One-time pouring forming construction method for special-shaped high and large wall of sewage treatment plant

Abstract

The invention discloses a one-time pouring forming construction method for a special-shaped tall wall of a sewage treatment plant, which belongs to the technical field of pouring of special-shaped tall walls and particularly comprises the steps of building of a floor type double-row scaffold and a full framing, binding and pre-burying construction of wall steel bars, manufacturing, mounting and reinforcing of a wall template and concrete pouring. According to the reinforcing method, a variable-scale water stop screw rod, a square steel pipe and a 48 common steel pipe are matched with a standard formwork for reinforcing, the variable-scale water stop screw rod is arranged in a standard hole of the formwork in a penetrating mode, abutted seams between the adjacent formworks are connected through a Martin, the wall formworks are connected to form an integral large formwork without back ridges, and then the square steel pipe, the 48 common steel pipe and the variable-scale water stop screw rod are assisted to form a formwork reinforcing system. It is guaranteed that the formwork system has enough strength, rigidity and stability after being reinforced, the formworks are connected through Martin, the wall formworks are reinforced and formed at a time, and the integrity of the formworks is improved; the concrete forming quality of the wall body is improved while the construction joints of the wall body are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of casting special-shaped tall walls of sewage treatment plants, and relates to a one-time casting and molding construction method for special-shaped tall walls of sewage treatment plants. Background Art

[0002] The sewage treatment plant combines the sewage treatment process, and the sewage treatment pool structure is characterized by a variety of wall section size specifications, tall walls, and special shapes. The structural anti-seepage requirements are extremely high, and the construction quality of the wall structure is related to many issues such as the later operation of the sewage treatment plant, sewage treatment quality, and environmental protection. The special-shaped tall walls of a certain wine wastewater treatment plant include flotation tanks and pretreatment tanks, high-efficiency sedimentation tanks, ozone contact oxidation tanks, sludge concentration tanks, and sludge storage tanks. The special-shaped tall walls are mainly two single structures, the flotation tank and the pretreatment tank. Both are reinforced concrete box structures, and the base area of ​​the flotation tank is 7076.76㎡. The outer wall of the pool is a special-shaped wall that is narrow at the top and wide at the bottom. The cross-sectional size is 500mm to 800mm, which gradually changes with the height. Figure 8 As shown, the cross-sectional dimensions of the arc-shaped guide wall are 450mm, the B-axis wall is 800mm; the walls of axes 2 and 3 are 700mm; the wall of axis 4 is 450mm; and the wall of axis 5 is 500mm. Two longitudinal and one horizontal expansion joints were designed, and the raft foundation and walls were divided into nine sections based on these expansion joints. Construction was carried out using the skip-bin method. The walls were cast in a single, continuous, layered manner. The pretreatment pool wall base area is 5,000 square meters. The walls are all special-shaped, narrow at the top and wide at the bottom, with cross-sectional dimensions ranging from 500mm to 900mm. Two longitudinal post-cast strips were designed, and the walls were constructed in three sections, one after the other. The walls were cast in a single, continuous, layered manner.

[0003] For the formwork reinforcement during the casting and forming process of building walls, the traditional reinforcement method of using wooden squares + steel pipes + ordinary water stop screws + concrete lining is used. However, when applied to the casting and forming of tall walls, there is a problem of poor stability. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a one-time casting and molding construction method for special-shaped tall walls of a sewage treatment plant, so as to solve the technical problems existing in the prior art.

[0005] The technical solution adopted by the present invention is: a one-time casting construction method for special-shaped tall walls of a sewage treatment plant, the method comprising the following steps:

[0006] 1) Construction preparation:

[0007] (1) Plan preparation

[0008] 1) Verify the stability of the full-floor support frame. Preliminarily select the steel pipe model, erection range, vertical pole spacing and horizontal pole pitch based on the structure's clear height, plate thickness and beam cross-section size. Select the frame erection height based on the structure's height. Determine the material model and layout spacing by verifying the bending strength of the steel pipe fittings, the anti-slip bearing capacity of the connecting fasteners, the vertical pole stability and the vertical pole foundation bearing capacity.

[0009] 2) Verify the wall formwork. Based on the wall cross-sectional dimensions, which include the cross-sectional dimensions and height of the wall, preliminarily select the formwork model, waterstop material and type, and primary and secondary stud models and spacing. Verify the lateral pressure of the concrete on the formwork based on the wall cross-sectional dimensions, height, and lateral pressure of the concrete. Based on the verification, determine the material, primary and secondary studs, and waterstop spacing.

[0010] (2) Processing and manufacturing of fixed-length water-stop screws

[0011] The outer wall of the flotation tank is a special-shaped wall with a narrow top and wide bottom section. The size of the waterstop screw needs to be scaled along the height direction. Based on the results of the lateral pressure verification of concrete on the formwork, the spacing between the vertical and horizontal waterstop screws is 450mm. The waterstop screws are scaled by 1.53cm every 450mm. There are 19 sizes of waterstop screws for the outer wall. A 40*40*3 waterstop piece is welded in the middle of the waterstop screw, and limit wires are welded at both ends to control the wall cross-section size. This can prevent the formwork from sinking due to wall reinforcement.

[0012] 2) Installation of double-row floor-standing scaffolding and full-floor support

[0013] A ground-type double-row scaffolding is set up outside the flotation tank. The frame height is 10.7m and ordinary 48mm steel pipes are used. The first row of vertical poles is set 350mm away from the wall, and the spacing between the two rows of vertical poles is 1800mm. The first horizontal pole is set 200mm above the ground, and the horizontal pole step distance is 600mm. The top floor is covered with steel mesh. The height of the protective railing is 1500mm. A diagonal brace is set every 4-6m in the horizontal direction.

[0014] The inner side of the flotation tank is partially open. A full-height bracket is set up where the structural plate is set up. Ordinary 48mm steel pipes are used. The first row of vertical poles is set up 350mm away from the wall. The vertical and horizontal spacing of the vertical poles is 600*900mm. The first horizontal pole is set 200mm above the ground. The horizontal pole step is 1500mm. Vertical scissors braces are set at intervals of 6-9m. Two horizontal scissors braces and horizontal nets are set in the horizontal direction. An anti-slip fastener is added to the bottom of the top beam and the bottom of the plate. After the frame is erected, it is inspected before use and can be used only after passing the inspection.

[0015] 3) Wall reinforcement binding and pre-embedded construction

[0016] Before tying the steel bars, the wall base should be roughened and cleaned in advance according to the construction joint treatment method; the roughening standard is to dig holes of 5*4cm (horizontal size and depth) with a spacing of 10-15cm around to ensure that the concrete on the construction surface is firmly bonded;

[0017] The wall reinforcement is tied twice in the height direction. The reinforcement is connected with straight thread sleeves. The joint rate of the reinforcement within the same section is 50%. After the cushion layer is poured, the wall control line is laid out on the cushion layer. The raft reinforcement is tied first. At the same time as the raft reinforcement is tied, the first horizontal reinforcement of the vertical wall is tied according to the wall control line. The vertical reinforcement and horizontal distribution reinforcement of the vertical wall at the first height end are tied first.

[0018] For the inclined surface (the other side of the vertical wall), after the first height end of the wall is tied, vertical reinforcement is placed at 2m intervals. The horizontal reinforcement is 1.5m away from the first horizontal reinforcement at the bottom. Tie them firmly and place fixed-length hook bars at the 1.5m horizontal reinforcement to form a continuous reinforcement skeleton. Then, tie the vertical and horizontal reinforcements firmly in sequence. Repeat the above process until the wall reinforcement is tied. There are 15 fixed-length hook bars in total, with a 20mm reduction every 60cm along the height direction. The hook bars are arranged in a plum blossom shape, with a horizontal and vertical spacing of 60cm.

[0019] 4) Wall formwork production, installation and reinforcement

[0020] (1) Template processing

[0021] After the formwork arrives at the site, the thickness, specifications and dimensions of the formwork are inspected and accepted; after passing the acceptance, it is handed over to the carpentry team to make it according to the wall dimensions, and to mix materials and drill holes according to the dimensions of each wall segment;

[0022] Before installing the wall formwork, the construction joints at the foot of the wall should be cleaned again and cleaned with clean water, and the finished concrete pads should be tied to the vertical reinforcement of the wall; the formwork with holes drilled in advance should be hoisted to the wall to be installed, and one side of the formwork should be installed to the bottom of the pipe trench at the top of the wall first; the formwork and the formwork should be temporarily connected with Martin using an air nail gun to connect them into a whole; before installing the other side of the formwork, the water stop screws should be installed together, and after installing them to the bottom of the pipe trench, the pipe trench side formwork should be installed, and then the pipe trench side formwork should be installed together with the exterior wall formwork. After the formwork is installed, the vertical secondary keel should be installed, and the verticality of the wall formwork should be checked with a plumb line. At least three measuring points, "upper, middle and lower", should be taken for each wall formwork surface. The verticality deviation of the wall formwork should not be greater than 8mm. After the verticality is checked, 48 ordinary steel pipes and water stop screws should be used for reinforcement. The formwork reinforcement at the expansion joint should be reinforced with water stop screws and horseshoe clips.

[0023] 5) Concrete pouring

[0024] (1) Before pouring concrete, the steel bars, embedded parts and formwork should be inspected and accepted. After passing the inspection, proceed to the next step to ensure the stability of the frame.

[0025] (2) Before pouring the wall, the first batch of concrete should be made of mortar with the same mix ratio as the concrete, and the thickness should be controlled at 30-50cm;

[0026] (3) The slump of concrete is controlled at 180±10 to reduce the lateral pressure of concrete on the formwork;

[0027] (4) Concrete is poured in layers continuously using a sky pump supplemented by a conduit method. To avoid excessive concrete pouring height, aggregate impact on the water stop screw and steel bars causing segregation, and to reduce the impact of concrete on the water stop screw (to prevent formwork explosion), the wall concrete is poured first in the vertical wall, and after the layered pouring is completed, the beam and structural top slab concrete are poured; the conduit is placed in the wall according to the pouring sequence diagram of the wall concrete drawing, and the wall concrete is poured in four layers continuously; the pouring height of the first three layers of concrete is controlled within 2m, and the pouring height of the fourth layer of concrete is 2.7m. It should be arranged during the day, and the formwork and frame should be monitored;

[0028] (5) When pouring concrete, the quality of vibration should be strengthened and the speed of lifting the rod should be controlled. Three vibrators should be used for each wall section. The vibrators should be 50-type and 12m long. One vibrator should be placed on each side of the conduit and one should be placed 6-9m away from the conduit. The three vibrators should be operated synchronously. First, the vibrator should be placed at the bottom of the wall. During the pouring process, as the concrete is discharged, the vibrator should be lifted while vibrating. The pouring speed, layered pouring and layered vibration should be strictly controlled to ensure that the concrete in this section is vibrated and compacted.

[0029] (6) When pouring wall concrete, two formwork inspectors are assigned to each side of the wall. If any unusual noise is heard or any slippage of the water stop screw bolt is seen at the pouring site, the bolts should be tightened promptly.

[0030] (7) Casting operators should wear safety helmets, safety belts, and non-slip shoes;

[0031] 6) After the wall concrete is poured, the formwork can be removed after 3 days of curing. The remaining non-load-bearing side formwork, including beam and wall side formwork, can be removed as long as the concrete strength ensures that its surface and edges are not damaged by removing the formwork;

[0032] During formwork removal construction, it is strictly forbidden to perform rough construction such as prying and bending from the corners of the wall; the removed formwork must be cleaned (cleaned of cement slurry), damaged formwork must be replaced, and neatly stacked for turnover use.

[0033] After the formwork is removed, watering and curing are carried out to promote the early strength development of the concrete and avoid cold joints and deformation caused by excessive temperature or dryness.

[0034] The beneficial effects of the present invention are as follows: compared with the prior art, the present invention enables the one-time casting and forming of the special-shaped tall walls of the sewage treatment plant by adopting a structure consisting of a ground-type double-row scaffolding on the outer wall of the pool, an inner concrete formwork support system, and a wall formwork reinforcement system for one-time casting; variable-size water-stop screws + square steel pipes + 48 ordinary steel pipes are used in combination with standard formwork for reinforcement; variable-size water-stop screws are inserted into the standard eyes of the formwork, and the joints between adjacent formworks are connected by Martin, so that the wall formworks are connected into an integral large formwork without back ribs; square steel pipes, 48 ​​ordinary steel pipes, and variable-size water-stop screws are then used to form a formwork reinforcement system; the variable-size water-stop screws are customized according to the cross-sectional size of the wall, and the specifications and spacing of the water-stop screws meet the design requirements of the scheme, ensuring that the formwork system has sufficient strength, rigidity and stability after reinforcement is completed, and the formwork is connected by Martin, and the wall formwork is reinforced and formed in one time, thereby improving the integrity of the formwork; a conduit layered continuous casting method is adopted to ensure that the tall wall is cast and formed in one time; while reducing the construction joints of the wall, the concrete forming quality of the wall is improved. Abandon the traditional reinforcement method of wood + steel pipe + ordinary water stop screw + concrete lining. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a structural diagram of a one-time casting construction method for special-shaped tall walls in a sewage treatment plant;

[0036] Figure 2 This is a schematic diagram of a fixed-length waterstop screw;

[0037] Figure 3 Drilling diagram for wall template;

[0038] Figure 4 This is a schematic diagram of the wall formwork installation structure;

[0039] Figure 5 This is a schematic diagram of the wall formwork reinforcement installation structure;

[0040] Figure 6 This is a schematic diagram of the layered casting structure;

[0041] Figure 7 This is a schematic diagram of the layered arrangement of the wall;

[0042] Figure 8 Schematic diagram of construction section division and wall section dimensions;

[0043] Figure 9 This is the concrete pouring sequence layout diagram;

[0044] Figure 10 This is a schematic diagram of the installation structure of the external rubber waterstop;

[0045] Figure 11 This is a schematic diagram of the steel edge waterstop installation structure;

[0046] Figure 12 This is the waterproof structural drawing of the underground expansion joint of the exterior wall;

[0047] Figure 13 This is the waterproof structural drawing of the expansion joint on the ground of the exterior wall;

[0048] Figure 14 This is a schematic diagram of the construction joint of the outer wall of the box;

[0049] Figure 15 This is a schematic diagram of the steel bar fixing clamp for the waterstop strip on the outer wall of the pool;

[0050] Figure 16 This is a schematic diagram of the cross-sectional structure of an external rubber waterstop;

[0051] Figure 17 This is a schematic diagram of the cross-sectional structure of a center-mounted waterstop;

[0052] Figure 18 Schematic diagram of the cross-sectional structure of the steel edge waterstop. DETAILED DESCRIPTION

[0053] The invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0054] Geological structure and environmental geological conditions of sewage treatment plants

[0055] Exploration revealed that within the 19m depth, the strata at this site consisted of Quaternary artificial fill layers (Q4 ml ), Quaternary Holocene alluvial deposits (Q4 al+pl ) fine sand and pebbles, with the underlying bedrock being reddish-brown sandy mudstone of the Penglaizhen Formation (J3p) of the Upper Jurassic. The lithology of each stratum is described from top to bottom as follows: The strata within the exploration depth range are divided into eight stratigraphic units and two sub-strata, which are briefly described from top to bottom as follows:

[0056] Quaternary Holocene artificial fill layer (Q4 ml )

[0057] Plain fill: Brownish yellow, gray, loose to slightly dense, wet. Primarily composed of pebbles, with a small amount of fine sand and plant roots, the hard content is 80% to 90%. Backfilled 5 to 10 years ago, the fill is primarily soil from the Fujiang River sand and gravel mining operation, and the backfill is manual. Most areas have been compacted by sand and gravel transport vehicles. This layer is distributed throughout the site. Layer thickness ranges from 0.8 to 21.1 meters.

[0058] Quaternary Holocene alluvial deposits (Q4 al+pl )

[0059] Fine sand: bluish-gray, wet to saturated, loose, primarily composed of feldspar and quartz, with mica as a secondary component, and occasionally interspersed with small amounts of pebbles. This layer is primarily distributed as a thick layer above the pebbles and as a lens in the middle of the pebble layer, with a thickness of 0.5 to 8.5 m. It is ubiquitous throughout the site.

[0060] Pebbles: Blue-gray, grayish-yellow, wet to saturated, loose to slightly dense. Pebbles are primarily composed of igneous and metamorphic rocks. They have good roundness, predominantly sub-round, with a small amount of rounded pieces. They have poor sorting, are moderately to slightly weathered, and a small amount is strongly weathered. The pebble content is generally 50-70%, with particle sizes ranging from 2 to 15 cm, and the largest particle size exceeding 20 cm. The filling material is primarily fine sand and rounded gravel. The coefficient of uniformity Cu = 44.4 to 218.50; the coefficient of curvature Cc = 0.6 to 1.70, indicating poorly graded pebbles. According to the "Code for Investigation of Geotechnical Engineering" (GB 50021-2001) (2009 edition), pebble particles are divided into three sub-layers based on particle content and N120 dynamic penetration sounding: loose pebbles, slightly dense pebbles, and medium-dense pebbles.

[0061] Loose pebbles: mainly blue-gray, wet to saturated, pebble content of about 50% to 55%, particle size is generally 2 to 5 cm, filled with round gravel and fine sand, pebbles have good roundness, layer thickness of 0.5 to 5.8 m, and are widely distributed in the site.

[0062] Slightly dense pebbles: blue-gray, wet to saturated, slightly dense, pebbles account for about 55% to 60%, particle size is generally 2 to 8 cm, round gravel and fine sand filling, stone components are mainly sandstone, quartz sandstone, limestone and granite, etc., with good roundness and poor sorting, layer thickness of 0.5 to 5.0 m, widely distributed in the site.

[0063] Medium-dense pebbles: blue-gray, medium-dense, slightly dense in some areas, saturated, pebble content 60% to 70%, filled with rounded gravel sand, pebble particle size is mostly 2 to 15 cm, containing individual boulders; the original rock of the pebbles is quartz sandstone and granite, with a layer thickness of 0.5 to 4.8 m, and is widely distributed in the site.

[0064] Sandy mudstone of the Tuopaizhen Formation of the Upper Jurassic (J3p)

[0065] Within the survey depth, the top of the rock layer is generally strongly weathered, and the lower part is moderately weathered. According to the degree of weathering, it is divided into two sublayers.

[0066] Highly weathered sandy mudstone: reddish-brown to purple-red. Soft, with a muffled percussion sound, muddy texture, and layered structure. Horizontal joints are well-developed. Cores are mostly blocky, with a few short columns, and can be broken by hand. The core recovery rate is 50-60%, with a RQD of 60-65, and layer thicknesses of 0.3-5.2 meters, distributed throughout the site. The rock mass is crushed, with no obvious corrosive minerals. The rock mass is classified as extremely soft rock, and its basic quality grade is Class V.

[0067] Moderately weathered sandy mudstone: reddish-brown to purple-red. It has a muddy, layered structure and is relatively soft, with a hammer sound of half-dull to brittle. Joints and fissures are well-developed, with a black oxide film visible on local fissure surfaces. The rock mass is relatively intact, with cores mostly in long columns, with a small number of short columns and fragments. The core recovery rate is 80-90%, with a RQD of 75-90, distributed throughout the site. The rock mass is relatively intact, with no obvious corrosive minerals observed. The rock mass is classified as extremely soft rock, with a basic rock quality grade of V. The exposed thickness ranges from 3.1 to 9.5 meters, and this layer was not penetrated during this survey.

[0068] The height of the flotation pool frame is more than 8m, the plate thickness is 300mm, the maximum beam cross-section size is 450*1000, and the flotation pool is affected by the distribution of arc walls, so the frame erection is subject to certain restrictions to ensure that no collapse accidents occur during the concrete pouring process.

[0069] Construction arrangement: A truck-mounted pump is used for pouring concrete. According to the distribution of the wall, the initial setting time of the concrete, and the slump, a continuous layered pouring method of "from far to near" is adopted. The independent wall (red number) is poured first, and then the connecting wall (blue number) is poured. The wall is poured in four times. The height of each pouring for the first three times is 2.5m, and it is poured to the bottom plate of the return channel. When the concrete of the return channel and the lower wall is about to set, the upper wall (1.2m) is poured. After the wall pouring is completed, stop for 1 to 1.5 hours before continuing to pour the upper beam and slab.

[0070] C30P8 concrete (containing HEA high-efficiency concrete waterproofing agent, HS-CA preservative, HS-F polypropylene fiber), fixed-length waterstop screws, fixed-length pull hooks, 48 ​​ordinary steel pipes, 2mm thick square steel pipes, steel-edged rubber waterstops (horizontal construction joints of guide walls), center-mounted waterstops with grouting flower pipes (external wall underground and above-ground expansion joints), CB rubber waterstops (external pool wall expansion joints), external waterstops (raft foundation bottom and outer pool wall surface), seamless steel pipes, shear keys, PE foam strips, kraft paper, and polysulfide sealant.

[0071] Example 1: Figures 1-4 As shown, a one-time casting construction method for a special-shaped tall wall of a sewage treatment plant comprises the following steps:

[0072] 1) Construction preparation:

[0073] (1) Plan preparation

[0074] 1) Verify the stability of the full-floor support frame. Preliminarily select the steel pipe model, erection range, vertical pole spacing and horizontal pole pitch based on the structure's clear height, plate thickness and beam cross-section size. Select the frame erection height based on the structure's height. Determine the material model and layout spacing by verifying the bending strength of the steel pipe fittings, the anti-slip bearing capacity of the connecting fasteners, the vertical pole stability and the vertical pole foundation bearing capacity.

[0075] 2) Verify the wall formwork. Based on the wall cross-sectional dimensions, which include the cross-sectional dimensions and height of the wall, preliminarily select the formwork model, waterstop material and type, and primary and secondary stud models and spacing. Verify the lateral pressure of the concrete on the formwork based on the wall cross-sectional dimensions, height, and lateral pressure of the concrete. Based on the verification, determine the material, primary and secondary studs, and waterstop spacing.

[0076] (2) Processing and manufacturing of fixed-length water-stop screws

[0077] The outer wall of the flotation tank is a special-shaped wall with a narrow top and wide bottom section. The size of the waterstop screw needs to be scaled along the height direction. Based on the results of the lateral pressure verification of concrete on the formwork, the spacing between the vertical and horizontal waterstop screws is 450mm. The waterstop screws are scaled by 1.53cm every 450mm. There are 19 sizes of waterstop screws for the outer wall. A 40*40*3 waterstop piece is welded in the middle of the waterstop screw, and limit wires are welded at both ends to control the wall cross-section size. This can prevent the formwork from sinking due to wall reinforcement.

[0078] 2) Installation of double-row floor-standing scaffolding and full-floor support

[0079] A ground-type double-row scaffolding is set up outside the flotation tank. The frame height is 10.7m and ordinary 48mm steel pipes are used. The first row of vertical poles is set 350mm away from the wall, and the spacing between the two rows of vertical poles is 1800mm. The first horizontal pole is set 200mm above the ground, and the horizontal pole step distance is 600mm. The top floor is covered with steel mesh. The height of the protective railing is 1500mm. A diagonal brace is set every 4-6m in the horizontal direction.

[0080] The inner side of the flotation tank is partially open. A full-height bracket is set up where the structural plate is set up. Ordinary 48mm steel pipes are used. The first row of vertical poles is set up 350mm away from the wall. The vertical and horizontal spacing of the vertical poles is 600*900mm. The first horizontal pole is set 200mm above the ground. The horizontal pole step is 1500mm. Vertical scissors braces are set at intervals of 6-9m. Two horizontal scissors braces and horizontal nets are set in the horizontal direction. An anti-slip fastener is added to the bottom of the top beam and the bottom of the plate. After the frame is erected, it is inspected before use and can be used only after passing the inspection.

[0081] 3) Wall reinforcement binding and pre-embedded construction

[0082] Before tying the steel bars, the wall base should be roughened and cleaned in advance according to the construction joint treatment method; the roughening standard is to dig holes of 5*4cm (horizontal size and depth) with a spacing of 10-15cm around to ensure that the concrete on the construction surface is firmly bonded;

[0083] The wall reinforcement is tied twice in the height direction. The reinforcement is connected with straight thread sleeves. The joint rate of the reinforcement within the same section is 50%. After the cushion layer is poured, the wall control line is laid out on the cushion layer. The raft reinforcement is tied first. At the same time as the raft reinforcement is tied, the first horizontal reinforcement of the vertical wall is tied according to the wall control line. The vertical reinforcement and horizontal distribution reinforcement of the vertical wall at the first height end are tied first.

[0084] For the inclined surface (the other side of the vertical wall), after the first height end of the wall is tied, vertical reinforcement is placed at 2m intervals. The horizontal reinforcement is 1.5m away from the first horizontal reinforcement at the bottom. Tie them firmly and place fixed-length hook bars at the 1.5m horizontal reinforcement to form a continuous reinforcement skeleton. Then, tie the vertical and horizontal reinforcements firmly in sequence. Repeat the above process until the wall reinforcement is tied. There are 15 fixed-length hook bars in total, with a 20mm reduction every 60cm along the height direction. The hook bars are arranged in a plum blossom shape, with a horizontal and vertical spacing of 60cm.

[0085] 4) Wall formwork production, installation and reinforcement

[0086] (1) Template processing

[0087] After the formwork arrives at the site, the thickness, specifications and dimensions of the formwork are inspected and accepted; after passing the acceptance, it is handed over to the carpentry team to make it according to the wall dimensions, and to mix materials and drill holes according to the dimensions of each wall segment;

[0088] Before installing the wall formwork, the construction joints at the base of the wall should be cleaned again and cleaned with clean water. Tie the finished concrete pads to the vertical reinforcement of the wall; lift the formwork with pre-drilled holes to the wall to be installed, and first install one side of the formwork to the bottom of the wall top trench; use an air nail gun with Martin to temporarily connect the formwork to form a whole; before installing the other side of the formwork, install the water stop screw together, and after installing it to the bottom of the trench, complete the installation of the trench side formwork, and then install the trench side formwork together with the exterior wall formwork. After the formwork is installed, install the vertical secondary keel. After completion, use a plumb line to check the verticality of the wall formwork. Take at least three measuring points of "top, middle, and bottom" for each wall formwork surface. The verticality deviation of the wall formwork should not exceed 8mm. After the verticality verification is completed, use 48 ordinary steel pipes and water stop screws for reinforcement. The formwork reinforcement at the expansion joint uses water stop screws with horseshoe clips;

[0089] Installation of expansion joint waterstop and shear key:

[0090] (1) According to the design drawings, an external rubber waterstop is used at the bottom of the raft foundation and on the outside of the exterior wall. A central waterstop with a grouting tube is used in the middle of the raft foundation. The width of the expansion joint is 200 mm. A central waterstop with a grouting tube is used in the middle of the exterior wall expansion joint. A shear key is set every 40 cm along the height direction in the joint. A42 seamless steel pipe is embedded on the side where concrete is poured first. The length of the seamless steel pipe is 50 cm. The length of the shear key steel bar is 1 m (C40@400 (HRB400)). It is filled with butter to facilitate the sliding of the shear key steel bar. Before the adjacent wall is poured, the C40@400 (HRB400) steel bar is inserted into the seamless steel pipe. A CB-type rubber waterstop is used in the middle of the expansion joint of the inner wall of the pool. A shear key steel bar is set every 40 cm along the height direction of the joint. An A32 seamless steel pipe with a length of 50 cm and a shear key length of 1 m (C28@400 (HRB400)) is embedded on the side where concrete is poured first. The seamless steel pipe is filled with butter to facilitate the sliding of the shear key steel bar. Before pouring the adjacent wall, C40@400 (HRB400) steel bars are inserted into the seamless steel pipe.

[0091] (2) Cut the seamless steel pipe into short tubes of 50cm in length according to the design drawings. Weld an iron gasket with the same diameter as the steel pipe at one end to seal it. Fill the inside with butter and seal the other end with tape. Fix the processed seamless steel pipe on the wall deformation on the first pouring side. Tie a horizontal steel bar with the same cross-sectional size as the wall according to the wall height, and spot weld the processed seamless steel pipe on the horizontal steel bar.

[0092] (3) Drill a circular hole above the waterstop and insert a hook bar into the hole to fix the waterstop to the top of the wall. After the reinforcement of the wall templates on both sides is completed, use two templates to "clamp" the waterstop. The exposed length of the waterstop is 900mm. The main keel of the end wall template uses two 48 short steel pipes and the secondary keel uses 40*90 square wood. Use horseshoe clips and waterstop screws for reinforcement. The reinforcement spacing is 40~60cm.

[0093] 5) Concrete pouring

[0094] (1) Before pouring concrete, the steel bars, embedded parts and formwork should be inspected and accepted. After passing the inspection, proceed to the next step to ensure the stability of the frame.

[0095] (2) Before pouring the wall, the first batch of concrete should be made of mortar with the same mix ratio as the concrete, and the thickness should be controlled at 30-50cm;

[0096] (3) The slump of concrete is controlled at 180±10 to reduce the lateral pressure of concrete on the formwork.

[0097] (4) Concrete is poured in layers continuously using a sky pump supplemented by a conduit method. To avoid excessive concrete pouring height, aggregate impact on the water stop screw and steel bars causing segregation, and to reduce the impact of concrete on the water stop screw (to prevent formwork explosion), the wall concrete is poured first in the vertical wall, and after the layered pouring is completed, the beam and structural top slab concrete are poured; the conduit is placed in the wall according to the pouring sequence diagram of the wall concrete drawing, and the wall concrete is poured in four layers continuously; the pouring height of the first three layers of concrete is controlled within 2m, and the pouring height of the fourth layer of concrete is 2.7m. It should be arranged during the day, and the formwork and frame should be monitored;

[0098] (5) When pouring concrete, the quality of vibration should be strengthened and the speed of lifting the rod should be controlled. Three vibrators should be used for each wall section. The vibrators should be 50-type and 12m long. One vibrator should be placed on each side of the conduit and one should be placed 6-9m away from the conduit. The three vibrators should be operated synchronously. First, the vibrator should be placed at the bottom of the wall. During the pouring process, as the concrete is discharged, the vibrator should be lifted while vibrating. The pouring speed, layered pouring and layered vibration should be strictly controlled to ensure that the concrete in this section is vibrated and compacted.

[0099] (6) When pouring wall concrete, two formwork inspectors are assigned to each side of the wall. If any unusual noise is heard or any slippage of the water stop screw bolt is seen at the pouring site, the bolts should be tightened promptly.

[0100] (7) Casting operators should wear safety helmets, safety belts, and non-slip shoes;

[0101] 6) After the wall concrete is poured, the formwork can be removed after 3 days of curing. The remaining non-load-bearing side formwork, including beam and wall side formwork, can be removed as long as the concrete strength ensures that its surface and edges are not damaged by removing the formwork;

[0102] During formwork removal, it is strictly forbidden to pry or bend the formwork from the corners. The removed formwork must be cleaned (cleaned of cement slurry), damaged formwork must be replaced, and neatly stacked for easy use.

[0103] After the formwork is removed, watering and curing are carried out to promote the early strength development of the concrete and avoid cold joints and deformation caused by excessive temperature or dryness.

[0104] In summary, in order to enable the sewage treatment plant's special-shaped tall walls to be cast and formed in one go, a structure consisting of a double-row ground-based scaffolding on the right pool's outer wall, an inner concrete formwork support system, and a wall formwork reinforcement system was used for one-time casting. Variable-size waterstop screws + square steel pipes + 48 ordinary steel pipes were used in conjunction with standard formwork for reinforcement. Variable-size waterstop screws were inserted into the standard eyes of the formwork, and Martin was used to connect the joints between adjacent formworks, so that the wall formworks were connected into an integral large formwork without back ribs. The formwork reinforcement system was then formed using square steel pipes, 48 ​​ordinary steel pipes, and variable-size waterstop screws. The variable-size waterstop screws were customized according to the cross-sectional dimensions of the wall, and the specifications and spacing of the waterstop screws met the design requirements of the scheme, ensuring that the formwork system had sufficient strength, rigidity, and stability after reinforcement. The formwork was connected using Martin, and the wall formwork was reinforced and formed in one go, thereby improving the integrity of the formwork. The conduit was used for layered continuous casting to ensure that the tall walls were cast and formed in one go, reducing the construction joints of the wall while improving the concrete forming quality of the wall. Abandon the traditional reinforcement method of wood + steel pipe + ordinary water stop screw + concrete lining.

[0105] The construction method has the following advantages:

[0106] (1) Template eyelets are produced in batches. Standard templates are spliced ​​one by one using Martin to form large-surface templates. There are no seams between templates.

[0107] (2) The standard holes of the template are on the same horizontal line, which makes template configuration and reinforcement more convenient and has a high turnover rate;

[0108] (3) Use variable-length water-stop screws to control the cross-sectional dimensions of the wall, replacing cement lining strips and saving costs;

[0109] (4) The structure is simple, the operation is convenient, there is no slurry leakage, and the wall concrete has a good visual quality;

[0110] (5) It can cast and shape tall walls in one go, which speeds up construction, saves costs, and shortens construction period;

[0111] (6) The template at the expansion joint is reinforced with horseshoe clips to ensure the safety of the template.

[0112] The main materials required for construction are: formwork, square steel pipe 40mm×40mm×2.5mm×6000mm, square steel pipe 40mm×40mm×2.5mm×4000mm, 48×2.7mm steel pipe, water stop screw, air nail gun, and Martin.

[0113] The outer wall of the flotation tank adopts variable-size waterstop screws, with a 4*4 circular waterstop plate welded in the middle of the waterstop screw, and limit steel wires welded at both ends of the screw according to the changes in the wall cross-sectional size; the turnover materials supporting the waterstop screw include butterfly buckles, horseshoe clips, and bolts.

[0114] The wall hook bars adopt variable length hook bars, and the hook bars are reduced by 20mm every 60cm along the height direction. The other machines and equipment used are shown in Table 6.3.

[0115] Table 1 Waterstop screw size table

[0116]

[0117]

[0118] Table 2 Wall hook reinforcement size table

[0119]

[0120] Comparison of economic benefits of construction methods

[0121] Traditional walls are constructed using steel pipes, wooden beams, waterstops, and butterfly buckles, and the walls must be poured in three sections, requiring two construction joints. This project uses a formwork system consisting of steel pipes, square steel pipes, fixed-length waterstops, and butterfly buckles. The formwork uses standard spacing, making it easy to install and disassemble, with a high turnover rate and convenient management. Combined with zoned, skip-slot construction, this accelerates wall construction. Compared to traditional wall formwork, 48-inch steel pipes and square steel pipes are used as primary and secondary keels. The fixed-length waterstops also serve as the concrete lining, saving significant timber resources and a steel-edged rubber waterstop, reducing construction costs and improving economic efficiency. Martin joints are used between formwork panels, ensuring high-quality joints and a superior appearance after the concrete is poured. The project's walls cover a total area of ​​23,600 square meters, with 8,500 square meters of formwork allocated for rotation. Once completed, the wall formwork can be transferred to other pool walls.

[0122] Table 3 Main materials of traditional wall Unit / section

[0123]

[0124] Note: ①The leasing period of 48mm ordinary steel pipe is calculated as 3 months

[0125] ②Steel edge water stop including labor cost 35 yuan / m

[0126] Table 4 Ingredients for one-time casting of tall and special-shaped walls Unit / section

[0127]

[0128] Note: ①The rental period of square steel pipe and 48 ordinary steel pipe is calculated as 3 months

[0129] ②Steel edge water stop including labor cost 35 yuan / m

[0130] From the comparison table of the main materials of the above two construction methods, it can be concluded that the one-time equipment table of the template project shows that the one-time casting construction method of high walls can cost 356,700 yuan. The larger the wall area of ​​the project, the more significant the effect.

[0131] This construction method solves the challenge of casting the tall walls of sewage treatment plants in one go. It utilizes double-row ground scaffolding, a concrete formwork support system, and a formwork reinforcement system, supplemented by M14 fixed-length waterstop screws, square steel pipes, 48 ​​standard steel pipes, butterfly buckles, and horseshoe clamps for reinforcement. This method provides greater formwork safety, ensuring both safety and economical practicality. The walls are cast in one go, reducing construction joints. After formwork removal, the walls are free of defects such as cold joints, honeycombs, rough surfaces, holes, or exposed rebar. The pool walls maintain excellent appearance and form quality, achieving the goal of casting the tall walls in one go.

[0132] like Figure 10-18 As shown in the figure, the specific construction process of installing the water stop and shear key of the expansion joint is as follows:

[0133] 1) Seamless steel pipe processing: select inner diameter The seamless steel pipe is cut into 1m lengths, with a metal round patch welded on one end and the other end sealed with transparent tape to prevent concrete from entering the steel pipe.

[0134] 2) Manufacturing and processing of steel bar fixing clamps: The steel bar fixing clamps are made of The HRB400 steel bar is made of fixed steel bar clamps with a total of 26 specifications and sizes. Every two steel bar clamps start to shrink in height.

[0135] 3) Placement of the external rubber waterstop at the bottom of the flotation tank raft: After the cushion layer 1 at the bottom of the valve plate 3 is poured, the details of the flotation tank structure are laid out on the cushion layer 1, the control lines of the expansion joint and the wall are popped out, and the external rubber waterstop 2 is placed at the expansion joint. The external rubber waterstop 2 should be connected by hot vulcanization, and the connection joints should be placed away from the corners of the structure, and the corners should be arc-shaped.

[0136] 4) Binding of raft reinforcement: The entire pool is divided into nine parts according to the deformation joints for zoning construction. The raft foundation reinforcement is constructed using the skipping method. First, the bottom reinforcement of the raft is tied, with the short reinforcement at the bottom and the long reinforcement at the top. After the bottom reinforcement is tied, a "J"-shaped horse stool reinforcement is installed and tied on the bottom reinforcement. The horse stool reinforcement is strengthened with oblique support to prevent the reinforcement from collapsing. The horse stool reinforcement is arranged in a rectangular shape with a spacing of 2m*2m. After the horse stool reinforcement is arranged, longitudinal and transverse reinforcement are placed on the horse stool reinforcement to form a reinforcement skeleton. A grid is first established, and longitudinal and transverse reinforcements are arranged in the grid according to the design drawings. The reinforcement skeleton has two functions: one is to place reinforcement, and the other is steel After the reinforcement is placed, it is convenient for people to walk and tie; the remaining longitudinal and transverse reinforcements are placed in the reinforcement skeleton grid and tied firmly to the reinforcement skeleton, the top raft slab reinforcement is tied, the reinforcement fixing clamps of the middle deformation joint of the raft slab and the raft slab edge sealing reinforcement are installed, and the central waterstop 4 with grouting flower pipe is installed in the reinforcement fixing clamp of the middle deformation joint of the raft slab. At the same time, the central waterstop with grouting flower pipe at the intersection of the vertical deformation joint (central waterstop 4) and the horizontal deformation joint (external rubber waterstop on the cushion layer) is welded into one by hot vulcanization method; after the raft slab reinforcement tying and the installation of the middle deformation joint of the raft slab are completed, the valve plate template is installed; the bottom of the raft slab and the outer wall are both provided with external rubber waterstop. A central waterstop 4 with a grouting flower tube is used between the middle of the raft slab and the inner wall of the pool. Shear keys are installed in the expansion joint of the inner wall of the pool to prevent water seepage. PE foam strips 7, kraft paper 8, and polysulfide sealing paste 9 are embedded in the expansion joint from the inside to the outside.

[0137] 5) Installation of steel-edge rubber waterstop: The horizontal construction joint of the outer wall of the flotation tank is set at 500mm above the raft foundation. A 350*30mm steel-edge rubber waterstop 5 is set in the construction joint with the width direction facing vertically. Before installing the steel-edge rubber waterstop 5, a circular hole 501 with a diameter of about 10mm is drilled every 2m on the exposed side of the steel edge of the steel-edge rubber waterstop 5. The circular hole 501 is used to fix the steel-edge rubber waterstop. The first height section is 500mm above the raft foundation. After the vertical wall reinforcement is tied, the steel edge rubber water stop 5 is unfolded in the horizontal direction of the wall and placed in the preformed wall. According to the design requirements, after the guide wall is cast, the upper exposed size of the steel edge rubber water stop 5 is 175mm (the other half is located inside the guide wall). This is used as the installation requirement of the steel edge rubber water stop 5. During installation, a threaded steel bar 502 of HRB400 with a diameter of 10 is inserted into the circular hole drilled in advance, and the two ends of the threaded steel bar 502 are spot welded to the vertical steel bars of the wall.

[0138] 6) Concrete pouring: The concrete strength grade of the flotation tank is C30P8. HEA high-efficiency concrete waterproofing agent, HS-CA preservative and HS-F polypropylene fiber are added to the concrete to form a special concrete. The concrete is poured using a sky pump and cured for 14 days after the concrete pouring is completed;

[0139] 7) Guide wall roughening: Before tying the steel bars, the wall base should be roughened and cleaned in advance according to the treatment method of construction joints; the roughening standard is to dig holes of 5*4cm (horizontal size and depth) with a spacing of 10-15cm around to ensure that the concrete on the construction surface is firmly bonded;

[0140] 8) Vertical wall binding: The wall reinforcement is tied twice from the height direction. The reinforcement is connected with straight thread sleeves. The joint rate of the reinforcement in the same section is 50%. After the cushion layer is poured, the wall control edge line is laid out on the cushion layer. The raft reinforcement is tied first. At the same time as the raft reinforcement is tied, the first horizontal reinforcement of the vertical wall is tied according to the wall control line. The vertical wall is tied first with the vertical reinforcement and horizontal distribution reinforcement of the vertical surface 2500mm above the raft foundation.

[0141] Tie the steel bars of the inclined surface of the vertical wall on the other side of the vertical wall reinforcement (the other side of the vertical wall). After the reinforcement of the wall facing the raft foundation is completed at 2500mm above the raft foundation, place a vertical steel bar at a vertical interval of 2m. The horizontal steel bar is 1.5m away from the first horizontal bar at the bottom. Tie them firmly and place fixed-length hook bars at the 1.5m horizontal bar to form a continuous steel skeleton. Then tie the vertical and horizontal steel bars firmly in turn. Repeat the above process until the vertical wall reinforcement is tied. There are 15 fixed-length hook bars in total. They are reduced by 20mm every 60cm in the height direction. The hook bars are arranged in a plum blossom shape, with a horizontal and vertical spacing of 60cm.

[0142] 9) Pre-embedded seamless shear key solution: After the vertical wall reinforcement is tied, according to the design drawings, the inner diameter of the seamless steel pipe for the outer wall is 42mm, and the inner diameter of the seamless steel pipe for the inner wall is 32mm. Two seamless steel pipes are installed horizontally at intervals of 400mm along the height direction, and the seamless steel pipes are fixed with horizontal steel bars.

[0143] The advantages of expansion joint construction are as follows:

[0144] (1) A multi-level composite water-stop structure is used, namely, the bottom of the raft slab: an external rubber water-stop is used (hot vulcanized connection, corner arc treatment; the middle of the raft slab and the inner partition wall innovatively use a central water-stop with a grouting flower pipe: the intersection of the vertical and horizontal deformation joints is welded into a whole by hot vulcanization and matched with 26 customized steel bar fixing clips (Φ14mm HRB400 steel bars), with a 20mm reduction every 60cm in the height direction, accurately adapting to the gradual size of the structure. The composite water-stop structure avoids the problem of deformation joint leakage caused by water corrosion and uneven settlement in the flotation tank;

[0145] (2) Pre-buried seamless steel pipe grouting channel: Φ42mm seamless steel pipes are pre-buried in the exterior wall and Φ32mm seamless steel pipes are pre-buried in the interior wall, with two horizontal pipes set every 400mm in height; metal patches are welded to the ends of the steel pipes, filled with butter, and sealed with tape to form a non-clogging grouting channel; micro-leakage in the deformation joints can be repaired by grouting in the later stage (conventional construction does not have this active repair mechanism);

[0146] (3) Coordinated positioning of steel skeleton and waterstop: The raft reinforcement adopts the jump bin method for zoned construction, and the horse stool reinforcement (spacing 2m×2m) is added with diagonal bracing to prevent collapse; the first layered binding within the steel skeleton grid: ① Bottom reinforcement (short direction at the bottom, long direction at the top); ② Vertical / transverse main skeleton is erected on the horse stool reinforcement; ③ Secondary longitudinal and transverse reinforcement is filled in the skeleton grid (to enhance integrity); The steel bar fixing clamp is integrated with the central waterstop to ensure the synchronous positioning of the expansion joint and the reinforcement;

[0147] (4) Anchoring of steel edge waterstop: Drill Φ10mm holes (at intervals of 2m) on one side of the steel edge rubber waterstop (350×30mm) and insert Φ10mm HRB400 threaded steel bars. Spot weld the two ends to the vertical steel bars to accurately control the exposed height to 175mm (conventional reliance on template extrusion is prone to deviation);

[0148] (5) Concrete performance enhancement: C30P8 concrete is added with: HEA high-efficiency waterproofing agent (anti-seepage); HS-CA preservative (chemical corrosion resistance); HS-F polypropylene fiber (crack inhibition);

[0149] (6) Formwork precision control system: three-point calibration of formwork verticality (top / middle / bottom), deviation ≤8mm; water-stop screw + Φ48 steel pipe composite reinforcement, trench side formwork and exterior wall formwork integrated installation.

[0150] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed by the present invention, which should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A one-time casting construction method for special-shaped tall walls of a sewage treatment plant, characterized in that: The method comprises the following steps: 1) Construction preparation: (1) Plan preparation 1) Verify the stability of the full-floor support frame. Preliminarily select the steel pipe model, erection range, vertical pole spacing and horizontal pole pitch based on the structure's clear height, plate thickness and beam cross-section. Select the frame erection height based on the structure's height. Determine the material model and layout spacing by verifying the bending strength of the steel pipe fittings, the anti-slip bearing capacity of the connecting fasteners, the vertical pole stability and the vertical pole foundation bearing capacity. 2) Verify the wall formwork. Based on the wall cross-sectional dimensions, which include the cross-sectional dimensions and height, initially select the formwork model, waterstop material and type, and primary and secondary stud models and spacing. Verify the lateral pressure of the concrete on the formwork based on the wall cross-sectional dimensions, height, and lateral pressure of the concrete. Based on these calculations, determine the material, primary and secondary studs, and waterstop spacing. (2) Processing and manufacturing of fixed-length water-stop screws The outer wall of the flotation tank is a special-shaped wall with a narrow top and wide bottom section. The size of the waterstop screw needs to be scaled along the height direction. Based on the results of the lateral pressure verification of concrete on the formwork, the spacing between the vertical and horizontal waterstop screws is 450mm. The waterstop screws are scaled by 1.53cm every 450mm. There are 19 sizes of waterstop screws for the outer wall. A 40*40*3 waterstop piece is welded in the middle of the waterstop screw, and limit wires are welded at both ends to control the wall section size. 2) Erection of double-row floor-standing scaffolding and full-floor support A ground-type double-row scaffolding is set up outside the flotation tank. The frame height is 10.7m and ordinary 48mm steel pipes are used. The first row of vertical poles is set 350mm away from the wall, and the spacing between the two rows of vertical poles is 1800mm. The first horizontal pole is set 200mm above the ground, and the horizontal pole step distance is 600mm. The top floor is covered with steel mesh. The height of the protective railing is 1500mm. A diagonal brace is set every 4-6m in the horizontal direction. The inner side of the flotation tank is partially open. A full-height bracket is set up where the structural plate is set up. Ordinary 48mm steel pipes are used. The first row of vertical poles is set up 350mm away from the wall. The vertical and horizontal spacing of the vertical poles is 600*900mm. The first horizontal pole is set 200mm above the ground. The horizontal pole step is 1500mm. Vertical scissors braces are set at intervals of 6-9m. Two horizontal scissors braces and horizontal nets are set in the horizontal direction. An anti-slip fastener is added to the bottom of the top beam and the bottom of the plate. After the frame is erected, it is inspected before use and can be used only after passing the inspection. 3) Wall reinforcement binding and pre-embedded construction Before tying the steel bars, the wall base should be roughened and cleaned in advance according to the construction joint treatment method; the roughening standard is to dig a 5*4cm hole with a spacing of 10-15cm around it; The wall reinforcement is tied twice in the height direction. The reinforcement is connected with straight thread sleeves. The joint rate of the reinforcement within the same section is 50%. After the cushion layer is poured, the wall control line is laid out on the cushion layer. The raft reinforcement is tied first. At the same time as the raft reinforcement is tied, the first horizontal reinforcement of the vertical wall is tied according to the wall control line. The vertical reinforcement and horizontal distribution reinforcement of the vertical wall at the first height end are tied first. For inclined reinforcement binding, after the first height end of the wall is tied, vertical reinforcement is placed at 2m intervals. The horizontal reinforcement is 1.5m away from the first horizontal reinforcement at the bottom. Tie them firmly and place fixed-length hook bars at the 1.5m horizontal reinforcement to form a continuous reinforcement skeleton. Then, tie the vertical and horizontal reinforcements firmly in sequence. Repeat the above process until the wall reinforcement is tied. There are 15 fixed-length hook bars in total, with a 20mm reduction every 60cm in the height direction. The hook bars are arranged in a plum blossom shape, with a horizontal and vertical spacing of 60cm. 4) Wall formwork production, installation and reinforcement (1) Template processing After the formwork arrives at the site, the thickness, specifications and dimensions of the formwork are inspected and accepted; after passing the acceptance, it is handed over to the carpentry team to make it according to the wall dimensions, and to mix materials and drill holes according to the dimensions of each wall segment; Before installing the wall formwork, the construction joints at the base of the wall should be cleaned with clean water; Tie finished concrete pads to the vertical reinforcement of the wall; hoist the pre-drilled formwork to the wall to be installed, and first install one side of the formwork to the bottom of the wall top trench; use an air nail gun and Martin to temporarily connect the formwork to form a whole; before installing the other side of the formwork, install the water stop screws together. After installing it to the bottom of the trench, complete the installation of the trench side formwork. After installing the trench side formwork together with the exterior wall formwork, install the vertical secondary keel. After completion, use a plumb line to check the verticality of the wall formwork. At least three measurement points (top, middle, and bottom) are taken on each wall formwork surface. The verticality deviation of the wall formwork should not exceed 8mm. After the verticality verification is completed, use 48 ordinary steel pipes and water stop screws for reinforcement. The formwork at the expansion joint is reinforced with water stop screws and horseshoe clamps. 5) Concrete pouring (1) Before pouring concrete, the steel bars, embedded parts and formwork should be inspected and accepted, and the next step can be taken after passing the inspection; (2) Before pouring the wall, the first batch of concrete should be made of mortar with the same mix ratio as the concrete, and the thickness should be controlled at 30-50cm; (3) The slump of concrete is controlled at 180±10; (4) Concrete is poured in layers continuously using a sky pump supplemented by a conduit method. The vertical wall is poured first. After 30-45 minutes of layered wall pouring, the beam and structural top slab concrete are poured. The conduit is placed in the wall according to the pouring sequence diagram of the wall concrete drawing. The wall concrete is poured in four layers continuously. The pouring height of the first three layers of concrete is controlled within 2m, and the pouring height of the fourth layer of concrete is 2.7m. It should be arranged during the day, and the formwork and frame should be monitored. (5) When pouring concrete, the quality of vibration should be strengthened and the speed of lifting the rod should be controlled. Three vibrators should be used for each wall section. The vibrators should be 50-type and 12m long. One vibrator should be placed on each side of the conduit and one should be placed 6-9m away from the conduit. The three vibrators should be operated synchronously. First, the vibrator should be placed at the bottom of the wall. During the pouring process, as the concrete is discharged, the vibrator should be lifted while vibrating. The pouring speed, layered pouring and layered vibration should be controlled to ensure that the concrete within the section is vibrated and compacted. (6) When pouring wall concrete, two formwork inspectors are assigned to each side of the wall. If any unusual noise is heard or any slippage of the water stop screw bolt is seen at the pouring site, the bolts should be tightened promptly. 6) After the wall concrete is poured, the formwork can be removed after 3 days of curing. The remaining non-load-bearing side formwork, including beam and wall side formwork, can be removed as long as the concrete strength ensures that its surface and edges will not be damaged by removing the formwork; When removing the formwork, avoid prying or twisting the formwork from the corners; clean the removed formwork, remove the cement slurry, and stack them neatly for easy reuse; After the formwork is removed, the wall is watered and maintained.

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