William T. Holmes

Development of building damage functions for earthquake loss estimation

This paper describes building damage functions that were developed for the FEMA/NIBS earthquake loss estimation methodology (Whitman et al., 1997). These functions estimate the probability of discrete states of structural and nonstructural building damage that are used as inputs to the estimation of building losses, including economic loss, casualties and loss of function (Kircher et al., 1997). These functions are of a new form and represent a significant step forward in the prediction of earthquake impacts. Unlike previous building damage models that are based on Modified Mercalli Intensity, the new functions use quantitative measures of ground shaking (and ground failure) and analyze model building types in a similar manner to the engineering analysis of a single structure.

Seismic evaluation of existing reinforced concrete building columns

Past earthquakes have emphasized the vulnerability of reinforced concrete columns having details typical of those built before the mid-1970s. These columns are susceptible to axial-flexural, shear, and bond failures, which subsequently may lead to severe damage or collapse of the building. Research was undertaken to investigate the lateral and vertical load-resisting behavior of reinforced concrete columns typical of pre-1970s construction. Eight full-scale specimens were constructed and were loaded with constant axial load and increasing cyclic lateral displacement increments until failure. Test data are presented and compared with behavior estimated by using various evaluation methods.

A Functional Loss Assessment of a Hospital System in the Bío-Bío Province

The objectives of this study were to introduce a damage and loss-of-function survey tool that can be used to standardize future assessment of hospital performance, to assess the impact of the 2010 Chilean earthquake on the functions of the public hospital system in the Bío-Bío Province, and to translate these results as lessons that can be applied to U.S. hospitals. This study focused on damage to structural and nonstructural components, utility services, and equipment, as well as loss of supplies and personnel. Structural engineers completed a visual inspection of facilities, and hospital administrators were surveyed to assess the overall impact on operations. All hospitals lost communications, electrical power, and water for several days. All hospitals reported some physical damage although only one suffered significant structural damage. The lessons learned from Chile are applied to U.S. practice of hospital seismic mitigation.

The 1997 NEHRP Recommended Provisions for Seismic Regulations for New Buildings and Other Structures

This paper follows the evolution of the NEHRP Recommended Provisions for Seismic Regulations for New Buildings and Other Structures from the development of ATC 3-06 to the 1997 edition of the document. The features of the 1997 NEHRP Provisions are described in detail. Complementary information about the NEHRP Provisions is found in several other papers in this volume of Earthquake Spectra. Subject areas covered elsewhere are specifically referenced in this paper.

Policies and Standards for Reoccupancy Repair of Earthquake‐Damaged Buildings

Following a damaging earthquake, many buildings may be closed pending determination of safety and necessary repairs. A lack of repair standards and criteria for reoccupancy created controversy and denied owners use of their buildings after recent earthquakes. Conservative standards may delay the economic recovery of the community. Unconservative standards could lead to an equal or worse situation in the next earthquake. In order to develop technical standards that will solve this problem, the acceptable levels of safety for reoccupancy first must be established. Development of rational standards has been hindered by a limited ability to estimate actual lateral-load capacity of buildings of various materials and in various damage states. Once a policy for acceptable levels of safety is established, however, technical guidelines could be developed which would improve the current situation.

Application of the Recommendations of the Canterbury Earthquakes Royal Commission to the Design, Construction, and Evaluation of Buildings and Seismic Risk Mitigation Policies in the United States

An unprecedented level of data concerning building performance in the Canterbury earthquake sequence of 2010–2011 has been collected by the Canterbury Earthquake Royal Commission of Inquiry. In addition to data from a technical investigation undertaken by the New Zealand Department of Building and Housing on four specific buildings, the Royal Commission has collected data from many other invited reports, international peer reviews of reports, submitted testimony, and oral testimony and examination at public hearings. Contained in the Commissions seven-volume final report are 189 specific recommendations for improvements in design codes and standards, hazard mitigation policy, post-earthquake building safety and occupancy tagging, and other topics. Some of these recommendations are unique to New Zealands system of government, engineering practice, or codes and standards, but many are applicable in the United States.