Ken Hatayama

Damage to Oil Storage Tanks from the 2011 Mw 9.0 Tohoku-Oki Tsunami

The Mw 9.0 2011 Tohoku-oki tsunami damaged 418 oil storage tanks and moved 157 of them. Using data on the severity of damage and the maximum inundation depth of the tsunami, a fragility curve representing the damage to oil storage tank plumbing is presented in this paper: P(η)= Φ ((ln η − 1.02)/0.574), where P is the damage rate, η is the maximum inundation depth in meters, and Φ is the standard normal cumulative distribution function. The existing method of predicting the movement of tanks exposed to a tsunami is validated by comparing the predicted damage with actual damage data from the 2011 tsunami. The accuracy (hit rate) is 76%.

Study on Damage of a Floating Roof-Type Oil Storage Tank due to Thermal Stress

Several cracks were found on some actual floating roofs of a crude oil tank in the oil refinery located in southern Japan. We assumed that one of reasons would be due to thermal stress caused by temperature changes during the day. In order to consider whether the thermal stress could the cause damages on the floating roof, strain and temperature were measured on the actual floating roof by using optical fiber gauges. Furthermore, thermal stress analysis was carried out as effective analysis.

Fracture probability analysis of crack occurrence on a floating roof due to thermal stress

Several cracks were found on some actual floating roofs of a crude oil tank in the oil refinery located in southern Japan. We assumed that one of reasons would be due to thermal stress caused by temperature changes during the day. In order to consider whether the thermal stress could the cause damages on the floating roof, strain and temperature were measured on the actual floating roof by using optical fiber gauges. Furthermore, fracture possibility due to thermal stress was calculated to discuss whether thermal stress could cause fracture or not. As a result, the probability showed that thermal stresswasnot enough to cause fracture. Anotherexternal factor such as Typhoon could be related.

Study on the damage of the floating roof due to thermal stress

Several cracks were found on some actual floating roof of the crude oil tank in southern Japan. We assumed that one of causes is due to thermal stress during the day. In order to figure out whether the thermal stress could cause damages on the floating roof, strain and temperature were measured on the actual floating roof by using optical fiber gauges. Furthermore, thermal stress analysis and fracture possibility estimation were also carried out.

Building a Real Time System for Evaluating Oil Storage Tank Damage Due to Earthquakes in Petroleum Stockpiling Bases

It will be difficult to prevent the damage of oil storage tanks caused by a large earthquake even if extreme care has been exercised. Therefore, rational emergency responses will be required for preventing expansion into secondary disaster. In this paper, we propose a system that can estimate ground motion distribution in a whole of petroleum stockpiling base using a seismic record and evaluate damage of oil storage tanks just after an earthquake in order to support rational emergency responses. Spectral ratios of horizontal and vertical component of microtremors were used for evaluation of relative surface soil amplification. The system can assess the hazard for circumferential shell stress, axial shell stress, seismic capacity and liquid sloshing wave height immediately using the ground motion at each tank site estimated from both the relative soil amplification factors and a seismic record at a petroleum stockpiling base just after a large earthquake.Copyright

Comparison of Loss Estimation for Various Seismic Source Models: The Case of the 1995 Hyogo-ken Nanbu Earthquake

We compare the distribution of damage to housing caused by the 1995 Hyogo-ken Nanbu (Kobe) earthquake with those estimated for several source models proposed for this earthquake. This comparison aims at identifying source models that can provide loss estimates that are most appropriate for planning emergency response activities just after earthquakes and/or for preparing effective countermeasures for mitigation of future earthquake disasters. The results suggest the necessity of finite-fault slip models that can reproduce or predict accurately strong ground motion within a frequency range closely related to damage. The loss estimation just after earthquakes based on source models can be counted on in areas without dense strong-ground-motion observation networks. Even with the dense networks, source models will also be useful for accurate loss estimation in the immediate vicinity of earthquake source faults.