World Trade Center

LIST OF FIGURES IV

ERROR! NO TABLE OF FIGURES ENTRIES FOUND.EXECUTIVE SUMMARY IV

EXECUTIVE SUMMARY V

1 вЂ" INTRODUCTION VI

1.1 вЂ" HISTORY VI

1.1.1 вЂ" Inspiration for towers vi

1.1.2 вЂ" Brief summary of the project vi

1.1.3 вЂ" Demise of the towers vi

2 вЂ" FRAMED TUBE SYSTEM VII

2.1 вЂ" THE CENTRAL CORE VII

2.1.1 вЂ" Design specifications vii

2.1.2 вЂ" Components housed within the core vii

2.2 вЂ" THE OUTER SHELL VII

2.2.1 вЂ" Design specifications vii

2.2.2 вЂ" Construction materials viii

2.3 вЂ" BENEFITS OF THE TUBE FRAMED SYSTEM VIII

2.3.1 вЂ" Less demanding on materials viii

2.3.2 вЂ" Reduced specifications viii

3 вЂ" EFFICIENCY IX

3.1 вЂ" SKY LOBBIES IX

3.1.1 вЂ" Explanation of system ix

3.1.2вЂ" Spatial savings ix

3.1.3вЂ" Capacity ix

3.2вЂ" IMPORTANCE OF ELEVATORS X

3.2.1вЂ" Searching for solutions x

3.2.2вЂ" Simulation analysis x

4 вЂ" EXTERIOR PANELING XI

4.1 вЂ" CONSTRUCTION XI

4.1.1 вЂ" Materials xi

4.1.2 вЂ" Fabrication xi

4.2 вЂ" DESIGN XI

4.2.1 вЂ" Wind loadings xi

4.2.2 вЂ" Specifications xi

5 вЂ" CONCLUSION XII

5.1 вЂ" FRAMED TUBE SYSTEM XII

5.1.1 вЂ" Superiority in complex loadings xii

5.2 вЂ" ELEVATORS XII

5.2.1 вЂ" Efficiency of sky lobby system xii

5.3 вЂ" EXTERIOR PANELING XII

5.3.1 вЂ" Safety xii

5.3.2 вЂ" Loading benefits xii

LIST OF REFERENCES XIV

List of figures

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Executive summary

1 вЂ" Introduction

1.1 вЂ" History

1.1.1 вЂ" Inspiration for towers

The idea for the World Trade Center originated during the 1939 World Fair in New York. However, it was not until 1960, when American technology was on the rise, that the planning for the construction was put to fruition under the powerful leadership of Chase Manhattan Bank’s David Rockefeller. The location for the engineering marvel was to be set in lower Manhattan. Along with The Port of New York Authority, Minoru Yamasaki and Associates, as well as many other design firms, began the design for the world’s largest office complex which was unveiled in 1964. Construction of the enormous project began in 1968 and in1970, thirty one years after its inspiration, the World Trade Center accommodated its first tenants.

1.1.2 вЂ" Brief summary of the project

The design of the World Trade Center was a modern day masterpiece. It consisted of a framed tube system, which was necessary to carry the massive weight of the building. The framed tube system was also perfect for housing the emergency services and elevators. The elevators were stacked in a manor that increased efficiency of travel throughout the building. Exterior panels were prefabricated and simply had to be put together like puzzle pieces once at the job site; enabling rapid construction. These panels were specially designed to withstand large external loadings caused by strong winds. The logistics and tracking involved in the construction of the World Trade Center was unprecedented.

1.1.3 вЂ" Demise of the towers

The Two Towers stood dwarfing all other skyscrapers in Manhattan, until their ultimate demise on September 11, 2001, when the towers were hit by two Boeing 767-200ER aircrafts in a devastating terrorist attack. The towers were able to withstand the initial collision from the aircrafts; however, the fuel from the aircrafts drastically weakened the columns within the towers resulting in their collapse.

2 вЂ" Framed tube system

One of the main design innovations of the World Trade Center is the framed tube system which extends the entire height of the building to support the building. The system is comprised of two parts: the central core and the external panelling.

2.1 вЂ" The central core

The central core is analogous as the backbone of the building, where the body is held upright by the spine and vital lifelines pass through the spine to the rest of the body. The central core provides the same function. The cores of the towers were constructed as a steel �tube’, instead of bone, which housed all of the support systems for the entire building.

2.1.1 вЂ" Design specifications

The weight distribution of the towers was not symmetrical where approximately sixty percent of the tower was supported by the central core and the remaining forty percent was support by the exterior panelling. A cross-sectional view of the framed