Performance of Physical Structures in Hurricane Katrina and Hurricane Rita: A Reconnaissance Report

This is the final report on the National Institute of Standards and Technology (NIST) led-reconnaissance to assess the performance of physical structures during Hurricane Katrina and Hurricane Rita. The report describes the environmental conditions (wind speed, storm surge, and flooding) that were present during the hurricanes in regions that were affected by the hurricanes. The report further documents the NIST-led team’s observations of damage to major buildings, infrastructure, and residential structures resulting from wind and wind-borne debris, storm surge, surge-borne debris, and surge-induced flooding. Following Hurricane Katrina’s landfall on August 29, 2005, NIST began planning for a two-phase reconnaissance to study and document damage to major buildings, infrastructure, and residential structures. In phase 1, NIST deployed a roofing expert with a team assembled by the Roofing Industry Committee on Weathering Issues (RICOWI) during the week of September 6, 2005 to study damage to roofing systems in Mississippi Gulf Coast region. NIST deployed four structural engineers in cooperation with the FEMA Mitigation Assessment Team (MAT) during the week of September 26, 2005 to study damage in the Mississippi Gulf Coast region. Two NIST members of this team also inspected the breaches in the floodwalls and levees, as well as damage to major buildings, in New Orleans. These phase 1 deployments provided input that was used to plan a broader phase 2 reconnaissance to study damage in the Mississippi coastal area, New Orleans, and Southeast Texas (the area affected by Hurricane Rita). In the phase 2 reconnaissance, 26 experts from the private sector, universities, and federal agencies (including 6 from NIST) deployed during the weeks of October 10, 2005 and October 17, 2005. This report documents the observations made during these deployments and subsequent analysis of damage data and environmental actions. It also outlines the major findings of the NIST-led reconnaissance team. The report concludes with 23 recommendations for:
(1) improvements to practice that will have an immediate impact on the rebuilding of structures damaged or destroyed by the hurricanes;
(2) improvements to standards, codes, and practice; and (3) further study or research and development.
Keywords: Hurricane, wind, wind-borne debris, storm surge, surge-borne debris, flooding, major buildings, physical infrastructure, residential structures, building codes and standards, building practices.

Guide for Seismic Evaluation of Active Mechanical Equipment

The purpose of this Guide is to provide recommendations for evaluating the seismic operability of valves, pumps compressors, fans, air handling units, and chillers. The recommendations are in the form of seismic evaluation checklists, static and dynamic calculation methods and seismic testing protocols.
The Guide provides the background and technical basis for the proposed seismic evaluation methods. This background consists of equipment descriptions, analytical experience, seismic test experience, lessons learned from earthquake investigations, and observations of operating failure modes and equipment maintenance.
The Guide covers the seismic adequacy of the equipment itself, but does not address its power supplies, instrumentation and controls. These need to be addressed separately, if the equipment is required to operate during or after the earthquake.
Chapter 2 of the guide addresses the principles of seismic equipment engineering and provides a review of existing seismic qualification methods and standards.
Chapters 3 to 7 address the five classes of active mechanical equipment: Valves (Chapter 3), Pumps (Chapter 4), Compressors (Chapter 5), Fans and Air Handling Units (Chapter 6), and Chillers (Chapter 7).
Each one of these equipment chapters is structured in a consistent manner and addresses, in order: (1) equipment description, (2) equipment performance during earthquakes, (3) equipment performance in seismic tests, (4) methods, rules and limitations of seismic analysis, and (5) equipment vulnerabilities based on common – non-seismic – operation and failures (corrective maintenance). Each equipment chapter concludes with a seismic attributes checklist. In addition, the guide includes two chapters that apply to all classes of equipment: anchorage to concrete (Chapter 8) and evaluation of seismic interactions (Chapter 9). The seismic attributes checklist, together with the support and anchorage checks of Chapter 8 and the interaction checks of Chapter 9, constitute the basis for seismic qualification of the equipment.

Applications of Titanium Dioxide Photocatalysis to Construction Materials

Titanium dioxide photocatalysis is based on the semiconducting nature of its anatase crystal type. Construction materials with titanium photocatalyst show performances of air purification, self-cleaning, water purification, antibacterial action.

This book describes principles of titanium dioxide photocatalysis, its applications to cementitious and noncementitious materials, as well as an overview of standardization of testing methods.

Content Level » Research

Keywords » air purification - building materials - civil engineering structures - photocatalysis - self-cleaning - sustainable construction - sustainable engineering - titanium dioxide

Related subjects » Applied & Technical Physics - Engineering - Nanotechnology

a study on the seismic behaviour of a 52-story steel frame building

European Manual for in-situ Assessment of Important Existing Structures

The European Manual for in-situ Assessment of the Earthquake Resistance of Important Existing Structures consists of Part I: Training and Part II: Practical Application and focuses on state of the art methods and innovative procedures for the assessment of the following important existing structures:
• Buildings whose integrity during earthquakes is of vital importance for civil protection, e.g. hospitals, fire stations, power plants, telecommunication facilities, etc. (importance class IV according to EN1998-1:2005)
• Bridges of critical importance for maintaining communications, especially in the immediate post-earthquake period, bridges where failure is associated with a large number of probable fatalities and major bridges, where a design life greater than normal is required (importance class III according to EN 1998-2:2005)
• Buildings whose seismic resistance is of importance in view of the consequences associated with a collapse, e.g. schools, assembly halls, cultural institutions, etc. (importance class III according to EN1998-1:2005)
• Industrial facilities, where secondary risks exist, e.g. the risk of release of toxic and/ or explosive materials
• Cultural heritage These structures must remain greatly undamaged and serviceable after an earthquake.
In order to achieve this goal a pre-earthquake phase involving investigations, structural analysis and safety assessment is required. The results of this activities provide the “state of consistence” of the structure and allow to plan and undertake measures for seismic upgrading in due time, if necessary. Normally the highest level of knowledge is necessary to afford safety assessments for such structures and it is attained by setting a detailed, often 3D, structural model, based on careful surveys and updated by using measured insitu dynamic properties. It is one of the basic ideas of SP5 to integrate experimental techniques into the assessment procedure, which is an advantage one has in the case of existing buildings

Specification for Foamed Concrete

This report describes the nature of foamed concrete, its composition and properties and how it could be specified for use in civil engineering works. Because the properties of foamed concrete can vary widely, and it can be used in a wide variety of applications, it is important to define performance requirements for each case. Current usage in the UK of foamed concrete is of the order of 250,000 tonnes per year Despite this fairly significant tonnage there is, as yet, no definitive guidance on how the material should be tested and specified for use. Furthermore there is a paucity of information on some of its properties, particularly regarding its long-term performance. This situation might be restricting the wider use of foamed concrete for ground engineering and structural applications. The report provides a brief history of the development of foamed concrete and gives examples of contemporary uses. The quality control tests that might be applied to foamed concrete are described; some of these differ from those used for normal weight concrete. An example specification for foamed concrete is provided, which includes both mandatory and optional requirements. Distinction is made between clauses for use with all applications and those required for specific applications. Guidance on acceptance criteria and actions to be taken in the event of non-conformance is also provided.

Underwater Construction Using Cofferdams

DRILLED SHAFTS FOR BRIDGE FOUNDATIONS