SYSTEMS OF MODULAR CONSTRUCTION & THEIR DESIGN IMPLICATIONS

Presented by:NIKHIL MITTAL2011BARC003

“The last place you would want to build a building is on a building site.”

Contents• Aim of the Research• Objective of the Research• Methodology• Background Study & Research question• Literature Studies

•Habitat 67•Nakagin Tower

• Case Study•BDA Housing, Bangalore

• Inferences

Aim of the ResearchTo study various systems of volumetric modular construction and identify the design opportunities associated with each of them in the context of apartment housing.

Objectives of the Research•To identify the different systems of volumetric modular construction based on variations in their structural details and assembly techniques.

•To document the structural details, assembly techniques and average module sizes associated with the different systems identified above.

•To understand the structural behaviour of the building as a whole in each case.

•To do a comparative analysis with parameters based on design opportunities relating to different module configurations and stacking patterns.

Background StudyPrefabrication and Modularisation

Mass Production PREFABRICATION

Integration of prefabrication and modularisation principles into the manufacturing process has revolutionised almost all major industries during the 19th and 20th

centuries

CONSTRUCTION INDUSTRY

“ Prefabrication is an offsite manufacturing process that takes place at a

specialized facility in which various materials and building systems are joined to form

a component or part of a larger final installation “(Haas et al. 2000).

TYPES OF PREFABRICATION TECHNIQUES

Modular Construction

Modular construction is a process in which a building is constructed off-site, under controlled plant conditions, using the same materials and designing to the same codes and standards as conventionally built facilities.

Buildings are produced in “modules” which are fully/partially finished parts that enclose some habitable space, and are hence volumetric in nature.

Once at the site, these modules are assembled into a complete building. Hence, the onsite construction is reduced to foundation work and module assembly.

CASE STUDIES

Habitat 67, Montreal, Canada

In 1967, Moshe Safdie, introduced an innovative modular system for the high-density housing development of Habitat 67, built as part o f the Expo ’67 world housing showcase in 1967, Montreal, Canada. Habitat 67 exemplified the use of prefabricated dwelling modules with unique three-dimensional modular configurations to form a multi-storeyed residential building that demonstrated an alternative to the monolithic apartment block.

No. of units built: 158 DUs

No. of bedrooms: 1 bhk to 4 bhk

Area of each unit: 600 to 1700 sq. ft

No. of Modules: 354

Size of each module: 5.8m X 11.6m

Completion time: 10 months

GENERAL INFORMATION

TYPE OF STRUCTURAL SYSTEM: LOAD BEARING + POST TENSIONING

The Modular Units

•The prefabrication process of the 19x38x10 ft concrete rectilinear 90-ton boxes took place on-site.

•The basic modular shape was molded in a reinforced steel cage,

•Once cured, the concrete box was transferred to an assembly line for the insertion of electrical and mechanical systems, as well as insulation and windows.

•To finalize the production, modular kitchens and bathrooms were installed, and finally a crane lifted each unit to its designated position.

Casting units at the factory yard

Erection and Assembly at Site

• the standardized 354 modules were stacked vertically and horizontally together.

•individual modules had to bear the weight of the units above them,

•Three separate elevator cores direct vertical circulation throughout the complex

•Every part of the building, including units, pedestrian streets and elevator cores, participate as load-bearing members;

•units are connected to each other by post-tensioning, high tension rods, cables and welding, forming a continuous suspension system.

Casting units at the factory yard

CONFIGURATION OF MODULES INTO 15 UNIT TYPES

A DUPLEX DWELLING UNIT MADE FROM 4 MODULES

MODULE CONFIGURATIONS

STRUCTURAL STACKING OF MODULES FOR VERTICAL LOADS TRANSFERPLAN AND SECTION OF A DWELLING UNIT

The modular prefabricated concrete units are designed to become part of the structure of the whole building. Habitat is a three-dimensional space structure in which all the parts of the building, including the units, the pedestrian streets, and the three elevator cores participate as load-bearing members.

POST TENSIONING DETAILS FOR MODULE ASSEMBLY

BUILDING STRUCTURE AND ASSEMBLY

INFERENCES

• Combination of two loading systems, i.e. vertical load bearing and post tensioning provide versatality and stability to structure.

• Such a system provides more flexibility in the design and configurations of modules.

• It also makes it possible to have different floor layouts, thus adding versatality to the form of the building.

• Since the module acts as a structural unit in itself, it is possible to give cantilevers.

• A wide number of stacking patterns can be experimented with this system, thus making it possible to give terraced gardens and open spaces within the building, breaking the rigid tower typology.

• However, in order to provide post tensioning, the modules must be in close proximity to the lift core.

Nakagin Capsule Tower, Japan

The Nakagin Capsule Tower is a mixed-use residential and office tower designed by architect Kisho Kurokawa and located in Tokyo, Japan. Completed in 1972, the building is a rare remaining example of Japanese Metabolism, an architectural movement emblematic of Japan's postwar cultural resurgence. It was the world's first example of capsule architecture built for permanent and practical use.The module was created with the intention of housing traveling businessmen that worked in central Tokyo during the week. It is a prototype for architecture of sustainability and recycleability, as each module can be plugged in to the central core and replaced or exchanged when necessary.

No. of units built: 140 UNITS

No. of bedrooms: Studio type

Area of each unit: 10 sqm

No. of Modules: 140

Size of each module: 4m X 2.5m

Completion time: 4 months

GENERAL INFORMATION

TYPE OF STRUCTURAL SYSTEM: MODULES ATTACHED TO RCC CORE WITH HIGH TENSION BOLTS

The Modular Units

•Each capsule measures 2.3 m by 3.8 m by 2.1 m and functions as a small living or office space. Capsules can be connected and combined to create larger spaces.

• Each capsule is connected to one of the two main shafts only by four high-tension bolts and is designed to be replaceable.

•The capsules were fitted with utilities and interior fittings before being shipped to the building site, where they were attached to the concrete towers. Each capsule is attached independently and cantilevered from the shaft INTERIORS OF THE CAPSULE UNIT

Erection and Assembly at Site

The building is composed of two interconnected concrete towers, respectively eleven and thirteen floors, which house 140 self-contained prefabricated capsules.The cores are rigid-frame, made of a steel frame and reinforced concrete.The capsules are bolted to this steel frame through 4 high tension bolts.

MODULE CONFIGURATION

Every module is independently attached to the metal framework on the RCC core through high tension bolts.

INFERENCES

• Such a system provides more flexibility in configurations of modules.

• It also makes it possible to have different floor layouts, thus adding versatality to the form of the building.

• Since the module acts as a structural unit in itself, it is possible to give cantilevers.

• However, in order to provide post tensioning, the modules must be in close proximity to the lift core.

•Also, Using bolts to hold the modules restricts their sizes due to structural system.

BDA Housing, Alur, Bangalore

This is an innovative EWS housing in Bangalore and is the first of its kind modular construction in India’s housing sector. It offers 1500 dwelling units in G+3 buildings made entirely from prefabricated volumetric modules. The project has been designed and executed by “Moore Living,” a architecture and construction firm from New Zealand.

No. of units built: 1500 DUs

No. of bedrooms: 1 bhk

Area of each unit: 380 sqft

No. of Modules: 3000

Size of each module: 3m X 6m + 2.2 m X 4.6 m

Completion time: 18 months

GENERAL INFORMATION

TYPE OF STRUCTURAL SYSTEM: Vertical Load Transfer through Steel Columns

The Modular Units

Dwelling unit plan made from 3 modules

The modules are composed of 4 panels of walls and 1 slab forming the floor, binded together.

The modules are structurally supported by 4 MS Box Sections positioned at the 4 corners of the modules.

These columns are welded to base plates at their 2 ends, flushes with the top most and lower most exterior surface of the module

Hence, when the modules are stacked, the base plates are bolted together, forming a continuous system for vertical load transfer.

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