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Charlie Burchfield Univ. of Mississippi Tezeswi Tadepalli Univ. of Cal. at San Diego, SDSC Christopher Mullen Univ. of Mississippi Slide 2 Overview Introduction Hazard Exposure Preliminary Design Live Loads Load Combinations Beam Column Lateral Loads Blast Conclusions Slide 3 Introduction University Of Mississippi is evaluating the blast resistance of moment-frame structures. Damage Mapping has been developed and applied to RC columns subjected to air blast loading. Work is currently being done on the performance of steel columns subjected to air blast loading. Slide 4 Characterize multi-hazard loading parameters Structural design procedure (IBC 2006- LL,DL,WL & EQ) P-I curvesBlast damage mapping Seismic design Defines member capacities Member capacity curvesDamage levels Slide 5 Hazard Exposure Source: usgs.gov Slide 6 Hazard Exposure Lafayette County/Oxford, MS Area Approximately 270 miles from the Gulf of Mexico Coast. Approximately 150 mile from the southern termination of the New Madrid fault. Also, several high value buildings within the area. Federal Court House Federal Office Buildings Etc. Slide 7 Hazard Exposure Building Size 3 Story Two 20 foot transverse bays Three 40 foot longitudinal bays. Slide 8 Preliminary Design Complete design was in accordance with the International Building Code 2006. References ASCE/SEI 7-05 ANSI/AISC 360-05 Slide 9 Preliminary Design Live Loads Determine from the Minimum Uniformly Distributed Live Loads and Minimum Concentrated Live Loads from IBC 2006 Used Office Use and Ordinary Flat Roof Load Combinations From ASCE 7-05, Load and Resistance Factor Design DeadDead and LiveDead, Live, and Earthquake 1.4D1.2D+1.6L1.2D+1.0E+f 1 L f 1 = 0.5 Slide 10 Beam Design Using AISC 360-05 W18x50 7.5 18 Slide 11 Column We looked at an interior column due to it being the worst case scenario. Determined to be a W8x31 Axial Load Capacity Ratio is 0.75 8 8 Slide 12 Preliminary Design Completed SAP2000 Model Slide 13 Preliminary Design Completed SAP2000 Model Slide 14 Lateral Loads Seismic Loading controls even though in a moderately low seismic area. Developed the seismic load using IBC 2006 and ASCE 7-05. Applied these loads to a computer model using SAP 2000 v.12 to determine moments. Section size was still efficient. Capacity Ratio increased from 0.75 to 0.77 for an interior lower level column Slide 15 Preliminary Design SAP 2000 view of lateral load displacements Slide 16 Blast Pressures are estimated Leads to acquiring standoff distances and charge weights. New Load Case developed Using a Military Technical Manuel, TM5-1300, Structures to Resist the Effects of Accidental Explosion. Slide 17 The threshold of acceptable blast resistance can be determined by considering alternate pressure scenarios and column and beam damage levels. Severe Moderate Slight No damage Slide 18 Department of Civil Engineering At the University of Mississippi Subcontract from the Department of Homeland Security-sponsored Southeast Region Research Initiative (SERRI) at the Department of Energy's Oak Ridge National Laboratory. Slide 19