Page 246 - Bridge and Highway Structure Rehabilitation and Repair

CHAPTER 5 LOAD AND RESISTANCE FACTOR RATING AND REDESIGN 221

B. Superstructure Design for Extreme Events

Table 5.8 LRFD primary and secondary load combinations for extreme events.
Primary Loads Extreme Loads
(DC1 4 DC2) (LL+ IM 4 PL) FR BR CT CV BL DER CER EQ
4 DW 4 (CE) 4 ( LS)
Earthquake p EQ 1.00 1.00
Braking force 1.00
Vehicle collision with 1.00
superstructure/fi re
Vessel collision with 1.00
superstructure
Connections failure due 1.00
to design error
Connections failure due 1.00
to construction error
Superstructure collapse 1.00
due to blast load
Note: 1. Besides earthquakes, there are additional extreme events such as vessel loads.
2. The live load and dynamic impact factor for equestrian and elephant loads are different from pedestrian loads.

5.6.7 Superstructure Design for Service Loads
Table 5.9a LRFD primary and secondary load factors for superstructures.
PRIMARY LOADS SECONDARY LOADS
(DC1 4 (LL 4 IM 4 (WS) (WL) (EL) (TU) 4 (TG) (SE)
DC2) 4 DW BR 4 PL) 4 (CR 4 SH)
(CE) 4 (LS)
(DL 4 LL 4 wind) 1.0 1.0 0.30 1.0 1.0 1.00/1.20 TG SE
4 secondary loads
Service I
(DL 4 max. LL ) 1.0 1.30 — — 1.0 1.00/1.20 — —
4 secondary loads
Service II
(DL 4 min. LL) 4 1.0 0.80 — — 1.0 1.00/1.20 TG SE
secondary loads
Service III
(DL 4 wind) 1.0 — 0.70 — 1.0 1.00/1.20 — 1.00
Service IV