Dynamic/earthquake analysis - Computational Analysis and Design of Bridge Structures - page 540

Table 17.7 Modal analysis results

(a) Modal periods and frequencies

Period Frequency CircFreq Eigenvalue

OutputCase StepType StepNum sec cyc/sec rad/sec rad 2 /sec 2

Modal Mode 1.000000 0.966007 1.0352E + 00 6.5043E + 00 4.2306E + 01

Modal Mode 2.000000 0.526100 1.9008E + 00 1.1943E + 01 1.4263E + 02

Modal Mode 3.000000 0.210878

4.7421E + 00 2.9795E + 01 8.8777E + 02

Modal Mode 4.000000 0.125163 7.9896E + 00 5.0200E + 01 2.5200E + 03

Modal Mode 5.000000 0.081535 1.2265E + 01 7.7061E + 01 5.9385E + 03

Modal Mode 6.000000 0.068764 1.4543E + 01 9.1373E + 01 8.3491E + 03

Modal Mode 7.000000 0.048488 2.0624E + 01 1.2958E + 02 1.6792E + 04

Modal Mode 8.000000 0.034272 2.9178E + 01 1.8333E + 02 3.3610E + 04

Modal Mode 9.000000 0.030670 3.2605E + 01 2.0486E + 02 4.1969E + 04

Modal Mode 10.000000 0.024273

4.1198E + 01 2.5885E + 02 6.7004E + 04

Modal Mode 11.000000 0.022045 4.5361E + 01 2.8501E + 02 8.1233E + 04

Modal Mode 12.000000 0.018333 5.4547E + 01 3.4273E + 02 1.1747E + 05

(b) Modal participation factors

Period UX UY UZ

OutputCase StepType StepNum sec kip-s 2 kip-s 2 kip-s 2

Modal Mode 1.000000 0.966007 11.908197 0.254998 0.000000

Modal Mode 2.000000 0.526100 0.273393 −11.131288 0.000000

Modal Mode 3.000000 0.210878 −1.907E−12 −9.051E−14 0.000000

Modal Mode 4.000000 0.125163 −0.001474 −4.179216 0.000000