This paper is concerned with the problem of soil ampli cation and structural damage due to local site conditions in sedimentary valleys during earthquakes. It focuses on a small valley in Kirovakan, for which one dimensional (1D) wave propagation analyses have failed to provide adequate answers for the large extent and spatial distribution of damage during the 1988 Armenia Earthquake. A more re...

The Sonic Boom Simulator at NASA Langley Research Center was used to (1) quantify subjective loudness of simulated composite sonic booms, each of which was comprised of a simulated direct (non-reflected) boom combined with a simulated reflection of the direct boom, and (2) evaluate several metrics as estimators of loudness for these composite booms. The direct booms consisted of selected N-wave...

Many autonomous ground vehicle (AGV) missions, such as those related to agricultural applications, search and rescue, or reconnaissance and surveillance, require the vehicle to operate in difficult outdoor terrains such as sand, mud, or snow. To ensure the safety and performance of AGVs on these terrains, a terrain-dependent driving and control system can be implemented. A key first step in imp...

Adaptation of kinetics response when running on different surface has been commonly measured by the ground reaction force (GRF). GRF was extensively been used in studies related to surface characteristics such irregularity, incline and types. Since surface hardness effects on the ground reaction force response and the foot adaption is remain unclear, the present study was carried out to address...

Seismic design procedures in current building provisions are based on linear and nonlinear static approaches that use capacity-demand index relationships such as the relationship between the lateral strength and the maximum lateral displacement. Previous research on the development of these relationships is based on linear-elastic ground motion acceleration response spectra, whereas the current...

During the last decades, the railway traffic in densely populated areas has increased. At the same time, passenger trains have become faster and freight trains have become heavier. Consequently, trains are an increasing source of ground vibration, which may be a nuisance to people, buildings and sensitive equipment. In this research, a two-dimensional dynamic system, including underground train...

Nowadays it is common to use the fragility curves in probabilistic methods to determine the collapse probability resulting from an earthquake. The uncertainties exist in intensity and frequency content of the earthquake records are considered as the most effective parameters in developing the fragility curves. The pulse-type records reported in the near-fault regions might lead to the major dam...

A prime requirement in discrimination between UXO and non-UXO metallic fragments (clutter) is to determine accurately the response parameters that characterize a metallic object in the ground. Lawrence Berkeley National Laboratory has been involved in assessing and comparing existing systems, and designing an optimum system for UXO detection. A prototype of a new electromagnetic system will be ...

Attenuation relation (Ground-motion prediction equation) The term “attenuation relation” is a former short-hand notation in earthquake engineering for “empirical ground-motion attenuation relationship”, now referred to as “ground-motion prediction equation” (GMPE). Attenuation relations represent empirical scaling equations that relate observed ground-motion intensity measures to parameters of ...