PREDICTION OF INJURIES TO BUILDING OCCUPANTSFROM COLUMN FAILURE AND PROGRESSIVE COLLAPSEWITH THE BICADS COMPUTER PROGRAM

摘要

This paper describes the methods used to predict column failure, progressive collapse,rnand building occupant injuries from progressive collapse in the BICADS (Building InjuryrnCalculator And DatabaseS) computer program. The BICADS program, which wasrndeveloped recently by Baker Engineering and Risk Consultants, Inc. (BakerRisk) for thernU.S. Department of Defense, is an approximate methodology that estimates injuries tornoccupants from structural and nonstructural components in a wide variety of blast-loadedrnbuildings. The percentages of occupants with each of four different injury levels arerncalculated from blast-damaged walls, columns, roofs, floor systems, windows, andrninterior nonstructural components that are part of sixteen different conventional buildingrntypes or a user input building type. Simplified or detailed input options defining thernbuilding structural components are available with photographs, explanatory text boxes,rnand several help files to aid user input.rnThis paper describes the methodology used in BICADS to predict column failure andrnprogressive collapse for typical concrete and steel framed buildings. The simplified, fast-runningrnmethodology is based on pressure-impulse diagrams developed from theoreticalrnequations for single-degree-of-freedom response and on limited data from U.S.rnGovernment tests and terrorist bombs on full-scale columns with close-in explosive loads.rnShear response is assumed to control concrete column failure. Anchor bolt response isrnassumed to control steel column failure if there is a shear plane through the bolts.rnFlexural response is assumed to control if the column baseplate is buried in the floor slabrnor the column is continuous into a basement. Column failure causes progressive collapsernif the column spacing is large enough or if the column is a corner column. All buildingrnoccupants within the tributary building area subject to progressive collapse are assumedrnto have the highest BICADS injury level, which primarily includes fatalities. This isrnconsistent with injury data from the Oklahoma City bombing.