Probabilistic holistic seismic risk evaluation methodology for port structures

Probabilistic holistic seismic risk evaluation methodology for port structures

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Part of #Probabilistic holistic seismic risk evaluation methodology for port structures# :

Publishing year : 2012

Conference : The 9th International Conference on Coastal, Ports and Marine Structures

Number of pages : 10

Abstract: Seaports are also a major part of transport networks because they act both as sources and loads for freight traffic. That flows through the transport infrastructure of the acountry. In the past, the ports have suffered serious damage from earthquakes, because their locationnear estuaries and river deltas and their construction on landfills has made them particularly susceptible to the degradation and ground failure. Damage to port structures that reduces their functionality will limit the operational capacity of the port and result in not only monetary losses attributed to the repair and replacement costs of the structures, but will also result in loss of revenue due to reduced throughput. The operational capacity of a maritime port after a landquake of great concern to port authorities and tenants, since port revenues and market shareretention largely depend on the continuing operation of the berthing facilities. Moreover, freight movement through the port is important for local industries and factories. For many regions, capacity reduction in the port system results in severe economic consequences. Two recent events demonstrate that a earthquake can severely affect port operations. After the1989 Loma Prieta, California, a landquake, one of the 8 container terminals of the Port of Oakland sustained heavy damage and had to cease shipping operations completely. It took almost six months to fully restore operations while the repairs continued. Eventually, the portestimates it spent $ 14 million (in 1989 dollars) and it took 23 months to inspect, analyze, design, bid, and reconstruct 922m damaged wharf in that terminal [7]. After the Great Hanshin earthquake in Kobe, Japan in 1995, the direct repair costs incurred by theport of Kobe were estimated (in 1995). $ 5.5 billion and the economic impacts of the port-dependent industries due to the loss of operations in the port were estimated at about $ 6 billion [28]. During the earthquake, the port lost about 80% of its operational capacity due to the extensive wharf damage. It was reported [9] that the Port of Kobe had only recovered 80.4% of its monthly amount of exports and imports compared to before the earthquake. Thispermanent loss of business occurred even though the port had recovered 75% of its cargohandlingcapacity one year later. What is more astonishing in the case of Kobe Port is that although Japan is a country of earthquakes and during the last 100 years there were 185 earthquakes with a Richter magnitude larger than seven, Kobe did not experience a earthquake magnitude greater than seven in the last thousand Years Therefore, the potential for losses to a port2 subjected to a earthquake can not be ignored but should be evaluated based on the region's seismicity and should be pursued. Consequently, it is necessary to examine the possiblereercussion of potential failures due to such extreme events and account for them in their capitalallocation program. In this paper, a probabilistic methodology for the assessment of holistic seismic risk in port structures is introduced. The results of the model contain the probability of unsafe situations and economic impacts of damages in all levels. The effect of secondary hazards on damages and losses is also estimated through probabilistic framework as well.