scholarly journals Performance Evaluation of Rigid Braced Indirect Suspended Ceiling with Steel Panels

2021 ◽  
Vol 11 (5) ◽  
pp. 1986
Author(s):  
Jae-Sub Lee ◽  
Dam-I Jung ◽  
Doo-Yong Lee ◽  
Bong-Ho Cho
Keyword(s):  
United States ◽  
Seismic Design ◽  
Shaking Table Test ◽  
The United States ◽  
Shaking Table ◽  
Personal Injury ◽  
Safety Standard ◽  
Design Standards ◽  
Design Life ◽  
Steel Panels

In Korea, the earthquakes in Gyeongju (2016) and Pohang (2017) have led to increased interest in the seismic design of nonstructural elements. Among these, the suspended ceiling can cause personal injury and property damage. In addition, most suspended ceilings that are used in Korea neither have seismic design details nor meet the current seismic design standards. There are two seismic design methods for suspended ceilings using a perimeter clip and a brace. In the United States and Japan, seismic design of ceilings is typically used, but the concepts of applying and installing braces are different. This is because the typical ceiling systems are different in the United States and Japan. In this study, a brace-applied ceiling system that is suitable for a suspended ceiling with a steel panel was applied in the indirect suspended ceiling mainly used in Korea. In addition, the seismic performance was verified through a shaking table test. All the specimens were applied with anti-falling clips that are designed to prevent the panels from falling, and they satisfy KDS 41 17 00, which is a Korean seismic design life safety standard. Without considering these factors, the performance level is lower than a nonseismic designed ceiling, which is not properly designed or constructed.

scholarly journals Quantitative Ice Accretion Information from the Automated Surface Observing System

2007 ◽  
Vol 46 (9) ◽  
pp. 1423-1437 ◽  
Author(s):  
Charles C. Ryerson ◽  
Allan C. Ramsay
Keyword(s):  
United States ◽  
The United States ◽  
Ice Thickness ◽  
Ice Storm ◽  
Design Standards ◽  
Ice Storms ◽  
Ice Accumulation ◽  
Direct Measurements ◽  
Improved Design ◽  
Precipitation Events

Abstract Freezing precipitation is a persistent winter weather problem that costs the United States millions of dollars annually. Costs and infrastructure disruption may be greatly reduced by ice-storm warnings issued by the National Weather Service (NWS), and by the development of climatologies that allow improved design of infrastructure elements. However, neither the NWS nor developers of climatologies have had direct measurements of ice-storm accumulations as a basis for issuing warnings and developing storm design standards. This paper describes the development of an aviation routine/special weather report (METAR/SPECI) remark that will report quantitative ice thickness at over 650 locations during ice storms using new algorithms developed for the Automated Surface Observing System (ASOS). Characteristics of the ASOS icing sensor, a field program to develop the algorithms, tests of accuracy, application of the algorithms, and sources of error are described, as is the implementation of an ice-thickness METAR/SPECI remark. The algorithms will potentially allow freezing precipitation events to be tracked with regard to ice accumulation in near–real time as they progress across the United States.

Seismic Design of Highway Bridges in the United States

1980 ◽  
Vol 106 (1) ◽  
pp. 13-27
Author(s):  
Roland L. Sharpe ◽  
Ronald L. Mayes ◽  
James D. Cooper
Keyword(s):  
United States ◽  
Seismic Design ◽  
Highway Bridges ◽  
The United States

scholarly journals Laboratory Tests for Subgrade Reaction Coefficient in Seismic Design of Underground Engineering Domain

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Kunpeng Xu ◽  
Liping Jing ◽  
Xinjun Cheng ◽  
Haian Liang ◽  
Jia Bin
Keyword(s):  
Seismic Design ◽  
Shaking Table Test ◽  
Free Field ◽  
Deformation Mode ◽  
Shaking Table ◽  
Subgrade Reaction ◽  
Underground Structures ◽  
Testing Methods ◽  
Underground Engineering ◽  
Reaction Coefficient

Subgrade reaction coefficient is commonly considered as the primary challenge in simplified seismic design of underground structures. Carrying out test is the most reliable way to acquire this intrinsic soil property. Owing to the limitations of experimental cost, time consumption, soil deformation mode, size effect, and confined condition, the existing testing methods cannot satisfy the requirements of high-precision subgrade reaction coefficient in seismic design process of underground structures. Accordingly, the present study makes an attempt to provide new laboratory testing methods considering realistic seismic response of soil, based on shaking table test and quasistatic test. Conventional shaking table test for sandy free-field was performed, with the results indicating that the equivalent normal subgrade reaction coefficients derived from the experimental hysteretic curves are reasonable and verifying the deformation mode under seismic excitation. A novel multifunctional quasistatic pushover device was invented, which can simulate the most unfavorable deformation mode of soil during the earthquake. In addition, the first successful application of an innovative quasistatic testing method in evaluating subgrade reaction coefficient was reported. The findings of this study provide preliminary detailed insights into subgrade reaction coefficient evaluation which can benefit seismic design of underground structures.

Seismic Design Requirements for Regions of Moderate Seismicity

2000 ◽  
Vol 16 (1) ◽  
pp. 205-225 ◽  
Author(s):  
Guy J. P. Nordenson ◽  
Glenn R. Bell
Keyword(s):  
United States ◽  
Seismic Design ◽  
Soft Soil ◽  
The United States ◽  
Mitigation Measures ◽  
Quarter Century ◽  
Seismic Codes ◽  
The Past ◽  
Moderate Seismicity ◽  
High Seismicity

The need for earthquake-resistant construction in areas of low-to-moderate seismicity has been recognized through the adoption of code requirements in the United States and other countries only in the past quarter century. This is largely a result of improved assessment of seismic hazard and examples of recent moderate earthquakes in regions of both moderate and high seismicity, including the San Fernando (1971), Mexico City (1985), Loma Prieta (1989), and Northridge (1994) earthquakes. In addition, improved understanding and estimates of older earthquakes in the eastern United States such as Cape Ann (1755), La Malbaie, Quebec (1925), and Ossippe, New Hampshire (1940), as well as monitoring of micro-activity in source areas such as La Malbaie, have increased awareness of the earthquake potential in areas of low-to-moderate seismicity. Both the hazard and the risk in moderate seismic zones (MSZs) differ in scale and kind from those of the zones of high seismicity. Earthquake hazards mitigation measures for new and existing construction need to be adapted from those prevailing in regions of high seismicity in recognition of these differences. Site effects are likely to dominate the damage patterns from earthquakes, with some sites suffering no damage not far from others, on soft soil, suffering near collapse. A number of new seismic codes have been developed in the past quarter century in response to these differences, including the New York City (1995) and the Massachusetts State (1975) seismic codes. Over the same period, the national model building codes that apply to most areas of low-to-moderate seismicity in the United States, the Building Officials and Code Administrators (BOCA) Code and the Southern Standard Building Code (SSBC), have incorporated up-to-date seismic provisions. The seismic provisions of these codes have been largely inspired by the National Earthquake Hazard Reduction Program (NEHRP) recommendations. Through adoption of these national codes, many state and local authorities in areas of low-to-moderate seismicity now have reasonably comprehensive seismic design provisions. This paper will review the background and history leading up to the MSZ codes, discuss their content, and propose directions for future development.

Performance Goal-Based Seismic Design Standards for Critical Facilities in the United States

2003 ◽  
Author(s):  
Quazi A. Hossain
Keyword(s):  
United States ◽  
Seismic Design ◽  
Functional Performance ◽  
Design Method ◽  
The United States ◽  
Department Of Energy ◽  
Performance Goals ◽  
United States Department ◽  
Active Member ◽  
Performance Goal

For more than the last fifteen years, the United States Department of Energy (DOE) has been using a probabilistic performance goal-based seismic design method for structures, systems, and components (SSCs) in its nuclear and hazardous facilities. Using a graded approach, the method permits the selection of probabilistic performance goals or acceptable failure rates for SSCs based on the severity level of SSC failure consequences. The method uses a site-specific probabilistic seismic hazard curve as the basic seismic input motion definition, but utilizes the existing national industry consensus design codes for specifying load combination and design acceptance criteria in such a way that the target probabilistic performance goals are met. Recently, the American Nuclear Society (ANS) and the American Society of Civil Engineers (ASCE) have undertaken the development of a number of national consensus standards that will utilize the performance goal-based seismic design experience base in the DOE complex. These standards are presently in various stages of development, some nearing completion. Once completed, these standards are likely to be adopted by various agencies and organizations in the United States. In addition to the graded approach of DOE’s method, these standards incorporate design provisions that permit seismic design of SSCs to several levels of functional performance. This flexibility of choosing a functional performance level in the design process results in an optimum, but risk-consistent design. The paper will provide an outline of two of these standards-in-progress and will present the author’s understanding of their basic philosophies and technical bases. Even though the author is an active member of the development committees for these two standards, the technical opinions expressed in this paper are author’s own, and does not reflect the views of any of the committees or the views of the organizations with which any member of the committees are affiliated.

Development of Performance Requirements for a Rail Passenger Workstation Table Safety Standard

2010 ◽  
Author(s):  
Michelle Muhlanger ◽  
Daniel Parent ◽  
Kristine Severson ◽  
Benjamin Perlman
Keyword(s):  
United States ◽  
Public Transportation ◽  
Injury Risk ◽  
Dynamic Models ◽  
The United States ◽  
Transportation Systems ◽  
Initial Stiffness ◽  
Safety Standard ◽  
Sled Test ◽  
Draft Standard

The American Public Transportation Association’s (APTA) Construction and Structural committee, a railroad industry group, with the support of the Federal Railroad Administration (FRA) and the John A. Volpe National Transportation Systems Center (Volpe Center), is creating an industry safety standard for an energy absorbing table. Workstation tables in passenger trains are an increasingly popular seating configuration both in the United States and abroad. Although a well-attached table can provide convenience and compartmentalization for the occupant, there is a risk of abdominal injury during a rail accident. In Fact, there have been several accidents in the United States in which impacts with workstation tables have severely or fatally injured occupants. In 2006, in response to these injuries, an FRA sponsored program developed a prototype table that distributed load over a wider area of the abdomen and absorbed energy during a collision. This table design was tested with specialized anthropomorphic test devices (ATDs) instrumented to measure abdominal impact response and was shown to decrease injury risk compared to a baseline table design. Building on the knowledge gained in the development of the prototype table, the proposed standard requires force to the abdomen be limited while energy is absorbed by the table. Since manufacturers do not have access specialized ATDs, researchers proposed a two part testing requirement. The first part is a quasi-static test which measures the energy absorption capacity of the table with a maximum force level determined from testing with specialized abdominal ATDs. The second part is a sled test with a standard Hybrid III 50th percentile (HIII) ATD to assess compliance with occupant protection standards of compartmentalization and ATD injury assessment reference values (IARVs). This paper discusses the research performed to develop the performance requirement in the draft standard. Current injury measures, originally developed for the automotive industry, were examined to assess their applicability to workstation table impacts. Multiple Mathematical Dynamic Models (MADYMO) model simulations show the estimated injuries during a simulated sled test scenario. Several force-crush parameters were examined, including the initial stiffness of the force-crush curve, the plateau force and the target energy absorbed by the table, to determined the force-crush design characteristics of a table that are likely to reduce injury risk. The results of this study, combined with testing of the current prototype table described in a companion paper [1], led to a draft standard that will greatly improve the safety of workstation tables in passenger rail cars.

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