Bridges are built in a variety of locations, many of which are susceptible to multiple extreme hazards (earthquakes, vehicle collisions, tsunamis or storm surges, and blasts are considered in this research since they are present as a minimum for some locations). This underscores the need to develop an innovative design concept for bridges from a multi-hazard perspective in which all hazards and...

By considering the near-field vertical seismic spectrum and calculating change in contact force between main beam pier, possible separation condition of a bridge is deduced. extreme value pier–beam longitudinal deformation pier under structural separation, influence on failure determined. Separation increases risk compression, bending, shear, different times lead to responses from first mode di...

local scouring around bridge piers is a natural phenomenon caused by the erosive process of flowing stream on alluvial beds. the 3d flow field around bridge piers interacting with the bed materials increases complexity of local scour process. the local scour depth develops in accelerated flows and if it is not predicted correctly, the bottom level of local scour hole will exceed the original le...

the efficiency of a collar in reducing the scour depth around circular and rectangular piers is studied at different flow intensities (ratio of upstream shear stress to sediment critical shear stress). rectangular piers aligned with the flow as well as skewed at 5º, 10º, 20º were examined. previous studies had shown that with collar the equilibrium time of scouring increases considerably. to re...

Structural fuses, easily replaceable sacrificial elements to dissipate seismic energy while preventing damage to the gravity loadresisting structural system, are proposed as part of a multicolumn accelerated bridge construction (ABC) pier concept. Different types of structural fuses are investigated to compare the effect of each on ABC bridge bents. The piers of a three span-continuous bridge p...

Experimental proof is provided of an unconventional seismic design concept, which is based on deliberately underdesigning shallow foundations to promote intense rocking oscillations and thereby to dramatically improve the seismic resilience of structures. Termed rocking isolation, this new seismic design philosophy is investigated through a series of dynamic centrifuge experiments on properly s...

scoure is the removal of particle sediment which results variation of flow pattern. local scour is considered as one of the reasons of instability and ultimately failure of bridges.therefore, proposing some controlling methods to reduce this phenomenon is essential. in the study, effects of two types of squar and circular collar on a single cylindrical model have been investigated. in the next ...