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Civil Engineering Disasters

STRUCTURAL FAILURES

Introduction
Structural failures are a result of many causes that need to be analyzed and studiedbefore allowing the occupants to live. These appear because of the lack of proper care while construction of buildings. Whenever a small crack appears, this eventually goes on enlarging itself unless treated by structural engineers. For prevention, it is advised to keep vigilance and strict supervision or inspection from time to time by experts to avoid any kind of accidents. There are some instances where the quantity is given importance over quality on construction sites. This is because money is mostly the governing factor at sites which effects the quality. At first, the work may seem to be perfect without any appearance of failure, but when time goes by, the real problem starts to show up. Some preventive measures are taken to repair such failures, but it is better to take preventive measures at site than after damage to the buildings.
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Complete Report on Failure Analysis of World Trade Center 5

By
Kevin J. LaMalva
Simpson Gumpertz & Heger, Inc.

Abstract
This research involves a failure analysis of the internal structural collapse that occurred in World Trade Center 5 due to fire exposure alone on September 11, 2001. It is hypothesized that the steel column-tree assembly failed during the heating phase of the fire. Abaqus/Standard was used to predict the structural performance of the assembly when exposed to the fire. Results from a finite element, thermal-stress model confirms this hypothesis, for it is concluded that the catastrophic, progressive structural collapse occurred approximately 2 hours into the fire exposure.

Keywords:
Collapse, Coupled Analysis, Failure, Fire, Heat Transfer, Interface Friction, Structural, Thermal-Stress, World Trade Center (WTC)

1. Background
World Trade Center 5 (WTC 5) was a nine-story building in the World Trade Center complex in New York City, NY (Figure 1). On September 11, 2001, flaming debris from the World Trade Center Tower collapses ignited fires in WTC 5. These fires burned unchecked, ultimately causing a localized interior collapse from the 8th floor to the 4th floor in the eastern section of the building (Figure 2). Debris impact was not a direct factor in this failure; the collapse was caused by fire alone.
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Minneapolis I-35W Bridge Collapse – Engineering Evaluations and Finite Element Analysis

by Carl R. Schultheisz, Alan S. Kushner (National Transportation Safety Board), Toshio Nakamura (State University of New York, Stony Brook), Justin Ocel (Federal Highway Administration), William Wright (Virginia Polytechnic Institute and State University) and Min Li (SIMULIA Central)

Abstract
The National Transportation Safety Board (NTSB) investigates accidents to identify the probable cause and to make recommendations that would prevent similar accidents. Following the collapse of the I-35W bridge in Minneapolis on August 1, 2007, the NTSB worked with the Federal Highway Administration, the Minnesota Department of Transportation and other parties with information and expertise, including SIMULIA Central, to determine the circumstances that contributed to the collapse of the bridge, completing the investigation in 15 months. The NTSB concluded that the collapse of the bridge was caused by the inadequate load capacity of gusset plates used to connect the truss members, as a result of an error by the bridge design firm, Sver-drup & Parcel and Associates, Inc. The loading conditions included a combination of (1) substantial increases in the weight of the bridge caused by previous bridge modifications, and (2) the traffic and concentrated construction loads on the bridge on the day of the collapse. Evidence from the collapsed bridge structure, engineering evaluations of the design, and results from the finite element analyses used to support the investigation are reviewed.

Keywords: Bridge Collapse, Gusset Plate, Plasticity, Instability, Riks, Fasteners.
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Socio Economic Impact Of Failure Of Transmission Line Tower Foundations

A report by Christian Johnson and Thirugnanam

ABSTRACT
Transmission line towers are constructed for power evacuation purpose from generating stations to various load centers. Though they are considered to be the most stable and versatile semi-permanent structure, often they collapse due to failure of foundations, disrupting transfer of large blocks of power affecting the society to a larger extent. A brief review of literature on failure of transmission line tower foundations have been made and Case study involving data collection and visual inspection of transmission line tower foundation apart from diagnosis of transmission line tower stubs and laboratory experimentations have been presented. Based on the literature review and the case study undertaken as a part of the research, three predominant causes leading to failure of transmission line tower foundations have been discussed. Socio – economic impact of failure of transmission line tower foundations have been discussed. Remedial measures found through the research study for preventing failure of transmission line tower foundations have been briefly outlined.

Keywords:
Corrosion, Foundations, Failure, socio- economic, transmission line tower
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Failure Analysis Of Mishap At DMRC On 12 July

It was 12th July 2009 which proved to be the darkest day in the history of DMRC. After achieving a milestone of providing a reliable and easy mean of transportation to the capital of India, it is now facing huge problems which are not only causing loss of human lives but also causing immense damage to the most reputed infrastructure organization of India. So far, this company has achieved every target ahead of schedule under the excellent guidance of Mr. Sreedharan.

Let us try understanding what went wrong on that disastrous day

On 12th July, 2009, while lifting segments of the superstructure, an accident happened in the Badarpur – Secretariat section near P-67. The pier cap of pier P-67 got collapsed causing subsequent collapse of the
(i) Launching Girder
(ii) Span between P-66 and P-67 which had got erected and pre-stressed, already
(iii) Segments of the superstructure for the span between P-67 and P-68.

The incident left 6 people dead and many injured.

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