Concrete portal cutting construction method

Abstract

The invention relates to the technical field of tunnel portal cutting, and discloses a concrete tunnel portal cutting construction method, which is characterized in that an underground diaphragm wall tunnel portal between an accessory structure and a main body structure of an open cut subway station is cut by a hole digging method. According to the concrete tunnel portal cutting construction method, an upper crown beam retaining wall is reserved, a ground wall at the connecting position of a lower tunnel portal is cut through a rope saw and chiseled away through an artificial air pick in a mutually matched mode, and during cutting, cutting is divided into units in the transverse direction and then in the vertical direction, and layer-by-layer cutting is conducted from top to bottom; one-time cutting in the horizontal direction is completed; the top block, the middle block and the bottom block are cut one by one and hoisted one by one in the vertical direction, the cut construction waste can be rapidly hoisted away after cutting is completed, a static breaking mode can be adopted during manual chiseling, construction personnel can operate conveniently, and time and labor are saved.

Description

Technical Field

[0001] The present invention relates to the technical field of portal cutting, and particularly to a construction method for cutting a concrete portal. Background Art

[0002] With the construction of cities, subway travel has become an efficient, environmentally friendly and convenient public transportation method. Subway stations often have multiple entrances and exits to meet the needs of passengers and functional requirements. At the same time, passage interfaces need to be reserved in areas with dense underground commercial spaces to prepare for the connection of future underground commercial spaces.

[0003] During the construction process of rail transit projects, during the construction stage of auxiliary projects such as subway entrances and exits, ventilation shafts, and reserved interfaces, the auxiliary structure needs to be effectively connected to the completed main structure. Before the structure is connected, a necessary task needs to be completed, that is, to demolish the main retaining structure at the main and auxiliary interface parts. The main retaining structure under soft soil geological conditions is often a diaphragm wall.

[0004] Currently, when cutting the concrete door opening of a ventilation shaft, methods such as excavator crushing, water drill block-by-block demolition, or manual pickax chiseling are often used. Among them, excavator crushing is often not allowed due to characteristics such as large disturbance, high noise, irregular contour, and even damage to the structure. Water drill block-by-block demolition has a wavy edge, which is not conducive to lifting out the blocks. Manual pickax chiseling is time-consuming, laborious, and inefficient, and is only used for local chiseling of special parts. Therefore, a construction method for cutting a concrete portal is needed to solve the above problems. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention provides a construction method for cutting a concrete portal, which solves the problems mentioned in the above background.

[0006] The present invention provides the following technical solution: A construction method for cutting a concrete portal, the structure of the construction area includes a main structure, an auxiliary structure, and a diaphragm wall to be demolished at the portal. The diaphragm wall to be demolished at the portal is located at the interface between the main structure and the auxiliary structure. On the upper end of the side of the diaphragm wall to be demolished at the portal away from the main structure is the auxiliary structure, and a reverse corbel is provided at the lower end of the side of the auxiliary structure close to the main structure.

[0007] The diaphragm wall to be demolished at the portal includes a wire saw cutting area and a manual chiseling area outside the wire saw cutting area. A plurality of cutting holes are opened at the connection between the wire saw cutting area and the manual chiseling area. The wire saw divides the wire saw cutting area into a plurality of lifting blocks through the cutting holes, and lifting holes are opened on the lifting blocks.

[0008] Adopting the demolition method of digging a portal opening, its construction method includes:

[0009] Step S1, construction preparation;

[0010] Step S2, marking the cutting unit and block size;

[0011] Step S3, drilling cutting holes and lifting holes;

[0012] Step S4, cutting by the first unit wire saw;

[0013] Step S5, hoisting layer by layer;

[0014] Step S6, installing support columns;

[0015] Step S7, cutting and hoisting of the remaining units;

[0016] Step S8, loading onto trucks for shipment.

[0017] Preferably, in step S1, construction preparation includes planning for the demolition period of the tunnel portal ground wall; planning for the configuration of the main tunnel portal cutting machinery; and planning for the configuration of personnel.

[0018] Preferably, in step S2, the ground wall to be demolished at the opening is divided into a plurality of units to be cut; and then, according to the size of the opening, the type of crane selected, and the on-site lifting conditions, the size of each auxiliary cutting block is also different, and the weight of each block is controlled within 10t, and then the body to be cut is marked before construction.

[0019] Preferably, in step S3, drilling is performed using a water drill according to the layered and block marking lines; after the drilling is completed, it should be inspected and accepted in a timely manner; a lifting hole needs to be drilled in each block, and the rope saw cutting holes can be set in multiple blocks; two lifting holes are arranged horizontally on each block.

[0020] Preferably, in step S4 and step S5, the ground wall corresponding to the door opening of the main structure is cut by a rope saw. During cutting, the rope saw device is placed on the structural bottom plate. After the rope saw chain passes through the cutting hole and is connected to the device, various safety measures are checked, the power is turned on, and the device is remotely started for cutting;

[0021] The auxiliary structure is equipped with a 650mm high small-volume cutting area, namely the top block, at the top of the rope saw cutting area. It is cut and hoisted out first to free up a 650mm high space on the top. When it is difficult to hoist the top block out directly, it can be pulled out horizontally by a hand winch. Before the horizontal pull-out operation, the cutting block needs to be hung with a lifting rope and cooperated with the crane to prevent it from falling. It is strictly forbidden to stand at the bottom. When cutting, it is divided into units, first horizontally and then vertically, cutting layer by layer from top to bottom. The horizontal cutting is completed in one go. In the vertical direction, it is cut and hoisted one by one in the order of top block, middle block and bottom block.

[0022] Preferably, in step S6, the tunneling method of breaking is adopted. After each unit portal is cut, the installation of the support columns is immediately carried out. A support column is arranged every 12m to 15m. The support column adopts a lattice column of 460*460mm. A steel plate is welded to the top and bottom of the column respectively. The steel plate is fixed to the diaphragm wall by 4 M18 expansion bolts. After the support column is installed, the cutting and hoisting of the next unit diaphragm wall continue.

[0023] Preferably, in step S7:

[0024] Step S71, if the diaphragm wall corresponding to the main structure range is not separated, manual chiseling is required. When working at heights, a portal frame is used as the working platform. A safety railing is set on the top of the platform, and outriggers are set around it. Outriggers are set at the four corners of the frame body;

[0025] Step S72, after the frame body is erected, manual pneumatic pick chiseling is immediately carried out. If static breaking is adopted, first chisel the outer row of steel bar protection layers, use gas cutting to cut off the outer row of main steel bars of the diaphragm wall, use a pneumatic drill to drill holes in the diaphragm wall with a diameter of 4cm and a depth of 70cm, and the left-right and front-back spacing is 25cm; after the drilling is completed, load the expansive agent, and after standing for 12 hours, use the self-expanding extrusion force to cause cracks in the concrete, and then manually chisel with a pneumatic pick; the concrete blocks generated by the chiseling are cleaned up in time.

[0026] Preferably, in step S72, if the diaphragm wall corresponding to the main structure range is in a separated state and the part where cutting conditions are met, the wire saw cutting method is adopted. First, the vertical cutting and the setting of the hoisting holes are completed, and finally the horizontal cutting is carried out. Before each horizontal cutting, a crane is used for pre-hoisting to prevent falling, and at the same time, the personnel below are evacuated; for the part of the diaphragm wall corresponding to the main structure range that is in a separated state but does not meet the cutting conditions, the method of manual plus static breaking is adopted.

[0027] Preferably, corresponding civilized construction guarantee measures are taken during the implementation of this scheme: a temporary water retaining wall is built in the main middle slab before construction, and a temporary water retaining sill is set in the affiliated operation area; after the cutting work is completed, the sewage is pumped out in time to the ground drainage ditch and discharged to the three-stage sedimentation tank, and the sedimented mud on the affiliated slab is cleaned up; the concrete blocks loaded on the vehicle for external transportation should be bundled.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. For this concrete portal cutting construction method, the diaphragm wall at the portal connection is cut by a wire saw and manually chiseled with a pneumatic pick in a coordinated manner. And when manually chiseling, the static breaking method can be adopted. First, the outer row of main steel bars of the diaphragm wall is peeled off, and then holes are drilled and the expansive agent is loaded. After the concrete expands and cracks, large-area manual chiseling can be carried out, improving the efficiency;

[0030] Among them, before the wire saw cutting, the cutting area is divided into cutting units in advance, and the cutting area is marked by spraying paint on site to ensure that the weight of each cutting body does not exceed the allowable weight, ensuring the safety of hoisting.

[0031] 2. For this concrete portal cutting construction method, a small-volume cutting area is set at the top of the wire saw cutting area. First, it is cut and hoisted out to create space at the upper part, so as to facilitate the hoisting of the large-volume cutting blocks at the lower part. When it is difficult to directly hoist out the top block, it can be horizontally pulled out by a chain block. Before pulling out, the crane conducts a preliminary hoisting to avoid the cutting block falling and damaging the existing structure at the moment of pulling out.

[0032] During cutting, it is divided by units. First, horizontally and then vertically, cutting layer by layer from top to bottom; the horizontal direction is cut in one go; in the vertical direction, it is cut and hoisted one by one in the order of the top block, the middle block, and the bottom block. After cutting is completed, the cut construction waste can be quickly hoisted away, which is convenient for the construction personnel to operate and saves time and effort.

[0033] For the working condition that the capping beam support structure at the upper part of the cutting area needs to be retained, steel column supports are erected to resist the risk of flexural deformation or even fracture of the large-span capping beam structure at the upper part after the lower part is dug out.

[0034] 3. For this concrete portal cutting construction method, the watering and dust reduction measures taken for the wire saw during cutting will generate a large amount of sewage. Therefore, a temporary water retaining wall should be built in the main middle slab before construction, and a temporary water retaining sill should be set in the auxiliary operation area to prevent the sewage from overflowing; after the cutting work is completed, the sewage is pumped out in time to the ground drainage ditch and discharged to the three-stage sedimentation tank, and the mud deposited on the auxiliary slab is cleaned up, creating conditions for maintaining the civilized construction of the site. Description of the Drawings

[0035] Figure 1 It is a schematic diagram of the demolition range of the diaphragm wall of the portal of the auxiliary structure of the present invention;

[0036] Figure 2 It is a schematic diagram of the cutting holes and hoisting holes on the diaphragm wall to be demolished of the auxiliary structure of the present invention;

[0037] Figure 3 It is a vertical cutting view of the diaphragm wall of the auxiliary structure of the present invention;

[0038] Figure 4 It is a schematic diagram of the small-volume cutting at the top of the auxiliary structure of the present invention;

[0039] Figure 5 It is a schematic diagram of cutting under the condition that the main structure is separated from the diaphragm wall of the present invention;

[0040] Figure 6 It is a schematic diagram of the support column structure of the present invention;

[0041] Figure 7This is the force state diagram of the hoisting rope of the present invention;

[0042] Figure 8 This is the present invention Figure 2 The enlarged schematic diagram of the structure at position A in the present invention;

[0043] Figure 9 This is the present invention Figure 4 The enlarged schematic diagram of the structure at position B in the present invention.

[0044] In the figure: 1. Main structure; 2. Auxiliary structure; 3. Inverted corbel; 4. Diaphragm wall to be demolished at the opening; 401. Wire saw cutting area; 402. Manual chiseling area; 403. Hoisting block; 404. Hoisting hole; 5. Cutting hole; 6. Support column; 601. Iron plate; 7. Chain block. Specific embodiments

[0045] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0046] Please refer to Figures 1-9 , a construction method for cutting a concrete portal, and the structure of the construction area includes a main structure 1, an auxiliary structure 2, and a diaphragm wall 4 to be demolished at the opening. The diaphragm wall 4 to be demolished at the opening is located at the interface between the main structure 1 and the auxiliary structure 2. The upper end of the side of the diaphragm wall 4 to be demolished at the opening away from the main structure 1 is the auxiliary structure 2, and an inverted corbel 3 is provided at the lower end of the side of the auxiliary structure 2 close to the main structure 1;

[0047] The diaphragm wall 4 to be demolished at the opening includes a wire saw cutting area 401 and a manual chiseling area 402 located outside the wire saw cutting area 401. A plurality of cutting holes 5 are opened at the connection between the wire saw cutting area 401 and the manual chiseling area 402. The wire saw divides the wire saw cutting area 401 into a plurality of hoisting blocks 403 through the cutting holes 5, and hoisting holes 404 are opened on the hoisting blocks 403;

[0048] Adopt the demolition method of digging a hole in the door, and its construction method includes:

[0049] Step S1, construction preparation;

[0050] Step S2, mark the cutting unit and the block size;

[0051] Step S3, drill the cutting holes 5 and the hoisting holes 404;

[0052] Step S4, the first unit wire saw cutting;

[0053] Step S5, hoisting layer by layer;

[0054] Step S6, installing the support column 6;

[0055] Step S7, cutting and hoisting of the remaining units;

[0056] Step S8, loading onto trucks for shipment.

[0057] In step S1, construction preparation includes planning for the demolition period of the portal ground wall, planning for the configuration of the main portal cutting machinery, and planning for the personnel configuration.

[0058] In step S2, the ground wall 4 to be demolished at the opening is divided into a plurality of units to be cut; and then the sizes of the attached cutting blocks are different according to the size of the opening, the type of crane, and the on-site lifting conditions. The weight of each block is controlled within 10t, and the bulk density of reinforced concrete is 25KN / m 3 Considering that, according to the cutting and block division, the maximum size of a single floor wall block is 2.5m*2m*0.8m, and considering the marking and cutting errors, the area of ​​a single cut body shall not exceed 5㎡, and then mark shall be made on the body to be cut before construction.

[0059] In step S3, according to the layered and block marking lines, a water drill is used to drill holes for threading the rope saw; after the drilling is completed, it should be inspected and accepted in time to determine that the block size meets the requirements; each block needs to have a lifting hole 404 drilled, and the rope saw cutting hole 5 can be set in multiple blocks; the diameter of the cutting hole 5 is not less than 40mm, and the diameter of the lifting hole 404 is determined according to the type and size of the sling used, and two lifting holes 404 are arranged horizontally on each block.

[0060] In step S4 and step S5, the ground wall corresponding to the door opening of the main structure is cut by a rope saw. During cutting, the rope saw device is placed on the structural bottom plate. After the rope saw chain passes through the cutting hole 5 and is connected to the device, various safety measures are checked, the power is turned on, and the device is remotely started for cutting. During the cutting process, the chain is cooled and dust is reduced by using a water pipe;

[0061] The auxiliary structure 2 is provided with a 650mm high small volume cutting area, i.e., the top block, at the top of the rope saw cutting area 401. The area is cut and hoisted out first to free up a 650mm high space at the top to facilitate the hoisting out of the large volume cutting blocks at the bottom, i.e., the middle block and the bottom block. When it is difficult to hoist the top block directly, it can be pulled out horizontally by a hand winch 7. Before the horizontal pulling operation, the cutting block needs to be hung with a hoisting rope to cooperate with the crane to prevent it from falling, and it is strictly forbidden to stand at the bottom. When cutting, it is divided into units, first horizontally and then vertically, and cut layer by layer from top to bottom. The horizontal direction is cut in one go. The vertical direction is cut and hoisted one by one in the order of the top block, the middle block, and the bottom block. The auxiliary structure 2 is a subway entrance and exit or a wind pavilion structure.

[0062] In step S6, the tunneling method of breaking is adopted. After the cutting of each unit opening is completed, the installation of the support column 6 is immediately carried out. A support column 6 is arranged at intervals of 12 m to 15 m. Special parts such as turns and corners need to be additionally arranged as the situation requires. The support column 6 adopts a lattice column with a size of 460*460 mm. A steel plate 601 with a thickness of 20 mm and a size of 700*700 mm is welded to the top and bottom of the column respectively. The steel plate 601 is fixed to the diaphragm wall through 4 M18 expansion bolts. After the support column 6 is installed, the cutting and hoisting of the next unit diaphragm wall continue.

[0063] In step S7:

[0064] In step S71, if the diaphragm wall corresponding to the range of the main structure 1 is not separated, manual chiseling is required. When working at heights, a portal frame is used as the working platform. A safety railing not less than 1.2 m is set at the top of the platform, and outriggers are set around. Outriggers are set at the four corners of the frame to prevent the frame from tipping over;

[0065] In step S72, after the erection of the frame is completed, manual pneumatic pick chiseling is immediately carried out. When adopting static breaking, first chisel the outer row of steel bar protection layers, use gas cutting to cut the outer row of main steel bars of the diaphragm wall, and use a pneumatic drill to drill holes in the diaphragm wall with a diameter of 4 cm and a depth of 70 cm, with a left-right and front-back spacing of 25 cm; after the drilling is completed, load the expansive agent, and after standing for 12 hours, use the self-expanding extrusion force to cause cracks in the concrete, which is convenient for manual pneumatic pick chiseling; the concrete blocks produced by the chiseling are cleaned up in time;

[0066] For the parts of the diaphragm wall corresponding to the range of the main structure 1 that are in a separated state and have cutting conditions, such as the middle column of the opening and the area corresponding to the top structure of the opening, the wire saw cutting method is adopted. First, complete the vertical cutting and the setting of the hoisting hole 404, and finally carry out the horizontal cutting. Before each horizontal cutting, a crane is used for pre-hoisting to prevent falling, and at the same time, the personnel below are evacuated; for the parts of the diaphragm wall corresponding to the range of the main structure 1 that are in a separated state but do not have cutting conditions, the method of manual plus static breaking is adopted.

[0067] Among them; corresponding civilized construction guarantee measures should be taken during the implementation of this plan: during the cutting process, a large amount of sewage will be generated by the water spraying and dust reduction measures taken for the wire saw. Therefore, a temporary water retaining wall should be built in the main middle plate before construction, and a temporary water retaining sill should be set in the affiliated operation area to avoid the overflow of sewage; after the cutting work is completed, the sewage should be pumped out to the ground drainage ditch in time and discharged to the three-stage sedimentation tank, and the sedimented mud on the affiliated slab should be cleaned up; the concrete blocks should be bundled when loaded and transported to avoid falling during transportation; the noise of pneumatic pick chiseling is relatively large, and chiseling construction at night should be avoided as much as possible to affect the surrounding residents.

[0068] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art will appreciate that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A concrete portal cutting construction method, characterized in that: The construction area structure comprises a main structure (1), an auxiliary structure (2) and a ground wall (4) to be removed at the opening, wherein the ground wall (4) to be removed at the opening is located at the interface between the main structure (1) and the auxiliary structure (2), the upper end of the ground wall (4) to be removed at the opening facing away from the main structure (1) is the auxiliary structure (2), and the lower end of the auxiliary structure (2) close to the main structure (1) is provided with an inverted corbel (3); The hole-to-be-removed ground wall (4) comprises a wire saw cutting area (401) and a manually-cut area (402) located outside the wire saw cutting area (401), a plurality of cutting holes (5) are provided at the connection between the wire saw cutting area (401) and the manually-cut area (402), and the wire saw cuts the wire saw cutting area (401) into a plurality of hanging blocks (403) through the cutting holes (5), and the hanging blocks (403) are provided with hanging holes (404); The demolition method of digging out the door hole includes: Step S1, construction preparation; Step S2, marking the cutting unit and block size; Step S3, drilling cutting holes (5) and hanging holes (404); Step S4, cutting by the first unit wire saw; Step S5, hoisting layer by layer; Step S6, installing the support column (6); Step S7, cutting and hoisting of the remaining units; Step S8, loading onto trucks for shipment.

2. A concrete portal cutting construction method according to claim 1, characterized in that: In step S1, construction preparation includes planning for the demolition period of the portal ground wall, planning for the configuration of the main portal cutting machinery, and planning for the personnel configuration.

3. A concrete portal cutting construction method according to claim 1, characterized in that: In step S2, the ground wall (4) to be demolished at the opening is divided into a plurality of units to be cut; and then, according to the size of the opening, the type of crane selected, and the on-site lifting conditions, the sizes of the attached cutting blocks are also different, and the weight of each block is controlled within 10 tons, and then the body to be cut is marked before construction.

4. A concrete portal cutting construction method according to claim 1, characterized in that: In step S3, drilling is performed using a water drill according to the layered and block marking lines; after the drilling is completed, it should be inspected and accepted in a timely manner; each block needs to have a hoisting hole (404) drilled, and the rope saw cutting holes (5) can be set in multiple blocks; two hoisting holes (404) are arranged horizontally on each cut block.

5. A concrete portal cutting construction method according to claim 1, characterized in that: In step S4 and step S5, the ground wall corresponding to the door opening of the main structure is cut by a rope saw. During cutting, the rope saw device is placed on the structural bottom plate. After the rope saw chain passes through the cutting hole (5) and is connected to the device, various safety measures are checked, the power is turned on, and the device is turned on by remote control for cutting; The auxiliary structure (2) is provided with a 650mm high small volume cutting area, i.e., the top block, at the top of the rope saw cutting area (401). The top block is cut and hoisted out first to free up a 650mm high space at the top. When it is difficult to hoist the top block out directly, it can be pulled out horizontally by a hand winch (7). Before the horizontal pulling operation, the cutting block needs to be hung with a hoisting rope and cooperated with a crane to prevent it from falling. It is strictly forbidden to stand at the bottom. When cutting, it is divided into units, first horizontally and then vertically, and cut layer by layer from top to bottom. The horizontal direction is cut in one go. The vertical direction is cut and hoisted one by one in the order of the top block, the middle block, and the bottom block.

6. A concrete portal cutting construction method according to claim 1, characterized in that: In step S6, a door hole cutting method is adopted, wherein after each unit door hole is cut, the support column (6) is immediately installed, and the support column (6) is arranged at intervals of 12m to 15m. The support column (6) adopts a 460*460mm lattice column, and a piece of iron plate (601) is welded to the top and bottom of the column respectively. The iron plate (601) is fixed to the ground wall by 4 M18 expansion bolts. After the support column (6) is installed, the cutting and hoisting of the next unit ground wall is continued.

7. A concrete portal cutting construction method according to claim 1, characterized in that: In step S7: Step S71, if the ground wall corresponding to the main structure (1) is not separated, it needs to be removed manually. When working at height, a portal scaffolding is used as a working platform, with a guardrail on the top of the platform, and braces around it. Braces are set at the four corners of the frame; Step S72, after the frame is erected, it is immediately removed by manual pneumatic picks. When static removal is adopted, the protective layer of the outer row of steel bars is first removed, and the outer row of main bars of the ground-connected wall are removed by gas cutting. The ground-connected wall is drilled with a pneumatic drill, with a diameter of 4 cm, a depth of 70 cm, and a left-right and front-back spacing of 25 cm. After the drilling is completed, the expansion agent is filled and left to stand for 12 hours. The extrusion force of its own expansion is used to make cracks in the concrete, which are removed by manual pneumatic picks. The concrete blocks produced by the chiseling are cleaned up in time.

8. A concrete portal cutting construction method according to claim 7, characterized in that: In step S72, the ground wall corresponding to the range of the main structure (1) is in a separated state. For the parts that meet the cutting conditions, a rope saw is used for cutting. First, vertical cutting and setting of the lifting holes (404) are completed, and finally horizontal cutting is performed. Before each horizontal cutting, a crane is used for pre-lifting to prevent falling, and at the same time, people below are evacuated; for the parts of the ground wall corresponding to the range of the main structure (1) that are in a separated state but do not meet the cutting conditions, manual and static breaking methods are used.

9. A concrete portal cutting construction method according to claim 1, characterized in that: During the implementation of this plan, corresponding measures to ensure civilized construction shall be taken: before construction, a temporary water retaining wall shall be built inside the middle plate of the main body, and a temporary water retaining ridge shall be set up in the auxiliary operation area; after the cutting work is completed, the sewage shall be promptly pumped to the ground drainage ditch and discharged into the tertiary sedimentation tank, and the mud precipitated on the auxiliary plates shall be cleaned; concrete blocks shall be bundled when loaded onto trucks for transportation.

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