CN114542092A - Shield receiving construction method without bottom plate structure - Google Patents
Shield receiving construction method without bottom plate structure Download PDFInfo
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- CN114542092A CN114542092A CN202210071837.XA CN202210071837A CN114542092A CN 114542092 A CN114542092 A CN 114542092A CN 202210071837 A CN202210071837 A CN 202210071837A CN 114542092 A CN114542092 A CN 114542092A
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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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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/20—Hydro energy
Abstract
The invention discloses a shield receiving construction method without a bottom plate structure, which comprises four steps of preparation before receiving, shield arrival construction, shield machine translation construction and shield machine hoisting. The invention provides a construction process and construction parameters for receiving, translating and hoisting a shield machine in a body-free structure, verifies the effectiveness and feasibility of the construction scheme through actual monitoring data on site, successfully solves construction difficulties such as large construction organization difficulty, short construction period, high cost and the like in the shield receiving process, saves construction cost, is beneficial to control of construction cost, and provides experience for similar projects.
Description
Technical Field
The invention relates to the technical field of shield tunnel construction engineering, in particular to a shield receiving construction method without a bottom plate structure.
Background
With the rapid development of urban rail transit in China, shield construction faces a series of problems of narrow construction site, short construction period, complex geology, limited excavation and the like, and the construction period is seriously delayed to a great extent. In order to complete the shield receiving task on time, construction enterprises generally need to invest a large amount of manpower, material resources and financial resources to deal with the construction period, so that the construction period of the node issued by an owner is guaranteed. How to safely and smoothly complete the shield receiving task becomes a construction problem which has to be considered by many projects.
The shield receiving technology generally adopted in China at present is carried out on the premise that the construction of structures such as a bottom plate, a side wall, an inner column, a middle plate and a top plate of a main structure of a receiving well is completed, the construction of the main structure of the receiving well usually needs 6-18 months, the tunneling speed of the shield machine is not reduced in order to wait for the completion of the construction of the main structure, and the lease or the use cost of the shield machine is inevitably increased due to the reduction of the use efficiency.
Disclosure of Invention
The invention aims to solve the defects and provides a shield receiving construction method without a bottom plate structure.
In order to solve the technical problems, the invention adopts the following technical scheme: the shield receiving construction method of the bottomless plate structure comprises the following steps:
s1, preparation before reception
(1) Mounting a receiving bracket: the receiving bracket is in a steel structure form and is used as a base for the shield tunneling machine to reach a receiving well, when the receiving bracket is installed, the spatial position of the receiving bracket is reversely deduced according to the position and the elevation of a central plane of a tunnel portal and the elevation of a bottom plate for placing the receiving bracket, the receiving bracket is placed on a pre-paved steel plate, and the steel plate is additionally arranged at the bottom of the receiving bracket as required to adjust the position of the receiving bracket so as to ensure that the shield tunneling machine just falls on the receiving bracket after receiving;
(2) sealing the tunnel door: the hole door sealing device at the hole outlet end is directly arranged on an underground continuous wall of the enclosure structure and comprises a rubber curtain cloth, a turning plate and an expansion bolt;
s2, shield arrival construction:
(1) after the assembled duct piece enters 8 rings before receiving, the slurry is changed into quick-hardening slurry, and muddy water in the stratum is blocked outside a receiving end so as to prevent water from gushing at the tunnel portal;
(2) after the last ring pipe piece of the pipe piece is assembled, injecting double-liquid slurry to block through a secondary grouting hole of the pipe piece;
(3) when the shield shell of the shield front body is pushed out of the tunnel portal, the flap pressing plate is adjusted through a steel wire rope on the turning plate clamping ring to enable the flap pressing plate to tightly press the cord fabric rubber plate; when the duct piece is dragged out of the shield tail, the steel wire rope is tensioned again, so that the pressing plate can compress the rubber cord fabric;
(4) fastening and retightening the bolts of the rear 20-ring segment; tensioning the rear 20 ring pipe pieces longitudinally along the tunnel by using flat iron, and connecting the rings to enable the rear 20 ring pipe pieces to be connected into a whole;
(5) after all the shield tunneling machines drive onto the receiving brackets, grouting the range of the tunnel portal, and plugging to form a ring;
s3, shield constructs quick-witted translation construction:
(1) separating the shield machine from the rear matched equipment:
1) adjusting the position of the assembling machine to enable the assembling machine to move forwards to the maximum stroke;
2) moving the shield tunneling machine forward until the shield tunneling machine is completely positioned on the receiving bracket;
3) disconnecting the connection of water, electricity and hydraulic pipelines and a steel structure between the shield tunneling machine and the trolley;
4) welding a limiting steel plate for preventing the shield machine from rotating on the shield machine shell, and simultaneously welding a steel plate for preventing the shield machine from moving in a hinged mode;
(2) the shield tunneling machine translation construction process comprises the following steps:
1) translating the shield tunneling machine and the receiving bracket from the receiving position by using a jack to provide counter force;
2) adding a cushion counter-force profile steel behind the jack to continuously provide counter-force until the shield machine reaches a hoisting area;
3) fine adjustment is carried out on the receiving bracket through a jack until the supporting beam cannot shield the shield machine;
s4, hoisting of the shield tunneling machine: the shield machine is disassembled, and then the shield tail, the cutter head, the middle shield and the front shield are hoisted out in sequence by adopting the crawler crane.
Further, in the step S3, the initial thrust of the forward movement of the shield machine from the standstill is controlled within 1000KN, and the thrust during the subsequent translation is controlled between 300KN and 500 KN.
Furthermore, after the second step, the rear corollary equipment is translated, the three flat cars are connected into a whole by using the three flat cars as transverse moving carriers, a trolley track is arranged on each flat car, a flat car track is arranged on the bottom plate, the flat cars directly run on the trolley tracks on the flat cars, the flat cars are translated to the middle space position of the receiving end through the flat car tracks, and then the rear corollary equipment is hoisted.
Further, the preparation before reception in the step S1 further includes the following steps:
step 1, paving a steel plate in advance: after the bottom plate is excavated to the elevation, leveling a pouring cushion layer, arranging an embedded steel plate at the position of the pre-paved steel plate below the receiving bracket during pouring, and welding the pre-paved steel plate and the embedded steel plate;
step 3, horizontal hole probing of the tunnel portal at the shield receiving position: carrying out horizontal hole probing construction before receiving by the shield machine, and determining whether slurry replenishing treatment is needed or not according to the permeation condition of underground water;
and 6, chiseling a hole: chiseling the tunnel portal by using a small crushing hammer before receiving, and chiseling the diaphragm wall towards the soil facing surface after the tunnel portal exploration is finished;
and 7, pumping and draining water in the foundation pit: when the shield is received, 4 submersible sewage pumps with power more than 16kw are prepared on site, and accumulated water in the foundation pit is discharged to the ground;
Further, after the step of S1, the method for controlling parameters of each stage includes the following steps:
(1) tunneling of a shield transition section (9-30 m before receiving): the tunneling speed and the soil bin pressure of the transition section are the same as those of normal section tunneling, the tunneling direction of the shield tunneling machine is made to be consistent with the original design axis direction as much as possible, the shield tunneling machine is made to keep horizontal posture forward or slightly head-up posture forward at a position 20m before receiving, and the axis deviation during tunneling is controlled within a range of 20 mm;
(2) second stage before reception (0.2 m to 9m before reception): when the concrete of the tunnel portal is loosened or cracked, the tunneling is stopped;
(3) the third stage of station entry (the second stage is completed till the shield machine is exposed): the shield machine continues to advance and assemble the duct pieces, and the tunneling of the rest of the enclosure structure is completed; the shield machine continues to advance, and the steel wire rope on the turning plate is immediately tensioned after the turning plate passes through the turning plate, so that the soil in the sealed cabin is removed.
Further, in the step 1, in order to strengthen the connection between the embedded steel plate and the ground, 5 pieces of reinforcing steel bars with the diameter of 22 are implanted below the embedded steel plate, and the reinforcing steel bars and the embedded steel plate are welded firmly.
Furthermore, in the step 3, 9 horizontal holes with the hole diameter of 50mm and the drilling depth of 2500mm are drilled in the range of the tunnel portal, and when the total amount of collected water per hour exceeds 20L, grouting treatment needs to be performed in an effective area such as a tunnel face or a tunnel upper side.
Further, in the step 6, the order of removing the opening is to remove the upper portion and then the lower portion, divide the opening into 9 pieces, sequentially remove the concrete, cut the exposed reinforcing bars, and then lift the exposed reinforcing bars.
Further, before the step 1, measurement guidance, shield tail clearance and shield machine attitude control are carried out, line retest including connection measurement is carried out when the shield machine penetrates through the tunnel by 150-200m, control measurement rechecking of the whole system is carried out on all measurement control points in the tunnel, precise and accurate adjustment calculation is carried out on coordinates of all the control points, and retest is carried out on a guidance system at positions of 100m and 50 m.
Further, the installation method of the sealing device in the step S1 includes the steps of removing concrete on the surface of the diaphragm wall to expose the diaphragm wall steel bars, positioning the turning plate, welding the turning plate with the diaphragm wall steel bars, and fixing the turning plate and the diaphragm wall by using expansion bolts to penetrate through the turning plate and the rubber curtain cloth.
Compared with the prior art, the invention has the following beneficial effects: the invention provides a construction process and construction parameters for receiving, translating and hoisting a shield machine in a body-free structure, verifies the effectiveness and feasibility of the construction scheme through actual monitoring data on site, successfully solves construction difficulties such as large construction organization difficulty, short construction period, high cost and the like in the shield receiving process, saves construction cost, is beneficial to control of construction cost, and provides experience for similar projects.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:
fig. 1 is a schematic flow chart according to an embodiment of the invention.
FIG. 2 is a top view of a receiving bracket mounting of one embodiment of the present invention;
fig. 3 is a schematic cross-sectional view of a pre-laid steel plate according to an embodiment of the present invention.
Fig. 4 is a schematic view of an enclosure according to an embodiment of the present invention.
Fig. 5 is a schematic cross-sectional view of a receiving end according to an embodiment of the invention.
FIG. 6 is a plan view of a receiving bracket reinforcement according to an embodiment of the present invention.
Fig. 7 is a front view of a temporary diagonal brace for reinforcement of a diaphragm wall according to an embodiment of the present invention.
Fig. 8 is a side view of a temporary diagonal brace for reinforcement of a diaphragm wall according to an embodiment of the present invention.
Fig. 9 is a schematic top view of a shield tunneling machine moving onto a receiving bracket according to an embodiment of the present invention.
Fig. 10 is a schematic top view of a shield tunneling machine on a receiving bracket according to an embodiment of the present invention.
Fig. 11 is a schematic top view of a shield tunneling machine according to an embodiment of the present invention after being translated.
Fig. 12 is a schematic top view of the shield tunneling machine after translation according to the embodiment of the present invention.
Fig. 13 is a schematic top view of a shield machine hoisting according to an embodiment of the present invention.
FIG. 14 is a graph comparing deformation before and after receiving for wall body inclination measurement according to an embodiment of the present invention.
FIG. 15 is a graph of maximum deformation rate for wall body inclination measurement according to an embodiment of the present invention.
Fig. 16 is a schematic view of a sealing device according to an embodiment of the present invention.
In the figure: 1. a ground connecting wall; 2. a shield well; 3. slightly weathered gravelly-containing coarse sandstone; 4. a shield machine; 5. receiving a bracket; 6. a cushion layer; 7. pre-burying a steel plate; 8. a step; 9. i-shaped steel; 10. a bracket support; 11. a temporary diagonal bracing; 12. h-shaped steel; 13. a jack; 14. reaction-force profile steel; 15. a support beam; 16. a crawler crane; 17. balancing weight; 18. pre-paving a steel plate; 19. a sealing device; 20. rubber cord fabric; 21. turning over a plate; 22. an expansion bolt.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The embodiments and features of the embodiments in the present application may be combined with each other without conflict. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture, and if the specific posture is changed, the directional indications are changed accordingly.
In addition, if there is a description relating to "first", "second", etc. in the embodiments of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and/or" appearing throughout includes three juxtapositions, exemplified by "A and/or B" including either A or B or both A and B. In addition, "a plurality" means two or more. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.
As shown in fig. 1 to 16, the invention relies on the Guangzhou subway No. 7 line Dashadong station, and only needs to complete the construction of the enclosure structure, firstly provides a shield receiving construction method without a bottom plate structure, and carries out intensive research on the shield receiving construction method.
The Guangzhou seven-line second-stage Dashadong station is connected with Yufeng surrounding station in the south, and is connected with Jitang station in the north, and the station of the Dashadong station is located in the north side of the intersection of the Dashadong road and the Zhedong road, and is arranged along the south and north directions of the Zhedong road, and the receiving position of the big mileage end is located in the intersection of the Zhedong road and three paths, and the section line extends the Zhedong road to enter the Dashadong station, and the main body of the Dashadong station is of an underground four-layer structure, the total length of the foundation pit is 159 meters, the width of the shield well 2 at the big mileage end is 28.9 meters, and the excavation depth is 36.63 meters.
As shown in fig. 4, the earth-side wall 1 of the east station of the big sand is provided with an inner support enclosure, the earth-side wall 1 with the thickness of 800mm is provided with an I-steel 9 joint and is embedded and fixed for 1.5m, the end shield well 2 with the big mileage is provided with six concrete supports, the end shield well 2 with the small mileage is provided with five concrete supports, the standard section is provided with 3 concrete supports and 3 steel supports, the end shield well 2 with the big mileage is provided with six concrete supports, the middle part of the foundation pit is provided with temporary upright posts with the intervals of 6m and 9m, and the temporary upright posts are bored cast-in-place pile foundations and extend into the foundation for 4 meters.
The conditions of the foundation pit stratum are plain filling soil, viscous plain filling soil, silt medium coarse sand, silty clay, medium coarse sand, fully weathered gravel-containing coarse sandstone, strongly weathered gravel-containing coarse sandstone, medium weathered gravel-containing coarse sandstone (the average strength is 8.44MPa), slightly weathered gravel-containing coarse sandstone 3 (the average value is 25.34MPa and the maximum is 62.3MPa), the sand layer burial depth is 12.3m, and the thickness is about 2-7 m; the vault of the tunnel is about 16m from the bottom of the sand layer. Belonging to a typical composite stratum with soft upper part and hard lower part.
The hole body penetrates through the stratum: medium weathering gravel-containing coarse sandstone and slightly weathering gravel-containing coarse sandstone 3.
Underground water: the fourth series of loose rock pore water has uneven water content in soil, but has poor water-rich property and small water quantity; the aquifer is mainly a medium coarse sand 3-2 layer with a relative water-resisting layer on the upper part, and has certain pressure bearing performance; the bedrock fracture water exists in weathering fractures of strong and medium weathering zone rock layers of clastic rock.
The specific construction method comprises the following steps:
1. a translation preparation step:
1.1 measurement of guidance, shield tail clearance and 4-attitude control of shield tunneling machine
Performing circuit retesting including contact measurement 150-200m before the shield machine 4 is run through, performing control measurement recheck of the whole system on all measurement control points in the tunnel, performing precise and accurate adjustment calculation on coordinates of all the control points, retesting the guide system at positions 100m and 50m, moving the shield to the station for the last time before the shield arrives at the station, fully utilizing the result of the circuit retesting 150-200m before the run through, precisely measuring the coordinates and elevations of the measurement station and a rear viewpoint, and further enhancing duct piece posture monitoring at 50m before the run through;
1.2 site leveling and steel plate laying
As shown in fig. 5, the bottom of the foundation pit is slightly weathered gravelly-containing sandstone 3, the excavation of the foundation pit is in a form of crushing by a hydraulic crusher, the flatness cannot meet the requirements of installation of a receiving bracket 5 and translation of a shield machine 4, therefore, after the excavation is carried out to the elevation of a bottom plate, a cushion layer 6 is poured and leveled, the cushion layer 6 is poured by adopting C30 concrete, the pouring thickness is 30cm, 4 steel plates of 0.5m × 0.5m are pre-buried at the position of a pre-buried steel plate 18 below the receiving bracket 5 when the concrete is poured, the pre-buried steel plate 18 is welded with a pre-buried steel plate 7, 5 phi 22 steel bars are implanted in a quincunx shape below the pre-buried steel plate 7 for strengthening the pre-buried steel plate 7, the steel bars are stably welded with the pre-buried steel plate 7 for facilitating the reinforcement of the receiving bracket 5, a step 8 of 0.6m height is reserved at the position away from the ground connecting wall by 115.5m and during the excavation, and facilitating the reinforcement of the receiving bracket 5;
1.3 soil body reinforcement at the receiving end
The receiving end of the Dashadong station does not need soil body reinforcement according to design drawings and detailed survey reports of rock and soil, the underground diaphragm wall 1 in the contour line range of the shield zone at the end of the Dashadong station adopts single-sided glass fiber reinforced plastics, and tunnel portal chiseling work is needed during shield receiving;
1.4 horizontal tunnel portal exploration hole at shield receiving position
Carrying out horizontal hole probing construction before the shield machine 4 receives the water, judging the underground water seepage condition, and determining whether slurry replenishing treatment is needed or not according to the underground water seepage condition;
horizontal coring: drilling 9 horizontal holes within the range of a tunnel portal, wherein the hole diameter is 50mm, the drilling depth is 2500mm, judging according to the water yield of the 9 holes, and if the total amount of catchment per hour exceeds 20L, performing grouting treatment on effective areas such as a tunnel face or a tunnel upper part;
1.5 hole door seal
As shown in fig. 16, because a station main body structure is not constructed, a portal steel ring and a portal sealing device 19 cannot be normally installed, the sealing device 19 comprises a rubber curtain cloth 20, a turning plate 21 and an expansion bolt 22, the portal sealing device 19 at a hole outlet end needs to be directly installed on an underground continuous wall of an enclosure structure, in order to ensure the installation firmness and reliability of the portal sealing device 19, firstly, exposed reinforcing steel bars of concrete on the surface of the underground continuous wall 1 are removed, the turning plate 21 is welded with the reinforcing steel bars of the underground continuous wall 1 after being positioned, then, the expansion bolt 22 penetrates through an opening of the turning plate 21 for fixing, the expansion bolts 22 are arranged at 5 degrees in division, and 72 turning plates 21 are installed after the installation and the fixing of the turning plate 21;
1.6 receiving bracket Reinforcement
As shown in fig. 2, 3 or 6, a triangular steel plate with a waist length of 300 × 300mm is made of a steel plate with a thickness of 20mm, and is vertically welded on a steel plate at the tail part of the receiving bracket 5 to strengthen the longitudinal limit of the receiving bracket 5 and prevent the receiving bracket 5 from sliding when the shield tunneling machine 4 receives the steel plate; the 22# b I-steel 9 is used for supporting and reinforcing, so that left and right stability is guaranteed; because a main structure bottom plate is not constructed, in order to facilitate the reinforcement of the receiving bracket 5, a concrete bracket support 10 with the ground exposed by 0.3m is poured on one side of the non-underground diaphragm wall 1, and when the I-shaped steel 9 is propped to one side of a supporting surface, a steel plate with the thickness of 20mm is welded on the I-shaped steel 9 to enlarge the supporting stress area and reduce the supporting damage probability; c30 concrete is poured into a top bracing beam with the length of 5m multiplied by the width of 1m multiplied by the height of 1.25m (exposed out of the ground by 0.25m) at a position 1m away from the tail part of the receiving bracket 5, and the top bracing beam at the tail part of the receiving bracket 5 is reinforced by I-shaped steel 9, so that counter force is provided for fixing the shield receiving bracket 5, and the receiving bracket 5 is prevented from moving forwards due to pushing in the receiving process;
1.7 ground is wall reinforcement even
As shown in fig. 7 and 8, in order to ensure the safety, stability and reliability of the pit enclosure structure when the shield is taken out of the tunnel and prevent the shield machine 4 from driving and generating adverse effects on the enclosure structure underground diaphragm wall 1 in the receiving process, a temporary inclined strut 11 is additionally arranged between the receiving end and the underground diaphragm wall 1, the temporary inclined strut 11 uses H-shaped steel 12(400 x 400mm), the arrangement mode is that 4 channels are arranged on the center side of the tunnel near the end head, wherein 2 channels are arranged on the left and right lines, and 1 channel is arranged on the side near the underground diaphragm wall 1; one end of the diagonal brace is welded with a steel plate with the thickness of 20mm, and the steel plate is anchored on the underground diaphragm wall 1 by using an expansion bolt 22 so as to enlarge the bracing area of the diagonal brace; c30 concrete is poured on the inclined strut base to form a concrete bracket, 50cm is continuously excavated under the bracket, and phi 28 steel bars are implanted;
1.8 door chiseling
The tunnel portal underground diaphragm wall 1 at the large mileage end of the large sand east station adopts single-sided glass fiber reinforcements, the tunnel portal soil-facing surface adopts glass fiber reinforcements, the back soil surface adopts common threaded reinforced concrete, the tunnel portal is chiseled by a small-sized breaking hammer before receiving, in order to reduce the receiving time of the shield machine 4, after the tunnel portal exploration is completed, under the premise of meeting the safety of the tunnel portal, the 1900mm tunnel portal diaphragm wall is planned to be chiseled towards the soil-facing surface, the sequence of chiseling the tunnel portal is that the upper part is chiseled firstly, the lower part is chiseled secondly, the tunnel portal underground diaphragm wall is totally divided into 9 blocks, the area of each block is about more than 3.8m2, the concrete is sequentially chiseled, and the exposed reinforcing steel bars are cut off and then lifted out;
1.9 drainage in foundation pit
When the shield receives, more underground water possibly flows out from the tunnel portal; during receiving, due to weather influence, precipitation can also cause water accumulation in the foundation pit, 4 submersible sewage pumps (with the lift larger than 46m) with the power of more than 16kw are prepared on site, and the water accumulation in the foundation pit is discharged to the ground;
1.10 ground reinforcement
The foundation pit stratum conditions are plain filling soil, silt medium coarse sand, silty clay, medium coarse sand, fully weathered gravel-containing coarse sandstone, strongly weathered gravel-containing coarse sandstone, medium weathered gravel-containing coarse sandstone and slightly weathered gravel-containing coarse sandstone from top to bottom, the burial depth of a sand layer is averagely 12.5m, the bottom of the sand layer is 17m to the top of a receiving surface, in order to prevent downward water seepage and sand leakage at the joint of the diaphragm wall 1 during receiving, grouting and reinforcing are planned for the ground, a drilling and grouting integrated machine is adopted for grouting, a slurry type is selected from two-fluid slurry, the two-fluid slurry is mixed slurry of cement slurry and water glass, the setting time of the two-fluid slurry is controlled to be 45-60 seconds, and the slurry mixing ratio is: water: cement is 1: 0.5;
the method comprises the following steps of (1) avoiding a pipeline during grouting, probing a hole in a manual hole digging mode, wherein the hole probing depth is 3m, the hole probing width is 0.2m, if the pipeline is probed out, the hole probing is continued according to the position deviation of the pipeline by 20-30 cm, the grouting depth is 11m, the grouting pressure is less than 0.5MPa, the distance between a hole position and the soil facing side of the diaphragm wall 1 is 0.3m, when the grouting position is lifted to 5m away from the ground, hole sealing is carried out, so that ground uplift and pipeline deformation caused by grouting are prevented, if grouting cannot be carried out on site due to monitoring points, pipelines and the like, the number of grouting holes can be reduced, and grouting reinforcement of the joint position of the diaphragm wall 1 is required to be performed during grouting;
2. parameter control of each stage before shield receiving
After the shield machine 4 enters the receiving end, the thrust force is reduced, the propelling speed and the rotating speed of the cutter head are reduced, the soil output is controlled, the pressure value of the soil bin is monitored constantly, the set value of the soil pressure is gradually reduced, the influence of larger thrust force on the stability of the soil body in the range of the tunnel portal is avoided, the shield machine receiving tunneling can be divided into three stages, in the stages, different construction parameters and different control side points are adopted,
2.1 Shield transition tunneling (9 m-30 m before receiving)
The tunneling speed and the soil bin pressure of the transition section are the same as those of normal section tunneling, construction is focused on strengthening attention to adjusting the posture of the shield machine 4, the tunneling direction of the shield machine 4 is enabled to be consistent with the original design axis direction as much as possible, the shield machine 4 is enabled to keep horizontal posture forward or slightly head-up posture forward at a position 20 meters before receiving, normal receiving during exiting is guaranteed, and axis deviation during tunneling is controlled within a range of 20 mm;
2.3 second stage before reception (0.2 m-9 m before reception)
During the tunneling process, the state of a tunnel portal is closely concerned until concrete of the tunnel portal is loosened or cracked, and no tunneling is possible, because the stratum at the receiving end of the great sand east station is mainly a 3-layer slightly weathered gravelly-contained sandstone, the soil quality is hard, the pressure setting value of a soil bin is initially set to 0bar for controlling the propulsion axis and protecting a cutter head, fine adjustment is carried out according to relevant parameters such as the thrust of a shield and the ground monitoring condition during propulsion, the speed at the stage is generally 5-10 mm/min, when the shield machine 4 approaches 20-30 cm of the tunnel portal, the propulsion is stopped, fragments and soil are removed, backfill grouting is carried out in time, the safety of the enclosure structure of the great sand east station is prevented from being influenced, and the installation of a tunnel portal sealing ring and the preparation work of a receiving support are carried out before;
2.3 the third stage of arrival (the second stage is completed until the shield machine 4 enters the big sand east station to be exposed)
The shield machine 4 continues to advance and assemble the segments, the tunneling of the rest of the enclosure structure is completed, the speed at this stage is determined according to the actual situation, no pressure exists, the cutter head stops rotating and the collapsed soil body is removed, the shield machine 4 continues to advance, the steel wire rope on the turning plate 21 is immediately tensioned after the turning plate 21 passes through, the soil in the sealed cabin is removed, the shield center is measured after the machine is stopped, and whether the requirement on the penetration precision is met or not is judged;
during shield receiving, ground surface settlement monitoring work needs to be enhanced, and water level monitoring is carried out;
3. shield arrival construction
3.1 Shield arrival
(1) After the shield enters the arrival section, the monitoring of surface subsidence is enhanced, and information is fed back in time to guide the shield tunneling machine 4 to tunnel;
(2) when the distance between the cutter head of the shield machine 4 and the through mileage is less than 10m, a specially-assigned person is responsible for observing the change condition of the hole outlet in the tunneling process, always keeping contact with a driver of the shield machine 4 and adjusting tunneling parameters in time;
(3) after the assembled duct pieces enter 8 rings before receiving, the slurry is changed into quick-hardening slurry, and muddy water in the stratum is blocked outside the receiving end, so that water gushing from the tunnel portal is prevented;
(4) after the last ring pipe piece of the pipe piece is assembled, injecting double-liquid slurry for plugging through a secondary grouting hole of the pipe piece, closely paying attention to the situation of a hole door in the grouting process, and immediately stopping grouting and treating once the slurry leakage phenomenon is found;
(5) when the shield shell of the shield front body is pushed out of the tunnel portal, the steel wire rope on the turning plate 21 snap ring is used for adjusting the flap pressing plate to press the cord fabric rubber plate so as to prevent soil and slurry of the tunnel portal from leaking out, and when the duct piece is pulled out of the shield tail, the steel wire rope is tensioned again so that the pressing plate can press the rubber cord fabric 20 and the cord fabric can play a sealing role all the time;
(6) because the thrust is small when the shield arrives at the station, the connection between the segment ring and the ring near the tunnel portal is not tight enough, so the bolt fastening and the re-fastening work of the segment with the rear 20 rings are done, the segment with the rear 20 rings is tensioned by flat iron along the longitudinal direction of the tunnel, and the ring are connected, so the segment with the rear 20 rings is connected into a whole, and the sealing and waterproof effect is prevented from being influenced by the loose segment;
(7) after the shield machine 4 drives on the receiving bracket 5, secondary grouting is carried out on the range of the tunnel portal in time, and rapid plugging and ring forming are carried out;
(8) cleaning the residue soil in the cutter head in time;
(9) when the shield is tunneled within the range of 9m before receiving, the shield is controlled according to the principle of 'low thrust, low cutter head rotating speed and disturbance reduction', so that the shield propulsion is ensured not to influence the end wall;
3.2 protection of door seal
When the shield machine 4 enters the station, the cutter head possibly damages the rubber curtain cloth 20 or causes the turning plate 21 to displace, so when the shield machine 4 enters the station, the protection of the rubber curtain cloth 20 needs to be paid attention to, and the tunnel door turning plate 21 is timely adjusted;
3.3 Emergency Material preparation
Receiving an operation surface at the end of a Dashadong station, preparing emergency materials and tools such as sandbags, cotton yarns, water pumps, water pipes, square timbers, air picks, quick cement, polyurethane and the like to prevent water gushing and sand gushing at a cave door, and preparing a double-liquid grouting machine, a connecting pipe, 3t cement and 1t glass water on the ground;
4. translation construction of shield machine
4.1 shield machine and back corollary equipment separation
1) Adjusting the position of the assembling machine to enable the assembling machine to move forwards to the maximum stroke; rotating the screw machine to clean the residue soil in the screw machine;
2) moving the shield tunneling machine 4 forward until the shield tunneling machine 4 is completely positioned on the receiving bracket 5;
3) disconnecting the connections of water, electricity and hydraulic pipelines and a steel structure between the shield machine 4 and the trolley, numbering the pipelines, and well cleaning and protecting the pipelines;
4) welding a limiting steel plate for preventing the shield machine 4 from rotating on the shell of the shield machine 4, and simultaneously welding a steel plate for preventing the shield machine from moving in a hinged mode;
4.2 translation construction process of shield tunneling machine
As shown in fig. 9-12, the receiving bracket 5 and the shield machine 4 are translated to a predetermined hoisting position by using the thrust of the jack 13, the shield machine 4 moves forward from a standstill with an initial thrust controlled within 1000KN, the thrust is controlled between 300KN and 500KN in the subsequent translation process, and the shield machine 4 and the receiving bracket 5 are moved to a hoisting area by the host machine of the shield machine 4 by pushing the jack 13 in the receiving well;
11) the shield tunneling machine 4 pushes the shield tunneling machine to the receiving bracket 5;
2) fixing the shield tunneling machine 4 and the receiving bracket 5, and welding an anti-torsion device;
3) cleaning the lower part of the receiving bracket 5;
4) disconnecting the shield machine 4 from the rear matched equipment;
5) dismantling the temporary diagonal brace 11 and the I-steel 9 and the bracket support 10 arranged on the receiving bracket 5;
6) translating the shield tunneling machine 4 and the receiving bracket 5 from the receiving position by using a jack 13 to provide a counter force, and cushioning a counter force steel section 14 behind the jack 13;
7) the reaction section steel 14 behind the jack 13 is continuously lengthened, full welding is carried out between the reaction section steel 14, the integral stability of the reaction section steel 14 behind the jack 13 is guaranteed, the risk that the shield machine 4 translates due to deformation and deviation of the reaction section steel 14 is reduced, and the shield machine 4 and the receiving bracket 5 are conveyed to a hoisting area;
8) after reaching the hoisting area, fine adjustment is carried out through a jack 13, and the shield tunneling machine 4 is ensured to be in a state without being shielded by a supporting beam 15;
4.3 rear support translation
Three flat cars are used as a transverse moving carrier, the three flat cars are connected into a whole, a trolley track is arranged on each flat car, a flat car track is arranged on a bottom plate, the trolley directly runs onto the trolley track on the flat cars, the flat cars are translated to the middle space position of a receiving end through the flat car tracks, and then hoisting of rear supporting equipment is carried out;
5. shield machine hoist and mount
As shown in fig. 13, in combination with the actual field situation and the performance and size of the crane equipment, the receiving and hoisting equipment of 2 secondary shield machines 4 on the left and right sides of the large mileage end of the great east station all adopt 300T crawler cranes 16, the crawler cranes 16 are provided with counterweights 17, and the crawler cranes 16 sequentially hoist out the shield tail, the cutter head, the middle shield and the front shield;
as shown in fig. 14-15, in the shield receiving, translating and hoisting processes, deformation and displacement conditions of the continuous wall are monitored in real time through monitoring points arranged at the ends of the foundation pits, and according to the monitoring conditions of the continuous wall in the shield hoisting process by a monitoring group, the enclosure structure of the station in the shield hoisting process is confirmed to be safe and controllable, and specific monitoring data are shown in table 1 below.
Table 1 wall inclination survey data change comparison table
The invention is based on Guangzhou subway No. 7 line large sand east station, systematically expounds the construction process and construction parameters of the shield machine without a main body structure under the objective conditions of complex stratum, tight construction period, high environmental risk, large construction difficulty and the like, verifies the effectiveness and feasibility of the construction scheme through the actual monitoring data on site, successfully solves the construction problems of large construction organization difficulty, tight construction period, high cost and the like in the shield receiving process, saves the construction cost to a certain extent, is beneficial to construction cost control, and provides experience for similar engineering.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Claims (10)
1. The shield receiving construction method of the structure without the bottom plate is characterized in that: the method comprises the following steps:
s1, preparation before reception
(1) Mounting a receiving bracket: the receiving bracket (5) is in a steel structure form and is used as a base of the shield tunneling machine (4) after reaching a receiving well, when the receiving bracket (5) is installed, the space position of the receiving bracket (5) is reversely deduced according to the position and the elevation of a central plane of a tunnel portal and the elevation of a bottom plate on which the receiving bracket (5) is placed according to the actual measurement of the tunnel, the receiving bracket (5) is placed on a pre-paved steel plate (18), and a steel plate is additionally arranged at the bottom of the receiving bracket (5) according to requirements to adjust the position of the receiving bracket (5) so as to ensure that the shield tunneling machine (4) just falls on the receiving bracket (5) after receiving;
(2) sealing the tunnel door: a hole door sealing device (19) at the hole outlet end is directly arranged on an underground continuous wall of the enclosure structure, and the sealing device (19) comprises a rubber curtain cloth (20), a turning plate (21) and an expansion bolt (22);
s2, shield arrival construction:
(1) after the assembled duct piece enters 8 rings before receiving, the slurry is changed into quick-hardening slurry, and muddy water in the stratum is blocked outside a receiving end so as to prevent water from gushing at the tunnel portal;
(2) after the last ring pipe piece of the pipe piece is assembled, injecting double-liquid slurry to block through a secondary grouting hole of the pipe piece;
(3) when the shield shell of the shield front body is pushed out of the tunnel portal, the flap pressing plate is adjusted through a steel wire rope on the turning plate (21) clamping ring to press the curtain cloth rubber plate; when the duct piece is dragged out of the shield tail, the steel wire rope is tensioned again, so that the pressing plate can press the rubber cord fabric (20);
(4) fastening and retightening the bolts of the rear 20-ring segment; tensioning the rear 20 ring pipe pieces longitudinally along the tunnel by using flat iron, and connecting the rings to enable the rear 20 ring pipe pieces to be connected into a whole;
(5) after the shield machine (4) drives on the receiving bracket (5), grouting is carried out on the range of the tunnel portal, and plugging is carried out to form a ring;
s3, shield constructs quick-witted translation construction:
(1) separating the shield machine from the rear matched equipment:
1) adjusting the position of the assembling machine to enable the assembling machine to move forwards to the maximum stroke;
2) moving the shield tunneling machine (4) forward until the shield tunneling machine (4) is completely positioned on the receiving bracket (5);
3) disconnecting the hydroelectric and hydraulic pipelines and the steel structure between the shield machine (4) and the trolley;
4) welding a limiting steel plate for preventing the shield machine (4) from rotating on the shell of the shield machine (4), and simultaneously welding a steel plate for preventing the shield machine from moving in a hinged mode;
(2) the shield tunneling machine translation construction process comprises the following steps:
1) the shield machine (4) and the receiving bracket (5) are translated from the receiving position by using a jack (13) to provide counter force;
2) adding cushion reaction force section steel (14) behind the jack (13) to continuously provide reaction force until the shield machine (4) reaches a hoisting area;
3) the receiving bracket (5) is finely adjusted through the jack (13) until the supporting beam (15) can not shield the shield machine (4);
s4, hoisting of the shield tunneling machine: the shield machine (4) is disassembled, and then a crawler crane (16) is adopted to sequentially lift out the shield tail, the cutter head, the middle shield and the front shield.
2. The shield receiving construction method of a bottomless plate structure as claimed in claim 1, wherein: in the step S3, the shield machine (4) moves forwards from a standstill to an initial thrust controlled within 1000KN, and the thrust is controlled between 300KN and 500KN in the subsequent translation process.
3. The shield receiving construction method without a floor structure as claimed in claim 1 or 2, wherein: and after the second step, translating the rear corollary equipment, connecting the three flat cars into a whole by using the three flat cars as transverse moving carriers, arranging a trolley track on the flat cars, arranging a flat car track on the bottom plate, directly driving the flat cars to the trolley track on the flat plates, translating the flat cars to the middle space position of the receiving end through the flat car track, and then hoisting the rear corollary equipment.
4. The shield receiving construction method of a bottomless plate structure as claimed in claim 1, wherein: the preparation before reception in the step of S1 further includes the steps of:
step 1, paving a steel plate in advance: after the bottom plate is excavated to the elevation, leveling of a pouring cushion layer (6), arranging an embedded steel plate (7) at the position of a pre-paved steel plate (18) below a receiving bracket (5) during pouring, and welding the pre-paved steel plate (18) and the embedded steel plate (7);
step 2, reinforcing the land at the receiving end: reinforcing the land at the receiving end to prevent the occurrence of the phenomena of sand and mud gushing;
step 3, horizontal hole probing of the tunnel portal at the shield receiving position: horizontal hole probing construction is carried out before the shield machine (4) receives the slurry, and whether slurry replenishing treatment is needed or not is determined according to the permeation condition of underground water;
step 4, receiving bracket reinforcement: vertically welding a triangular steel plate at the tail part of the receiving bracket (5), and supporting and reinforcing by using 22# b I-steel (9);
step 5, reinforcing the underground diaphragm wall: a temporary inclined strut (11) is additionally arranged between the receiving end and the underground diaphragm wall (1), the temporary inclined strut (11) is made of H-shaped steel (12) and is arranged in a mode that 4 channels are arranged on the center side of the tunnel close to the end head, wherein 2 channels are arranged on the left and right lines respectively, and 1 channel is arranged on one side close to the underground diaphragm wall (1);
and 6, chiseling a hole: chiseling the tunnel portal by using a small crushing hammer before receiving, and chiseling the diaphragm wall (1) towards the soil facing surface after the tunnel portal exploration is finished;
and 7, pumping and draining water in the foundation pit: when the shield is received, 4 submersible sewage pumps with power more than 16kw are prepared on site, and accumulated water in the foundation pit is discharged to the ground;
step 8, ground reinforcement: grouting and reinforcing the ground, selecting double-liquid slurry for the slurry type, controlling the setting time of the double-liquid slurry to be 45-60 seconds, and controlling the cement slurry mixing ratio to be: water: cement 1: 0.5.
5. The shield receiving construction method of a bottomless plate structure as claimed in claim 4, wherein: after the step of S1, controlling parameters of each stage, including the steps of:
(1) tunneling of a shield transition section (9 m-30 m before receiving): the tunneling speed and the soil bin pressure of the transition section are the same as those of normal section tunneling, the tunneling direction of the shield machine (4) is consistent with the original design axis direction as much as possible, the shield machine (4) is enabled to keep horizontal posture forward or slightly head-up posture forward at a position 20m before receiving, and the axis deviation during tunneling is controlled within the range of 20 mm;
(2) second stage before reception (0.2 m to 9m before reception): when the concrete of the tunnel portal is loosened or cracked, the tunneling is stopped;
(3) the third stage of station entry (the second stage is completed till the shield machine (4) is exposed): the shield machine (4) continues to advance and assemble the duct pieces, and the tunneling of the rest of the enclosure structure is completed; the shield machine (4) continues to advance, the steel wire rope on the turning plate (21) is immediately tensioned after passing through the turning plate (21), and soil in the sealed cabin is removed.
6. The shield receiving construction method of a bottomless plate structure as claimed in claim 4, wherein: in the step 1, in order to strengthen the connection between the embedded steel plate (7) and the ground, 5 pieces of reinforcing steel bars with the diameter of 22 are implanted below the embedded steel plate (7), and the reinforcing steel bars and the embedded steel plate (7) are welded firmly.
7. The shield receiving construction method of a bottomless plate structure as claimed in claim 4, wherein: in the step 3, 9 horizontal holes with the aperture of 50mm and the drilling depth of 2500mm are drilled in the range of the portal, and when the total amount of catchment per hour exceeds 20L, grouting treatment needs to be carried out in effective areas such as a tunnel face or a tunnel upper side.
8. The shield receiving construction method of a bottomless plate structure as claimed in claim 4, wherein: in the step 6, the order of removing the portal is to remove the upper part and then remove the lower part, divide the portal into 9 pieces, remove the concrete in sequence, cut the exposed steel bars, and then lift out the exposed steel bars.
9. The shield receiving construction method of a bottomless plate structure as claimed in claim 3, wherein: before the step 1, measurement guidance, shield tail clearance and shield machine (4) attitude control are carried out, when the shield machine (4) penetrates through the front 150-200m, line retest including contact measurement is carried out, control measurement rechecking of the whole system is carried out on all measurement control points in the tunnel, precise and accurate adjustment calculation is carried out on coordinates of all the control points, and retest is carried out on a guidance system at 100m and 50 m.
10. The shield receiving construction method of a bottomless plate structure as claimed in claim 1, wherein: the installation method of the sealing device (19) in the step S1 comprises the steps of firstly removing concrete on the surface of the diaphragm wall (1) to expose out of the diaphragm wall (1) steel bars, positioning the turning plate (21) and then welding the turning plate with the diaphragm wall (1) steel bars, and then fixing the turning plate (21) and the rubber curtain cloth (20) on the diaphragm wall (1) through expansion bolts (22).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210071837.XA CN114542092A (en) | 2022-01-21 | 2022-01-21 | Shield receiving construction method without bottom plate structure |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210071837.XA CN114542092A (en) | 2022-01-21 | 2022-01-21 | Shield receiving construction method without bottom plate structure |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114810111A (en) * | 2022-06-28 | 2022-07-29 | 北京建工土木工程有限公司 | Device for chiseling shield opening enclosure integrally and construction method |
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2022
- 2022-01-21 CN CN202210071837.XA patent/CN114542092A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114810111A (en) * | 2022-06-28 | 2022-07-29 | 北京建工土木工程有限公司 | Device for chiseling shield opening enclosure integrally and construction method |
| CN114810111B (en) * | 2022-06-28 | 2022-10-21 | 北京建工土木工程有限公司 | Device for chiseling shield opening enclosure integrally and construction method |
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