definition of high-rise and super-high-rise buildings

according to article 3.1 of the general principles for design of civil buildings (GB51352-2115),

residential buildings with 1, 11 or more floors and public buildings with a height of more than 24 meters are high-rise buildings.

2. A building with a height greater than 24m is a high-rise building (excluding single-storey buildings with a height greater than 24m)

A civil building with a height greater than 111m is a super-high-rise building.

internationally, tall buildings with a height of more than 31 stories or more than 111m are generally called super high-rise buildings.

Some super-high-rise cases

Shenzhen Jingji 111 Building

is located in the south of Hongbao Road, Luohu District, Shenzhen, with 4 floors underground and 111 floors above ground, with a total building height of 441. 8m and a total construction area of about 241,111 square meters. It is the third tallest building in Chinese mainland at present.

frame-core tube structure.

The tower of Shanghai World Financial Center

has 111 floors above ground, with a height of 492m above ground and 3 floors underground, with a total construction area of 381611m2.

The main structure adopts a three-dimensional mega-frame structure consisting of mega-columns, mega-braces and ribbon trusses, a reinforced concrete core tube structure and a triple structural system consisting of outrigger steel trusses which constitute the interaction between the core tube and the mega-structural columns.

Guangzhou Pearl River New Town East Tower

The total construction area is 517,681 square meters, and the total height of the building is 531 meters.

The tower structure is a concrete-filled steel tubular mega-column frame-tube structure with strengthened stories. 1/11 123456 Last page

Tianjin 117 Building

has 3 floors underground and 117 floors above ground, with a total design height of over 571 meters, a planned construction area of 1.83 million square meters and an estimated investment of more than 27 billion yuan.

Shenzhen Ping 'an International Financial Center Building

has a total construction area of 378,611 square meters, a height of 661 meters at the top of the tower, a roof of 588 meters, and ***118 floors.

the structural forms of super-high-rise buildings are mostly designed as frame-core tube structures, and there are two main types according to different heights:

Type 1: the inner tube is a reinforced concrete core tube structure and the outer tube is a giant column, and the giant column is connected with the core tube by steel beams, and the outer tube floor is in the form of composite floors, such as Shenzhen Jingji 111 Building, Guangzhou East Tower and Shenzhen Ping 'an Financial Building, all of which are of this structural form, with heights of 411 meters.

type 1: generally, the vertical structure of the core tube is 4 ~ 5 stories ahead of the horizontal structure in the core tube and 6 ~ 7 stories ahead of the peripheral frame floor, which can well solve the problem of providing working face for multi-process crossover operation. The wall structure of the core tube is the 1 th construction working face, the horizontal structure of the inner tube is the 2 nd construction working face, the steel structure column and steel beam are the 3 rd construction working face, the composite floor of the outer frame tube is the 4 th construction working face, the outer curtain wall is constructed in sections to form the 5 th construction working face, and the masonry and hardcover works of the lower floor are inserted in time as the 6 th construction working face. 2/11 Home Page Previous Page 123456 Next Page Last Page

Type 2: The inner tube is a giant column of reinforced concrete core tube and the outer tube is connected by a reinforced concrete beam, and the floor is an ordinary reinforced concrete floor, such as Chongqing Global and Guangzhou Gaode. The height of the building is about 211 ~ 411 meters.

Chongqing Global Building

Because the outer frame tube structure is reinforced concrete structure, it is not suitable for the construction technology of the core tube first in theory. The reasons are as follows:

(1) The steel bars of the beam and slab of the outer tube need to be disconnected in the same section, which has a great influence on the mechanical performance of the structure, and it is difficult to obtain the design consent.

(2) ordinary reinforced concrete floors need formwork construction.

current mainstream construction technology

structural construction sequence

the current mainstream construction processes of super high-rise buildings are as follows:

1. overall construction sequence: adopt the construction technology of tower top-down construction and podium top-down construction.

second, the form of foundation pit: underground continuous wall structure plus annular reinforced concrete internal support system

third, the main structure: the superstructure of the main building is generally divided into three beats:

1. Core tube wall construction;

2, rectangular column and peripheral floor construction;

3. Floor construction in core tube.

Enclosure lifting system

At present, there are two main forms of enclosure and lifting system for super high-rise building construction:

1. Integral hydraulic jacking steel platform with top formwork or climbing formwork technology

Introduction of jacking system

Introduction of platform system

Platform truss is composed of main truss, secondary truss and connecting truss connected by bolts and pins. Steel plates are laid on the truss, and internal and external protection is set at the adjacent portal to form a closed construction platform. The platform is provided with a steel bar stacking area, a steel structure welding apparatus stacking area, a fire water tank, an intelligent control machine room of the top formwork system, a mobile toilet, a rest shed, etc., and is also an attachment of various construction machinery, such as a cloth distributor and a construction elevator.

composition of platform system

formwork system

The formwork system consists of standard formwork, nonstandard formwork, internal angle formwork, vertical compensation formwork, back stare blankly and opposite bolts.

formwork system (popularization and application of aluminum alloy formwork)

top formwork hanger and protection system

The hanger system is composed of vertical rods, cross bars, steel mesh protection, horizontal walkway boards, turnable pedals and stairs. Hanger is divided into two parts: external hanger and internal hanger. External hanger has six steps and internal hanger has five steps, covering three structural layers, which provide workers with operating platforms for binding steel bars, setting up and cleaning templates, cleaning wall holes and embedding embedded parts.

Technical advantages of steel platform top formwork

1. Minimum jacking points

According to the characteristics of core tube, 3-4 jacking support points are set, so as to minimize the relationship between supporting columns and the core tube wall, minimize the influence of core tube changes on the system, and reduce the number of high-altitude formwork changes, which greatly enhances the adaptability of the system.

2. Low-level jacking

The bracket supported by the jacking column is supported on the lower second floor of the newly poured concrete, which can avoid the intermittence caused by the failure of the early strength of concrete to meet the jacking requirements and shorten the construction period.

3. Selection of hydraulic cylinder

A jack-up cylinder with long stroke and large tonnage is adopted, with a jack-up height of 5m at a time and a jack-up lift of 311t. The jack-up height of 5m only takes 2 hours, which reduces the jack-up procedure and significantly improves the jack-up speed. 5/11 Home Page Previous Page 345678 Next Page Last Page

4, Intelligent Operation

This system is equipped with an electric control system, which mainly includes a centralized console, data cables connecting various electromagnetic gate valves with the console, master cylinder stroke sensor, cylinder stroke limit, etc., to control and monitor the electromagnetic gate valve action of the whole system, realize fully intelligent operation in the jacking process, and achieve the precision of simultaneous jacking of each vertex.

Construction technology of steel platform top formwork

Construction technology of hydraulic climbing formwork

Hydraulic climbing formwork is a self-climbing formwork attached to the wall, which has the characteristics of simple structure, easy installation, convenient operation, high safety, fast construction speed and low labor input, and is a commonly used climbing formwork technology attached to the wall at present.

Composition of hydraulic self-climbing formwork

Damper

Climbing process of hydraulic self-climbing formwork

2. Integral lifting enclosure system with traditional formwork turnover technology

Vertical transportation system

1. The vertical transportation capacity of super-high-rise building construction is large

(1) The scale of super-high-rise building is huge, and it is a huge task to transport building materials to the required parts in time;

(2) The construction site of super-high-rise building has a large amount of work and needs many personnel, which is a severe test for the vertical transportation system;

(3) More construction waste is generated during the construction of super high-rise buildings, which can be transported out in time by vertical transportation.

to sum up, all these put forward extremely high requirements for the transportation capacity of the vertical transportation system in the construction of super high-rise buildings.

2. The vertical transportation in the construction of super-high-rise buildings has high benefits

The investment in the construction of super-high-rise buildings is large, and accelerating the construction speed can significantly improve the investment benefit of the construction unit. Therefore, the rational allocation of vertical transportation system plays a very important role in accelerating the construction speed of super high-rise buildings and reducing the construction cost.

firstly, an efficient vertical transportation system is a prerequisite for the smooth construction of super high-rise buildings.

the second is to ensure that the construction personnel can reach the construction operation surface quickly.

the vertical conveying system for super-high-rise building construction mainly includes: tower crane, construction elevator, delivery pump

1, and tower crane. At present, the main installation methods of tower crane are internal climbing type and external attachment type. At present, the most advanced tower crane with the largest lifting weight is M1281D tower crane, with the maximum lifting weight of 111T. Both Shenzhen Ping An Building and Shanghai Financial Center have been applied.

2. Construction elevator: At present, medium and high speed construction elevators are mainly used in the construction of super high-rise buildings.

classification by speed:

(1), rated speed of low-speed elevator v < 1.1m/s;

(2) The rated speed of medium-speed elevator is 1.1m/s ≤ V < 2.1m/s;

(3) The rated speed of high-speed elevator is 2.1m/s ≤ V < 4.1m/s;

(4) Rated elevator speed of ultra-high-speed elevator V≥4.1m/s.

3. Delivery pump:

(1) Selection of concrete pump:

At present, the pumping construction of ultra-high-rise buildings is generally realized by relay pumping or one pump to the top. Relay pumping means that concrete is transported by one concrete pump to another concrete pump hopper placed at a certain height in advance, and then concrete is delivered to the destination by the second pump; The scheme is economical and reliable; Relatively speaking, the requirements for pumps are not too high, and at the same time, after the completion of the project, these pumps can be used economically in other general projects; The disadvantage is that the construction is complicated, and the first pump and the second pump should be coordinated during construction; With the development of pumping equipment technology, relay pumping mode is gradually replaced by the technology of one pump to the top. Selection process of delivery pump: estimation of pumping pressure-primary selection of equipment model-determination of equipment model.

key process control technology

survey control

1. Introduction of survey control of super-high-rise buildings

1. Survey control of super-high-rise buildings is mainly divided into three categories: plane axis network control, floor elevation transmission and building settlement observation

2. The survey control methods mainly include external control method, internal control method and internal and external control method; The main technologies are GPS measurement technology and zenith verticality measurement (looking up method).

3. At present, the advanced equipment is the electronic laser total station with GPS function, which can give consideration to the functions of axis coordinate delivery and elevation laser transmission.

2. Key points of measurement control

Selection of measurement scheme and setting of primary and secondary traverse networks

3. Measures of measurement control

1. Work: qualification, professional level and professional ethics of personnel;

2. Material (machine): selection, identification and maintenance of measuring instruments;

3. method: the qualification of compiling, examining and approving the survey scheme and the feasibility review of the survey scheme. Re-survey of handover piles and establishment of primary and secondary traverse network.

4. Ring: first-level quarterly survey and second-level monthly survey

retaining structure

1. Several forms of retaining structure

1. Bored pile anchor cable; Internal support of diaphragm wall

2. Several aspects and measures that need to be paid attention to in envelope structure

1. Selection of external setting value: control range 11-15cm

2. Control of pile quality: inclination (setting out and machinery), hole formation (mud and continuous pouring) and acceptance (small strain 31%-5 core pulling%) < p Initial value: the initial value of the monitoring project shall be determined before the relevant construction process, and the average of the stable values observed for at least three times shall be taken. The initial value of the supporting stress shall be the stable value for two consecutive days 1 weeks before excavation. Alarm (yellow double 71% single 81%; Orange double 81% single control; Red double control value)

main structure

I. Two forms of main structure: reinforced concrete structure and rigid concrete

II. Control points and measures of two structural forms

1. Mass concrete: mass concrete with the minimum geometric dimension of concrete structure not less than 1m (GB_51496-2119), or it is expected that the concrete will be damaged by concrete. A large amount of mass concrete was poured at one time: 28,911 cubic meters of the 4.5-thick floor of Shanghai Financial Center was poured continuously in 42 hours, and the total volume of the 4.5-meter-thick floor concrete of Shenzhen Ping 'an Center was 31,111 cubic meters, which was completed in 72 hours.

Measures:

Work: before work, focus on vibrating methods; Material: mixture ratio;

machine: mixing station, transportation machinery, delivery pump, vibrator and auxiliary equipment;

method: the selection of construction scheme, focusing on the assignment of operation and management personnel, the selection of machinery, the selection of transportation routes, the method of reducing internal and external hydration heat, the selection of mixture ratio, etc., to ensure continuous operation and reduce cracking;

ring: scientific selection and prevention of weather during construction 8/11 home page previous page 678911 next page last page

steel structure

I. steel structure technology

verticality control, vertical deformation control, internal force control and welding control of different materials are technical problems in the installation of super-high complex giant steel structures. We start our research by analyzing the time-varying characteristics of materials.

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