Evidence of significant forward rupture directivity aggravated by soil response in an Mw6 earthquake and the effects on monuments

2017 ◽  
Vol 46 (13) ◽  
pp. 2103-2120 ◽  
Author(s):  
E. Garini ◽  
G. Gazetas ◽  
I. Anastasopoulos
Keyword(s):  
Rupture Directivity ◽  
Soil Response ◽  
Forward Rupture Directivity

Performance of Seismic-Isolated Bridges in Relation to Near-Fault Ground-Motion and Isolator Characteristics

2006 ◽  
Vol 22 (4) ◽  
pp. 887-907 ◽  
Author(s):  
Murat Dicleli
Keyword(s):  
Ground Motion ◽  
Seismic Isolation ◽  
Elastic Stiffness ◽  
Rupture Directivity ◽  
Directivity Effect ◽  
Critical Design ◽  
Near Fault ◽  
Near Fault Ground Motion ◽  
Isolated Bridges ◽  
Forward Rupture Directivity

This paper investigates the performance of seismic-isolated bridges (SIBs) subjected to near-fault (NF) earthquakes with forward rupture directivity effect (FRDE) in relation to the isolator, substructure, and NF earthquake properties, and examines some critical design clauses in AASHTO's Guide Specifications for Seismic Isolation Design. It is found that the SIB response is a function of the number of velocity pulses, magnitude of the NF ground motion, and distance from the fault. Particularly, a reasonable estimation of the expected magnitude of the NF ground motion according to the characteristics of the bridge site is crucial for a correct design of the SIB. It is also found that the characteristic strength and post-elastic stiffness of the isolator may be chosen based on the characteristics of the NF earthquake. Furthermore, some of the AASHTO clauses are found to be not applicable to SIBs subjected to NF ground motions with FRDE.

Analysis of Near-Source Ground Motion from the 2019 Ridgecrest Earthquake Sequence

2020 ◽  
Vol 110 (4) ◽  
pp. 1495-1505 ◽  
Author(s):  
Georgios Baltzopoulos ◽  
Lucia Luzi ◽  
Iunio Iervolino
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Ground Motions ◽  
Strong Motion ◽  
Rupture Directivity ◽  
Surface Rupture ◽  
Ground Acceleration ◽  
Ground Motion Records ◽  
Manual Classification ◽  
Forward Rupture Directivity

ABSTRACT The Ridgecrest seismic sequence began on 4 July 2019 in California, on a hitherto relatively unmapped orthogonal cross-faulting system, causing mainly nonstructural or liquefaction-related damage to buildings in the vicinity of Ridgecrest and Trona, and also causing substantial surface rupture. The present study considers the near-source ground-acceleration recordings collected during the two principal events of the sequence—the 4 July moment-magnitude M 6.4 foreshock and the 6 July M 7.1 mainshock—to identify pulse-like ground motions, which may have arisen due to forward rupture directivity. Pulse-like seismic input is of particular interest to earthquake engineering due to its peculiar spectral shape and possibly increased damaging potential, and expanding the strong-motion databases with such records is a topical issue. In this context, a pulse identification methodology is implemented, partially based on computer-aided signal processing, but also involving manual classification. Nine ground-motion records were classified as pulse-like by this procedure. Further investigation led to the conclusion that, for some of these records, the impulsive characteristics could most likely be attributable to forward rupture directivity, whereas for others fling step may have also been an issue. Finally, clear signs of directionality were observed in these ground motions at periods near the pulse duration, manifesting as a polarization of the spectral ordinates toward the orientation of the impulsive component.

Soil Response during Globally Drained and Undrained Freeze–Thaw Cycles under Deviatoric Loading

2021 ◽  
Vol 147 (2) ◽  
pp. 06020030
Author(s):  
Sang Yeob Kim ◽  
Junghee Park ◽  
Wonjun Cha ◽  
Jong-Sub Lee ◽  
J. Carlos Santamarina
Keyword(s):  
Soil Response ◽  
Freeze Thaw

Soil response to chemicals used in a field experiment

2013 ◽  
Vol 27 (2) ◽  
pp. 151-158 ◽  
Author(s):  
S. Jezierska-Tys ◽  
A. Rutkowska
Keyword(s):  
Alkaline Phosphatase ◽  
Enzymatic Activity ◽  
Field Experiment ◽  
Soil Microorganisms ◽  
Block Design ◽  
Soil Samples ◽  
Alkaline Phosphatases ◽  
Soil Response ◽  
Negative Effect ◽  
Set Up

Abstract The effect of chemicals (Reglone 200 SL and Elastiq 550 EC) on soil microorganisms and their enzymatic activity was estimated. The study was conducted in a field experiment which was set up in the split-block design and comprised three treatments. Soil samples were taken six times, twice in each year of study. The results showed that the application of chemicals generally had no negative effect on the number of soil microorganisms. The application of Reglone 200 SL caused an increase of proteolytic and ureolytic activity and affected the activity of dehydrogenases, acid and alkaline phosphatases in the soil. The soil subjected of Elastiq 550 EC was characterized by lower activity of dehydrogenases, protease, urease and alkaline phosphatase.

Determination and prediction of the stress-strain state of pipeline, taking into account soil changes during operation

2020 ◽  
Vol 10 (4) ◽  
pp. 372-378
Author(s):  
Aydar К. Gumerov ◽  
◽  
Rinat M. Karimov ◽  
Robert М. Askarov ◽  
Khiramagomed Sh. Shamilov ◽  
...  
Keyword(s):  
Strain State ◽  
Mathematical Framework ◽  
Equilibrium Equations ◽  
Stress Strain ◽  
Optimal Method ◽  
Initial Stress State ◽  
Soil Response ◽  
Stress Strain State ◽  
Support Reaction ◽  
Key Factor

The key factor determining the strength, reliability, service life and fail-safe operation of the main pipeline is its stress-strain state. The purpose of this article is to develop a mathematical framework and methodology for calculating the stress-strain state of a pipeline section laid in complex geotechnical conditions, taking into account all planned and altitude changes and impacts at various points of operation, as well as during repair and after its completion. The mathematical framework is based on differential equations reflecting the equilibrium state of the pipeline, taking into account the features of the sections (configuration, size, initial stress state, acting forces, temperature conditions, interaction with soil, supports, and pipe layers). The equilibrium equations are drawn up in a curvilinear coordinate system – the same one that is used for in-pipe diagnostics. According to the results of the solution, all stress components are determined at each point both along the length of the pipeline and along the circumference of any section. At the same time, transverse and longitudinal forces, bending moments, shearing forces, pipeline displacements relative to the ground and soil response to displacements are determined. As an example, a solution is given using the developed mathematical framework. During the course of calculation, the places where the lower form of the pipe does not touch the ground and the places where the support reaction becomes higher than a predetermined limit are determined. A comparative analysis was accomplished, and the optimal method for section repair has been selected.

scholarly journals The effects of slab geometries and wave directions on the steep wave-induced soil response and liquefaction around gravity-based offshore foundations

2019 ◽  
Vol 15 (8) ◽  
pp. 866-877
Author(s):  
Yuzhu Li ◽  
Muk Chen Ong ◽  
Ove Tobias Gudmestad ◽  
Bjørn Helge Hjertager
Keyword(s):  
Soil Response ◽  
Wave Induced ◽  
Steep Wave

Recent Advances in Soil Response Modeling for Well Conductor Fatigue Analysis and Development of New Approaches

2015 ◽  
Author(s):  
Arash Zakeri ◽  
Ed Clukey ◽  
Buba Kebadze ◽  
Philippe Jeanjean ◽  
Dan Walker ◽  
...  
Keyword(s):  
Fatigue Analysis ◽  
Soil Response ◽  
New Approaches ◽  
Recent Advances ◽  
Response Modeling

scholarly journals 1-g Experimental investigation of bi-layer soil response and kinematic pile bending

2014 ◽  
Vol 67 ◽  
pp. 219-232 ◽  
Author(s):  
Andrea Chidichimo ◽  
Roberto Cairo ◽  
Giovanni Dente ◽  
Colin A Taylor ◽  
George Mylonakis
Keyword(s):  
Experimental Investigation ◽  
Soil Response
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