CN202227476U - High-altitude large-span overhung corridor-type reinforced concrete structure - Google Patents

Abstract

The utility model relates to a high-altitude and large-span cantilevered corridor-shaped steel concrete structure, the corridor part is a stiff beam structure, the beam formwork support system utilizes the bearing capacity of the shaped steel itself, and adopts U-shaped screw rods and nuts to fix square steel. Type formwork support system; the floor adopts self-supporting steel truss formwork, which is welded to the pre-embedded steel plate on the stiff beam by nails. Corresponding floors at the lower part of the corridor are equipped with steel platforms as operation and safety protection platforms for formwork support construction. The beneficial effect of the utility model is that the formwork support construction method of using I-beam or profiled steel beams to build the operation platform, the rigid beam dry hanging self-supporting, and the floor slab self-supporting solves the difficulty in formwork support of the high-altitude and large-span cantilevered corridor structure. The problem, greatly saving the turnover materials, reducing the construction cost, speeding up the construction progress, and ensuring safety. The pre-embedded steel plate on the stiff beam solves the problem of effective connection between the floor deck and the stiff beam, enables the floor deck and the stiff beam to work together, and ensures structural safety.

Description

A high-altitude and long-span cantilevered corridor-shaped steel concrete structure

technical field

The utility model relates to the technical field of high-altitude cantilevered corridor rigid concrete structure construction, in particular to a high-altitude large-span cantilevered corridor shaped steel concrete structure.

Background technique

With the development of urban construction, architects have given full play to their ingenuity and whimsy, and many buildings with peculiar shapes and complex structures have emerged one after another, which have brought visual impact to people, but also brought great challenges to engineers' construction. Great challenge. In particular, public buildings often adopt the method of high-altitude and large cantilever to meet the needs of the shape. For example, in the towers of several high-rise and super high-rise buildings in a row, the design requires half of each to be cantilevered in mid-air through a reinforced concrete structure. The formation of corridors connects the structure into a whole again. The effect of voids is used to achieve the transparency of the environment and the visual impact. The light and shade of the facade and the virtual reality of the space reflect the architect's design intention.

However, there are not many similar projects in the country for the construction of stiff concrete structures with high-altitude and long-span cantilevered corridors. There are few construction technical measures and materials that can be referred to, and minor mistakes are prone to major safety accidents and major accidents caused by the collapse of the formwork system. Quality accidents, such as the occurrence of such accidents, will directly affect the life safety of construction workers and cause major quality accidents, which will cause huge losses to the country and enterprises, and also affect the reputation of enterprises.

The characteristics of formwork support for this type of structure are: large span, high height, large construction load, high construction technology requirements, and high difficulty. The construction method of stiffened concrete structure for cantilevered corridor is a new topic, which has very significant practical significance.

Utility model content

The purpose of this utility model is to use the operation platform built by I-beams or steel beams between the two towers between the cantilevered corridors to carry out formwork support and pouring of reinforced concrete for the cantilevered corridors. Self-supporting hanging formwork technology, the corridor floor is constructed with self-supporting floor slabs, forming a high-altitude and large-span cantilevered corridor-shaped steel concrete structure with simple construction methods, safe operation, convenient installation and disassembly, and conducive to civilized construction.

The technical scheme adopted by the utility model to solve its technical problems: the high-altitude and large-span cantilevered corridor-shaped steel concrete structure, the I-steel main beam is installed between the lower floor structure of the east and west tower structures, and the anchor ring of the main beam is pre-buried In the lower floor structure, the I-beam main girder is fixedly connected with the anchor ring of the main beam at the end after hoisting and installation; I-steel diagonal tie rods are installed between the upper floor structures, and I-steel secondary beams are installed on the lower floor structure. The U-shaped screw of the beam fixes the bottom formwork of the beam and the inner corrugated square wood through square steel and double nuts. The inner corrugated square wood is arranged parallel to the axis of the beam, and the square steel is arranged perpendicular to the axis of the beam; Double-steel pipe outer corrugated and tensioned connection of tensioning screws; pre-embedded stiff plates welded with steel truss formwork on the top of stiff main beams and stiff secondary beams, thick stiff plates and stiff main beams, stiff secondary beams Beam stirrup welded connection.

The construction method of this high-altitude large-span cantilevered corridor steel concrete structure, the construction method steps are as follows;

Overall design idea: the corridor part is a stiff beam structure, the beam formwork support system utilizes the bearing capacity of the section steel itself, and uses a hanging formwork support system in the form of U-shaped screws and nuts to fix square steel; the floor adopts a self-supporting steel truss formwork , using studs welded to the embedded steel plate on the stiff beam. Corresponding floors at the lower part of the corridor are equipped with steel platforms as operation and safety protection platforms for formwork support construction.

1 According to the type of engineering structure, construction load, "Building Structure Load Code" GB50009, "Steel Structure Design Code" GB50017, "Concrete Structure Design Code" GB50010, "Steel Tube Fastener Scaffold Specification" JGJ130, "Building Construction Formwork Safety Technical Code 》JGJ162 and other relevant specifications to prepare the construction plan, determine the embedded floor, location and type and specification of the I-shaped negative or section steel and wire rope of the embedded parts;

2 Installation of the I-beam main beam of the operation platform: bury anchor bars or anchor ring-type embedded parts at the corresponding positions of the determined floors; after the concrete strength of the corresponding floor slab construction reaches 2.0MPa, install the I-beam main beam of the operation platform Work, when encountering shear wall 31, it is necessary to reserve a hole in the installation position of the I-beam main beam for later demolition.

a. Preparation for installation and construction

The installation of platform section steel shall be completed when the corresponding floor structure is completed and the concrete strength reaches 2.0MPa. The main girder of the operation platform is placed between the two towers with 22a# I-beam. The inner anchors at both ends are 1250mm, and the total length is 16m. Since the maximum length of a single beam produced by the manufacturer is 9m, the connection of the section steel must be done in advance before hoisting. For work, the steel connecting bolts are grade 8.8, M20 friction-type high-strength bolts.

The embedded parts of the I-beam main girder oblique tie rods must be pre-embedded according to the designed size and position before pouring the tower structure of the first floor on the operation platform.

I-beam primary and secondary beams are hoisted by tower cranes. Before hoisting, stake out according to the dimensions on the floor plan of the scaffolding of the operating platform. Inspection and acceptance of section steel, steel pipe, fasteners and scaffolding shall be carried out in accordance with the regulations.

b. Installation method of I-beam main beam of operating platform

The I-beam main girder of the operation platform is hoisted directly by a tower crane and placed in place according to the pre-stretched line. After the I-beam main girder is hoisted in place, use a wooden wedge to wedge the I-beam and the pre-buried Φ20 pressure ring tightly.

c. Installation of main girder I-beam pre-control wire rope

In order to prevent the I-beam main girder from being too large during the installation of the secondary beam and the inclined stay rod, the Φ20 pull ring is pre-embedded on the I-beam main beam and the tower structure beam on the upper floor of the operation platform, and 6×19Φ20 steel wire ropes are used for pre-control. , the pre-controlled steel wire rope is on the upper layer of the operating platform with a structural strength level of 75%, and the secondary beams and diagonal stay rods of the operating platform are set in place before installation.

3 Construction pre-embedded oblique tie rod embedded parts, after the concrete strength reaches 75% of the design strength, install the oblique tie rod and the secondary beam of the operation platform.

a. Diagonal tie rod installation

After the concrete strength reaches 75% and the pre-controlled steel wire rope is installed in place on the first floor structure on the operation platform of the two towers, install the diagonal stay rod. The diagonal stay rods are made of 16# I-beam, and the I-beam main girder pull joints are set at 3.6m from both ends. In the vertical direction, the tie joints are pre-embedded on the structural beams and columns of the tower on the first floor of the operation platform, and a steel wire rope is pre-embedded. When the ring, secondary beam I-beam and diagonal stay rod are removed in the later period, the steel wire rope is temporarily tied to the main beam as a safety reserve, forming an included angle of 45°. In order to facilitate the installation of the diagonal tie rods, short stiffeners are welded on the embedded parts and the 22a# I-beam main beam, and finally the stiffeners are connected with the 16# I-beam tie rods with high-strength bolts. See Attachment VII for details

b Diagonal stay rod installation steps:

Step 1: After the main girder I-beam is installed, a temporary frame needs to be erected in the installation range of the diagonal stay as an operating platform for the installation of the diagonal stay. First, install the I-beam secondary beam within 3.6m of the span of the diagonal stay and fix it firmly with the main beam. After the secondary beam is fixed, use square wood and plywood to lay the operator's operating platform on the secondary beam.

The second step is to install the diagonal tie rod: the diagonal stay rod is made of 16# I-beam, and the tower crane is used to assist in the installation. The diagonal tie rods are connected with high-strength bolts. First, lift the diagonal stay rods to the height of the embedded parts on the wall, and then temporarily fix them with the embedded parts on the wall. The nuts are not tightened temporarily, and the command tower crane slowly lowers the diagonal stay rods to the main beam pull joints. position, connect the pull-up joints of the main beam I-beam, and finally tighten the nuts.

c. Installation of I-beam secondary beam

The secondary beam is used as the support foundation of the operation platform, resting on the 22a# I-beam main beam, arranged vertically with the main beam at a distance of 1000mm, and fixed with the main beam by spot welding after installation in place. After the secondary beam is installed and fixed, weld two Φ20 short steel bar heads with a length of 100mm on the secondary beam according to the pole spacing of 1000mm to prevent the displacement of the support pole.

4 For the roof structure and column construction of the tower above the operation platform, after the concrete strength of the column reaches 75% of the design strength, the hoisting of the stiff beam section steel of the anchor section in the corridor, structural formwork, steel bar construction, and concrete pouring will be carried out.

5 Erection of the operating platform frame.

When setting up the platform support, firstly, a temporary master operation platform is laid with square wood and formwork on the installed and fixed secondary beam I-beam, and then the upright pole is set up, and the upright pole is inserted into the short steel bar welded in advance , in order to prevent displacement, causing the base of the frame to be suspended. To set up the pole, first erect the pole according to the four corners of the rectangle of 4m×4m, then connect the sweeping pole and the horizontal pole to make the frame stable, and then set up according to the distance between the poles.

The step distance of the support is 1.800m, and the vertical and horizontal two-way sweeping poles are set at 200mm from the ground. The oblique scissors braces are installed every four spans around the frame body, and a horizontal scissors brace is set at the height of the second step frame.

After the frame body is erected, the scaffolding boards are fully spread on the lower layer and the top layer of the frame, and fixed firmly with iron wires.

The pre-embedded steel plate on the shear wall is set up in two steps and two spans, and finally welded with the frame body tie steel pipe for details. Attachment 15

6 After the structural concrete strength of the non-corridor part of the roof layer reaches 75% of the design strength, the tower crane is used to hoist and fix the section steel of the corridor.

After the hoisting of the 7-shaped steel and the erection of the operation platform are completed, the formwork, steel bars and concrete construction of the stiff beam at the corridor will be carried out, and the steel plate welded with the steel truss formwork will be pre-embedded on the top of the beam, and the main beam and half of the corridor will be constructed. Concrete pouring of side beams at the height of the section.

a. After the stiffened beam profile steel is installed in place, the manufactured U-shaped screw is welded upside down on the profiled steel beam, and fixed by spot welding. The spacing between the U-shaped screws should meet the spacing requirements in the scheme calculation.

b. Install the beam bottom formwork. The formwork is made of 18mm thick plywood. After the formwork is prepared, the inner corrugated square wood is nailed to the formwork panel and inserted into the U-shaped screw fixed on the section steel. The holes reserved on the formwork need to be matched with the U-shaped screw. The positions are consistent, and for the convenience of installation, bolts can be used to temporarily fix the installed formwork.

c Install the outer corrugated square steel and nuts at the bottom of the beam: the hole on the outer corrugated square steel and the screw rod must be opened in advance and meet the spacing requirements of the screw. , can be fine-tuned with nuts. The outer corrugated square steel is fixed with 3 nuts.

d. Installation of steel bars for stiff beams and pre-embedded steel plates on top of beams

The installation sequence of beam reinforcement: beam longitudinal reinforcement connection - stirrup installation - stirrup hook installation.

Installation of pre-embedded steel plates on the top of the beam: Since the corridor floor uses a self-supporting steel truss formwork, the steel truss formwork needs to be welded and fixed to the beam during installation. Therefore, a full-length steel plate is pre-embedded on the top of the stiff beam as Base metal welded with steel truss formwork. The width of the steel plate is the same as that of the steel beam with a thickness of 10mm. The pre-embedded tie of the steel plate adopts a U-shaped hook of Φ10200.

Before pre-embedding, the theodolite is used to determine the position of the axis, and the wire is drawn on the beam stirrup as the control line when the steel plate is pre-embedded, and then pre-embedded. After the axis position and elevation are correct, weld the U-shaped hook to the beam reinforcement.

e. Rigid beam side formwork installation

After the beam reinforcement and embedded parts are installed, the side formwork shall be closed, and the beam side formwork shall be fixed with the outer corrugated steel pipes tied with the pull screw.

Step 1: Install the pull screw. For the part that needs to pass through the steel web, it is necessary to make holes in advance to install and fix the bolts.

Step 2: Install the beam side formwork and square wood Installation: After the formwork is prepared, nail the inner corrugated square wood on the formwork panel and put it into the fixed tension screw.

Step 3: Beam side formwork fixation: Use fan-shaped clamps to clamp the outer corrugations of the double steel pipes, and fasten them with double nuts.

8. Concrete pouring of the secondary beam and the remaining half of the side beam at the corridor

Considering that the deflection of the end of the stiff main beam is relatively large when the concrete of the stiff main beam, the secondary beam, and the floor slab are poured at the same time, segmental pouring is adopted, and half the height of the main beam and side beam is poured first, so that the concrete strength of the main beam and side beam is equal After the level reaches 100%, the remaining height of the side beam and the concrete pouring of the secondary beam will be carried out, and the floor concrete will be poured after the concrete strength level of the equal side beam and secondary beam reaches 75%.

9 Construction of reinforced truss formwork, pouring floor concrete.

10 Remove the formwork at the bottom of the beam.

11 Remove the operating platform

a. Preparation for demolition

Before the demolition, remove the sundries on the scaffolding, put a warning rope on the bottom of the corridor and 15m around it, and prohibit pedestrians from entering; the technical person in charge of the project will explain the technical details of the safe demolition and perform the signing procedures; the demolition operators must wear safety helmets and safety belts .

b. Removal of the frame

The first step is to remove the garbage and sundries on the scaffolding board of the frame body, and remove the safety net.

The second step is to remove the scaffolding on the frame body: the removal sequence is from both sides of the border to the middle, leaving a width of about 1.5m as the channel for final removal.

The third step is to remove the oblique scissors brace and horizontal scissors brace.

The fourth step is to remove the small crossbar, large crossbar and vertical pole from top to bottom. When the frame body is dismantled, the upper floor is closed, and the removed steel pipes and fasteners cannot be hoisted immediately by the tower crane. The removed steel pipes and fasteners are transported to the floor through the opening of the passage, and it is strictly forbidden to stack them on the frame body to be dismantled. superior.

c. Removal of secondary beam I-beams and diagonal stays

Before the demolition of the secondary beam, use square timber and formwork to lay a temporary passage on the secondary beam.

According to the site conditions, the demolition is divided into two sides first and then the middle, leaving a passage in the middle, and finally demolishing.

The operator must fasten the safety belt and ensure that the safety belt has a reliable pull point before proceeding with the operation. First, the springboard is placed on the temporary work platform and the secondary beam and after being stabilized, the operator stands on the springboard and uses a grinder to connect the secondary beam with the main beam. Cut off the fixed welding spot of the beam, then tie the rope to the side of the I-beam 2 of the secondary beam, drag the I-beam to the temporary work platform, transport it to the floor, and then remove the next section of the secondary beam, and dismantle the vertical I-beam At the end, move the platform inward into a span, and remove the secondary beam below in the same way.

After the temporary platform is moved to the innermost side, it is dismantled step by step according to the span of the main girder in a backward manner. Firstly, the diagonal tie rods are removed. To ensure safety, the 6×19Φ20 safety wire ropes must be installed in place before the diagonal stay rods are removed. The oblique tie rod has a large dead weight and needs to be dismantled by gas cutting in 4 stages. After the oblique tie rods are removed, the scaffold board is removed, and the secondary beam I-beam is removed, and finally the pre-control wire rope is cut to facilitate the final removal of the main beam I-beam.

Finally, the secondary beam at the channel part is removed.

d. Removal of the main beam of the operating platform

To dismantle the I-beam of the main beam, adopt: install a hoist at the settlement joint in the middle of the roof corridor. Lock the winch brake straight back. After the secondary beam I-beam, diagonal stay rods, and wire ropes are removed, gas welding is used to cut off the main beam I-beam from both ends, and the winch brake is turned on to lift the main beam I-beam slowly to the ground, and finally transported to the stack site.

e. Remove the pull ring on the outer wall

The pull ring on the outer wall is disassembled by using the hanging basket when the outer wall is decorated.

The beneficial effects of the utility model are:

1. The formwork construction method of using I-beam or profiled steel beams to build the operation platform, stiff beams to hang self-supporting, and floor slabs to support the formwork solves the problem of difficult formwork support of the high-altitude and large-span cantilevered corridor structure, which greatly saves Turnover materials, reduce construction costs, speed up construction progress, and ensure safety.

2. The pre-embedded steel plate on the stiff beam solves the problem of effective connection between the floor deck and the stiff beam, enables the floor deck and the stiff beam to work together to ensure structural safety.

3. Large-span steel girders are welded with rings, and steel wire ropes are used for mitering the diagonal stays before installation, which effectively solves the problem of excessive deflection of steel girders or I-beams during installation, and ensures the safety of the installation and removal of the operating platform .

4. Add stiffeners to the I-beam main beam, that is, weld a steel bar with a diameter of 20mm on the left and right sides of the I-beam web every 2 meters, so as to avoid the excessive deflection of the hoisting process and affect the main beam The quality of splicing welds.

5. The load of the upper operating platform of the support system of the utility model is transmitted to the I-beam and the diagonal tie rod through the steel pipe bracket and the connecting beam, and the force transmission is clear and the force is reasonable. The installation of tie rods is convenient and safe, with less steel consumption and high economy. In addition, the weight of a single component is small, the process is simple and has no special requirements, and it occupies less space, which is convenient for high-altitude operation. The construction process is simple, the structure is reliable, the stability is strong, and the assembly and disassembly Convenient and practical.

Description of drawings

Accompanying drawing 1 flowchart;

Attached drawing 2 is the plane layout of the scaffolding of the operation platform;

Accompanying drawing 3 is the sectional view of the scaffolding of the operation platform;

Attached drawing 4 is the connection diagram of the roof corridor stiff beam and self-supporting steel truss floor;

Attached drawing 5 is a detailed drawing of the suspension formwork of the stiffened beam;

Attached drawing 6 is a partial enlarged view of the side view of the stiff beam suspension formwork;

Attached drawing 7 is a large sample diagram of the inclined rod of the operation platform

Accompanying drawing 8 basic detailed diagram of operation platform

Accompanying drawing 9 is the dismantling sequence diagram of the operating platform

Explanation of reference signs: lower floor structure 1, upper floor structure 2, mansion scaffolding operation platform 3, roof layer floor structure 4, I-shaped steel main beam 5, I-shaped steel diagonal tie rod 6, I-shaped steel secondary beam 7. Vertical scissors support 8, horizontal scissors support 9, full pavement scaffolding 10, edge protection diagonal brace 11, diagonal tie rod embedded parts 12, vertical and horizontal steel pipes 13, superior climbing ladder 14, isolation layer 15, safety slope Pulling wire rope 16, safety cable-stayed wire rope ring 17, scaffold pole 18, self-supporting steel truss formwork 19, stiffening plate 20, stiffening main beam 21, stiffening secondary beam 22, square steel 23, double steel pipe outer corrugation 24 , Beam side formwork 25, opposite tension screw 26, U-shaped screw 27, double nut 28, inner corrugated square wood 29, connecting ear plate 30, shear wall 31, wall connecting piece 32, main beam suspension ring 33, high-strength bolt 34, Temporary access platform 35, main beam anchor ring 36, deformation joint 37, beam bottom template 38.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described:

As shown in the figure, in this high-altitude and large-span cantilevered corridor-shaped steel concrete structure, the I-shaped steel main beam 5 is installed between the lower floor structure 1 of the east and west tower structures, and the main beam anchor ring 36 is embedded in the lower floor. In structure 1, the I-beam main girder 5 is fixedly connected to the main girder anchor ring 36 at the end after hoisting and installation; Between the structure 1 and the upper floor structure 2, there is an I-shaped steel diagonal tie rod 6, and the lower floor structure 1 is equipped with an I-shaped steel secondary beam 7. Connection; the U-shaped screw rod 27 of the rigid main beam 21 and the rigid secondary beam 22 fixes the beam bottom formwork 38 and the inner corrugated square wood 29 through the square steel 23 and double nuts 28, and the inner corrugated square wood 29 is arranged parallel to the axis of the beam. The steel 23 is arranged vertically to the beam axis; the beam side template 25 is equipped with inner corrugated square wood 29 and is fastened and connected by double steel pipe outer corrugated 24 and tension screw 26; Bury the stiffened plate 20 welded with the steel bar truss formwork, and the thick stiffened plate 20 is connected with the stiffened main beam 21 and the stiffened secondary beam 22 by stirrup welding.

Example: With a frame-shear structure, the main building consists of two towers in the east and west, with one floor underground and 24 floors above ground, with a total building height of 108.700 meters; the podium has three floors, a frame structure, and a building height of 16.900 meters. The main building is divided into two independent towers in the east and west starting from 10.950m on the third floor. The towers in the west area are 1-7 axes, and the towers in the east area are 8-14 axes. The elevation of the roof layer is 91.85m). Form the 7-8 axis room of the high-altitude corridor. Take a building with a bottom elevation of 92.45m and a top elevation of 108.7m as an example.

The floor slabs of the corridor have a net height of 80.950m from the third floor +10.950m to the roof layer of 91.850m, and cantilever 6.725m outwards to form a high-altitude corridor. 150mm thick self-supporting reinforced truss concrete floor. The section size of the rigid main beam is 450mm×1200mm, using 250mm×900mm section steel, the section of the stiffened secondary beam is 300mm×1200mm, using 150mm×400mm section steel, the section steel is Q345B steel, and the design strength of beam and slab concrete is C30.

The construction method is as follows;

The construction steps of the corridor are as follows: the east and west towers are divided into east and west towers by the deformation joint 37, and the east and west towers are constructed in layers up to the floor structure 2 of the 24th floor → the roof layer floor structure 4 is installed with stiff beams → the tower and the corridor are erected Floor structure 4 formwork support → tower, corridor roof structure 4 reinforcement, concrete construction.

After optimization of various schemes, the construction method of setting up high-altitude operation platform and stiff beam hanging formwork is adopted, that is, a steel structure operation platform is set up on the floor structure 1 of the 23rd floor, the operation floor with full hall feet is 3, and the floor structure of the roof floor is 4 stiff The beams are constructed with hanging formwork, and the slabs are constructed with self-supporting floor slabs.

The specific steps of the construction method are as follows;

The first step: installation of the I-beam main beam of the operation platform: after the construction of the lower floor structure 1 of the east and west tower structures is completed and the concrete strength reaches 2.0MPa, the installation of the I-beam main beam 5 of the operation platform is carried out. The main girder 5 is hoisted to the lower floor structure 1 after being connected by the sling of the tower crane to the main girder ring 33. The main girder anchor ring 36 needs to be pre-embedded before the pouring of the lower floor structure 1. Most of them are shear wall structures, so the shear walls need to reserve holes at the installation part of the I-beam main beam when setting up the formwork, so as to facilitate the later demolition. After the I-beam main beam 5 is hoisted and installed, fix it with the main beam anchor ring 36 at the end;

Step 2: When constructing the upper floor structure 2, pre-embed the embedded part 12 of the inclined stay rod and the suspension ring 17 of the safety cable-stayed steel wire rope. For the installation of the beam 7, the I-beam diagonal stay rod 6 is connected with the connecting ear plate 30 through the high-strength bolt 34;

The third step: the column construction of the upper floor structure 2 and the roof floor structure 4, after the concrete strength of the column reaches 75% of the design strength, the hoisting of the anchor section steel beam section in the corridor, structural formwork, steel bar construction, concrete pouring;

Step 4: Carry out the erection of the 3-frame body of the scaffolding operation platform in the whole hall, that is, the installation and erection of the vertical and horizontal steel pipes 13 of the operation platform, the horizontal scissors brace 9, the isolation layer 15, the climbing ladder 14, and the edge protective diagonal brace 11, and the isolation layer 15 Hang safety nets under scaffolding;

Step 5: After the structural concrete strength of the non-corridor part of the roof layer reaches 75% of the design strength, the tower crane is used to hoist and fix the rigid main beam 21 and the rigid secondary beam 22 steel in the corridor part;

Step 6: After the steel hoisting of the rigid main beam 21 and the rigid secondary beam 22 is completed, and the scaffolding operation platform 3 is erected, install the U-shaped screw 27 and the U-shaped screw 27 of the rigid main beam 21 and the rigid secondary beam 22 Fix the beam bottom formwork 38 and the inner corrugated square wood 29 through the square steel 23 and double nuts 28, the inner corrugated square wood 29 is arranged parallel to the beam axis, and the square steel 23 is arranged perpendicular to the beam axis; when the beam bottom formwork 38 is installed and fixed, carry out Installation of steel bars inside the beam and installation of beam side formwork 25, installation of inner corrugated square wood 29 on the outside of beam side formwork 25 and fastening by double steel pipe outer corrugation 24 and tension screw 26; after the beam bottom formwork 38 and beam side formwork 25 are installed The stiffening plate 20 welded with the reinforcement truss formwork is pre-buried on the top of the stiff main beam 21 and the stiff secondary beam 22, and the thick stiff plate 20 is welded on the stirrups of the stiff main beam 21 and the stiff secondary beam 22, Concrete pouring of the rigid main beam 21 of the corridor and the edge beam of half the height of the section; the scaffold pole 18 is fixedly connected with the shear wall 31 through the connecting wall piece 32;

Step 7: concrete pouring of the rigid secondary beam 22 at the corridor and the remaining half of the side beam;

The eighth step: the construction of the self-supporting steel truss formwork 19, pouring the roof layer floor structure 4 concrete;

The ninth step: remove the formwork 38 at the bottom of the beam;

Step 10: Remove the mantang scaffolding operating platform 3, the I-steel diagonal tie rod 6, the I-steel secondary beam 7, and the I-steel main beam 5.

a. Removal of the frame

The first step is to remove the garbage and sundries on the scaffolding operation platform 3, and remove the safety net.

The second step is to dismantle the scaffold board on the scaffolding operation platform 3 in the whole hall: the dismantling sequence is carried out from the north and south sides to the middle, and the temporary access platform 35 with a width of about 1.5m is used as the passage for final dismantling.

The third step is to remove the vertical scissors support 8 and the horizontal scissors support 9.

The fourth step is to remove the vertical and horizontal steel pipes 13 and scaffolding poles 18 from top to bottom. The dismantled steel pipes and fasteners are transported to the floor through 35 openings of the temporary access platform.

c. The I-beam secondary beam 7 and the I-beam oblique tie rod 6 are removed.

Before the I-beam secondary beam 7 is removed, square timber and templates are used to lay a temporary passage for people on the I-beam secondary beam 7 .

According to the site conditions, the demolition is divided into two sides and then the middle, leaving a temporary access platform 35 in the middle, and finally demolishing.

The operator must fasten the safety belt and ensure that the safety belt has a reliable pull point before carrying out the operation. First, the springboard is placed on the temporary work platform and the I-beam secondary beam 7 and stabilized. The operator stands on the springboard and uses a grinder to grind the The I-beam secondary beam 7 and the I-beam main beam 5 are cut off at the fixed welding spot, and then the rope is tied on both sides of the I-beam secondary beam 7, and the I-beam is dragged to the temporary work platform, transported to the floor, and then carried out The demolition of the lower section of the secondary beam 7, the removal of a vertical I-beam 7 is completed, and the platform is moved inwards into a span, and the following secondary beam 7 is removed in the same way.

After the temporary platform is moved to the innermost side, it is dismantled in sections according to the span of the I-steel main girder 5. Firstly, the I-steel diagonal tie rod 6 is removed. To ensure safety, the I-steel diagonal stay rod 6 must be removed first. Safety cable-stayed wire rope 16 is installed in place, and one end of insurance cable-stayed wire rope 16 is fixed on the safety cable-stayed wire rope suspension ring 17, and the other end is connected with main beam suspension ring 33. The I-beam diagonal tie rod 6 has a large dead weight and needs to be dismantled by gas cutting in 4 sections. After the I-beam oblique tie rod 6 is removed, the scaffold board is removed, and the I-beam secondary beam 7 is removed, and the safety cable-stayed wire rope 16 is cut off at last, so that the final I-beam main beam 5 is removed.

Finally, the secondary beam at the channel part is removed.

d. Removal of the I-beam main beam 5 of the operating platform

To dismantle the I-beam main beam 5, adopt: install a hoist at the settlement joint in the middle of the roof corridor, and when removing the I-beam secondary beam 7, fix the steel wire rope of the manual hoist on the pull ring of the I-beam main beam 5, and then Lock the hoist brake after straightening the hanging wire rope. After the I-shaped steel secondary beam 7, I-shaped steel oblique stay rod 6, and safety cable-stayed wire rope 16 are dismantled, gas welding is used to cut off the I-shaped steel main beam 5 from the ends of both sides, and the winch is opened to brake the I-shaped steel main beam 5. Slowly hoisted to the third floor, and finally transported to the stacking site.

e. Remove the pull ring on the outer wall

The pull ring on the outer wall is disassembled by using the hanging basket when the outer wall is decorated.

The load of the upper operating platform of the support system of the utility model is transmitted to the I-shaped steel beam and the diagonal stay rod through the steel pipe support and the connecting beam, so that the force transmission is clear and the force is reasonable. The installation of tie rods is convenient and safe, with less steel consumption and high economy. In addition, the weight of a single component is small, the process is simple and has no special requirements, and it occupies less space, which is convenient for high-altitude operation. The construction process is simple, the structure is reliable, the stability is strong, and the assembly and disassembly Convenient and practical.

In addition to the above embodiments, the utility model can also have other implementations. All technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the utility model.

Claims (1)

1. high-altitude long-span vestibule steel reinforced concrete structure of encorbelmenting; It is characterized in that: i iron girder (5) is installed between east, the XiTaLou structure bottom floor structure (1); Girder anchor ring (36) is embedded in lower floor's floor structure (1), and i iron girder (5) lifting is installed the back and is fixedly connected with girder anchor ring (36) in the end; Upper floor structure (2) is embedded with diagonal member built-in fitting (12) and insurance oblique rollering steel silk rope suspension ring (17); Be provided with i iron diagonal member (6) between lower floor's floor structure (1) and the upper floor structure (2); I iron secondary beam (7) is installed on lower floor's floor structure (1), i iron diagonal member (6) through high-strength bolt (34) be connected otic placode (30) and connect; The U-shaped screw rod (27) of stiffness girder (21), stiffness secondary beam (22) through square steel (23) and double nut (28) clamped beam soffit formwork (38) and in the stupefied lumps of wood (29); In the stupefied lumps of wood (29) be parallel to the beam axis arranged, the vertical cross girders axis arranged of square steel (23); The stupefied lumps of wood (29) and be fastenedly connected in install in side template (25) outside by two steel pipes outer stupefied (24) and Screw arbor with nut at both-ends (26); At the stiffness plate (20) of pre-buried good and reinforcement bar truss mould plate welding of stiffness girder (21), stiffness secondary beam (22) back, thick stiffness plate (20) and stiffness girder (21), stiffness secondary beam (22) stirrup are welded to connect.

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