Tunnel blind pipe grooving construction method

Abstract

The invention discloses a construction method for tunnel blind pipe grooving. The construction method comprises the steps of surveying and lofting, concrete spraying, laser positioning, excavator single-hook scribing, manual grooving and forming, blind pipe trial assembly and blind pipe installation. By the adoption of the annular drainage blind pipe grooving construction technology, the construction method is easy to operate, grooves are formed well, the working procedure time is shortened, the construction progress is accelerated, the compactness of the arch wall lining is improved, and formation of holes behind the lining is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction, and in particular to a construction method for tunnel blind pipe grooving. Background Art

[0002] When laying the waterproof layer at the annular blind pipe, it is easy to have holes. At the same time, because the blind pipe is attached to the outside of the primary support surface, it is easy to cause physical quality problems such as holes behind the secondary lining and insufficient thickness of the secondary lining, which affects the quality of the project. In order to avoid this problem, all the annular blind pipes are grooved. The initial support surface groove construction was first adopted at the entrance of Hongyuan No. 1 Tunnel. During the construction period, many attempts were made. Pre-buried PVC pipes were tried. Because the pre-buried pipes are combined with concrete, when the pre-buried pipes are removed, the concrete around the pipes is affected by the removal of the pipes and the edges and corners are broken. The blind pipe groove forming effect is too poor and the primary support surface is damaged. After the pre-buried pipes are installed, it is easy to cause problems such as loose sprayed concrete behind the pipes. The shaped steel frame is processed separately, and the arch frame is enlarged by 5cm at the position of the embedded pipe. Since the arch frame will be misaligned after being enlarged by 5cm, the construction quality of the subsequent arch frame installation, mesh overlap, and connecting rib welding processes is also difficult to guarantee. In the end, there will be problems such as misalignment of the primary support surface, local bulging, and poor initial support flatness, which are not very ideal. Summary of the invention

[0003] The purpose of the invention is to solve the problem of difficulty in blind pipe grooving in the prior art and to propose a construction method for blind pipe grooving in a tunnel.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A construction method for tunnel blind pipe grooving comprises the following steps:

[0006] Step 1: Measurement and setting out;

[0007] Step 1.1: Arch installation;

[0008] Step 1.2: Surveyors use a total station to locate and stake out on site according to the designed mileage position of the blind pipe;

[0009] Step 1.3: Avoid the steel arch and use pre-buried steel bars to locate the blind pipe groove. Pre-buried a steel bar every 2 meters in the circumferential direction to ensure the circumferential verticality when cutting the groove. It can also check the thickness of the shotcrete.

[0010] Step 2: Shotcrete;

[0011] Use a robot to spray C25 concrete, and spray concrete in layers from bottom to top. During construction, be careful not to knock off or spray the reserved steel bars on the steel frame. When constructing the last layer of sprayed concrete, the attendant will notify the groove carver to enter the site for advance preparation.

[0012] Step 3: Laser positioning;

[0013] Step 3.1: 10 minutes after the last layer of shotcrete is completed, use a circular laser light to accurately mark the position of the embedded steel bars;

[0014] Step 3.2: Adjust the level to align the position of the embedded steel bars, observe whether the position is offset, and ensure that the position of the blind pipe is symmetrical;

[0015] Step 4: Marking line with single hook of excavator;

[0016] According to the position of laser positioning, the construction time of preliminary marking with a single hook of an excavator is 6 to 8 minutes;

[0017] Step 5: Artificial groove forming;

[0018] According to the initial setting time of shotcrete, construction is carried out immediately after the shotcrete is completed. After the excavation platform is in place, workers use tools such as slotters to accurately cut grooves on the excavation platform. The slotters are used to cut lines along the laser positioning lines, and the concrete in the grooves is chiseled from bottom to top with a pickaxe.

[0019] Step 6: Blind pipe test installation;

[0020] After the groove is completed, a 50 blind pipe is used for trial installation. The position where the groove cannot be inserted is grooved again to avoid the blind pipe being unable to be installed due to the uneven groove width and depth after the subsequent blind pipe is installed, resulting in a cavity behind the waterproof board.

[0021] Step 7: Blind pipe installation;

[0022] After the groove is formed, the blind tube is tied with wire and fixed to the initial support surface by nailing on the fixing belt with a nail gun.

[0023] Preferably, in step 4, the grooving construction of the lower and middle steps is carried out first, and after the upper step is shotcrete-casted, the grooving is carried out and the invert arch is shotcrete-casted.

[0024] Preferably, in step 5, the groove depth is 7 cm, the width is 7 cm, the construction time is 10 to 15 minutes, and the groove line is straight and the groove position is neat.

[0025] Preferably, in step 5, a 7 cm deep position is marked on the pickaxe with red paint before construction, and the mark is promptly re-marked when it is unclear. At the same time, a 7 cm wide position is marked with steel bars at the 7 cm position to ensure the quality of the grooving construction.

[0026] Preferably, in step 7, a 3 cm×15 cm long narrow strip of waterproof board is used to fix the φ50 permeable blind pipe in the groove.

[0027] Preferably, in step 7, a DG blind pipe with an inner diameter of 50 mm is circumferentially arranged behind the arch wall lining waterproof board, and the circumferential blind pipe is arranged at a spacing of 9 m in general areas and at a spacing of 4 m in water-rich areas.

[0028] The present invention also proposes a method for notching a blind tunnel pipe, comprising the following steps:

[0029] Compared with the prior art, the present invention provides a construction method for tunnel blind pipe grooving, which has the following beneficial effects:

[0030] 1. The construction method of the blind pipe grooving of the tunnel adopts the annular drainage blind pipe grooving construction technology. The construction method is simple to operate, the groove is well formed, the process time is shortened, the construction progress is accelerated, the compactness of the arch wall lining is improved, and the formation of voids behind the lining is reduced.

[0031] 2. The tunnel blind pipe grooving construction method reduces concrete waste by adopting the annular drainage blind pipe grooving construction process. Moreover, this process does not require additional labor and equipment, thus saving costs.

[0032] The parts not involved in the device are the same as those in the prior art or can be implemented by using the prior art. The present invention has a simple structure and is easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Figure 1 A method for constructing a tunnel blind pipe groove comprises the following steps:

[0035] Step 1: Measurement and setting out;

[0036] Step 1.1: Arch installation;

[0037] Step 1.2: Surveyors use a total station to locate and stake out on site according to the designed mileage position of the blind pipe;

[0038] Step 1.3: Avoid the steel arch and use pre-buried steel bars to locate the blind pipe groove. Pre-buried a steel bar every 2 meters in the circumferential direction to ensure the circumferential verticality when cutting the groove. It can also check the thickness of the shotcrete.

[0039] Step 2: Shotcrete;

[0040] Use a robot to spray C25 concrete, spray concrete layer by layer from bottom to top. During construction, be careful not to knock off or spray the reserved steel bars on the steel frame. When the last layer of spray concrete is being constructed, the attendant notifies the groove cutter to enter the site for advance preparation. This can ensure the timing of groove cutting during subsequent construction.

[0041] Step 3: Laser positioning;

[0042] Step 3.1: 10 minutes after the last layer of shotcrete is completed, use a circular laser light to accurately mark the position of the embedded steel bars;

[0043] Step 3.2: Adjust the level to align the position of the embedded steel bars, observe whether the position is offset, and ensure that the position of the blind pipe is symmetrical;

[0044] Step 4: Marking line with single hook of excavator;

[0045] According to the position of laser positioning, the construction time of preliminary marking with a single hook of an excavator is 6 to 8 minutes;

[0046] Step 5: Artificial groove forming;

[0047] According to the initial setting time of shotcrete, construction is carried out immediately after the shotcrete is completed. After the excavation platform is in place, workers use tools such as slotters to accurately cut grooves on the excavation platform. The slotters are used to cut lines along the laser positioning lines, and the concrete in the grooves is chiseled from bottom to top with a pickaxe.

[0048] Step 6: Blind pipe test installation;

[0049] After the groove is completed, a 50 blind pipe is used for trial installation. The position where the groove cannot be inserted is grooved again to avoid the blind pipe being unable to be installed due to the uneven groove width and depth after the subsequent blind pipe is installed, resulting in a cavity behind the waterproof board.

[0050] Step 7: Blind pipe installation;

[0051] After the groove is formed, the blind tube is tied with wire and fixed to the initial support surface by nailing on the fixing belt with a nail gun.

[0052] In the step 1, the blind pipe positioning ribs are marked by measuring and setting out in advance, which effectively shortens the process time, so that the blind pipe position can be quickly located for construction after the shotcrete is completed.

[0053] In step 2, the grooves of the lower and middle steps are firstly carved, and the inverted arch is sprayed after the upper step is sprayed. This forms a process connection, and when spraying concrete, the lower, middle and upper steps are first sprayed in sequence, and the inverted arch is sprayed last. In this way, the grooves of the lower and middle steps can be firstly carved, and the inverted arch is sprayed after the upper step is sprayed. This does not affect the progress of the sprayed concrete construction, improves the work efficiency and reduces the cost.

[0054] In step 3, laser positioning is used quickly and accurately, and the grooves are carved along the laser line to ensure the straightness of the grooves.

[0055] In step 4, using a single hook of an excavator to carve grooves is faster, reduces the use of manpower, does not require an operating platform (excavation stand), is simple to operate, and can ensure that the initial groove is formed in one step.

[0056] In the step 5, the groove depth is 7 cm, the width is 7 cm, the construction time is 10 to 15 minutes, and the groove line is straight and the groove position is neat; and before construction, the 7 cm deep position is marked with red paint on the pickaxe, and the mark is re-marked in time when it is unclear. At the same time, steel bars are used to mark the 7 cm wide position at the 7 cm position to ensure the quality of the groove construction, avoid multiple rework, and achieve good molding effect.

[0057] In step 6, after the groove is carved, the trial installation of the blind tube can find out the non-standard position of the groove and repair it in time, avoiding the problem of partial failure to embed the blind tube during the later installation, which is labor-intensive.

[0058] In step 7, a φ50 permeable blind pipe is fixed in the groove using a 3 cm × 15 cm long narrow strip of waterproof board fixing tape; and a 50 mm inner diameter DG blind pipe is circumferentially arranged behind the arch wall lining waterproof board, and the circumferential blind pipe is arranged at a spacing of 9 m in general areas and at a spacing of 4 m in water-rich areas.

[0059] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A construction method for tunnel blind pipe grooving, characterized in that: The steps include: Step 1: Measurement and setting out; Step 1.1: Arch installation; Step 1.2: Surveyors use a total station to locate and stake out on site according to the designed mileage position of the blind pipe; Step 1.3: Avoid the steel arch and use pre-buried steel bars to locate the blind pipe groove. Pre-buried a steel bar every 2 meters in the circumferential direction to ensure the circumferential verticality when cutting the groove. It can also check the thickness of the shotcrete. Step 2: Shotcrete; Use a robot to spray C25 concrete, and spray concrete in layers from bottom to top. During construction, be careful not to knock off or spray the reserved steel bars on the steel frame. When constructing the last layer of sprayed concrete, the attendant will notify the groove carver to enter the site for advance preparation. Step 3: Laser positioning; Step 3.1: 10 minutes after the last layer of shotcrete is completed, use a circular laser light to accurately mark the position of the embedded steel bars; Step 3.2: Adjust the level to align the position of the embedded steel bars, observe whether the position is offset, and ensure that the position of the blind pipe is symmetrical; Step 4: Marking line with single hook of excavator; According to the position of laser positioning, the construction time of preliminary marking with a single hook of an excavator is 6 to 8 minutes; Step 5: Artificial groove forming; According to the initial setting time of shotcrete, construction is carried out immediately after the shotcrete is completed. After the excavation platform is in place, workers use tools such as slotters to accurately cut grooves on the excavation platform. The slotters are used to cut lines along the laser positioning lines, and the concrete in the grooves is chiseled from bottom to top with a pickaxe. Step 6: Blind pipe test installation; After the groove is completed, a 50 blind pipe is used for trial installation. The position where the groove cannot be inserted is grooved again to avoid the blind pipe being unable to be installed due to the uneven groove width and depth after the subsequent blind pipe is installed, resulting in a cavity behind the waterproof board. Step 7: Blind pipe installation; After the groove is formed, the blind tube is tied with wire and fixed to the initial support surface by nailing on the fixing belt with a nail gun.

2. A method for constructing a blind tunnel groove according to claim 1, characterized in that: In step 4, the grooves of the lower and middle steps are firstly carved, and after the upper step is shotcrete-casted, the grooves are then shotcrete-casted on the invert.

3. A method for constructing a blind tunnel groove according to claim 1, characterized in that: In step 5, the groove depth is 7 cm, the width is 7 cm, the construction time is 10 to 15 minutes, and the groove line is straight and the groove position is neat.

4. A method for constructing a tunnel blind pipe groove according to claim 1, characterized in that: In step 5, before construction, a 7 cm deep position is marked on the pickaxe with red paint, and if the mark is unclear, it is re-marked in time. At the same time, a 7 cm wide position is marked with a steel bar at the 7 cm position to ensure the quality of the groove construction.

5. A method for constructing a tunnel blind pipe groove according to claim 1, characterized in that: In step 7, a 3 cm×15 cm long narrow strip of waterproof board is used to fix the φ50 permeable blind pipe in the groove.

6. A method for constructing blind tunnel grooves according to claim 1, characterized in that: In step 7, a DG blind pipe with an inner diameter of 50 mm is circumferentially arranged behind the waterproof board of the arch wall lining, and the circumferential blind pipe is arranged at a spacing of 9 m in general areas and at a spacing of 4 m in water-rich areas.

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