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Earthquake effects and seismic slope analysis
Published in Robin Chowdhury, Phil Flentje, Gautam Bhattacharya, Geotechnical Slope Analysis, 2009
Robin Chowdhury, Phil Flentje, Gautam Bhattacharya
Seismic activity of sufficient strength to influence the environment or the integrity of structures is called strong ground motion and quantitative description of such motion is necessary for engineering analysis. (Microseismic activity, on the other hand, is mainly of interest to seismologists). Earthquake magnitude and source distance are two of the most important factors which determine ground motion or base rock motion at any particular location. Base rock motion in the form of an acceleration-time relationship or record is the most important seismic data for seismic analysis of a geotechnical structure or a slope. Often, however, the use of the whole of the record may be cumbersome. Therefore, one or more ground motion parameters, derived from the record, are used for assessments of stability and deformation. Typical parameters are peak ground acceleration, duration of motion and predominant period.
Challenges in design of steel structures subjected to exceptional earthquakes
Published in Federico M. Mazzolani, Stessa 2003, 2018
Due to the number of factors influencing the ground motions, each earthquake possesses peculiar and unique characteristics. Strong ground motion is characterized by many physical factors associated to magnitude, faulting process, source-site geometry, wave type, wave propagation in heterogeneous soil and geological structure, spatial variation of waves due to local site conditions, etc.
Cumulative Structural Damage Due to Low Cycle Fatigue: An Energy-Based Approximation
Published in Journal of Earthquake Engineering, 2021
Pablo Quinde, Amador Terán-Gilmore, Eduardo Reinoso
Several studies have been carried out to understand and characterize the seismic behavior of structures to strong ground motions with the goal of improving their earthquake-resistant design. The main goal and challenge of most seismic design regulations is to numerically characterize the behavior of structures. Consequently, these regulations require estimates of the dynamic response of earthquake-resistant systems, and its assessment using prescribed values of relevant design parameters (such as inter-story drift index). However, current regulations do not assess the potential level of damage that the structure may undergo during a given seismic event. This will happen in spite that the design objectives for any structural system are formulated in terms of acceptable levels of damage. The accepted worldwide approach for seismic design states that structural damage should be minimized for frequent low-intensity events, and that collapse, and irreparable damage should be avoided for rare high-intensity ones.
Seismic hazard assessment of the Shillong Plateau, India
Published in Geomatics, Natural Hazards and Risk, 2018
Olympa Baro, Abhishek Kumar, Alik Ismail-Zadeh
Seismic hazard can be defined as a seismic phenomenon that ‘may cause loss of life, injury or other health impacts, property damage, loss of livelihoods and services, social and economic disruption, or environmental damage’ (UNISDR 2009). In seismological and EQ engineering community, seismic hazard is assessed using strong ground motion parameters, such as, peak ground acceleration and/or seismic intensity. This assessment is based on the knowledge of seismic wave excitation at the source, seismic wave propagation, its attenuation, and site effect in the region under consideration. Meanwhile, a comprehensive seismic hazard assessment should combine the results of seismological, geomorphological, geological, and tectonic investigations and modeling (e.g. Ismail-Zadeh 2014).
Simulation for Ludian (August 3, 2014, MW 6.2) and Nepal (April 25, 2015, MW 7.8) Earthquakes with Improved Stochastic Point Source Method
Published in Journal of Earthquake Engineering, 2019
Normally, strong ground motion can lead to severe damage to various engineering structures, natural landscape, and so on. Such ground motions are generally required by engineers as the inputs for structural nonlinear dynamic analysis in seismic design, especially for those who are engaged in performance-based seismic design, and the recorded accelerograms are the most popular input motion used in practice because they provide basic data for the understanding of source processes [Boore, 1983]. But the high-quality recorded ground motions are very limited and sometimes it may be difficult to meet the requirement for special analysis conditions, such problems are very typical in most of regions in the world due to lack of, even without, strong ground motion recordings. So to solve such problems, amplitude scaling and spectral matching with typical recordings (e.g., records from Loma Prieta, Northridge, Chi-Chi earthquakes, and so on) are the widely used methods to generate enough numbers of ground motions that can be representative of various analysis conditions. However, the characteristics of the ground motion recordings may be modified during these scaling and matching process so that they are not consistent with the physical conditions in terms of earthquake source mechanism and local geology, and the results from these operations could have the features different from those of the real recordings [Bazzuro and Luco, 2006; Luco and Bazzurro, 2007]. Therefore, it is necessary to simulate different strong ground motions that can involve both the earthquake physical conditions and characteristics of the actual ground motion recordings.