RA no. 2 BRIDGE Flashcards
1
Q
OC
A
Operational Class
2
Q
EGM
A
Earthquake Ground Motion
3
Q
The design of bridges shall comply with minimum concepts specified in the
A
DPWH D.O. No. 75 “DPWH Advisory for Seismic Design of Bridges” 1992
- Continuous bridges with monolithic multi-column bents have high degree of
redundancy are recommended. Expansion joints and hinges should be kept to
minimum. - Decks should be made continuous if bridge is multi-span simple span.
- Restrainers or unseating device are required to all joints. Generous seat length should
be provided to piers and abutments to prevent from loss of span. - Transverse reinforcements in the zones of yielding are essential to confine the
longitudinal bars and the concrete within the core of column. - Plastic hinging should be forced to occur in the ductile column regions of the pier rather
than the foundation. - The stiffness of the bridge as a whole should be considered in the analysis including
the soil-structure interaction.
4
Q
The following shall be taken into account in the design of bridges:
A
- Topographical, geological, geotechnical soil and other site conditions that may affect
the seismic performance of the bridge. - Selection of appropriate structural system with high seismic performance that is
capable of fully resisting the earthquake forces utilizing the strength and ductility of
the structural members.
5
Q
The following two levels of EGM shall be considered in the BSDS:
A
- Level 1 EGM, considering seismic hazard from small to moderate earthquake with high
probability of occurrence during the bridge service life (100-year return period), for seismic
serviceability design objective to ensure normal bridge functions. - Level 2 EGM, considering a seismic hazard corresponding to an earthquake with return
period event of 1,000 years (7% probability of exceedance in 75 years) for life safety
performance objective under the large earthquake.
