Chapter 2. Introduction

ART 3.0, Güralp Systems' Strong-Motion Analysis and Research Tool is a windows program which allows users of seismometers (accelerometers or velocimeters) produced by Güralp Systems Ltd, to process and analyse their recorded data for engineering seismology and earthquake engineering purposes. The time-histories can be exported in a number of different strong-motion record formats that are currently in use today.

ART3.0 is a major update of the second version of ART (ART2.0), which was released in 2006. A number of improvements were made following requests received from users, which are listed in section 6.1.

ART 3.0 is supplied in the standard distribution of Scream! versions 4.5 and later. It is also compatible with older versions of Scream!.

ART works closely with Scream! to make analysing seismic data easy. Scream!'s visualization and filtering capabilities allow you to view time series and quickly identify events. Strong-motion records can then be directly imported into ART from Scream! by selecting the appropriate portion of the record in Scream! - this will automatically start ART. Previously recorded data in Güralp Compressed Format (GCF) can be read in from pre-recorded files and analysed. In addition, data can be imported into ART via a modem.

Currently the following functions, which are important for engineering seismologists and earthquake engineers, are supported. In addition most of these functions allow selection of multiple time-histories so a comparison between records is possible.

• plotting uncorrected acceleration, velocity and displacement against relative or absolute time;

• automatic correcting of recorded time-history for instrument response to obtain ground acceleration;

• filtering of acceleration time-history using user-defined filters;

• plotting corrected acceleration, velocity and displacement against relative or absolute time;

• calculation and plotting of Fourier amplitude spectra of time-histories and of pre-event portions of records including the signal-to-noise ratios;

• calculation and plotting of Arias intensities against time;

• calculation and plotting of energy densities against time;

• calculation and plotting, both on standard and tripartite graphs, of linear elastic response spectra;

• calculation and plotting of linear elastic absolute and relative input energy spectra;

• calculation and plotting of drift spectra for a cantilever shear-beam for different material types;

• calculation of peak ground acceleration (PGA), peak ground velocity (PGV) and peak ground displacement (PGD);

• calculation of PGV/PGA;

• calculation of A95 parameter;

• calculation of sustained maximum acceleration and velocity;

• calculation of JMA instrumental intensities;

• calculation of response spectrum intensities using user-defined limits;

• calculation of acceleration spectrum intensities using user-defined limits;

• calculation of RMS acceleration, velocity and displacement;

• calculation of cumulative absolute velocities using user-defined minimum acceleration thresholds;

• calculation of absolute and relative bracketed, significant and uniform strong-motion durations using user-defined limits;

• calculation of number of absolute and effective cycles of acceleration using peak counting - including or excluding non-zero crossings and rainflow counting techniques;

• calculation of mean, predominant spectral, smoothed spectral predominant and average spectral periods;

• plotting particle motions both in two and three dimensions;

• basic database functionality to allow earthquake and station metadata to be added, used and exported;

• comparison of observed elastic response spectra to predicted spectra from various ground-motion prediction equations and seismic design codes;

• plotting of acceleration, velocity and displacement time-histories on map;

• exporting the uncorrected and corrected spectra in these commonly used strong-motion record formats:

  • Columns;

  • CSMIP as used by the California Strong-Motion Instrumentation Program;

  • ISESD as used by the Internet Site for European Strong-Motion Data;

  • K-Net as used by Kyoshin Net;

  • PEER as used by Pacific Earthquake Engineering Research Center;

  • SMC as used by the US Geological Survey;

  • SAC as used by Seismic Analysis Code;

  • Microsoft Excel .xls;

  • Matlab .mat.