scholarly journals Potential Pitfalls in the Analysis and Structural Interpretation of Seismic Data from the Mars InSight Mission

2021 ◽  
Author(s):  
Doyeon Kim ◽  
Paul Davis ◽  
Ved Lekić ◽  
Ross Maguire ◽  
Nicolas Compaire ◽  
...  
Keyword(s):  
Ground Motion ◽  
Ambient Noise ◽  
Seismic Analysis ◽  
Transient Signal ◽  
Spectral Structure ◽  
Interior Structure ◽  
Seismic Experiment ◽  
Bias Interpretation ◽  
Selection Of ◽  
Insight Mission

ABSTRACT The Seismic Experiment for Interior Structure (SEIS) of the InSight mission to Mars has been providing direct information on Martian interior structure and dynamics of that planet since it landed. Compared with seismic recordings on the Earth, ground-motion measurements acquired by SEIS on Mars are not only made under dramatically different ambient noise conditions, but also include idiosyncratic signals that arise from coupling between different InSight sensors and spacecraft components. This work is to synthesize what is known about these signal types, illustrate how they can manifest in waveforms and noise correlations, and present pitfalls in structural interpretations based on standard seismic analysis methods. We show that glitches (a type of prominent transient signal) can produce artifacts in ambient noise correlations. Sustained signals that vary in frequency, such as lander modes that are affected by variations in temperature and wind conditions over the course of the Martian sol, can also contaminate ambient noise results. Therefore, both types of signals have the potential to bias interpretation in terms of subsurface layering. We illustrate that signal processing in the presence of identified nonseismic signals must be informed by an understanding of the underlying physical processes in order for high-fidelity waveforms of ground motion to be extracted. Whereas the origins of the most idiosyncratic signals are well understood, the 2.4 Hz resonance remains debated, and the literature does not contain an explanation of its fine spectral structure. Even though the selection of idiosyncratic signal types discussed in this article may not be exhaustive, we provide guidance on the best practices for enhancing the robustness of structural interpretations.

Conditioned Simulation of Ground-Motion Time Series at Uninstrumented Sites Using Gaussian Process Regression

2021 ◽  
Author(s):  
Aidin Tamhidi ◽  
Nicolas Kuehn ◽  
S. Farid Ghahari ◽  
Arthur J. Rodgers ◽  
Monica D. Kohler ◽  
...  
Keyword(s):  
Time Series ◽  
Gaussian Process ◽  
Ground Motion ◽  
San Francisco ◽  
Earthquake Engineering ◽  
Seismic Analysis ◽  
Ground Motions ◽  
Free Field ◽  
Gaussian Process Regression ◽  
Motion Time

ABSTRACT Ground-motion time series are essential input data in seismic analysis and performance assessment of the built environment. Because instruments to record free-field ground motions are generally sparse, methods are needed to estimate motions at locations with no available ground-motion recording instrumentation. In this study, given a set of observed motions, ground-motion time series at target sites are constructed using a Gaussian process regression (GPR) approach, which treats the real and imaginary parts of the Fourier spectrum as random Gaussian variables. Model training, verification, and applicability studies are carried out using the physics-based simulated ground motions of the 1906 Mw 7.9 San Francisco earthquake and Mw 7.0 Hayward fault scenario earthquake in northern California. The method’s performance is further evaluated using the 2019 Mw 7.1 Ridgecrest earthquake ground motions recorded by the Community Seismic Network stations located in southern California. These evaluations indicate that the trained GPR model is able to adequately estimate the ground-motion time series for frequency ranges that are pertinent for most earthquake engineering applications. The trained GPR model exhibits proper performance in predicting the long-period content of the ground motions as well as directivity pulses.

scholarly journals Approach for Selection of Rayleigh Damping Parameters Used for Time History Analysis

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
R. E. Spears ◽  
S. R. Jensen
Keyword(s):  
Seismic Analysis ◽  
Time History ◽  
System Response ◽  
Piping System ◽  
Nuclear Facilities ◽  
Rayleigh Damping ◽  
Modal Damping ◽  
American Society ◽  
Selection Of ◽  
Civil Engineers

Nonlinearities, whether geometric or material, need to be addressed in seismic analysis. One good analysis method that can address these nonlinearities is direct time integration with Rayleigh damping. Modal damping is the damping typically specified in seismic analysis Codes and Standards (ASCE 4-98, 1998, “Seismic Analysis of Safety-Related Nuclear Structures and Commentary,” American Society of Civil Engineers, Reston, Virginia and ASCE/SEI 43-05, 2005, “Seismic Design Criteria for Structures, Systems, and Components in Nuclear Facilities,” American Society of Civil Engineers, Reston, Virginia.). Modal damping is constant for all frequencies where Rayleigh damping varies with frequency. An approach is proposed here for selection of Rayleigh damping coefficients to be used in seismic analyses that is consistent with given modal damping. The approach uses the difference between the modal damping response and the Rayleigh damping response along with effective mass properties of the model being evaluated to match overall system response levels. This paper provides a simple example problem to demonstrate the approach. It also provides results for a finite element model representing an existing piping system. Displacement, acceleration, and stress results are compared from model runs using modal damping and model runs using Rayleigh damping with coefficients selected using the proposed method.

Effects of Seismic Incident Directionality on Ground Motion Characteristics and Responses of a Single-Mass Bi-Degree-of-Freedom System

2021 ◽  
pp. 2150119
Author(s):  
Jun Gong ◽  
Xudong Zhi ◽  
Feng Fan ◽  
Shizhao Shen ◽  
Da Qaio ◽  
...  
Keyword(s):  
Ground Motion ◽  
Large Scale ◽  
Seismic Analysis ◽  
Ground Motions ◽  
Propagation Distance ◽  
Degree Of Freedom ◽  
Different Types ◽  
Single Mass ◽  
Motion Characteristics ◽  
The Impact

To investigate the variability of ground motion characteristics (GMC) with the angle of seismic incidence (ASI) and the impact of seismic incident directionality on structural responses, first, a large-scale database of recorded ground motions was used to analyze the causes of GMC variability due to the seismic incident directionality effect (SIDE). Then a single-mass bi-degree-of-freedom system (SM-BDOF-S) with different types of symmetrical sections was selected to explore the influence mechanism of SIDE on the seismic responses. The results illustrated that the GMC has substantial variability with the ASI, which is independent of the earthquake source, propagation distance, and site condition, and exhibits complex random characteristics. Additionally, a classification method for ground motions is proposed based on this GMC variability to establish a criterion for selecting ground motions in seismic analysis considering the SIDE. Moreover, for an SM-BDOF-S, the response spectral plane is proposed to explain the transition behavior of spectral responses that are very similar among different stiffness ratios, but divergent for different types of ground motions. The influence of SIDE on structures is determined by their stiffness and stiffness ratio in the [Formula: see text]- and [Formula: see text]-directions, as well as the type of ground motion.

A Comparative Investigation of Structural Performance of Typical and Non-Ducitle Public RC Buildings Strengthened Using Friction Dampers and RC Walls

2017 ◽  
pp. 112-127 ◽  
Author(s):  
Erkan Akpinar ◽  
Seckin Ersin
Keyword(s):  
Ground Motion ◽  
Comparative Investigation ◽  
Rc Buildings ◽  
Post Intervention ◽  
Friction Dampers ◽  
History Analysis ◽  
Response History Analysis ◽  
Nonlinear Static ◽  
Selection Of

Strengthening of non-ductile public buildings is a never-ending issue. Selection of the suitable strengthening method and appropriate analysis type for the assessment of pre- and the post-intervention performances are still open to question. The displacement or drift limitations are crucial as well as demand capacity ratios for determination of such buildings performance under severe ground motion. In this chapter, an investigation of seismic performance focused on displacement criterion of strengthened non-ductile public RC buildings in Turkey is presented. Both the nonlinear static and response history analysis were conducted. Friction dampers which are fairly modern technique and conventional RC wall implementation method were introduced to as-is building. For the simplicity and the easy of the process, 2D frame selected for investigation. Comparison of the aforementioned techniques for non-ductile public RC buildings and performances particularly by means of displacement obtained using different methods for those investigated schemes are carried out and presented in the chapter.

A Comparative Investigation of Structural Performance of Typical and Non-Ducitle Public RC Buildings Strengthened Using Friction Dampers and RC Walls

2019 ◽  
pp. 1073-1089
Author(s):  
Erkan Akpinar ◽  
Seckin Ersin
Keyword(s):  
Ground Motion ◽  
Comparative Investigation ◽  
Rc Buildings ◽  
Post Intervention ◽  
Friction Dampers ◽  
History Analysis ◽  
Response History Analysis ◽  
Nonlinear Static ◽  
Selection Of

Strengthening of non-ductile public buildings is a never-ending issue. Selection of the suitable strengthening method and appropriate analysis type for the assessment of pre- and the post-intervention performances are still open to question. The displacement or drift limitations are crucial as well as demand capacity ratios for determination of such buildings performance under severe ground motion. In this chapter, an investigation of seismic performance focused on displacement criterion of strengthened non-ductile public RC buildings in Turkey is presented. Both the nonlinear static and response history analysis were conducted. Friction dampers which are fairly modern technique and conventional RC wall implementation method were introduced to as-is building. For the simplicity and the easy of the process, 2D frame selected for investigation. Comparison of the aforementioned techniques for non-ductile public RC buildings and performances particularly by means of displacement obtained using different methods for those investigated schemes are carried out and presented in the chapter.

scholarly journals Influence of Multiple-Support Excitation on Seismic Response of Reinforced Concrete Arch Bridges

2019 ◽  
Vol 10 (1) ◽  
pp. 17 ◽  
Author(s):  
Marta Savor Novak ◽  
Damir Lazarevic ◽  
Josip Atalic ◽  
Mario Uros
Keyword(s):  
Reinforced Concrete ◽  
Spatial Variation ◽  
Seismic Response ◽  
Ground Motion ◽  
Seismic Analysis ◽  
Numerical Study ◽  
Relative Significance ◽  
Multiple Support ◽  
Arch Bridges ◽  
Support Excitation

Although post-earthquake observations identified spatial variation of ground motion (i.e., multiple-support excitation) as a frequent cause of the unfavorable response of long-span bridges, this phenomenon is often not taken into account in seismic design to simplify the calculation procedure. This study investigates the influence of multiple-support excitation accounting for coherency loss and wave-passage effects on the seismic response of reinforced concrete deck arch bridges of long spans founded on rock sites. Parametric numerical study was conducted using the time-history method, the response spectrum method, and a simplified procedure according to the European seismic standards. Results showed that multiple-support excitation had a detrimental influence on response of almost all analyzed bridges regardless of considered arch span. Both considered spatial variation effects, acting separately or simultaneously, proved to be very important, with their relative significance depending on the response values and arch locations analyzed and seismic records used. Therefore, it is suggested that all spatially variable ground-motion effects are taken into account in seismic analysis of similar bridges.

Efficient Intensity Measures for Probabilistic Seismic Response Analysis of Anchored Above-Ground Liquid Steel Storage Tanks

2016 ◽  
Author(s):  
Hoang Nam Phan ◽  
Fabrizio Paolacci
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Nuclear Power ◽  
Power Plants ◽  
Seismic Analysis ◽  
Time History ◽  
Response Analysis ◽  
Storage Tanks ◽  
Intensity Measures ◽  
Study Results

Liquid storage tanks are vital lifeline structures and have been widely used in industries and nuclear power plants. In performance-based earthquake engineering, the assessment of probabilistic seismic risk of structural components at a site is significantly affected by the choice of ground motion intensity measures (IMs). However, at present there is no specific widely accepted procedure to evaluate the efficiency of IMs used in assessing the seismic performance of steel storage tanks. The study presented herein concerns the probabilistic seismic analysis of anchored above-ground steel storage tanks subjected to several sets of ground motion records. The engineering demand parameters for the analysis are the compressive meridional stress in the tank wall and the sloshing wave height of the liquid free surface. The efficiency and sufficiency of each alternative IM are quantified by results of time history analyses for the structural response and a proper regression analysis. According to the comparative study results, this paper proposes the most efficient and sufficient IMs with respect to the above demand parameters for a portfolio of anchored steel storage tanks.

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