steel rings are required to be firmly welded on the two sides in a water stopping mode, the sealing steel rings are firmly fixed on the pre-buried tunnel door rings through the inner and outer stiffening plates, and in order to ensure that the sealing rings are not damaged due to stress in the process of passing through the shield well, concrete is poured at the ring bottom in the range of 60 degrees at the upper parts of the sealing steel rings for filling;
2.2) the sealing steel ring circular plate is provided with 120 bolt holes, the cord fabric rubber plate is fixed between the circular plate and the sealing steel ring by bolts, the circular plate is positioned at the inner side of the sealing plate and fixed on the portal sealing ring steel plate by double-sided welding, the circular plate is connected with the turning plate by a pin shaft, the turning plate is used as a rigid support for cord fabric rubber sealing, the sealing ring is welded on the flange surface of the pre-embedded portal steel ring before the shield starts, and the rubber cord fabric and the circular plate are fixed on the sealing steel ring by the bolts after the portal is broken; processing a steel pipe ladder on site, symmetrically welding four lifting lugs on two sides, paving a 6-point position of a cord fabric rubber plate at the center of the ladder, placing a protruding edge face at one end of rubber downwards, then paving the ladder towards two sides by taking No. 60 and No. 61 bolt holes as boundaries, folding each side in an S shape, finally arranging No. 1 and No. 120 bolt holes at the uppermost side, and making the protruding edge face at one end of the rubber downwards so that all rubber protrusions are arranged at the inner edge of the annular cord fabric rubber plate; after the curtain cloth rubber plates have installation conditions, two hanging strips with the same length and four buckles are fastened on the four processed lifting lugs, the curtain cloth is lifted by a crane and placed on the highest layer of a scaffold, a first curtain cloth rubber plate is installed firstly, installation is started from an upper bolt hole, and bolts are installed towards the inside of a foundation pit when the first curtain cloth rubber plate and the second curtain cloth rubber plate are installed, so that the bolts are conveniently fastened; firstly, inserting a steel chisel from a No. 1 bolt hole of a sealing steel ring, installing a cord fabric rubber plate on the steel chisel corresponding to the bolt hole, then installing a No. 5 bolt hole, installing No. 1 and No. 5 bolt holes on the steel chisel, then installing No. 2, 3 and No. 4 bolt holes by bolts, then drawing out the steel chisel from No. 1 and No. 5 bolt holes, installing bolts, wherein every 5 bolt holes form a group, the central line of the steel ring is taken as a standard, the left and right sides are simultaneously installed, when the first cord fabric rubber plate is installed, a hole is opened again and the position nearby the hole, a folding turning plate is not installed temporarily, and after the whole installation is finished, the installation of the position is carried: turning plates at other parts are simultaneously installed in place along with the cord fabric rubber plates, and rubber gaskets and steel gasket rubber gaskets are additionally arranged on the two sides of each turning plate and are tightly attached to the turning plates; in the installation process of the curtain cloth, the left side and the right side are required to be installed at the same time, one side is installed too fast, the other side is difficult to install, and the whole installation period is prolonged; after the installation of curtain cloth rubber slab, for preventing that the future entrance to a cave breaks the waste residue and drops and influence sealed effect on the rubber slab, lay old bamboo offset plate in the sealing ring bottom and protect curtain cloth rubber slab, arrange simultaneously that the special messenger carries out the secondary fastening to the bolt because rubber curtain cloth size is great, the curtain cloth of bottom will be laid to the entrance to a cave direction after the installation of rubber curtain cloth is accomplished, it has certain influence to build the storehouse to muddy water, for avoiding the emergence of this kind of condition, respectively at twice curtain cloth inlayer, installation one deck spring steel sheet is used for propping up the curtain cloth and is located upright state.
4. The method for starting and trying to tunnel through a river tunnel shield according to claim 1, wherein the specific steps of the step 3) are as follows:
3.1) determining an originating axis before assembling the shield tunneling machine, wherein the centerline vertical section of a tunnel designed in an originating section is positioned above a 45% downhill, and in order to reduce the influence of head collapse of the shield tunneling machine, a certain gradient is adjusted upwards during originating of the shield tunneling machine and the shield tunneling machine is originated in a 44% downhill;
3.2) N negative rings are arranged between the reaction frame and the positive ring, each ring of pipe piece comprises 5 standard blocks, 2 adjacent blocks and 1 top sealing block, the negative ring adopts an A-shaped concrete pipe piece, after the shield machine is debugged and reaches a starting position, the jack supporting shoes are completely retracted to the reaction frame, the assembling of the negative N rings is started, and the front end surfaces of the negative N rings are used as reference surfaces for assembling the negative N-1 rings; the negative N-2 ring can be easily formed into a ring on the reference, and the circumferential gap is uniform after the ring is formed, so that no horn mouth is required; after the negative N-1 ring is adjusted in position, the negative N-1 ring is connected with a counter-force frame in a steel pipe welding mode, a steel plate is embedded in the segment during manufacturing, and the counter-force frame is a steel counter-force frame and is directly welded with the steel pipe; the shield machine moves forwards to assemble the negative N-2 ring, the thrust of the shield machine is slowly increased from 0, the shield machine is kept to move forwards slowly, the shield machine stops moving forwards when the shortest jack stroke reaches the design distance, and the negative N-2 ring duct pieces are assembled; when the shield machine moves forwards, the attitude condition and the connection condition of the assembled duct pieces are observed, if the duct pieces are unstable, the forward movement is stopped immediately, anti-twisting blocks for preventing the shield machine from twisting are arranged on two sides of the shield machine, the anti-twisting blocks are cut off in time after dragging out of an originating base, connecting points are cut off and polished completely, and the anti-twisting blocks are prevented from damaging a tunnel portal;
3.3) after the negative N-2 rings are assembled, the shield machine starts to advance, the negative N-3 rings are assembled after a specified stroke is reached, each segment is connected block by block and ring by ring, and the negative N-4 rings, the negative N-5 rings and the negative N-6 rings are assembled in the same way;
3.4) when the duct piece is separated from the shield tail, welding of a steel plate embedded outside the duct piece needs to be carried out in time, and the rigidity of a duct piece ring is ensured; after the duct piece is separated from the shield tail, the duct piece needs to be supported in time, and the support is divided into three parts: 1) inserting a steel wedge between the duct piece and the square steel of the guide rail of the shield tunneling machine to ensure that the duct piece does not drop; the steel wedges are arranged at the joint of the segment and in the center of the segment; 2) welding an I-shaped steel support below the side of the pipe piece; 3) and welding steel supports on two sides of the shield body in the horizontal direction, and driving wood wedges between the steel supports and the duct piece to compress the duct piece after the duct piece is separated from the shield tail.
5. The method for starting and trying to tunnel through a river tunnel shield according to claim 1, wherein the step 4) comprises the following specific steps:
4.1) underground continuous walls mainly affect shield starting in the tunnel portal range of shield starting, underground continuous wall chiseling construction in the tunnel portal range is arranged in the assembling and debugging period of a shield machine, the underground continuous wall chiseling construction can be carried out in the condition that the water level of end soil bodies is reduced to 2m below the arch bottom according to design requirements, the actual situation of the shield machine assembling field is considered, in order to reduce the influence of tunnel portal chiseling on shield assembling as much as possible and to start out a tunnel as soon as possible when the shield assembling is finished, the continuous wall walls in the tunnel portal range are chiselled out in three times; the first chiseling is carried out in the assembling process of the shield tunneling machine, concrete is chiseled, inner-layer steel bars of the underground continuous wall are stripped, concrete slag is arranged to be cleaned after chiseling is finished, and a temperature detecting hole is drilled in a tunnel door to detect whether temperature is frozen or not; and the second chiseling is arranged when the negative N ring pipe pieces of the shield tunneling machine are assembled, the concrete chiseling and cleaning work is completed two days before the shield is started to move forwards, and the concrete is chiseled: the third chiseling is completed within two days, when the shield machine carries out N-1 ring duct piece assembling, the residual concrete and the outside reinforcing steel bars of the underground continuous wall are chiseled, and chiseling concrete slag in the sealing ring is cleaned up, so that all chiseling and cleaning work is guaranteed to be completed before the shield machine starts;
4.2) chiseling concrete to set up a steel pipe support, wherein the support is made of seamless steel pipes, three rows are longitudinally set up, the steel pipes are connected through fasteners, a dense mesh protective net is pulled on the outer side of the support, a ballast cleaning operation platform is set up between the front of the starting base and the tunnel portal sealing steel ring, and chiseling concrete ballast is hoisted out of the foundation pit through a crane by using a hoisting bucket.
6. The method for starting and trying to tunnel through a river tunnel shield according to claim 1, wherein the step 5) comprises the following specific steps:
5.1) injecting plugging materials between the rubber curtain cloth in advance before building the bin;
5.2) the storehouse building is carried out in three steps:
the first step is as follows: the slurry prepared in the slurry field is injected into the excavation surface, and the slurry liquid level of the excavation bin is kept above the central line for 3 m;
the second step is that: slowly pressurizing the air pressure bin, wherein the pressurizing is not higher than 0.1bar each time, opening a grouting hole in a sealing steel ring of a tunnel door to exhaust air, and simultaneously paying attention to the display of liquid levels in the front bin and the rear bin in the shield tunneling machine; when the slurry starts to be sprayed out from the slurry injection hole at the top, the valve of the slurry injection hole is closed; checking the liquid level in the bubble bin, if the liquid level is between-0.5 m and +0.5m at the central line, no adjustment is needed, if the liquid level is out of the range, starting a slurry circulating system, finely adjusting the liquid level to the range, and displaying the notch pressure as 0;
the third step: increasing the air pressure in the bubble chamber to 2.2bar, maintaining the pressure of 2.2bar for 15 minutes, observing whether the abnormality such as leakage exists or not, and if so, taking a leakage stopping measure; if not, slowly reducing the air pressure until the incision pressure is slowly adjusted to 0 bar;
and (3) observing the sealing condition of the tunnel portal, plugging in time, if small-scale leakage occurs, adopting cotton cloth, cotton yarn, sand bags, polyurethane and shield tail sealing grease materials to plug the front side, properly increasing the viscosity of the slurry and the high-molecular plugging slurry, if large leakage occurs, immediately stopping filling the slurry, finding out the reason, continuously filling the slurry, and during the slurry warehousing process, according to the water leakage condition of the rubber curtain cloth, passing through a grease filling hole on the sealing ring near a leakage point, and filling the slurry to plug the gap between the rubber of the curtain cloth and the shield body between the first curtain cloth and the second curtain cloth for sealing.
7. The method for starting and trying to tunnel through a river tunnel shield according to claim 1, wherein the specific steps of the step 6) are as follows:
6.1) the shield tunneling machine tunnels forwards, after the last steel brush of the shield tail completely enters the sealing steel ring, a zero-ring segment is installed at the sealing steel ring, and a pre-buried steel plate is installed on the rear end face of the outer side face of the zero-ring segment; after the shield tail of the shield tunneling machine completely passes through the sealing plate, the edge of the circular ring plate is welded with the embedded steel plate on the outer side of the zero-ring segment by using the sealing steel plate to form secondary sealing, so that the slurry pressure balance of the shield tunneling machine is ensured, the sealing effect is improved, the smooth implementation of synchronous grouting of the shield tunneling machine is ensured, and the welding seam of the secondary sealing is required to be continuous and not leak.
8. The method for starting and trying to tunnel through a river tunnel shield according to claim 1, wherein the step 7) comprises the following specific steps:
7.1) starting trial excavation is divided into two sections: a stirring pile reinforcing section of 0-15m and an undisturbed soil section of 15-200 m;
7.2) in order to reduce and prevent settlement, in the shield tunneling process, sufficient serous fluid material is synchronously injected behind the lining segment which is separated from the shield tail as soon as possible to fill the annular building gap of the shield tail; synchronous grouting is simultaneously injected at 6 paths at the tail of the shield by adopting 3 double-piston grouting pumps of a shield machine, so that an annular gap between a duct piece and the stratum is filled in time, the stratum deformation is controlled, the duct piece structure is stabilized, the shield tunneling direction is controlled, and the self-waterproof capability of the tunnel structure is enhanced; during synchronous grouting, the pressure of grout in the stratum is required to be larger than the sum of the static water pressure and the soil pressure at the point, the grout is filled as much as possible and is not easy to split, and the grouting pressure is too high, so that the tunnel is disturbed by the grout to cause later-stage stratum settlement and tunnel self settlement, and grout leakage is easy to cause; and the grouting pressure is too low, the slurry filling speed is too low, the filling is insufficient, the deformation of the earth surface is increased, the synchronous grouting pressure is basically balanced with the muddy water pressure of the soil bin, the muddy water back-flowing or the mud front-flowing is avoided, and the synchronous grouting pressure of the engineering is set to be 0.3-0.4 MPa.
9. The method for starting and trying to tunnel through a river tunnel shield according to claim 1, wherein the step 8) comprises the following specific steps:
8.1) monitoring pipeline settlement; stopping arranging pipeline settlement monitoring points on underground pipelines in a range of 30m in both sides of a tunnel and in a parallel vertical shaking-in direction, wherein the monitoring points are arranged at intervals of 10-15m in the parallel tunneling direction and at intervals of 8-10m in the vertical tunneling direction;
8.2) building monitoring; monitoring point measurement is arranged at proper positions in the wall corners, the upright columns or the middle of the outer walls of all the building structures within the range of 30m above the axis of the tunnel; if the important crossing area is locally encrypted;
8.3) monitoring the surface subsidence; in the range of 50m of the entrance and exit hole, arranging a settlement monitoring point every 4m along the axis in the tunnel advancing direction, arranging a settlement monitoring profile every 24m, in the range of 50m of the entrance and exit hole, in the tunnel advancing direction, arranging a settlement monitoring point every 6m along the axis, and arranging a settlement monitoring profile every 40 m;
8.4) monitoring tunnel deformation, wherein the distance between monitoring points is 6m within the range of 50m between a hole and a hole, and the distance between monitoring points in other areas is 12 m.
10. The method for starting and trying to drive the shield of the tunnel across the river as claimed in claim 4, wherein in step 3.2), if the distance between the front end face of the negative N ring is greater than the sum of the distance between the jack shoe and the maximum distance of the jack stroke, the N ring must be spliced in an empty mode, and then the whole body is moved backwards to the final position.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112855209A (en) * | 2021-03-27 | 2021-05-28 | 南通铁建建设构件有限公司 | High-strength anti-seepage shield segment for river-crossing tunnel |
| CN113006808A (en) * | 2021-04-23 | 2021-06-22 | 中铁六局集团有限公司交通工程分公司 | Construction method for viscous geological shield initial section to penetrate shallow soil-covered river channel downwards |
| CN113047853A (en) * | 2021-05-10 | 2021-06-29 | 中铁九局集团第六工程有限公司 | Shield starting construction method for water-rich soft soil geological area |
| CN113107501A (en) * | 2021-04-13 | 2021-07-13 | 中铁六局集团有限公司交通工程分公司 | Initial tunneling construction method for portal extension steel ring |
| CN114370286A (en) * | 2021-12-08 | 2022-04-19 | 上海市基础工程集团有限公司 | Shield tunneling machine safe hole entering method for open caisson structure |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104594911A (en) * | 2015-02-16 | 2015-05-06 | 中建交通建设集团有限公司 | Construction method of close-range down-traversing operation lines at initial stages or receiving stages of shield |
| CN106761785A (en) * | 2016-12-05 | 2017-05-31 | 中交第三航务工程局有限公司 | A kind of subway tunnel shield originates construction technology |
| CN108678756A (en) * | 2018-04-27 | 2018-10-19 | 青岛新华友建工集团股份有限公司 | It closes on rivers highly permeable stratum major diameter slurry shield and originates construction safely |
| CN108868789A (en) * | 2018-07-05 | 2018-11-23 | 成都天佑智隧科技有限公司 | A kind of stratum active support and change method suitable for shield construction tunnel |
| CN111350509A (en) * | 2020-01-21 | 2020-06-30 | 中铁二十二局集团轨道工程有限公司 | Muck improvement and grouting method for sandy gravel stratum tunnel shield construction |
-
2020
- 2020-10-20 CN CN202011123760.3A patent/CN112160759A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104594911A (en) * | 2015-02-16 | 2015-05-06 | 中建交通建设集团有限公司 | Construction method of close-range down-traversing operation lines at initial stages or receiving stages of shield |
| CN106761785A (en) * | 2016-12-05 | 2017-05-31 | 中交第三航务工程局有限公司 | A kind of subway tunnel shield originates construction technology |
| CN108678756A (en) * | 2018-04-27 | 2018-10-19 | 青岛新华友建工集团股份有限公司 | It closes on rivers highly permeable stratum major diameter slurry shield and originates construction safely |
| CN108868789A (en) * | 2018-07-05 | 2018-11-23 | 成都天佑智隧科技有限公司 | A kind of stratum active support and change method suitable for shield construction tunnel |
| CN111350509A (en) * | 2020-01-21 | 2020-06-30 | 中铁二十二局集团轨道工程有限公司 | Muck improvement and grouting method for sandy gravel stratum tunnel shield construction |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112855209A (en) * | 2021-03-27 | 2021-05-28 | 南通铁建建设构件有限公司 | High-strength anti-seepage shield segment for river-crossing tunnel |
| CN113107501A (en) * | 2021-04-13 | 2021-07-13 | 中铁六局集团有限公司交通工程分公司 | Initial tunneling construction method for portal extension steel ring |
| CN113006808A (en) * | 2021-04-23 | 2021-06-22 | 中铁六局集团有限公司交通工程分公司 | Construction method for viscous geological shield initial section to penetrate shallow soil-covered river channel downwards |
| CN113047853A (en) * | 2021-05-10 | 2021-06-29 | 中铁九局集团第六工程有限公司 | Shield starting construction method for water-rich soft soil geological area |
| CN113047853B (en) * | 2021-05-10 | 2024-03-19 | 中铁九局集团第一建设有限公司 | Shield originating construction method for water-rich soft soil geological region |
| CN114370286A (en) * | 2021-12-08 | 2022-04-19 | 上海市基础工程集团有限公司 | Shield tunneling machine safe hole entering method for open caisson structure |
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