Elevated water tanks as one of the main lifeline elements are the structures of high importance. Since they are extremely vulnerable under lateral forces, their serviceability performance during and after strong earthquakes is a matter of concern. As such, in recent years, the seismic behavior of water tanks has been the focus of a significant amount of studies. In the present work, three reinforced concrete elevated water tanks, with a capacity of 900 cubic meters and height of 25, 32 and 39 m were subjected to an ensemble of earthquake records. The behavior of concrete material was assumed to be nonlinear. Seismic demand of the elevated water tanks for a wide range of structural characteristics was assessed. The obtained results revealed that scattering of responses in the mean minus standard deviation and mean plus standard deviation are approximately 60% to 70 %. Moreover, simultaneous effects of mass increase and stiffness decrease of tank staging led to increase in the base shear, overturning moment, displacement and hydrodynamic pressure equal to 10 - 20 %, 13 - 32 %, 10 - 15 % and 8 - 9 %, respectively.

In this paper, the assessment of four short-span steel bridges from 24 to 42 m under local overloaded trucks and ground motion records are presented and discussed. Bridges were virtually located in Mexico, and so the vehicular live loads, earthquake loads due to local seismicity, and other local loads were adapted in the design. A realistic condition of the local design truck for Mexico was selected from survey traffic flows reported for local highways. Nonlinear dynamic analyses were carried out using seven historical records associated with the largest vertical intensities from subduction earthquakes in Mexico. Results are intended to evaluate the local practice, which frequently adopts the current AASHTO LRFD Specifications in the absence of an official local design code for bridge structures. Thus, this research pretends to provide design recommendations for short-span steel bridges in Mexico.