CN115839251A - Up-down overlapping tunnel construction method based on advanced pre-reinforcement - Google Patents
Up-down overlapping tunnel construction method based on advanced pre-reinforcement Download PDFInfo
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- CN115839251A CN115839251A CN202211230210.0A CN202211230210A CN115839251A CN 115839251 A CN115839251 A CN 115839251A CN 202211230210 A CN202211230210 A CN 202211230210A CN 115839251 A CN115839251 A CN 115839251A
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Abstract
The invention discloses an up-down overlapping tunnel construction method based on advanced pre-reinforcement, which comprises the following steps: s1: constructing a tunnel in a lower interval of the overlapping section, and synchronously grouting and reinforcing the tunnel in the lower interval; s2: carrying out secondary deep hole grouting reinforcement on the soil body at the top of the tunnel in the lower section to form a secondary deep hole grouting reinforcement area; s3: performing advanced pre-grouting reinforcement on the soil body at the bottom of the tunnel at the upper section of the overlapping section in the shield tunneling machine to form an advanced pre-reinforcement area of the shield tunneling machine; s4: a telescopic supporting component is erected in the lower section tunnel for reinforcement; s5: and constructing the tunnel between the upper sections of the overlapping sections, and performing synchronous grouting reinforcement and secondary grouting reinforcement on the tunnel between the upper sections. The reinforcement structure of the overlapping tunnel can effectively control the deformation and the ground surface settlement of the tunnel between the upper section and the lower section through secondary deep hole grouting reinforcement of the tunnel between the lower section and advanced pre-reinforcement in the shield machine of the tunnel between the upper section and the lower section.
Description
Technical Field
The invention relates to the technical field of shield construction, in particular to an up-down overlapping tunnel construction method based on advanced pre-reinforcement.
Background
With the development of modern urban rail transit, china has entered the era of large-scale underground space development. In recent years, due to the increase of the depth and density of underground space development and the shortage of urban land resources, the situation of up-and-down overlapping construction between two or more shield tunnels gradually appears and has a more and more intense trend. In the context of such engineering, a number of new issues have emerged that are urgently to be resolved.
The shield tunnel overlapping problem is mostly double-line parallel overlapping or multi-line cross overlapping, and in the overlapping tunnel, according to the principle of optimizing the construction sequence under the worst engineering condition, the construction sequence of firstly going down and then going up is finally selected in the overlapping tunnel section on the construction site. The overlapping tunnel belongs to a small close range self-approaching project, the mutual obvious influence can be generated during the overlapping construction of an upper line and a lower line, and a larger construction risk exists, so how to effectively control the mutual influence during the construction of the upper tunnel and the lower tunnel is the key point and the difficulty of the overlapping tunnel construction.
For weak strata with poor geological conditions or for reducing the influence on surrounding buildings, the soil body is usually pre-reinforced by adopting a ground pre-reinforcing method in shield tunnel construction, and the soil body is also usually reinforced by adopting synchronous grouting and secondary grouting methods in construction of overlapping tunnels. The advanced pre-grouting reinforcement in the shield machine is to reinforce the soil body at the front end of the shield cutter head by using the grouting hole of the shield machine, so that the mutual influence caused by the construction of an upper tunnel and a lower tunnel can be effectively controlled during shield construction. Because the environment conditions such as buildings, lakes, wetlands and the like possibly exist above the overlapping tunnels and the pre-reinforcement cannot be carried out from the ground, the advance pre-reinforcement in the shield tunneling machine is very necessary.
Disclosure of Invention
The invention aims to solve the defects in the prior art, and provides an up-down overlapping tunnel construction method based on advanced pre-reinforcement.
In order to achieve the purpose, the invention adopts the following technical scheme:
an up-down overlapping tunnel construction method based on advanced pre-reinforcement comprises the following steps:
s1: constructing a lower interval tunnel of the overlapping section, and synchronously grouting and reinforcing the lower interval tunnel;
s2: carrying out secondary deep hole grouting reinforcement on the soil body at the top of the tunnel in the lower section to form a secondary deep hole grouting reinforcement area;
s3: performing advanced pre-grouting reinforcement on the soil body at the bottom of the tunnel at the upper section of the overlapping section in the shield tunneling machine to form an advanced pre-reinforcement area of the shield tunneling machine;
s4: a telescopic supporting component is erected in the lower section tunnel for reinforcement;
s5: and constructing the tunnel between the upper sections of the overlapping sections, and performing synchronous grouting reinforcement and secondary grouting reinforcement on the tunnel between the upper sections.
Preferably, the secondary deep hole grouting reinforcement in S2 is implemented by deep hole grouting reinforcement in a hole, the reinforcement range is 180 degrees at the top, the reinforcement depth is 3m, the advanced pre-grouting reinforcement in a shield machine in S3 is implemented, the reinforcement range is 180 degrees at the bottom, and the reinforcement depth is 2m.
Preferably, the secondary deep hole grouting reinforcement in S2 is performed by matching a hoisting hole reserved on the inner tube sheet of the tunnel in the lower section with a grouting pipe, the grouting slurry is cement-water glass double slurry, the water glass is diluted with water 1:3, cement: water =1:1, water glass: cement paste =1:1, grouting amount is more than or equal to 25m 3 A/ring.
Preferably, the shield machine in S3 is pre-grouted in advance, a drilling machine is matched with a pre-grouting hole reserved in the shield machine to perform grouting reinforcement, the hole diameter is 100mm, the shield machine comprises a front shield, a cutter head, a middle shield, a shield tail and a grouting platform, the soil layer below the front end of the cutter head is reinforced by the pre-grouting hole, segmented retreating grouting is adopted, superfine cement-water glass double grout is adopted as the grouting grout, the volume ratio is 1:1, superfine cement of MC-800 is adopted as the superfine cement, the water cement ratio of the superfine cement grout is 1:1, the baume degree of water glass is 38 ° Be, sodium dihydrogen phosphate is adopted as a retarder, the mixing amount is 1% of the superfine cement, phosphoric acid mixed liquid is adopted for water stop in the drilling process, the volume ratio of the phosphoric acid solution to the water glass solution is 1:1, 40 ° Bee water glass and water 1:1 are adopted to dilute the water into the water glass solution, and the phosphoric acid is mixed with water 1 to form 10.
Preferably, the drilling and grouting equipment for the segmented retreating type grouting adopts a drill rod with the diameter of 42mm, a spherical tooth-shaped drill bit is installed in front of the drill rod, the length of a single section of drill rod is 2m, the drill rods are connected through threads, the rotation direction of the threads is opposite to that of drilling, a grouting hole is formed in the drill rod, a flange plate is used for connecting and fixing the drilling hole at the position of a preformed hole of the shield tunneling machine, and a grout stop plug and a blowout preventer are used for preventing grout from leaking in the drilling and grouting process.
Preferably, the sectional retreating type groutingAdopt the principle of alternate hole drilling and grouting, the hoop interval is 1.2m between the drilling, total 8 injected holes, the thick liquid diffusion radius is 0.8m, adopt different angles to carry out the slip casting to same preformed hole, the slip casting angle for the first time is 13, the slip casting angle for the second time is 6, to the detailed record of drilling rod festival number, ensure that the drilling reaches the appointed degree of depth, the slip casting scope is blade disc front end 6m (about 4 ring sections) at every turn, 4 ring sections are once consolidated every tunnelling, the single hole slip casting volume is 4.6m 3 ；
After drilling, sealing, injecting a proper amount of phosphoric acid mixed liquid for stopping water, then injecting superfine cement-water glass double-liquid slurry, retreating the drill rod by 0.5m each time when the grouting pressure reaches, performing next section of grouting, and circulating the steps until the hole is grouted completely.
Preferably, the telescopic support assembly supports the lower block tunnel and extends forward while the upper block tunnel 1 is being driven.
Preferably, flexible supporting component includes the hydraulic cylinder of vertical setting and level setting, hydraulic cylinder's one end is connected with the one end of scalable hydraulic stem, the scalable hydraulic stem other end of vertical setting is connected with vertical circular steel pipe, the scalable hydraulic stem other end of horizontal setting is connected with horizontal circular steel pipe, the lateral wall of vertical circular steel pipe is connected with can dismantle square steel pipe, horizontal circular steel pipe runs through can dismantle square steel pipe, hydraulic cylinder, the tip of vertical circular steel pipe and horizontal circular steel pipe all is connected with the arc steel sheet, and the arc steel sheet is the same with tunnel segment internal diameter radian.
Preferably, two arc-shaped steel plates are connected through channel steel along the tunneling direction, the channel steel is connected with the arc-shaped steel plates through bolts, and the length of the arc-shaped steel plates in the vertical direction is larger than that of the arc-shaped steel plates in the horizontal direction.
Preferably, stiffening ribs are welded at the joints of the arc-shaped steel plates, the vertical circular steel pipes and the transverse circular steel pipes, and the stiffening ribs are distributed among the plurality of stiffening ribs at equal angles.
Compared with the prior art, the invention has the beneficial effects that:
(1) According to the reinforcement structure of the overlapping tunnel, the deformation and the ground surface settlement of the tunnel between the upper section and the lower section can be effectively controlled through measures such as secondary deep hole grouting reinforcement of the tunnel between the lower section and advanced pre-reinforcement in a shield machine of the tunnel between the upper section and the lower section, arrangement of a temporary arc-shaped steel plate and telescopic pre-axial force steel pipe support in the tunnel between the lower section and the like, a good reinforcement effect is achieved, and excavation risks are reduced;
(2) According to the invention, the shield machine is used for pre-reinforcing in advance, and aiming at the overlapped tunnels with the ground having buildings or weak stratums with poor geological conditions and incapable of being subjected to ground pre-reinforcing or external reinforcing measures, the ultra-fine cement-water glass double grout is adopted for grouting, compared with the traditional cement grout with the diffusion radius of 0.5-0.6 m, the grouting property is better, the diffusion radius can reach 0.8-1.0 m, the strength of a reinforcing body is enhanced by the full hydration reaction of the ultra-fine cement, and compared with the strength of common cement grout, the influence on the lower tunnels during the tunneling of the upper tunnels can be well controlled by doubling the strength of the ultra-fine cement grout;
(3) The temporary arc-shaped steel plate and the telescopic pre-axial force steel pipe support are adopted, telescopic movement is convenient, when the tunnel in the upper section is tunneled, the tunnel in the lower section can be synchronously temporarily supported, the temporary arc-shaped steel plate can be contracted along the tunneling direction and then erected and extended forwards, the steel pipe is pre-axial force pre-applied by the hydraulic oil cylinder, the bearing capacity of the steel pipe is increased, the mutual influence during tunneling of the tunnel is reduced, and the deformation of the tunnel is effectively controlled.
Drawings
In order to more particularly and intuitively illustrate an embodiment of the present invention or a prior art solution, a brief description of the drawings needed for use in the description of the embodiment or the prior art will be provided below.
FIG. 1 is a schematic view of the construction process of the present invention;
FIG. 2 is a cross-sectional view of a reinforcement of a lap section of the present invention;
FIG. 3 is a flow chart of advanced pre-grouting reinforcement in a shield tunneling machine according to the invention;
FIG. 4 is a schematic diagram of advanced pre-grouting reinforcement in a shield tunneling machine according to the present invention;
FIG. 5 is a schematic view of the temporary arc-shaped steel plate and the telescopic pre-stressed steel tube support according to the present invention.
In the figure: the tunnel comprises an upper section tunnel 1, a lower section tunnel 2, a shield machine advance pre-reinforcement area 3, a secondary deep hole grouting reinforcement area 4, a front shield 5, a cutter head 6, a middle shield 7, a shield tail 8, a grouting platform 9, a drill rod 10, a non-tunneling reinforcement area 11, a tunneling reinforcement area 12, a stiffening rib 13, an arc-shaped steel plate 14, a vertical round steel pipe 15, a telescopic hydraulic rod 16, a hydraulic oil cylinder 17, a channel steel 18, a detachable square steel pipe 19 and a transverse round steel pipe 20.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in 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.
Referring to fig. 1 to 5, a construction method of an up-and-down overlapping tunnel based on advanced pre-reinforcement, the construction method comprising the steps of:
s1: constructing the lower interval tunnel 2 of the overlapping section, and synchronously grouting and reinforcing the lower interval tunnel 2;
s2: carrying out secondary deep hole grouting reinforcement on the soil body at the top of the tunnel 2 in the lower section to form a secondary deep hole grouting reinforcement area 4;
s3: performing advanced pre-grouting reinforcement on the soil body at the bottom of the tunnel 1 at the upper section of the overlapping section in the shield tunneling machine to form an advanced pre-reinforcement area 3 of the shield tunneling machine;
s4: a telescopic supporting component is erected in the lower section tunnel 2 for reinforcement;
s5: and constructing the upper section tunnel 1 of the overlapping section, and performing synchronous grouting reinforcement and secondary grouting reinforcement on the upper section tunnel 1.
In the embodiment, the secondary deep hole grouting reinforcement in S2 is implemented by deep hole grouting reinforcement in a hole, the reinforcement range is 180 degrees at the top, the reinforcement depth is 3m, the advanced pre-grouting reinforcement in the shield machine in S3 is implemented, the reinforcement range is 180 degrees at the bottom, and the reinforcement depth is 2m.
And (3) secondary deep hole grouting reinforcement:
1. slurry requirement
The grouting slurry adopts a cement-water glass mixed solution, the water glass is diluted by water 1:3, and the cement: water =1:1, water glass: cement slurry =1:1.
The grouting amount is calculated as follows:
Q＝Anα(1+β)
q-one ring of deep hole grouting amount;
a-the soil volume in the grouting range;
n is the porosity of the soil layer, and the porosity of the soil layer is 0.4;
alpha is the slurry filling coefficient, and 0.8 is taken;
beta-slurry loss factor, 0.2.
Calculated, grouting amount: not less than 25m 3 A/ring.
2. Grouting range
As shown in fig. 2, the secondary deep hole grouting reinforcement range is a range of 180 degrees of the top of the entrance tunnel in the lower section, and the reinforcement depth is 3m.
3. Grouting management
(1) Before grouting, chiseling a protective layer on the outer side of a segment hoisting hole, connecting a pipeline and grouting;
(2) Performing secondary cement-water glass double-liquid slurry when the pipe piece is separated from the 5 rings of the shield tail, and completely injecting the slurry in the 7 rings of the pipe piece separated from the shield tail;
(3) The grouting pressure is strictly controlled between 0.3 and 0.5MPa;
(4) When injecting the double-slurry, injecting the pure water slurry for 1min, opening a water glass valve for mixing and injecting, and increasing the concentration of water glass when finishing the hole;
(5) And after the grouting is finished, the mixing valve and the connecting valve are flushed in time, so that the next grouting can be smoothly carried out, and after the secondary grouting is finished, each grouting hole is sealed to prevent water seepage.
In this embodiment, the secondary deep hole grouting in S2 is consolidated, and the grouting is performed through the matching of the hoisting hole reserved on the inner tube sheet of the lower interval tunnel 1 and the grouting pipe, and the grouting slurry adopts cement-water glass double slurry, and the water glass is diluted with water 1:3, cement: water =1:1, waterglass: cement paste =1:1, grouting amount is more than or equal to 25m 3 A/ring.
In the embodiment, advanced pre-grouting reinforcement is performed in a shield machine in S3, an advanced pre-grouting hole reserved in the shield machine is matched with a drilling machine for grouting reinforcement, the hole diameter is 100mm, the shield machine comprises a front shield 5, a cutter head 6, a middle shield 7, a shield tail 8 and a grouting platform 9, the soil layer below the front end of the cutter head 6 is reinforced by the advanced grouting hole, segmented retreating grouting is adopted, superfine cement-water glass double-slurry is adopted as the grouting slurry, the volume ratio is 1:1, superfine cement of MC-800 is adopted as the superfine cement, the water cement ratio of the superfine cement slurry is 1:1, baume degree of water glass is 38 Bee, sodium dihydrogen phosphate is adopted as a retarder, the mixing amount is 1% of the mass of the superfine cement, phosphoric acid mixed solution is adopted for water stop in the drilling process, the volume ratio of the phosphoric acid solution and the water glass solution is 1:1, 40 DEG B water glass and water 1:1 are mixed into a water glass solution, and the phosphoric acid is mixed into a phosphoric acid solution diluted water solution which is mixed into 10.
Advanced pre-grouting reinforcement in a shield tunneling machine:
1. slurry requirement
The grouting slurry is superfine cement-water glass double slurry, the volume ratio is 1:1, the superfine cement is MC-800 superfine cement, the water cement ratio of the superfine cement slurry is 1:1, the baume degree of water glass is 38 degrees Be, the retarder is sodium dihydrogen phosphate, the mixing amount is 1 percent of the mass of the superfine cement, phosphoric acid mixed liquor is adopted for water stop in the drilling process, the volume ratio of the phosphoric acid solution to the water glass solution is 1:1, 40 degrees Be water glass and water 1:1 are adopted for dilution, the water glass solution is formed, and phosphoric acid and water are mixed into the phosphoric acid solution in a ratio of 1.
In order to obtain a better grouting effect in the silt layer, the superfine cement-water glass double grout is adopted for grouting reinforcement, the grouting effect is better compared with the ordinary cement grout, the strength of a reinforced body is higher, and the following table shows the advantage and disadvantage comparison of the superfine cement-water glass double grout and the ordinary cement-water glass double grout.
The single hole grouting amount is calculated according to the following formula:
Q＝πR 2 Hnα(1+β)
q-single hole grouting amount;
r-slurry diffusion radius;
h-reinforcement depth;
n-porosity, the soil layer is 0.4;
alpha is the slurry filling coefficient, and 0.8 is taken;
beta-slurry loss rate, 0.2.
Calculated, the single-hole advanced grouting amount is 4.6m 3 。
2. Drilling and grouting
Fig. 4 is a schematic diagram illustrating the flow of advanced pre-consolidation.
Drilling and grouting operations are carried out on a scaffold platform erected in a shield shell, grouting is carried out by utilizing advanced grouting holes in the upper bottom and the middle part of a shield machine, before grouting, a gate valve at the position of a reserved hole is opened, then a drilling machine is installed for drilling and grouting operations, the bottom of a tunnel in a reinforcing range is 180 degrees, and the depth is 2m.
The drilling and grouting equipment for sectional retreating type grouting adopts a drill rod 10 with the diameter of 42mm, a spherical tooth-shaped drill bit is installed in front of the drill rod 10, the length of a single section of drill rod 10 is 2m, the drill rods 10 are connected through threads, the thread rotating direction is opposite to the drilling rotating direction, a grouting hole channel is formed in the drill rod 10, a flange plate is used for connecting and fixing the drilling hole opening of a preformed hole of a shield machine, and a grout stop plug and a blowout preventer are utilized to prevent grout leakage in the drilling and grouting process.
The sectional retreating type grouting adopts a hole-separating drilling grouting principle, the circumferential distance between drilled holes is 1.2m, 8 grouting holes are counted, the diffusion radius of slurry is 0.8m, grouting is performed on the same preformed hole at different angles, the first grouting angle is 13 degrees, the second grouting angle is 6 degrees, the number of drill rod sections is recorded in detail, the drilled holes are guaranteed to reach the specified depth, the grouting range is 6m (about 4 ring segments) at the front end of a cutter head, reinforcement is performed on each tunneling 4 ring segments, and the single-hole grouting amount is 4.6m 3 ；
After drilling, sealing, injecting a proper amount of phosphoric acid mixed liquid for stopping water, then injecting superfine cement-water glass double-liquid slurry, retreating the drill rod by 0.5m each time when the grouting pressure reaches, performing next section of grouting, and circulating the steps until the hole is grouted completely.
3. Advanced pre-consolidation grouting management
(1) Adopting an advanced grouting hole in a shield tunneling machine to perform grouting;
(2) In the grouting process, the drill rod is lifted while grouting, and the lifting amplitude is strictly controlled;
(3) The grouting pressure is strictly controlled in the grouting process;
(4) The cutter head is rotated frequently in the grouting process, so that the slurry is prevented from entering the soil bin to wrap the cutter head or the shield body.
In this embodiment, the telescopic support assembly supports the lower section tunnel 2 and extends forward and erects in synchronization with the driving of the upper section tunnel 1.
In this embodiment, flexible supporting component includes the hydraulic cylinder 17 of vertical setting and horizontal setting, the one end of hydraulic cylinder 17 is connected with the one end of scalable hydraulic stem 16, the scalable hydraulic stem 16 other end of vertical setting is connected with vertical circular steel pipe 15, the scalable hydraulic stem 16 other end of horizontal setting is connected with horizontal circular steel pipe 20, the lateral wall of vertical circular steel pipe 15 is connected with can dismantle square steel pipe 19, horizontal circular steel pipe 20 runs through can dismantle square steel pipe 19, hydraulic cylinder 17, the tip of vertical circular steel pipe 15 and horizontal circular steel pipe 20 all is connected with arc steel sheet 14, and arc steel sheet 14 is the same with tunnel segment internal diameter radian, two continuous arc steel sheets 14 pass through channel-section steel 18 along the tunnel tunnelling direction and connect, channel-section steel 18 passes through the bolt and links to each other with arc steel sheet 14, the length of arc steel sheet 14 of vertical direction is greater than the length of arc steel sheet 14 of horizontal direction, arc steel sheet 14 and vertical circular steel pipe 15 and horizontal circular steel pipe 20 junction all weld stiffening rib 13, and the equal angular distribution between a plurality of stiffening ribs 13.
As shown in fig. 5, when the upper section tunnel 1 is driven, the lower section tunnel 2 is supported by the telescopic support unit and can be extended forward and erected in synchronization with the driving of the upper section tunnel 1.
Adopt flexible supporting component to support, each intra-annular comprises four arc steel sheets 14 and four steel pipes, and arc steel sheet 14 is unanimous with section of jurisdiction internal diameter radian, and four steel pipes adopt retractable hydraulic stem to add circular steel pipe, shrink when can following the tunneling of upper portion and stretch out to the removal of place ahead again, arc steel sheet thickness 25mm, wide 1000mm, upper and lower arc steel sheet length be 4000mm, controls the arc steel sheet length and is 2000mm.
The telescopic pre-applied axial force steel pipe is a hydraulic rod and a circular steel pipe, the telescopic hydraulic rod 16 and the hydraulic oil cylinder 17 are adopted to pre-apply axial force, one end of the hydraulic oil cylinder 17 is welded on the arc-shaped steel plate 14, the telescopic hydraulic rod 16 at the other end is welded on the vertical circular steel pipe 15 or the transverse circular steel pipe 20, the other end of the vertical circular steel pipe 15 and the transverse circular steel pipe 20 is welded with the arc-shaped steel plate 14, the diameter of the vertical circular steel pipe 15 and the transverse circular steel pipe 20 is 60mm, which is 10mm smaller than the diameter of the telescopic hydraulic rod 16 connected by welding, the welding is convenient, the wall thickness of the vertical circular steel pipe 15 and the transverse circular steel pipe 20 is 20mm, the length is 300mm, the detachable square steel pipe 19 is fixed on the vertical circular steel pipe 15 by using bolts and is used for bearing and transversely supporting and lifting, when the vertical telescopic hydraulic rod 16 is lifted to a certain height, the transverse hydraulic device is operated, the arc-shaped steel plates 14 at two ends of the transverse hydraulic device are jacked to be stable, the detachable square steel pipe 19 is dismounted, the telescopic hydraulic rod 16 is continuously lifted, the upper arc-shaped steel plate 14 is jacked to a duct piece, and vice versa during contraction.
Through channel-section steel 18 with arc steel sheet 14 along two liang of connections in the tunnel excavation direction, channel-section steel 18 pass through bolted connection on arc steel sheet 14, channel-section steel 18 adopt 10# channel-section steel, height 100mm, wide 48mm, thickness is 5.3mm.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.
Claims (10)
1. A construction method of an up-and-down overlapping tunnel based on advanced pre-reinforcement is characterized by comprising the following steps:
s1: constructing a lower section tunnel (2) of the overlapping section, and synchronously grouting and reinforcing the lower section tunnel (2);
s2: carrying out secondary deep hole grouting reinforcement on the soil body at the top of the tunnel (2) in the lower section to form a secondary deep hole grouting reinforcement area (4);
s3: performing advanced pre-grouting reinforcement on a soil body at the bottom of the tunnel (1) at the upper section of the overlapping section in the shield tunneling machine to form an advanced pre-reinforcement area (3) of the shield tunneling machine;
s4: a telescopic supporting component is erected in the lower section tunnel (2) for reinforcement;
s5: and constructing the upper section tunnel (1) of the overlapping section, and performing synchronous grouting reinforcement and secondary grouting reinforcement on the upper section tunnel (1).
2. The construction method of the up-and-down overlapping tunnel based on advanced pre-reinforcement as claimed in claim 1, wherein the secondary deep hole grouting reinforcement in S2 is implemented by deep hole grouting reinforcement in a tunnel, the reinforcement range is 180 ° at the top, the reinforcement depth is 3m, the advanced pre-grouting reinforcement in a shield machine in S3 is implemented, the reinforcement range is 180 ° at the bottom, and the reinforcement depth is 2m.
3. The construction method of the up-and-down overlapping tunnel based on advanced pre-reinforcement as claimed in claim 2, wherein the secondary deep hole grouting reinforcement in S2 is performed by matching a hoisting hole reserved on the inner tube sheet of the lower interval tunnel (1) with a grouting pipe, the grouting slurry is cement-water glass double slurry, the water glass is diluted with water 1:3, and the cement: water =1:1, water glass: cement paste =1:1, grouting amount is more than or equal to 25m 3 A/ring.
4. The method for constructing the up-and-down overlapping tunnel based on advanced pre-reinforcement as claimed in claim 3, wherein the shield machine in S3 is pre-grouted and reinforced in advance, advanced pre-grouting holes reserved in the shield machine are used for matching with a drilling machine to perform grouting reinforcement, the hole diameter is 100mm, the shield machine comprises a front shield (5), a cutter head (6), a middle shield (7), a shield tail (8) and a grouting platform (9), the soil layer below the front end of the cutter head (6) is reinforced by the advanced grouting holes, sectional retreating type grouting is adopted, the grouting slurry adopts superfine cement-water glass double slurry, the volume ratio is 1:1, the superfine cement adopts MC-800 superfine cement, the water cement ratio of the superfine cement slurry is 1:1, the baume degree of water glass is 38 ° Bee, the retarder adopts sodium dihydrogen phosphate, the mixing amount is 1% of the superfine cement, and the mixed solution of phosphoric acid and the water glass is mixed into 3532 zxft Solution which is mixed into 3425 water solution.
5. The construction method of the up-and-down overlapping tunnel based on advanced pre-reinforcement is characterized in that the drilling and grouting equipment for the segmented retreating type grouting adopts a drill rod (10) with the diameter of 42mm, a spherical-tooth-shaped drill bit is installed in front of the drill rod (10), the length of a single section of drill rod (10) is 2m, the drill rods (10) are connected through threads, the rotation direction of the threads is opposite to the rotation direction of a drilled hole, a grouting hole channel is formed in the drill rod (10), a flange plate is used for connecting and fixing the drilling hole of a preformed hole of a shield tunneling machine, and a grout stop plug and a blowout preventer are used for preventing grout from leaking in the drilling and grouting process.
6. The construction method of the up-down overlapping tunnel based on the advanced pre-reinforcement as claimed in claim 5, wherein the segmented retreating grouting adopts a hole-separating drilling grouting principle, the circumferential distance between drilled holes is 1.2m, the total number of 8 grouting holes is 8, the slurry diffusion radius is 0.8m, different angles are adopted for the same preformed hole for grouting, the first grouting angle is 13 degrees, the second grouting angle is 6 degrees, the drilling rod section number is recorded in detail, the drilling hole is ensured to reach the designated depth, the grouting range is 6m (about 4 ring segments) at the front end of the cutter head each time, the reinforcement is carried out at each time of tunneling of 4 ring segments, and the single-hole grouting amount is 4.6m 3 ；
After drilling is finished, sealing, injecting a proper amount of phosphoric acid mixed liquid for stopping water, then injecting superfine cement-water glass double-liquid slurry, retreating the drill rod by 0.5m each time when the grouting pressure is reached, performing next section of grouting, and circulating the steps until the grouting of the hole is finished.
7. The method for constructing the up-and-down overlapping tunnel based on the advanced pre-reinforcement as claimed in claim 6, wherein the telescopic supporting components support the lower section tunnel (2) and extend forward and erect simultaneously with the driving of the upper section tunnel (1).
8. The up-down overlapping tunnel construction method based on advanced pre-reinforcement according to claim 7, wherein the telescopic supporting assembly comprises a vertically arranged hydraulic oil cylinder (17) and a horizontally arranged hydraulic oil cylinder (17), one end of the hydraulic oil cylinder (17) is connected with one end of a telescopic hydraulic rod (16), the other end of the vertically arranged telescopic hydraulic rod (16) is connected with a vertical round steel pipe (15), the other end of the transversely arranged telescopic hydraulic rod (16) is connected with a transverse round steel pipe (20), the side wall of the vertical round steel pipe (15) is connected with a detachable square steel pipe (19), the transverse round steel pipe (20) penetrates through the detachable square steel pipe (19), the end parts of the hydraulic oil cylinder (17), the vertical round steel pipe (15) and the transverse round steel pipe (20) are connected with arc-shaped steel plates (14), and the arc-shaped steel plates (14) are the same as the inner diameter radian of a tunnel segment.
9. The construction method of the up-and-down overlapping tunnel based on advanced pre-reinforcement is characterized in that two connected arc-shaped steel plates (14) are connected through channel steel (18) along the tunneling direction, the channel steel (18) is connected with the arc-shaped steel plates (14) through bolts, and the length of the arc-shaped steel plates (14) in the vertical direction is larger than that of the arc-shaped steel plates (14) in the horizontal direction.
10. The construction method of the up-down overlapping tunnel based on advanced pre-reinforcement according to claim 9, wherein stiffening ribs (13) are welded at the joints of the arc-shaped steel plates (14) and the vertical circular steel pipes (15) and the transverse circular steel pipes (20), and the stiffening ribs (13) are distributed at equal angles.
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| CN202211230210.0A CN115839251A (en) | 2022-10-08 | 2022-10-08 | Up-down overlapping tunnel construction method based on advanced pre-reinforcement |
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| CN202211230210.0A CN115839251A (en) | 2022-10-08 | 2022-10-08 | Up-down overlapping tunnel construction method based on advanced pre-reinforcement |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117266888A (en) * | 2023-11-21 | 2023-12-22 | 中铁电气化局集团有限公司 | Grouting device is reserved in upper and lower overlapping tunnel |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117266888A (en) * | 2023-11-21 | 2023-12-22 | 中铁电气化局集团有限公司 | Grouting device is reserved in upper and lower overlapping tunnel |
| CN117266888B (en) * | 2023-11-21 | 2024-01-23 | 中铁电气化局集团有限公司 | Grouting device is reserved in upper and lower overlapping tunnel |
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