cox design response spectra pap(11-19-10)
TRANSCRIPT
Design Acceleration Response Spectra forDesign Acceleration Response Spectra for Port-au-Prince
Brady R. Cox, Ph.D., P.E.Brady R. Cox, Ph.D., P.E.The University of Arkansas
Department of Civil Engineering
Geotechnical Earthquake Engineering for Seismic Design Workshop,
Department of Civil Engineering
Port-au-Prince, Haiti, November 18-19, 2010
Design Acceleration Response SpectraRequired by Seismic Provisions in Building CodesRequired by Seismic Provisions in Building Codes
IBC (2009) ASCE 7-05
Step 1: Locate Site
Presidential Palace
Hotel Karibe
ASCE 7-05
Step 2: Determine Ss and S1 for “Rock” ConditionsSpectral Accelerations with a 2% Probability of Exceedance in 50 years
Ss = Short Period Spectral Acceleration (T = 0.2 sec, f = 5 Hz)Ss Short Period Spectral Acceleration (T 0.2 sec, f 5 Hz)
S1 = 1-sec Period Spectral Acceleration (T = 1.0 sec, f = 1 Hz)
Determined from PSHA by USGS (Frankel et al. 2010)
Maps Provided in the GIS Database
ASCE 7-05Site Ss (g) S1 (g)
Presidential Palace 1.75 0.6
Hotel Karibe 2.0 0.7
Step 3: Determine Site ClassificationUse the Seismic Site Classification Map Provided in the GIS Database
Site Ss (g) S1 (g) Site Class
Presidential Palace 1.75 0.6 DPresidential Palace 1.75 0.6 D
Hotel Karibe 2.0 0.7 C
Step 4: Determine Site Amplification CoefficientsF Si A lifi i C ffi i f SFa = Site Amplification Coefficient for Ss
pg. 115 ASCE 7-05
Fv = Site Amplification Coefficient for S1
ASCE 7-05
Step 4: Presidential PalaceF Si A lifi i C ffi i f SFa = Site Amplification Coefficient for Ss
Ss = 1.75 g Fa = 1.0
Fv = Site Amplification Coefficient for S1
ASCE 7-05S1 = 0.6 gFv = 1.5
Step 4: Hotel KaribeF Si A lifi i C ffi i f SFa = Site Amplification Coefficient for Ss
Ss = 2.0 g Fa = 1.0
Fv = Site Amplification Coefficient for S1
ASCE 7-05S1 = 0.7 gFv = 1.3
Step 5: Determine SMs and SM1
Spectral Accelerations with a 2% Probability of Exceedance in 50 years Adjusted for Local Soil Conditions (Site Classification)
Often Termed the Maximum Considered Earthquake (MCE) Spectral Accelerations
pg 115 ASCE 7-05pg. 115 ASCE 7-05
Site Ss (g) S1 (g) Site Class Fa Fv SMs (g) SM1 (g)
Presidential Palace 1.75 0.6 D 1.0 1.5 1.75 0.90
Hotel Karibe 2.0 0.7 C 1.0 1.3 2.00 0.91
Step 6: Determine SDs and SD1
Design Spectral Acceleration Values
Maximum Considered Earthquake (MCE) Spectral AccelerationsMaximum Considered Earthquake (MCE) Spectral Accelerations Reduced by 1/3
pg 115 ASCE 7-05pg. 115 ASCE 7-05
Site Ss (g) S1 (g) Site Class Fa Fv SMs (g) SM1 (g) SDs (g) SD1 (g)
Presidential Palace 1.75 0.6 D 1.0 1.5 1.75 0.90 1.17 0.60
Hotel Karibe 2.0 0.7 C 1.0 1.3 2.00 0.91 1.33 0.61
Step 7: Calculate Design Response Spectrum
pg. 115 ASCE 7-05
C l fCan neglect for most structures (only for very tall buildings; > 30+buildings; > 30+ stories)
Step 7: Design Response Spectrum Equationspg. 115 ASCE 7-05
SDs
SD1D1PGA
T=1 0 T=3 0T 0 2*SD1 T=1.0 T=3.0T0=0.2*SD1SDs
T = SD1TS= D1SDs
Step 7: Design Response Spectrum Presidential Palace
SD = 1 17gSDs 1.17g
SDs = 0.6gPGA 0 47PGA = 0.47gSa = 0.2g
T = 0 1 secT0= 0.1 secTS= 0.51 sec T=1.0 T=3.0
Step 7: Design Response Spectrum Presidential Palace
T= 0 2 sec T= 1 secT 0.2 sec~ 2 stories
T 1 sec~ 10 stories
Remember, fso = Vb ~ W*Sa Refer to Code for More Details
Step 7: Design Response Spectrum Hotel Karibe
SD = 1 33gSDs 1.33g
SDs = 0.61gPGA 0 53PGA = 0.53gSa = 0.2g
T = 0 09 secT0= 0.09 secTS= 0.46 sec T=1.0 T=3.0
Step 7: Design Response Spectrum Hotel Karibe
T= 0 2 sec T= 1 secT 0.2 sec~ 2 stories
T 1 sec~ 10 stories
Remember, fso = Vb ~ W*Sa Refer to Code for More Details
Comparison
You Should Now Be Able to CalculateYou Should Now Be Able to Calculate Acceleration Design Response Spectra
A h i P t P i !Anywhere in Port-au-Prince!
You Will Need to Study the Building C d t D t i th D t il f thCodes to Determine the Details of the
Structural Designg
Questions?Questions?