Waveform data from a borehole network of broadband seismographic stations have been used to study microearthquakes along the Parkfield segment of the San Andreas fault (SAF). Analysis of almost 10 years of such data demonstrates that much of the seismicity in this region consists of repeating sequences, quasiperiodic sequences of earthquakes that are essentially identical in terms of waveform, ...

the objective of this paper is to present a new method for protecting the lives of residents in catastrophic earthquake failures of unreinforced masonry buildings by introducing some safe rooms within the buildings. the main idea is that occupants can seek refuge within the safe rooms as soon as the earthquake ground motions are felt. the information obtained from the historical ground motions ...

Although several studies have investigated the effect of degradation on the behavior of structures, investigations on collapse margin ratios are rare in the literature. In this study, the effect of strength and stiffness degradation on collapse capacity of steel moment frames is investigated. The aim is to determine margin of safety against collapse using a probabilistic approach. For this reas...

Hybrid moment frame come together with reinforced concrete columns with structural steel beams (RCS). This Composite system provides several key advantages over current steel or concrete moment resisting frame. Past studies have shown this system to be efficient in both design and building stage while able to keep sufficient strength and necessary ductility in seismic zone.Although past researc...

The decision whether to use peak or residual shear strengths for a stability analysis must be made in the context of a specific design situation. Yet even when the specific situation is defined, the decision of whether to use peak or residual shear strength is often unclear. In general, if there are potential construction, operation, or design conditions that might cause relative displacement b...

Moment resisting frames as one of the conventional lateral load resisting systems in buildings suffer from some limitations including code limitations on minimum span-to-depth ratio to ensure the formation of plastic hinges with adequate length at beam ends. According to seismic codes, in ordinary steel moment resisting frames the minimum span-to-depth ratios should be limited to 5 and in speci...

The worldwide use of precast concrete frames leads to an increase in the need for the investigation of efficient precast connections, particularly in the seismic regions. The current paper provides a numerical and experimental study on a dry precast connection. Experiments were conducted to validate the finite element method in the laboratory of the University of Science and Culture. To verify ...

This paper provides an experimental analysis of timber-framed walls, coated with carbon fibre-reinforced polymers (CFRP) strengthened fibre-plaster boards. The presented wall elements are usually used as main bearing capacity elements in the construction of prefabricated multi-level timber residential buildings. Since the tensile strength of fibre-plaster sheathing boards (FPB) is approximately...

The cataclysmic 18 May 1980 eruption at Mount St. Helens was preceded by intense seismic activity marking the mechanical response of the volcanic edifice to interior pressurisation. This seismicity is analysed to yield the temporal change in the seismic scaling exponent, D, inferred from the seismic b-value, that in-turn is related to the seismic moment of an earthquake. Time evolution of D pre...