Many sites around the world may be subjected to severe distant earthquakes alongside moderate-size, short sourceto-site distance events. The two scenarios have different impacts on high-rise buildings and should be therefore investigated. Dubai, a region with an exceptionally high rate of development, is vulnerable to the aforementioned earthquake hazard scenarios. The region represents one of the most rapidly growing in construction of tall buildings worldwide. It was therefore selected for the investigation described in the paper. A hazard study for the construction site of a 187 m high reinforced concrete tower is conducted. Seismicity of the region is outlined and a hazard assessment is carried out to evaluate peak ground accelerations and uniform hazard spectra for different probabilities of exceedance. A number of natural and synthetic records are selected to represent different seismic assessment scenarios at the site. The RC tower is then modeled and analyzed using state-of-the art analytical platforms. Three-dimensional elastic, inelastic pushover and response history analyses are carried out to verify the dynamic characteristic and estimate the capacity to compare it with the predicted demand. The significance of including severe distant earthquakes in design and assessment of high-rise buildings is confirmed. Records representing the latter scenario amplify the fundamental mode that may be overlooked in design using short sourceto-site earthquakes. A proposal is made for scaling the results from inelastic dynamic analysis to arrive at a safe and economical design level. The study not only presents comprehensive hazard and vulnerability study for the selected test case, but also gives conclusions that generically apply to the class of long-period buildings subjected to large-distant and small-close earthquakes.• Select a typical high-rise RC structure in an appropriate region for this investigation. An actual 54story high-strength RC building from Dubai was selected. 392 A. MWAFY ET AL.It is observed that the values shown in Table 1 are lower than the finding of GSHAP (2004). The latter maps indicate values for Dubai in the range of 0·24-0·33 g. However, it has been pointed out (GSHAP, 2004) that some of the assumptions made in the latter study might be conservative. Also, it should be pointed out that faults, like the Dibba fault and the fault on the west coast of the UAE, were not included in the GSHAP study. A recent seismic hazard assessment study for UAE (Abdallah and Al-Homoud, 2004) showed that the design horizontal peak ground acceleration in Greater Dubai, Sharjah and Ajman area is between 0·10 g and 0·20 g, with an average of 0·15 g. The highest PGA in the latter study (0·2 g) is assigned to Fujaira. These values are consistent with the finding of the current study and confirm the over-conservatism of the values suggested by GSHAP.The uniform hazard spectra for the site for 10%, 5% and 2% probability of exceedance in 50 years are shown on Figure 6. No smoothing has been performed on the respon...

Herein, a study on the hydrodynamic modelling of pontoon bridges is presented, with the Bergsøysund Bridge as a representative example. The model relies on the finite element method and linearized potential theory. The primary emphasis is placed on the stochastic response analysis within the framework of the power spectral density method. The quadratic eigenvalue problem is solved using a state-space representation and an iterative algorithm. The contribution of the fluid-structure interaction to the overall modal damping is investigated. Response effects due to changes in the sea state are studied. A frequency-independent approximation of the hydrodynamic coefficients is presented and discussed.

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A set of probabilistic seismic hazard maps for Thailand has been derived using procedures developed for the latest US National Seismic Hazard Maps. In contrast to earlier hazard maps for this region, which are mostly computed using seismic source zone delineations, the presented maps are based on the combination of smoothed gridded seismicity, crustal-fault, and subduction source models. Thailand's composite earthquake catalogue is revisited and expanded, covering a study area limited by 0 • -30 • N Latitude and 88 • -110 • E Longitude and the instrumental period from 1912 to 2007. The long-term slip rates and estimates of earthquake size from paleoseismological studies are incorporated through a crustal fault source model. Furthermore, the subduction source model is used to model the megathrust Sunda subduction zones, with variable characteristics along the strike of the faults. Epistemic uncertainty is taken into consideration by the logic tree framework incorporating basic quantities, such as different source modelling, maximum cut-off magnitudes and ground motion prediction equations. The ground motion hazard map is presented over a 10 km grid in terms of peak ground acceleration and spectral acceleration at 0.2, 1.0, and 2.0 undamped natural periods and a 5% critical damping ratio for 10 and 2% probabilities of exceedance in 50 years. The presented maps give expected ground motions that are based on more extensive data sources than applied in the development of previous maps. The main findings are that northern and western Thailand are subjected to the highest hazard. The largest contributors to short-and long-period ground motion hazard in the Bangkok region are from the nearby active faults and Sunda subduction zones, respectively.T. Ornthammarath (B) ROSE School,

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