scholarly journals Examination of simplified numerical analysis method of ground motion considering the surface low-velocity layer

2016 ◽  
Vol 16 (2) ◽  
pp. 2_40-2_63
Author(s):  
Genyuu KOBAYASHI ◽  
Yutaka MAMADA
Keyword(s):  
Numerical Analysis ◽  
Ground Motion ◽  
Analysis Method ◽  
Low Velocity ◽  
Numerical Analysis Method ◽  
Low Velocity Layer ◽  
Velocity Layer

scholarly journals Assessing Seismic Site Response at Areas Characterized by a Thick Buried Low-Velocity Layer

2021 ◽  
Author(s):  
Daniela Farrugia ◽  
Pauline Galea ◽  
Sebastiano D’Amico
Keyword(s):  
Ground Motion ◽  
Site Response ◽  
Low Velocity ◽  
Central Mediterranean ◽  
Ground Shaking ◽  
Velocity Inversion ◽  
Maltese Islands ◽  
Ground Conditions ◽  
Low Velocity Layer ◽  
Velocity Layer

Earthquake ground motion is dependent on various factors, including local ground conditions. Whilst many studies have characterized the effect of having outcropping “soft” geological layers which have the ability to amplify ground motion, there is minimal literature on the effect of having such layers embedded between two harder layers. This situation creates a seismic wave velocity inversion. The Maltese islands (Central Mediterranean) present a good opportunity for the study of velocity inversion as almost half of the islands are characterized by a thick buried layer of clay. The results presented in this chapter are a combination of studies which have been conducted on the Maltese islands, using non-invasive geophysical prospecting techniques in areas characterized by a thick buried low-velocity layer, to characterize the response of earthquake ground shaking in such geological situations.

scholarly journals Pervasive low-velocity layer atop the 410-km discontinuity beneath the northwest Pacific subduction zone: Implications for rheology and geodynamics

2021 ◽  
Vol 554 ◽  
pp. 116642
Author(s):  
Guangjie Han ◽  
Juan Li ◽  
Guangrui Guo ◽  
Walter D. Mooney ◽  
Shun-ichiro Karato ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Northwest Pacific ◽  
Low Velocity ◽  
Low Velocity Layer ◽  
Velocity Layer

Dynamic Analysis of the Pipe Lifting Mechanism on the Deepwater Pipelaying Vessel

2011 ◽  
Vol 199-200 ◽  
pp. 251-256
Author(s):  
Kai An Yu ◽  
Ke Yu Chen
Keyword(s):  
Numerical Analysis ◽  
Dynamic Analysis ◽  
High Efficiency ◽  
Transport Systems ◽  
Kinematic Pair ◽  
Analysis Method ◽  
Numerical Analysis Method ◽  
Upper Limit ◽  
Lifting Capacity ◽  
Limit Position

Based on requirements of pipe transport systems on deepwater pipelaying vessel, a new pipe lifting mechanism was designed. It was composed of crank-rocker and rocker-slider mechanism with good lifting capacity and high efficiency. When the slider went to the upper limit position, the mechanism could approximatively dwell, meeting the requirement for transverse conveyor operation. According to the theory of dynamics, numerical analysis method was used to the dynamic analysis of the mechanism. The results showed the maximum counterforce was at the joint between the rocker and ground, and this calculation could be a guideline for the kinematic pair structure designing.

Focal mechanisms of earthquakes related to the 29 November 1975 Kalapana, Hawaii, earthquake: The effect of structure models

1981 ◽  
Vol 71 (3) ◽  
pp. 713-729 ◽  
Author(s):  
R. S. Crosson ◽  
E. T. Endo
Keyword(s):  
Main Shock ◽  
Horizontal Layer ◽  
Focal Mechanisms ◽  
Local Network ◽  
The South ◽  
Low Velocity ◽  
Tectonic Model ◽  
Low Velocity Layer ◽  
Using Data ◽  
Velocity Layer

abstract Initial focal mechanism determinations for the 29 November 1975 Kalapana, Hawaii, earthquake indicated discrepancy between the mechanism determined from teleseismic data by Ando and the mechanism determined using data from the local U.S. Geological Survey network surrounding the epicenter region. The resolution of this difference is crucial to correctly understand this earthquake, as well as to understand the tectonics of the south flank of Kilauea volcano. When a model with a low-velocity layer at the base of the crust is used for projection back to the focal sphere for the local network mechanisms, the discrepancy vanishes. To further investigate this result, focal mechanisms were determined using several contrasting models for a set of well-recorded earthquakes. A large number of these earthquakes have mechanisms identical to the main shock when the low-velocity layer model is used. Dispersion of P and T axes is also minimized by use of this model. A low-angle slip direction, favored for the main shock and typical of most other solutions, exhibits remarkable stability normal to the east rift zone of Kilauea. Our results suggest a tectonic model, similar in nature to that proposed by Ando, in which the south flank of Kilauea consists of a mobile block of crust which is relatively free to move laterally on a low-strength zone at about 10 km depth. Forceful injection of magma along the rift zones provides the loading stress which is released by catastrophic failure in the weak, horizontal layer in a cycle of perhaps 100 yr.

scholarly journals Numerical analysis of stability of an axially-compressed i-beam rod subjected to constrained torsion

2020 ◽  
pp. 11-27
Author(s):  
Amirshokh Kh. Abdurakhmonov
Keyword(s):  
Numerical Analysis ◽  
Axial Force ◽  
Analytical Data ◽  
Practical Interest ◽  
Numerical Calculations ◽  
Analysis Method ◽  
Numerical Analysis Method ◽  
Open Section ◽  
Thin Walled ◽  
Analysis Of Stability

Introduction. Today thin-walled structures are widely used in the construction industry. The analysis of their rigidity, strength and stability is a relevant task which is of particular practical interest. The article addresses a method for the numerical analysis of stability of an axially-compressed i-beam rod subjected to the axial force and the bimoment. An axially compressed i-beam rod is the subject of the study. Materials and methods. Femap with NX Nastran were chosen as the analysis toolkit. Axially compressed cantilever steel rods having i-beam profiles and different flexibility values were analyzed under the action of the bimoment. The steel class is C245. Analytical data were applied within the framework of the Euler method and the standard method of analysis pursuant to Construction Regulations 16.13330 to determine the numerical analysis method. Results. The results of numerical calculations are presented in geometrically and physically nonlinear settings. The results of numerical calculations of thin-walled open-section rods, exposed to the axial force and the bimoment, are compared with the results of analytical calculations. Conclusions. Given the results of numerical calculations, obtained in geometrically and physically nonlinear settings, recommendations for the choice of a variable density FEM model are provided. The convergence of results is estimated for different diagrams describing the steel behavior. The bearing capacity of compressed cantilever rods, exposed to the bimoment, is estimated for the studied flexibility values beyond the elastic limit. A simplified diagram, describing the steel behaviour pursuant to Construction regulations 16.13330, governing the design of steel structures, is recommended to ensure the due regard for the elastoplastic behaviour of steel. The numerical analysis method, developed for axially-compressed rods, is to be applied to axially-compressed thin-walled open-section rods. National Research Moscow State University is planning to conduct a series of experiments to test the behaviour of axially-compressed i-beams exposed to the bimoment and the axial force. Cantilever i-beams 10B1 will be used in experimental testing.

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