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seminar report

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seminar report

  1. 1. VISVESWARAYA TECHNOLOGICAL UNIVERSITY “Jnana Sangama” Belgaum - 590018 SEMINAR REPORT ON “PREFABRICATED SKYSCRAPER” Submitted in the partial fulfilment of the Requirements for the award of the degree of Bachelor of Technology In Civil Engineering UNDER THE GUIDANCE OF Mrs. Jayalakshmi Raju Lecturer By Aashish Kuinkel 1SP11CV047 Department of Civil Engineering S.E.A COLLEGE OF ENGINEERING & TECHNOLOGY 2015
  2. 2. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 2 ACKNOWLEDGEMENT I express my gratitude and indebtness to our institution,S.E.A. COLLEGE OF ENGINEERING AND TECHNOLOGY, Bangalore,which has provided us an opportunity to fulfill the cherish desire to achieve our goal. Firstly, I wish to express profound sense of gratitude to our esteemed Principal Dr. Manjunath sir for inspiring and guiding on my seminar topic with whole hearted efforts. I too acknowledge our H.O.D. Mr. VENUGOPAL for his kind co-operation and guidance in my seminar topic.I also acknowledge our honorable project guide.Mrs. Jayalakshmi Raju Lecturer of Civil Engineering. I also like to thank all the staff members of CIVIL ENGINNERING, specially Mrs. Kavita A.V. who have directly and indirectly helped me with their valuable suggestions in the successful completion of this seminar report. Last but not the least I would like to thank my beloved parents for their blessings, love and encouragement to successfully complete the task by meeting all the requirements. With Thanks, AASHISH KUINKEL (1SP11CV047)
  3. 3. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 3 ABSTRACT Prefabricated skyscrapers are the tall buildings constructed by firstly prefabricating all the building components such as roof, column, beams etc. in the industries and then assembling these components in the site. Day by day increased popularity of this construction technique have provided structural engineers a new dimension for cheap, stable and fast construction method. Prefabricated building is a type of building that consists of several factory-built components or units that are assembled on-site to complete the unit. Prefabrication is the practice of assembling components of a structure in a factory or other manufacturing site, and transporting complete assemblies or sub-assemblies to the construction site where the structure is to be located. The term is used to distinguish this process from the more conventional construction practice of transporting the basic materials to the construction site where all assembly is carried out. A skyscraper is a tall, continuously habitable building of over 40-50 floors, mostly designed for office, commercial and residential use. A skyscraper can also be called a high-rise, but the term skyscraper is often used for buildings higher than 150 m (492 ft). For buildings above a height of 300 m (984 ft), the term Supertall can be used, while skyscrapers reaching beyond 600 m (1,969 ft) are classified as Megatall.
  4. 4. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 4 Contents:- Page No 1. Abstract 03 2. Introduction 04  Prefabrication  Skyscrapers 3. History 06  History of Prefabrication  History of Skyscrapers 4. Process of Prefabrication 08 5. Prefabrication Vs. Conventional Construction 11 6. Limitations 12 7. Prefabrication components 13 8. Prefabricated Skyscrapers 14 9. Conclusion 19 10. References 20
  5. 5. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 5 CHAPTER 1 INTRODUCTION 1.1. PREFABRICATED BUILDINGS Prefabricated building is a type of building that consists of several factory-built components or units that are assembled on-site to complete the unit. Prefabrication is the practice of assembling components of a structure in a factory or other manufacturing site, and transporting complete assemblies or sub-assemblies to the construction site where the structure is to be located. The term is used to distinguish this process from the more conventional construction practice of transporting the basic materials to the construction site where all assembly is carried out. The term prefabrication also applies to the manufacturing of things other than structures at a fixed site. It is frequently used when fabrication of a section of a machine or any movable structure is shifted from the main manufacturing site to another location, and the section is supplied assembled and ready to fit. It is not generally used to refer to electrical or electronic components of a machine, or mechanical parts such as pumps, gearboxes and compressors which are usually supplied as separate items, but to sections of the body of the machine which in the past were fabricated with the whole machine. Prefabricated parts of the body of the machine may be called 'sub-assemblies' to distinguish them from the other components. 1.2. SKYSCRAPERS A skyscraper is a tall, continuously habitable building of over 40-50 floors, mostly designed for office, commercial and residential use. A skyscraper can also be called a high-rise, but the term skyscraper is often used for buildings higher than 150 m (492 ft). For buildings above a height of 300 m (984 ft), the term Supertall can be used, while skyscrapers reaching beyond 600 m (1,969 ft) are classified as Megatall. One common feature of skyscrapers is having a steel framework that supports curtain walls. These curtain walls either bear on the framework below or are suspended from the framework above, rather than load-bearing walls of conventional construction. Some early skyscrapers have a steel frame that enables the construction of load-bearing walls taller than of those made of reinforced concrete. Modern skyscrapers' walls are not load-bearing and most skyscrapers are characterized by large surface areas of windows made possible by the concept of steel frame and curtain walls. However, skyscrapers can have curtain walls that mimic conventional walls and a small surface area of windows. Modern skyscrapers often have a tubular structure, and are designed to act like a hollow cylinder to resist lateral loads (wind, seismic, etc.). To appear more
  6. 6. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 6 slender, allow less wind exposure and to transmit more daylight to the ground, many skyscrapers have a design with setbacks. A relatively big building may be considered a skyscraper if it protrudes well above its built environment and changes the overall skyline. The maximum height of structures has progressed historically with building methods and technologies and thus what is today considered a skyscraper is taller than before. The Burj Khalifa is the tallest building in the world. Skyscrapers conserve space allowing us to build up instead of out. High-rise buildings are considered shorter than skyscrapers. There is no clear definition of any difference between a tower block and a skyscraper though a building lower than about thirty stories is not likely to be a skyscraper and a building with fifty or more stories is certainly a skyscraper. The term "skyscraper" was first applied to buildings of steel framed construction of at least 10 stories in the late 19th century, a result of public amazement at the tall buildings being built in major cities like Chicago, New York City, Philadelphia, Detroit, and St. Louis. The first steel frame skyscraper was the Home Insurance Building (originally 10 stories with a height of 42 m or 138 ft) in Chicago, Illinois in 1885. Some point to Philadelphia's 10-story Jayne Building (1849– 50) as a proto-skyscraper, or to New York's seven-floor Equitable Life Assurance Building, built in 1870, for its innovative use of a kind of skeletal frame, but such designation depends largely on what factors are chosen. Even the scholars making the argument find it to be purely academic. The structural definition of the word skyscraper was refined later by architectural historians, based on engineering developments of the 1880s that had enabled construction of tall multi-story buildings. This definition was based on the steel skeleton—as opposed to constructions of load- bearing masonry, which passed their practical limit in 1891 with Chicago's Monadnock Building. The Emporis Standards Committee defines a high-rise building as "a multi-story structure between 35–100 meters tall, or a building of unknown height from 12–39 floors" and a skyscraper as "a multi-story building whose architectural height is at least 100 m or 330 ft." Some structural engineers define a highrise as any vertical construction for which wind is a more significant load factor than earthquake or weight. Note that this criterion fits not only high-rises but some other tall structures, such as towers.The word skyscraper often carries a connotation of pride and achievement. The skyscraper, in name and social function, is a modern expression of the age-old symbol of the world center or axis mundi: a pillar that connects earth to heaven and the four compass directions to one another. A loose convention of some in the United States and Europe draws the lower limit of a skyscraper at 150 m or 490 ft.
  7. 7. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 7 CHAPTER 2 HISTORY 2.1. PREFABRICATED BUILDINGS Prefabricated construction stretches back to 1624 when a disassembled house was shipped from England to Cape Ann, Massachusetts to house a fishing fleet using ready-made—and trusted— English building techniques, familiar to settlers who had just arrived in America in 1620. In 1833, Chicago saw the first “balloon frame” building, St. Mary’s Church, erected on Lake Street.3 Credited to, alternately, a man named George W. Snow and a carpenter named Augustine Deodat Taylor, the innovation of the balloon frame involved using uniform, slender wood studs held together with newly mass-produced nails, rather than with more complex joinery. The technique, so called due to its lightness and precarious appearance, proved to be an expedient way of creating much-needed housing in burgeoning urban centers. By 1834, a simple balloon frame “shack” would take no more than a week to construct. Within a decade, the new mode of construction had spreadfrom the Midwest throughout the nation.4 By 1849 railroads carried prefabricated housing “kits” to California to provide expedient shelter for prospectors during the gold rush. Prefabricated housing was popular during the Second World War due to the need for mass accommodation for military personnel. The United States used Quonset huts as military buildings, and in the Britain prefabricated buildings used included Nissen huts and Bellman Hangars. 'Prefabs' were built after the war as a means of quickly and cheaply providing quality housing as a replacement for the housing destroyed during the Blitz. The proliferation of prefabricated housing across the country was a result of the Burt Committee and the Housing (Temporary Accommodation) Act 1944. Under the Ministry of Works Emergency Factory Made housing programme, a specification was drawn up and bid on by various private construction and manufacturing companies. After approval by the MoW, companies could bid on Council led development schemes, resulting in whole estates of prefabs constructed to provide accommodation for those made homeless by the War and ongoing slum clearance. Almost 160,000 had been built in the UK by 1948 at a cost of close to £216 million. The largest single prefab estate in Britain was at Belle Vale (South Liverpool), where more than 1,100 were built after World War 2. The estate was demolished in the 1960s amid much controversy as the prefabs were very popular with residents at the time.
  8. 8. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 8 By 1967, modularity was once again thrust into public consciousness with Moshe Safdie’s Habitat ’67, constructed for the Montreal World’s Fair. The large apartment building consisted of individual “modules” made from precast concrete and fitted together like a puzzle. 2.2. SKYSCRAPERS The evolution of skyscraper began with the innovation in mainly two sectors: Elevator and steel- skeleton frame. Vertical architecture would be impossible, first of all, without the elevator, the great equalizer of civilization, which by excessively rapid "express service," makes the twentieth floor scarcely more difficult to access than the third. Without [the elevator] its chief merit [of the tall building] would be gone; without it its upper stories would be as inaccessible as a mountaintop. The Equitable Life Assurance Company (1870) was the first building to use elevator. The tower building on Broadway was the first building to use steel skeleton frame structure and it is also considered the first skyscraper. Figure 1 Montreal World’s Fair 1967 Figure 2 First building to use vertical elevator
  9. 9. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 9 The use of elevator and steel skeleton frame to build the worlds tallest buildings. Singer building, Woolworth building etc are the earliest example of tall skyscrapers in the early 20th century. But along time the use of term skyscrapers have changed. The Dynamic Tower of Dubai is the first prefabricated skyscraper. There are only countable prefabricated skyscrapers in the world. Figure 3 Tower Building first skyscraper
  10. 10. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 10 CHAPTER 3 PROCESS OF PREFABRICATION The conventional method of building a house is to transport bricks, timber, cement, sand, steel and construction aggregate, etc. to the site, and to construct the house on site from these materials. In prefabricated construction, only the foundations are constructed in this way, while sections of walls, floors and roof are prefabricated (assembled) in a factory (possibly with window and door frames included), transported to the site, lifted into place by a crane and bolted together. The process of prefabrication of precast concrete is listed below. i. Assembly of mould ii. Mould cleaning and preparation iii. Fixing of rebar iv. Final inspection before casting v. Concreting vi. Curing vii. Demoulding Figure 4 Possible levels of prefabrication
  11. 11. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 11 Before fabrication shop drawings of individual precast elements are required to be prepared and detailed with the following information: i. Project location. reference number of elements, and their locations with respect to the building layout and elevation ii. Dimensions of elements, center of gravity weight and concrete volume iii. Locations of all reinforcing steel cast-in items for connection. lifting and bracing iv. Locations of embedded items such as service conduits uts and recesses as well as openings v. Jointing and interfacing details between elements vi. Water tightness details at joints vii. Architectural details and treatments where applicable The prefabricated moulds are then transported to the site from industries. These moulds are prepared to the exact dimensions are required. These moulds are than assembled in the site which is shown in the figure below. Multiple cranes and other vehicles are used to carry the prefabricated components to the upper floors as the skyscraper goes on constructing. As these prefabricated moulds are designed to exact dimension it should be properly carried or else it may get damaged which leads to construction of further other mould. Figure 5 Prefabrication in a Japanese Housing Company
  12. 12. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 12 Figure 6 Transportation of prefabricated components to site Figure 7 assembly of transported prefabricated components on the site
  13. 13. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 13 CHAPTER 4 PREFABRICATION VS. CONVENTIONAL Conventional construction is the method where buildings are constructed on site by using multiple labourers and workers which we see on any of the construction sites. Following are the advantages of prefabricated construction over conventional method of on field construction of building and skyscrapers: a. On site construction time is shortened considerably. b. Many health and safety risks can be reduced or eliminated through working in a safer factory environment. c. PMC (permanent modular construction or prefabricated buildings) is a form of lean construction - an approach which aims to maximise value and minimise waste. PMC produces less waste as materials are pre-measured, scheduled and fabricated at works. d. A project’s carbon footprint should be considerably less as fewer people are travelling to site. e. PMC ensures robust construction methods which can assist in the airtightness of the building, beneficial to energy efficiency and to achieving Passivhaus standards. f. PMC benefits the current skills shortage, with between 60-90% of work being manufactured off site in controlled environments. g. All fitted specialist components are factory quality controlled and have full mechanical and engineering equipment already in place before being installed on site. h. Safety systems are incorporated into each component, e.g. steel systems with pre-welded roof edge protection or safe tether points for fall restraint systems. i. Impact on the community during construction can be significantly reduced in terms of noise, traffic and period of work on site. j. Certainty of timescales for the delivery of projects is maximised through the allocation of manufacturing, fabrication and delivery slots. k. Developments in Building Information Modelling (BIM) has minimised the risk of design errors during the manufacturing process. BIM allows for a design to be properly tested for clashes and clearance zones, as well as the construction sequence before manufacturing. l. Using CAM (Computer Aided Manufacturing); components can be repeatedly cut into their exact digital representation. The accuracy at design stage often allows for a design to be more tolerant than current industry standards.
  14. 14. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 14 CHAPTER 5 LIMITATIONS a. Traditional construction allows for later design changes (on site if necessary) but with pre- fabricated buildings this is near impossible. As a result, early sign-off of final designs can be made an unnerving experience for clients. b. PMC can take away a project’s architectural flair as pre-fabricated buildings are often considered an off-the-shelf product. c. The suitability of sites for PMC must be fully considered at the outset in terms of access for the delivery of large modules and provision of adequate lifting equipment. d. Opportunities for a localism approach to construction can be decreased as PMC eliminates the need for local suppliers and sub-contractors. e. PMC can make the liaison stage of the project even more intense, as the components arriving on site are large and the logistics and planning to erect these components can be disruptive to the general public.
  15. 15. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 15 CHAPTER 6 PREFABRICATION COMPONENTS Prefabricated components are moulded or prepared on the industries and are transported to the site location. These system are not conventional so components which are used for building the prefabricated components should have following characteristics: i. Easy availability ii. Light weight for easy handling and transportation to site iii. Thermal insulation property iv. Easy workability v. Durability to all weather conditions vi. Non combustibility Figure 8 prefabricated wall along with windows
  16. 16. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 16 CHAPTER 7 PREFABRICATED SKYSCRAPERS There are only few prefabricated skyscrapers around the world. But the popularity it has achieved after the first skyscraper was planned in Dubai in 2008 we will be seeing a lot of these prefabricated skyscrapers in the future. Dynamic Tower is the first skyscraper built in the world. Chinese company Broad Sustainable Building (BSB) is building tallest of skyscrapers using prefabricated modules in China. Recently England and United States are also building the prefabricated skyscrapers. Sky City is expected to be the tallest skyscraper of the world. Figure 9 Proposed Prefabricated Skyscraperin China
  17. 17. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 17  Dynamic Tower, Dubai Based on the construction and features of Rotating Tower it will be the first skyscraper produced according to industrial process. Apart from the central concrete core 90% of buildings consists in prefabricated modules, assembled in an industrial park and transported to the building site to be connected to the central core. Considering that each floor of the tower consists of factory made modules that will arrive at the building site with electrical, plumbing, air conditioning system ready for use, Fisher method provides numerous advantages. Figure 10 Proposed Plan of Dynamic Tower
  18. 18. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 18 General Information on Dynamic Tower Type: Hotel Residence Office Location: Dubai Height: 420m Floors: 80 Cost: 330 million dollar The core of Dynamic Tower (22m diameter) was the only component of building built in the construction site. Each floor consists of 40 factory built modules fully furnished along with plumbing, electricity ready to be used. The time required to complete its 80 floor was expected to be 18 months. Apart from being the tallest prefabricated skyscraper it was also the first skyscraper which could rotate 360°. Dynamic Tower was proposed on 2008 but its construction is not started yet due to various causes. The developers are planning to construct the same structure in London. Figure 11 Construction of dynamic tower
  19. 19. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 19  T30 Hotel, China General Information: Location: China Floor: 30 Days for construction: 15 Resistance: 9 rector scale earthquake Figure 12 T30 Hotel
  20. 20. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 20 The T30 hotel constructed by BSB Company in China was completed in record 15 days. All the components were module on industry and transported to the location site where they were assembled. The same company in China is building prefabricated skyscrapers throughout China with the construction rate of 3 floors per day. Figure 13 Assembling of T30 Hotel
  21. 21. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 21 CHAPTER 8 CONCLUSION Prefabricated skyscrapers are at the early phase of construction. Though prefabrication has taken world by storm after it was proposed on 2008 it has faced a lot of criticism from all over the world. A lot of prefabricated structures have failed or are halted during construction phase raising a question whether this method of construction is even appropriate in such large scale. Estimating the deflection of beams and other structural components prior to prefabrication is difficult and again there is a problem when the skyscraper height and floors keep on increasing. But all prefabricated skyscrapers are not failure. China has been successfully designing and constructing skyscrapers using prefabricated modules. Even in London the design of 25 story prefabricated structure was a success. The safe and successful construction of prefabricated skyscrapers has shown that there is a high scope of prefabrication for building skyscrapers. With the reduced on site construction time and overall financial benefit over conventional construction method, prefabrication is a very suitable method of construction of skyscrapers in these modern high paced society. With numerous tests and construction going on around using prefabricated components for construction of skyscrapers we might in the near future get to see these skyscrapers rising all over the world without criticism. Maybe in few years we could even see the construction of prefabricated skyscrapers in India.
  22. 22. Prefabricated Skyscrapers SEA COLLEGE OF ENGINEERING Page 22 REFERENCES i. www.dynamicarchitecture.net ii. IS 15916: 2011 iii. Prefab Architecture- Ryan E Smith iv. The future of the city- Kheir Al-Kodmany v. The Unreality Industry: The Deliberate Manufacturing of Falsehood and what ... By Ian I. Mitroff, vi. http://bsbinc.net/ vii. Prefabricated residential construction -Ed Swierk, Project for ARCH 030, Spring 2005 viii. The Architecture and Development of New York City-Andrew S. Dolkart

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