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Characterizing Planets
Published in Thomas Hockey, Jennifer Lynn Bartlett, Daniel C. Boice, Solar System, 2021
Thomas Hockey, Jennifer Lynn Bartlett, Daniel C. Boice
The speed of P and S waves depends on the material through which they travel. P waves pass more quickly through dense rock than liquids. S waves do not travel through liquids or gasses at all because such substances lack rigidity; that is, you can grab the end of a skipping of rope and generate an S wave, but you cannot grab the water streaming from a garden hose and do so. By detecting changes in the speed and direction of these waves as they travel through a body, the boundary depths of different layers can be determined. Seismic studies allow us not only to estimate the composition of a planet layer-by-layer, but also the state of each layer (Figure 2.16).
Correlation of N value with S-wave velocity and shear modulus
Published in A. Verruijt, F.L. Beringen, E.H. De Leeuw, Penetration Testing, 2021
The velocity of S waves in the ground has come to be acknowledged as the most important geophysical property to be dealt with in seismic microzoning, earthquake engineering — which deals with the dynamic interrelationship between the ground and structures — as well as in the structural engineering fields of civil engineering and architecture. In 1967 the authors began research on the practical application of in situ S wave velocity measurement. There began the process of accumulating measurement data and checking out the reliability of measurement methods in a variety of grounds throughout Japan, with emphasis on the developed urban regions with their alluvial and diluvial deposits, but also including many other types of sites. As a part of this research, the “PS logging method”, a kind of well shooting, was developed and applied for OYO’s Borehole Pick, an inhole receiver that can be fixed to the borehole wall and detached at will at any depth. Measurement data from 400 boreholes in areas throughout Japan was accumulated.
Wave Propagation in an Elastic and Medium
Published in Swami Saran, Dynamics of Soils and Their Engineering Applications, 2021
The above expressions indicate that the rotation is propagated with velocity νs which is equal to √G/ρ. Shear wave is also referred as distortion wave or s-wave. It may be noted that shear wave propagates at the same velocity in both the rod and the infinite medium. Figure 3.12 shows plots of shear wave velocity and void ratio at several confining pressures for sands (Hardin and Richart, 1963).
Horizontal Seismic Effect on Fire Structure and Behavior
Published in Combustion Science and Technology, 2023
Tzu-Yan Tseng, Kuang-Chung Tsai
Fire following an earthquake is usually considered as a low-probability multi-hazard event (Suwondo et al. 2019). Thus, no previous studies have discussed the fire development and structure that experiences aftershock when the fire initially was initiated by an earthquake. However, the damage associated with post-earthquake conflagration can be very severe. This research aims to mimic real seismic conditions (based on reduce-scaled experiments) to discuss how earthquakes influence the fire behavior. Furthermore, seismic waves can be grouped by particle motion into two types, namely primary and secondary waves. Primary waves (P-waves) are compressional waves that are longitudinal, while secondary waves (S-waves) are shear waves that are transverse in nature. This study focuses on the S-waves in which the vibration is parallel to the direction of wave travels, i.e. horizontal vibration.
Verification and Validation of Transient Body Force in GOTHIC for Spent Fuel Pool Response to Seismic Events and Other Applications
Published in Nuclear Technology, 2022
P. C. Skelton, J. W. Lane, T. L. George, S. W. Claybrook
The ground motion induced by a seismic event appears to be chaotic and random but is directly related to the initiating event and the geologic characteristics of the surrounding region. Seismic events induce two types of body waves: pressure and shear. Pressure waves, sometimes referred to as primary or “p” waves, are classical longitudinal waves involving compression and rarefaction in the direction of wave propagation. They move at the sound speed of the transmitting material. Shear waves, sometimes referred to as secondary or “s” waves, are transverse waves that induce motion perpendicular to the direction of propagation. They move at a lower velocity than pressure waves. Seismic events also include surface waves, which have a lower frequency and travel slower than body waves, but can cause significant damage to structures. There are two types of surface waves: Love and Rayleigh waves. These cause the ground surface to move side to side and up and down.
Effect of Soil Properties and Input Motion on Site Amplification Using Validated Nonlinear Soil Model
Published in Nuclear Technology, 2021
Samyog Shrestha, Efe G. Kurt, Kyungtae Kim, Arun Prakash, Ayhan Irfanoglu
When an earthquake occurs, compressional waves and shear waves, i.e., P-waves and S-waves, respectively, are generated that travel through the interior of the earth. P-waves cause particles to move parallel to the direction of wave propagation whereas S-waves cause shearing deformation as they travel through a material. The velocities at which these waves travel in different soil layers are required to model soil behavior under compression and shear loading. S-wave and P-wave velocity profiles and acceleration time series recorded during different earthquakes are available in the KiK-net database. Acceleration data are recorded by the strong motion accelerometers installed at the base of the borehole and at the ground surface of each station. Table I shows the sites and details of the input motions including date of earthquake, moment magnitude, epicentral distance, and peak surface acceleration considered for validation of the benchmark numerical soil column model in MASTODON. Figure 2 shows locations of the selected sites and epicenters of the earthquakes considered. Three-component ground motion recorded during the event dated 11/22/2016 for the Iwaki-E (FKSH14) downhole array site is shown in Fig. 3.