Tutorial Rexel Eng

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REXEL v 3.4 betaComputer aided code-based real record selection for seismic analysis of structures

Iunio Iervolino, Carmine Galasso and Eugenio Chioccarelli 2008-2013Dipartimento di Ingegneria Strutturale, Universit degli Studi di Napoli Federico II, Naples, Italy

TUTORIAL09/30/12 Version

For information:[email protected]
mailto:[email protected]:[email protected]:[email protected]:[email protected]


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Summary

Preface ..................................................................................................................................................... 4

Guide to installation ................................................................................................................................ 6

Guide to step by step selection ................................................................................................................ 7

Definition of the target spectrum ........................................................................................................ 7

Looking at disaggregation ................................................................................................................... 7

Looking at conditional hazard ............................................................................................................. 8

Selection of the records to be considered in the compatibility analysis (Preliminary search) .......... 10

Spectral matching parameters and analysis options ........................................................................ 11

Output Management ............................................................................................................................. 13

EXAMPLES .............................................................................................................................................. 15

Case 1: Cosenza, SLD ......................................................................................................................... 16

Case 1a: Selection of a set of 7-unscaled accelerograms. ............................................................. 16

Case 1.1a: Selection of a set of 7-unscaled accelerograms choosing ranges of magnitude and

distance. ........................................................................................................................................ 16

Case 1.2a: Selection of a set of 7-unscaled accelerograms choosing ranges of magnitude,

distance and epsilon. ..................................................................................................................... 17

Case 1b: Selection of two sets of 7-unscaled accelerograms which dont share events............... 18

Case 1c: Selection of three sets of 7-unscaled accelerograms which dont share recordings....... 20

Case 2: Cosenza, SLC .......................................................................................................................... 22

Case 2a: Selection of a set of 7-scaled accelerograms according to the hazard disaggregation in

terms of PGA and Sa(T=1.0sec). .................................................................................................... 22

Case 3: Forl, SLV ................................................................................................................................ 24

Case 3a: Selection of a set of 7-unscaled accelerograms by using the Italian Accelerometric

Archive ITACA. ............................................................................................................................... 24

Case 3b: Selection of a set of 7-unscaled accelerograms for spatial analysis (3 components). .... 24

Case 4: SantAngelo dei Lombardi, SLV............................................................................................. 29

Case 4a: Selection of a set of 7-unscaled accelerograms by using disaggregation for Sa(T=1.0s).

....................................................................................................................................................... 29

Case 5: Napoli-Ponticelli, SLC ............................................................................................................ 32

Case 5a: Selection of a set of 7-unscaled accelerograms by using second disaggregation mode for

Sa(T=1.0s). ......................................................................................................................................... 32

Case 5b: Selection of a set of 7-scaled accelerograms by using IDconditional hazard. .................... 34


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Case 5c: Selection of an individual record using PGV as parameter for preliminary database search.

........................................................................................................................................................... 35

Case 5d: Selection of a set of 7-unscaled accelerograms using PGA as parameter for preliminary

database search. ............................................................................................................................... 36

Case 6: ASCE spectrum and SIMBAD database ................................................................................. 37

Caso 6a: Selection of a set of 30-scaled accelerograms. ............................................................... 37

Appendix A ............................................................................................................................................. 39

REFERENCES .......................................................................................................................................... 41


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Preface

REXEL 3.4 beta, available on the internet on the website of the Italian consortium of

earthquake engineering laboratories: Rete dei Laboratori Universitari di Ingegneria Sismica

ReLUIS (http://www.reluis.it/), allows to define the design spectra according to the Eurocode8 (EC8CEN, 2003), the new Italian Building Code (NIBC CS.LL.PP., 2008), ASCE Standard

ASCE/SEI 7-05 (ASCE, 2006) or completely user-defined. Based on these spectra, the

software allows to search for sets of 7 records compatible, in the average, with them, and

with the minimum dispersion of individual spectra (to follow).

The datasets included in REXEL are the European Strong-motion Database (ESD) (last

updated on July 2007), whose URL is http://www.isesd.cv.ic.ac.uk, the Italian

Accelerometric Archive (ITACA) (last updated on October 2010) by Istituto Nazionale di

Geofisica e Vulcanologia (INGV), whose URL is http://itaca.mi.ingv.it and the database with

Selected Input Motions for displacement-Based Assessment and Design (SIMBAD v 2.0)(last updated on November 2011) developed by Smerzini and Paolucci (2011) in the

framework of the ReLUIS 2010-2013 project (http://www.reluis.it/), in the task referring to

Displacement Based Approaches for Seismic Assessment of Structures.

All the records contained in REXEL satisfy the free-field conditions and were produced by

earthquakes of moment magnitude larger than 4 (5 in the case of SIMBAD). Figures below

show distributions regarding ESD, ITACA and SIMBAD in REXEL; the records of SIMBAD are

classified by the countries they come from. In the case of ITACA the Eurocode 8 soil

classification is that from task 2 of the project S4 of INGV (http://esse4.mi.ingv.it/)and may

be revised in the future.

WARNING: ESD, ITACA and SIMBAD have records in common although with different

seismological processing. There was no attempt by the authors to homogenize/combine the

three databases, which are separated in the software. Moreover, the three databases cover

different magnitude and distance ranges, therefore the appropriate database to use in

searches may also depend on which range of magnitude and distance one is interested in,

see figures below. The sources of ground motion records in SIMBAD are given in Table 1.

Magnitude vs epicentral distance distribution for ESD (left) and ITACA (right) datasets on

which REXEL operates. The records are grouped by site class according to EC8classification.
http://www.reluis.it/http://www.reluis.it/http://www.reluis.it/http://www.isesd.cv.ic.ac.uk/http://www.isesd.cv.ic.ac.uk/http://itaca.mi.ingv.it/http://itaca.mi.ingv.it/http://www.reluis.it/http://www.reluis.it/http://www.reluis.it/http://esse4.mi.ingv.it/http://esse4.mi.ingv.it/http://esse4.mi.ingv.it/http://esse4.mi.ingv.it/http://www.reluis.it/http://itaca.mi.ingv.it/http://www.isesd.cv.ic.ac.uk/http://www.reluis.it/


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Magnitude vs epicentral distance distribution for SIMBAD dataset (left) on which REXEL

operates. The records are grouped by site class according to EC8 classification; distribution

of the records of SIMBAD by the countries they come from (right).

Table 1 Sources of strong ground motion records of the SIMBAD database.

Country/areaNo.

of recordsSource Website

Japan 220

K-NET http://www.k-net.bosai.go.jp/

KiK-net http://www.kik.bosai.go.jp/

Italy 66ITalian ACcelerometric Archive:

ITACAhttp://itaca.mi.ingv.it/

USA 53

Center for Engineering Strong

Ground Motion Data: CESMDhttp://strongmotioncenter.org/

PEERStrong Motion Databasehttp://peer.berkeley.edu/peer_ground_m

otion_database

U.S. Geological Survey National

Strong Motion Project: NSMPhttp://nsmp.wr.usgs.gov/

Europe 17European Strong-Motion Data

Base: ESMDhttp://www.isesd.hi.is/

New Zealand 15Institute of Geological and

Nuclear Sciences: GNShttp://www.geonet.org.nz

Turkey 10Turkish National Strong Motion

Project: T-NSMPhttp://daphne.deprem.gov.tr

Iran 3Iran Strong Motion Network

ISMNhttp://www.bhrc.ac.ir/

Records from the 1995 Hyogo-ken Nanbu earthquake come from the ESG98 data distribution CD-ROM for the

Kobe Simultaneous Simulation

If you use REXEL, please cite as: Iervolino I., Galasso C., Cosenza E. (2010). REXEL: computer aided

record selection for code-based seismic structural analysis.Bulletin of Earthquake Engineering.

8:339-362, DOI 10.1007/s10518-009-9146

REXEL and this tutorial may be used and distributed for free while their modification and

commercialization are not authorized. The authors have made every effort in order to ensure the

accurate working of the software; however, any responsibility is declined for wrong results.
http://www.k-net.bosai.go.jp/http://www.kik.bosai.go.jp/http://strongmotioncenter.org/http://www.geonet.org.nz/http://www.geonet.org.nz/http://strongmotioncenter.org/http://www.kik.bosai.go.jp/http://www.k-net.bosai.go.jp/


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Guide to installation

1. Installation of MATLAB Component Runtime (MCR) v 7.11REXEL was developed in MATLAB environment; for its use the MATLAB Component Runtime

(MCR) 7.11 is required. Please launch the MCRInstaller.exe file and follow the instructions ofthe installation procedure. REXEL requires a specific version of MATLAB. If you have a

different version of MATLAB, it will not work with REXEL; for this reason, you must install the

MCR. The MATLAB Component Runtime is a free redistributable that allows you to run

programs written in a specific version of MATLAB without installing the MATLAB version

itself. There is no harm in having MATLAB and the MCR installed simultaneously, or in having

multiple versions of each one installed.

Image of the user interface of the software

2. Installation of REXEL v 3.4 beta

In order to install REXEL, please launch REXELInstaller.exe file and follows the instructions ofthe installation procedure. In order to remove REXEL, please select Programs > REXEL v 3.4

beta > Uninstall REXEL 3.4 beta and follow the instructions to complete the procedure.


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Guide to step by step selection

The steps needed to search real records sets compatible with a given target spectrum are

described below.

Definition of the target spectrum

First of all, it is necessary to build the acceleration elastic response spectrum for the site of

interest [Build code spectrum]. To this aim, if one wants to make a selection according to

the Italian Building Code spectra, it is necessary to enter the geographical coordinates of the

site, longitude and latitude in decimal degrees, and specify, through a drop-down menu,

developed in accordance with the requirements of code, the Site Class, the Topographic

category, Nominal Life, Functional Typeand the Limit Stateof interest.

For the Eurocode 8 spectra, it is necessary to specify only the anchoring value of the

spectrum, ag, and the ground type (see also Iervolino et al., 2010a). The value of agcan be

defined manually by the user or, in the case of sites on the Italian territory, can be derived

automatically from the geographical coordinates of the site (agvalues used in the software

are those of NIBC).

For ASCE Standard, the code specification requires three parameters to construct the

spectrum, as follow: Ss = short period spectral acceleration (T = 0.2s), S1 = 1s period spectral

acceleration and TL= the transition period between constant spectral velocity and constant

spectral displacement regions of the spectrum. Moreover, the site class has to be specified;

see the code for further details.

A fourth alternative is the possibility of using a reference spectrum completely defined by

the user [User define spectrum].

In addition, it is necessary to specify the component of the earthquake that will be

considered. The two orthogonal independent components that describe the horizontal

motion (X and Y) are characterized by the same elastic response spectrum, while the

component that describes the vertical motion (Z) is characterized by a specific spectrum. It is

possible to select X, Y and Z for finding three dimensional combinations of motion.

If the specified coordinates do not fall into a node of the reference grid of NIBC, the values

of the parameters useful for the definition of the target spectrum are automatically

calculated as a weighted average of the values that the parameter of interest assumed in the

vertices of the elementary mesh containing the site under examination, using as weights the

inverse of the distances between the site and the four nodes, as specified in Annex A of

NIBC.

Looking at disaggregationDisaggregation is a procedure which allows to identify the contribution to the hazard of each

variable (given the exceedance of the ground motion intensity measure corresponding to the

return period of interest): e.g., magnitude (M), source to site distance (R) and epsilon1( ).

Contributions are dependent on hazard assessment of the site, spectral ordinates and return

period. REXEL provides disaggregation results of each Italian site for four spectral ordinates,

1 For definition and further information about please see Appendix A.


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i.e. 0 second (PGA), 0.5, 1.0 and 1.5 second and for four return periods, i.e. 50 yr, 475 yr, 975

yr and 2475 yr. For all different return periods, REXEL provides automatically results of the

closer return period.

To visualize disaggregation distribution, the user must select the spectral ordinate of interest

and the desired couple of variables (M and R or M and ) and press the button

[Disaggregation].Disaggregation can provide indications about the intervals to be used in record selection

(see next section). Using disaggregation results following points have to be considered:

1. Official Italian hazard data and disaggregation results (only for PGA) are provided by INGVand are available at the web site http://esse1-gis.mi.ingv.it. Disaggregation results

provided by REXEL refer to a specific independent study.

2. Parameters of disaggregation analyses have been fitted for the whole Italian region andresults have been considered generally reliable even if in sites with low seismicity, hazard

evaluation (a preliminary step for disaggregation analysis) can be less accurate because

the software is not able to capture hazard variations with return period. As consequence,

also disaggregation results do not vary with return period and a particular attention hasto be used. In these conditions, approximation is lower for higher return periods. REXEL

shows a warning for all these cases.

3. Disaggregation plots suggest the best intervals of magnitude, distance and for recordselection but records availability is not insured. Moreover the choice of the right intervals

is up to users.

For further details and any technical aspect about disaggregation analysis refer to Iervolino

et al. (2011) and Convertito et al. (2009).

Looking at conditional hazard

Acceleration-based intensity measures (IMs, e.g., spectral ordinates) have been shown to beimportant and useful in the assessment of structural response of buildings. However, there

are cases in which it is desirable to account for other ground motion IMs, while selecting

records. For example, although it is generally believed that, under some hypotheses, integral

IMs associated to duration are less important for structural demand assessment with respect

to peak quantities of ground motion, there are cases in which the cumulative damage

potential of the earthquake is also of concern.

An easy yet hazard-consistent way of including secondary IMs in record selection is

represented by the conditional hazard curves (or maps); i.e., curves of secondary ground

motion intensity measures conditional, in a probabilistic sense, to the design hazard for the

primary parameter.To illustrate the conditional hazard concept, in the study of Iervolino et al. (2010b) the joint

distribution of PGA and a parameter which may account for the cumulative damage

potential of ground motion, was investigated.

The chosen energy related measure is the so-called Cosenza and Manfredi index (ID),

Equation (1), the ratio of the integral of the acceleration squared to the PGA and peak

ground velocity (PGV).

20

Et

D

a t dt I

PGA PGV

(1)

REXEL 3.4 beta includes the ID conditional hazard results, suggesting to the user the
http://esse1-gis.mi.ingv.it/http://esse1-gis.mi.ingv.it/http://esse1-gis.mi.ingv.it/


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distribution (in terms of complementary cumulative density functions) of IDvalue (for Italy)

given the design PGA (i.e. the anchoring value of the target spectrum). Moreover REXEL 3.4

includes also conditional hazard for PGV and Np, being the latter a proxy for spectral shape

parameter defined in Equation (2). This should allow for improving record selection for

earthquake engineering applications in a hazard consistent manner yet easily viable for

practitioners.

1 2 1 1 2, 0.5; 1.0avgNp Sa T T Sa T T T (2)

For further details and any technical aspect about conditional hazard analysis refer to

Iervolino et al. (2010b), Bojrquez and Iervolino (2011) and Chioccarelli et al. (2012).


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Selection of the records to be considered in the compatibilityanalysis (Preliminary search)

The user may select the records of database (ESD or ITACA, both contained in REXEL)

corresponding to a given range of:

1. M (moment magnitude for A-D site class records of ESD, local magnitude for E siteclass records; moment magnitude for all ITACA records) and R (epicentral), in

kilometers (e.g. this choice may be guided by disaggregation of hazard);

2. M, R and (e.g. this choice may be guided by disaggregation of hazard);3. peak ground acceleration (PGA) of horizontal components of motion, in fraction of g,

the acceleration of gravity;

4. peak ground velocity (PGV) of horizontal components of motion, in m/s (e.g. thischoice may be guided by conditional hazard);

5. Cosenza and Manfredi index (ID) (e.g. this choice may be guided by conditionalhazard) of horizontal components of motion;

6. Arias Intensity (IA) of horizontal components of motion, in m/s;7. Np(e.g. this choice may be guided by conditional hazard).

See for example Cosenza and Manfredi (2000) for a complete review of the ground motion

parameters that can be assumed as structural and non-structural damage measures.

To this aim, the user must specify the intervals [min, max] of the ground motion parameter

of interest in which he wants the accelerograms fall and the database of interest.

A parameter that is desirable to include in record selection is the site classification, affecting

both the amplitude and shape of response spectra. However, specifying a close match for

this parameter in record selection may not always be feasible, because for some soft soils,

only a few records are usually available. Moreover, if the spectral shape is assigned by thecode, the site class of real records may be of secondary importance.

In light of these considerations, there may be cases in which it may be useful to relax the

matching criteria for site classification.

Therefore, in REXEL it is possible to select records from Same as target spectrumsoil or from

Any site class. This, as shown in the following, should help to overcome some of the

problems when for specific site conditions it is hard to find spectrum matching sets.

Then, the software returns the number of records (and the corresponding number of events)

available in these ranges and to be considered in the compatibility analysis.

After these bounds are defined and confirmed [Check database], the software returns the

number of records (and the corresponding number of originating events) available in theintervals. This list constitutes the inventory of records in which to search for suites of seven

which are in the average compatible with the code spectra of step 1 above. These spectra

may also be plotted [Preliminary plot] along with the reference spectrum to have a picture

of the spectra REXEL will search among.


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Spectral matching parameters and analysis options

In this step the parameters related to the spectral compatibility are defined. In which period

range, [T1, T2], the target spectrum has to be matched has to be defined first. T1 and T2 can

be any pair in the 0s 4s range. Secondly, the tolerances allowed in spectral matching arerequired. This means the user has to specify the maximum deviations (lower and upper

tolerances) in percentage terms that the average spectrum of the combination can have

with respect to the target in the specified [T1, T2] range.

EC8, for example, explicitly states that the average elastic spectrum must not underestimate

the code spectrum, with a 10% tolerance (lower limit) but does not provide any indication

about the upper limit. It is economically viable to reduce as much as possible the

overestimation of the spectrum and this is why also an upper limit was introduced in REXEL.

In this phase is also possible to select the Scaled records option, which corresponds to

choose whether to search for unscaled or scaled record sets. In fact, REXEL allows to obtain

combinations of accelerograms compatible with the code spectrum which does not need tobe scaled, but it also allows choosing sets of accelerograms compatible with the reference

spectrum if linearly scaled. If this second option is chosen, the user have to check the Scaled

records box, which means the spectra of the list defined in step 2 are preliminarily

normalized dividing the spectral ordinates to their PGA. Combinations of these spectra are

compared to the non-dimensional code spectrum . If this option is selected it is also possible

to specify the maximum mean scale factor (SF) allowed; REXEL will discard combinations

with an average SF larger than what desired by the user.

The user can also select the option Im feeling lucky in order to stop the analysis after the

first compatible combination is found. This option, in most cases, allows to immediately get

a combination compatible with the reference spectrum, otherwise, the search forcompatible combinations may take a very long time (as warned by the software).

Alternatively, the maximum number of compatible combinations to find after which the

search has to stop, can be specified.


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Combination searchAt this point the initial list of records and the analysis parameters are set and it is possible to

decide which kind of search to perform. The software searches for:

(a) 7 1-component accelerograms [7 records (1 component)] whose average matches thetarget spectrum in the specified range of periods and with the provided upper- and

lower-bound tolerances. The found combinations can be applied in one direction for

plane analysis of structures2;

(b) 7 pairs of accelerograms [7 records (2 components)]. This option allows to search for 14records which are 7 2-components recordings (both X and Y components of 7 recording

stations only), which on average are compatible with the target spectrum; this kind of

search is for cases in which horizontal motion has to be applied in both directions of a

3D building;

(c) 7 triplets of accelerograms [7 records (3 component)] which include the two horizontaland the vertical component of seven recording stations (i.e., 21 records which are the X,

Y and Z components of 7 recording stations only) for full 3D analysis. In this case, the

selection proceeds in two sub-steps: first, the combinations compatible with the

horizontal component of the code spectrum are found, exactly as case (b); then, the

software analyzes the vertical components of only those horizontal combinations which

have been found to be compatible with the code spectrum, and verifies if the set of

their seven vertical components are also compatible with the vertical code spectrum.

The tolerances and period ranges in which average spectral matching of verticalcomponents may be different from that regarding horizontal components and may

defined by the user after the horizontal analysis has finished.

(d) 30 1-component accelerograms [30 records (1 component)] whose average matches thetarget spectrum in the specified range of periods and with the provided upper- and

lower-bound tolerances. The found combinations can be applied in one direction for

plane analysis of structures3;

(e) 30 pairs of accelerograms [7 records (2 components)]. This option allows to search for60 records which are 30 2-components recordings (both X and Y components of 30

recording stations only), which on average are compatible with the target spectrum; this

kind of search is for cases in which horizontal motion has to be applied in both

directions of a 3D building;

(f) Individual (horizontal) records [Individual record search] matching the target spectrumin the specified range of periods and with the provided upper- and lower-bound

tolerances.

2 Note that this options applies alternatively to horizontal or vertical components of motion, although it is

unlikely one is looking for a suites of seven vertical accelerograms only.3 Note that this options applies alternatively to horizontal or vertical components of motion, although it is

unlikely one is looking for a suites of seven vertical accelerograms only.


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An important feature of the code is that the list of records out of step 2, which is an input for

this phase, are ordered when the analysis is launched in ascending order of the parameter

defined in Equation 1, which gives a measure of how much the spectrum of an individual

record deviates from the spectrum of the code. In Equation (4), Saj(Ti) is the pseudo-

acceleration ordinate of the real spectrum jcorresponding to the period Ti, while Satarget(Ti)is the value of the spectral ordinate of the code spectrum at the same period, and N is the

number of values within the considered range of periods.

(4)

Preliminary ordering allows to analyze first the records which have a similar spectral shape

with respect to the target. This ensures the first combinations, e.g. the one found with the

Im feeling luckyoption, to be those with the smallest individual scattering in respect to thetarget spectrum as shown in the following examples.

Output Management

After the analysis has finished, REXEL returns [Output > Results > Horizontal (Vertical)] a list

of combinations whose average spectrum respects compatibility with the target in the

chosen range of periods and with the assigned tolerance.

The results of the analysis are sorted so that record combinations with the smallest

deviation from the spectrum of the code are the first of the output list, due to the

preliminary ordering of records according to j.

For all the combinations found, it is possible to calculate [Output > Deviation > Horizontal

(Vertical)] the deviation of each accelerograms of the combination compared to the target

spectrum, and the deviation of the average spectrum of the combination compared to the

elastic response spectrum again according to Equation (2), in which the average spectral

acceleration of the records replaces Saj(Ti).

Combinations returned are uniquely identified by a serial number; this code can be used

[Output > Results > Plot & get set > Horizontal (Vertical) for 7 record search orOutput >

Results > Plot & get recordfor individual record search] to graphically display the spectra of

a specific combination of interest and obtain the spectra and acceleration time-histories

grouped in a compressed file by REXEL.

If a specific combination is chosen REXEL also returns the mean value of magnitude and

distance of combination and the information about the individual records as retrieved by

ESD and ITACA that is, recording station, event (time, date and country), magnitude,

distance, fault mechanism, etc [Output > Info records plot]. In the case of non-dimensional

sets, the scale factors of individual record and the mean scale factor of the combination are

given.

Different 2 and Different 3 options

Although both considered codes only require a minimum size for suites of 7 to consider

mean effects on the structure, it is known how this number may affect the confidence (i.e.,the standard error) in the estimation of the structural response, which increases as the


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variability of individual records with respect to the target increases. Therefore, in case one

wants to run the analyses with a larger number of records REXEL has two options which both

are applicable to the list of results of the analyses discussed above:

- Different 2allows to search within the list of output, pairs of combinations, i.e., 2 sets of 7records of the type (a), (b), or (c) above, which have accelerograms from earthquakeevents which do not overlap. This allows to have a larger set of 14 one- or multi-

component records, spectrum matching in the average, in which there are no dominating

events. For each found pair of sets the software also computes the maximum deviation of

the two original combination and this may be a parameter for choosing one pair in

respect to another;

- Different 3allows to search within the list of output, triplets of combinations (3 set of 7one- or multi-component records) having no accelerograms in common although may

have common events. This analysis provides sets of 21 record which, still, match the

code-required average spectral compatibility with the given tolerances.

Repeat search excluding a station

In some cases, the analyst may want to exclude a particular record appearing in a found

combination. To this aim, REXEL includes the option Repeat search excluding a station, which

allows to repeat the performed analysis by excluding from the list of records created in the

Preliminary database searchone or more waveforms, in an iterative way.

Displacement spectra compatibility

REXEL allows to check the displacement spectra compatibility for a combination selected tomatch a pseudo-acceleration spectrum. For each period T, the elastic spectral displacement

is computed as inverse transformation of elastic pseudo-spectral acceleration.


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EXAMPLES

In the following some illustrative examples of automatic selection of spectrum-matching

accelerogram, using REXEL v 3.4 beta, are shown as well as some strategies aiming at a

better selection, although for further details the reader should refer to Iervolino et al.(2010a). In each example, the target spectra considered are built according to NIBC even if

the software itself permits to define any type of Eurocode 8 or user-defined spectrum. The

examples refer to different Italian sites, with different geographical location, site conditions

(according to EC8) and hazard level as expressed by the maximum value of acceleration on

rock (ag) with a 10% probability of exceedance in 50 years:

Cosenza(Southern Italy: latitude 39,314; longitude 16.215); Forl(Central Italy: latitude 44.218; longitude 12.054); SantAngelo dei Lombardi (Southern Italy: latitude 40.8931; longitude 15.1784); Ponticelli (Southern Italy: latitude 40.8516; longitude 14.3446);

Fuorigrotta (Naples, Southern Italy: latitude 40.829; longitude 14.191);

The considered cases are:

Case 1 : Cosenza, Site class A, selection for Damage Limit State (SLD)

Case 1a: selection of a set of unscaled accelerograms ;o Case 1.1a: Selection of a set of 7-unscaled accelerograms choosing ranges of

magnitude and distance.

o Case 1.2a: Selection of a set of 7-unscaled accelerograms choosing ranges ofmagnitude, distance and epsilon.

Case 1b: selection of two sets of unscaled accelerograms which dont share earthquakeevents;

Case 1c: selection of three sets of unscaled accelerograms which dont share records.Case 2: Cosenza, Site class A, selection for Collapse Limit State (SLC)

Case 2: selection of a set of scaled accelerograms according to the hazard disaggregationin terms of PGA and Sa(T=1.0s).

Case 3: Forl, Site class B, selection for Operability Limit State (SLV)

Case 3a: selection of a set of unscaled accelerograms according to the hazarddisaggregation in terms of PGA and using the Italian Accelerometric Archive (ITACA).

Case 3b: Selection of a set of unscaled accelerograms for spatial analysis (3 components).Case 4: SantAngelo dei Lombardi, Site Class A, selection for Collapse Limit State (SLV):

Case 4: selection of a set of unscaled accelerograms according to the hazarddisaggregation in terms of Sa(T=1.0s).

Case 5: Ponticelli, Site Class B, selection for Collapse Limit State (SLC):

Case 5a: selection of a set of unscaled accelerograms according to the hazarddisaggregation (second mode) in terms of Sa(T=1.0s).

Case 5b: selection of a set of scaled accelerograms by using conditional hazard. Case 5c: selection of an individual record using PGV as parameter for preliminary

database search.

Case 5d: selection of a set of unscaled accelerograms using PGA as parameter for


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preliminary database search.

Case 6: ASCE spectrum and SIMBAD database:

Case 6a: selection of a set of 30-scaled accelerograms.

Case 1: Cosenza, SLDIn the following, a set of 7 unscaled accelerograms for Cosenza (Latitude 39.314, Longitude

16.215) considering the Damage Limit State (SLD), a nominal life of 50 years, functional type

II, topographic category T1 and soil type A, according to NIBC, is selected. The first step is to

define the above mentioned parameters to determine the elastic acceleration response

spectrum, that is the target spectrum (Figure 1).

Figure 1. Definition of the target spectrum for Cosenza, case 1

Case 1a: Selection of a set of 7-unscaled accelerograms.

The range of magnitude [4.8 7.3] and of distance [0 km 50 km], obtained by the

disaggregation of seismic hazard in terms of Sa(T=1.0sec) with a probability of exceedance of

63% in 50 years (Figure 2a), allows to find 2x219 accelerograms (Soil A) from 99 different

events in the ESD (Figure 2c).

Case 1.1a: Selection of a set of 7-unscaled accelerograms choosing ranges of

magnitude and distance.Because of the large number of accelerograms found, the search may take a very long time,

so it is recommended to reduce the magnitude and distance ranges, excluding the records

with a magnitude value lower than 5.5 and higher than 6.5 and with a distance values higher

than 20. In this way intervals with higher hazard contribution are considered only (another

selection of records may be done considering higher values of distance and magnitude).

With new intervals the software finds 2x31 compatible records from 15 different events

(Figure 2d). In order to search for 1-component record sets, assigning a compatibilitytolerance between 10% and 30% in the range of period [0.15s 2s], in few seconds the


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software finds 100000 compatible combinations and, by default, it displays the first

combination (Figure 3a).

Case 1.2a: Selection of a set of 7-unscaled accelerograms choosing ranges of

magnitude, distance and epsilon.In order to consider more information provided by disaggregation, M and distribution can

be plotted by the software and ranges of magnitude, distance and can be used for

addressing record selection. More specifically, with the range of magnitude equal to [4.8

7.3], distance [0 km50 km] and [0 1.5], the software finds 2x15 compatible records

from 14 different events (Figure 2e). In order to search for 1-component record sets,

assigning a compatibility tolerance between 10% and 30% in the range of period [0.15s2s],

in few seconds the software finds 1147 compatible combinations and, by default, it displays

the first combination (Figure 3b).

(a) (b)

(c)

(d)

(e)

Figure 2. M-R (a) and M- (b) disaggregation distribution of the hazard in terms of Sa(T=1.0sec) for

Cosenza for a return period of 50 years; and definition of magnitude, distance (c and d) and (e)

intervals.


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Figure 3. First combinations found for Cosenza, case 1a without (a) and with (b) definition of

range.

Case 1b:Selection of two sets of 7-unscaled accelerograms which dont share

events.

In the following, it is supposed one wants to select two sets of 1-componets ground motions

starting from the case 1.1a. The user can use the option Different 2; this provides pairs of

sets with records which come from non-overlapping events. Using this option the software

finds in about five minutes 100000 compatible pairs and opens DIVERSI.txt file by default,

where the combinations are listed (Figure 4). To decrease the time of the analysis it is

suggested to select a lower number of desired pairs. Referring to the first pair found (Figure

5 a and b), the software provides 14 registrations from 12 different events.

Figure 4. Results by using the option Different 2.


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a) Combination 17372 ( Output> Plot & get records >17372)

b) Combination 54092 (Output > Plot & get records > 54092)

Figure 5. The first pair of sets (Different 2) found for Cosenza, case 1b

Waveform ID Earthquake ID Station ID Earthquake Name Date Mw Fault Mechanism

Epicentral

Distance [km]

EC8 Site

class

1243 473 ST575 Izmit (aftershock) 13/09/1999 5.8 oblique 15 A

5655 1825 ST2950 NE of Banja Luka 13/08/1981 5.7 oblique 10 A

359 174 ST136 Umbria 29/04/1984 5.6 normal 17 A

473 228 ST40 Vrancea 31/05/1990 6.3 thrust 7 A

383 176 ST153 Lazio Abruzzo (aftershock) 11/05/1984 5.5 normal 14 A

4675 1635 ST2487 South Iceland 17/06/2000 6.5 strike slip 13 A

7142 2309 ST539 Bingol 01/05/2003 6.3 strike slip 14 A

medie: 5.957143 12.85714286

Combinazione 17372

Waveform ID Earthquake ID Station ID Earthquake Name Date Mw Fault Mechanism

Epicentral

Distance [km]

EC8 Site

class

365 175 ST140 Lazio Abruzzo 07/05/1984 5.9 normal 5 A

6342 2142 ST2556 South Iceland (aftershock) 21/06/2000 6.4 strike slip 20 A

3802 1226 ST2368 SE of Tirana 09/01/1988 5.9 thrust 7 A


149 65 ST26 Friuli (aftershock) 15/09/1976 6 thrust 12 A

652 292 ST236 Umbria Marche (aftershock) 14/10/1997 5.6 normal 12 A


medie: 6.0143 10.71428571

Combinazione 54092


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Case 1c: Selection of three sets of 7-unscaled accelerograms which dont share

recordings.

In the following it is supposed one wants to select three sets of 1-componets ground

motions, for the case 1a, with no records in common. The user can use the option Different

3; in about ten minutes the software finds 100000 triplets of compatible combinations and

opens the DIVERSI.txt file by default where the triplets are listed (Figure 6). The first triplet is

shown in Figure 7.

Figure 6. Results by using the option Different 3.

a) Combination 419 (Output>Plot & get records > 419)

Waveform ID Earthquake ID Station ID Earthquake Name Date Mw

aut

Mechanism

p centra

Distance [km]

te

class

1243 473 ST575 Izmit (aftershock) 13/09/1999 5.8 oblique 15 A



3802 1226 ST2368 SE of Tirana 09/01/1988 5.9 thrust 7 A

149 65 ST26 Friuli (aftershock) 15/09/1976 6 thrust 12 A


6326 2142 ST2496 South Iceland (aftershock) 21/06/2000 6.4 strike slip 14 Amedie: 5.885714286 12.42857143

Combinazione 419


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b)Combination 89881 (Output> Plot & get records > 89881)

c)Combination 99444 (Output> Plot & get records >99444)

Figure 7. The first triplet found by using the option Different 3.


Fault

Mechanism

Epicentral

Distance [km]

EC8 Site

class

5655 1825 ST2950 NE of Banja Luka 13/08/1981 5.7 oblique 10 A

5655 1825 ST2950 NE of Banja Luka 13/08/1981 5.7 oblique 10 A385 176 ST155 Lazio Abruzzo (aftershock) 11/05/1984 5.5 normal 15 A


6115 2029 ST1320 Kozani 13/05/1995 6.5 normal 17 A



medie: 5.971428571 13.57142857

Combinazione 89881


au

Mechanism

p cen ra

Distance [km]

e

class







242 115 ST225 Valnerina 19/09/1979 5.8 normal 5 A

medie: 5.942857143 16.14285714

Combinazione 99444


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Case 2: Cosenza, SLC

Case 2a: Selection of a set of 7-scaled accelerograms according to the hazard

disaggregation in terms of PGA and Sa(T=1.0sec).

In the following, a set of unscaled accelerograms for Cosenza (Latitude 39.314, Longitude

16.215) considering the Collapse Limit State (SLC) of a structure on a type A soil with T1

topographic category, 50 years nominal life and Functional Class II, is selected. The first step

is to define the above mentioned parameters to determine the elastic acceleration response

spectrum, that is the target spectrum.

For this case, disaggregation of PGA and Sa(T=1.0sec) with a probability of exceedance of 5%

in 50 years are both shown in Figure 84. The ranges of magnitude [5.57] and of distance [0

km20 km] have been used and 2x32 (soil class A) accelerograms from 16 different events

in the ESD have been found.

Figure 8. Disaggregation of the hazard in terms of PGA (a) and Sa(T=1.0sec) (b) for Cosenza for a

return period of 975 years.

Assigning a compatibility tolerance between 10% and 30% in the range of period [0.15s2s],

the software doesnt find compatible combinations. By clicking on the Preliminary plotoption (Figure 9), it is clear that the analysis wont give back a positive response if the choice

falls on an unscaled set. The average spectrum of the scaled records seems more

encouraging, hence we prefer this solution. By clicking on Non-Dimensional option and by

choosing a maximum scale factor equal to 2, the software provides 2 compatible

combinations, with the same tolerance limits, the first of which is indicated in Figure 10.

Note that REXEL only limits the average scale factor, which may be larger than prescribed for

individual records.

4 The structural period should drive selection of appropriate disaggregation; REXEL 3.4 beta has embedded

disaggregation results for spectral acceleration at T=0s (PGA), T=0.5s, T=1.0s, T=1.5s (for Italian sites).


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Figure 9. Preliminary plot for Cosenza SLC: Case 2

Figure 10. The first combination found for Cosenza, case 2


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Case 3: Forl, SLV

Case 3a: Selection of a set of 7-unscaled accelerograms by using the Italian

Accelerometric Archive ITACA.

In the following, a set of unscaled accelerograms for Forl (Latitude 44.218, Longitude

12.054) considering the Safe Life Limit State (SLV), a nominal life of 50 years, functional type

II, topographic category T1 and soil type B, according to NIBC, is selected. The first step is to

define the above mentioned parameters to determine the elastic acceleration response

spectrum, that is the target spectrum. Defining arbitrary the range of magnitude [6 7] and

of distance [0 km 40 km], selecting the ITACA as database, considering the recordings of

any site class, REXEL finds 2x30 accelerograms from 5 different events .

Searching for 1-component ground motion sets, assigning a compatibility tolerance between

10% and 30% in the range of period [0.15s 2s], the software finds 100000 compatible

combinations, the first of which is shown in Figure 11.

Figure 11. The first scaled combination found for Forl, Case 3a

Case 3b: Selection of a set of 7-unscaled accelerograms for spatial analysis (3

components).

In the following, a set of unscaled accelerograms for Forl (Latitude 44.218, Longitude

12.054) considering the safe life limit state (SLV), a nominal life of 50 years, functional type

II, topographic category T1 and soil type B, according to NIBC, is selected. In this case it is

searched for a set which includes all three components of ground motion (i.e., including the

vertical one). The first step is to define the above mentioned parameters to determine the

horizontal and vertical elastic acceleration response spectra (Figure 12).


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Figure 12. Definition of the target spectrum for Forl, case 3

Considering intervals of magnitude and distance of respectively [4.5, 6] and [0, 30km]

obtained from the disaggregation of seismic hazard in terms of Sa(T=1.0sec) with a

probability of exceedance of 10% in 50 years (Figure 13), selecting ESD as database,

considering only the recordings on B class soil (Same as target spectrum), REXEL finds 3x237

accelerograms referred to 149 different events. Because of the large number ofaccelerograms found, the search may take a very long time; moreover, clicking on the

Preliminary plot option (Figure 14), it is clear that the analysis wont give back a positive

response.

Figure 13. Disaggregation of the hazard in terms of Sa(T=1.0sec) for Forl for a return period of 475years.


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Figure 14. Preliminary plot referring to M [4.5, 6] and R [0, 30Km]

Increasing the range of magnitude ([6, 8]) and decreasing the range of distance ([10, 20]),

the software finds 3x24 accelerograms from 12 different events. Assigning a compatibility

tolerance between 10% and 30% in the range of period [0.15s 2s] for the horizontal

component and assigning a compatibility tolerance between 10% e 70% in the range of

period [0.15 s 1 s] for the vertical component, REXEL finds 1005 compatible combinations

for the horizontal component, but doesnt find any compatible set with spectrum-

compatible vertical components. At this point the program asks the user if he wants tochange the compatible limits for the vertical component and then the user can decide to

decrease the range of periods or to increase the tolerance limits.

Its possible, for the same scenario of magnitude [6, 8] and distance [10, 20], to choose

records from all type of soil (Any site class) increasing the numbers of registrations to be

processed (Figure 15).


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Figure 15. Preliminary plot referring to M [6, 8] and R [10, 20Km]; Any site class

Processing 3x42 accelerograms from 19 events, assigning a compatibility tolerance between

10% and 30% in the range of period [0.15s2s] for the horizontal component and assigning

a compatibility tolerance between 10% e 70% in the range of period [0.15 s 1 s] for the

vertical component, REXEL finds 100000 combinations for the horizontal component and 31

for the vertical component . The program shows by default the first compatible three

dimensional combination found, which is that featuring the ID (referred to horizontal

components) number 53644 (Figure16).


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Figure 16. The first 3-components compatible combination found (Combination no. 53644) for

Forl, case 3b.

Waveform ID Earthquake ID Station ID Earthquake Name Date Mw Fault MechanismEpicentral

Distance [km]

EC8 Site

class

333 157 ST121 Alkion 24/02/1981 6.6 normal 20 C

1313 474 ST1100 Ano Liosia 07/09/1999 6 normal 16 B

134 63 ST24 Friuli (aftershock) 15/09/1976 6 thrust 14 B

170 81 ST46 Basso Tirreno 15/04/1978 6 oblique 18 C

4673 1635 ST2482 South Iceland 17/06/2000 6.5 strike slip 15 B


535 250 ST205 Erzincan 6.6 strike slip 13 B

medie: 6.314286 15.85714286


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Case 4: SantAngelo dei Lombardi, SLV

Case 4a: Selection of a set of 7-unscaled accelerograms by using

disaggregation for Sa(T=1.0s).

In the following, a set of unscaled accelerograms for SantAngelo dei Lombardi (Avellino)

(Latitude 40.8931, Longitude 15.1784) considering the Life Safety Limit State (SLV), a

nominal life of 50 years, functional type II, topographic category T1 and soil type A,

according to NIBC, is selected. The first step is to define the above mentioned parameters to

determine the elastic acceleration response spectrum, that is the target spectrum (Figure

17).

Figure 17. Definition of the target spectrum for SantAngelo dei Lombardi, case 4

Starting from the disaggregation of seismic hazard in terms of the Sa(T=1.0sec) with a

probability of exceedance of 10% in 50 years (Figure 18), selecting the ESD as database,

considering only the recordings on A class soil (Same as target spectrum) with high

magnitude [6.4-7.2] and low distance [5-15 km], REXEL finds 2x8 accelerograms referred to 3

different events in the ESD database. Clicking on the Preliminary plot option (Figure 19), it is

possible to imagine that the analysis will give back a positive response.


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Figure 18. Disaggregation of the hazard in terms of Sa(T=1.0sec) for SantAngelo dei Lombardi for a

return period of 475 years.

Figure 19. Preliminary plot referring to M [6.4, 7.2] and R [5, 15Km]; A class soil

Assigning a compatibility tolerance between 10% and 30% in the range of period [0.15s2s]

for the horizontal component, REXEL finds, by Im feeling lucky option, the compatible

combination of Figure 20.


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Figure 20. Set found for SanAngelo dei Lombardi, case 4


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Case 5: Napoli-Ponticelli, SLC

Case 5a: Selection of a set of 7-unscaled accelerograms by using second

disaggregation mode for Sa(T=1.0s).

In the following, a set of unscaled accelerograms for Ponticelli (Napoli) (Latitude 40.8516,

Longitude 14.3446) considering the Collapse Limit State (SLC), a nominal life of 100 years,

functional type IV, topographic category T1 and soil type B, according to NIBC, is selected.

The first step is to define the above mentioned parameters to determine the elastic

acceleration response spectrum, that is the target spectrum (Figure 21).

Figure 21. Definition of the target spectrum for Ponticelli, case 5

Starting from the second disaggregation mode of seismic hazard referred to the Sa(T=1.0sec)

with a probability of exceedance of 2% in 50 years (Figure 22), selecting the ESD as database,

considering only the recordings on B class soil (Same as target spectrum) with high

magnitude [6.3-7.6] and medium-high distance [15-100 km], REXEL finds 2x60 accelerograms

referred to 20 different events in the database. Clicking on the Preliminary plot option

(Figure 23), it is possible to imagine that the analysis will give back a positive response.


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Figure 22. Disaggregation of the hazard in terms of Sa(T=1.0sec) for Ponticelli for a return period of

475 years.

Figure 23. Preliminary plot referring to M [6.4, 7.2] and R [5, 15Km]; A class soil



combination of Figure 24.


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Figure 24. Set found for Ponticelli, case 5a

Case 5b: Selection of a set of 7-scaled accelerograms by using IDconditionalhazard.

Considering again the same example in Ponticelli, lets consider selection of horizontal scaled

accelerograms according to conditional hazard (Iervolino et al., 2010b) in terms of I Dgiven

the design value of PGA (i.e. the value of PGA from code-based target spectrum). To this aim,

using the [ID conditional hazard] option of REXEL, the software returns the complementary

cumulative density functions of IDconditional on PGA for the site (Figure 25).

Figure 25. Probability of exceedance of IDgiven PGA for Ponticelli, case 5b


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Specifying the ID intervals to [5, 10], i.e., an intervals chosen on the basis of conditional

hazard in terms of IDwith an exceedance probability greater than 50% given PGA (Figure 25),

and selecting the Same as target spectrum option, REXEL founds 105 x 2 components of

motion record from 94 different earthquakes (ESD database). Assigning, as tolerances for

the average spectral matching, 10% lower and 30% upper in the period range 0.15s 2s and

selecting the options to stop the search after the first combination is found, REXELimmediately returns the combination of scaled accelerograms in Figure 26.

Figure 26. Set found for Ponticelli, case 5b

Case 5c: Selection of an individual record using PGV as parameter for

preliminary database search.

Considering again the same example in Ponticelli, lets consider selection of an individual

horizontal record using PGV as parameter for preliminary database search.

Specifying the PGV intervals to [0.3m/s, 0.5m/s] and selecting the Same as target spectrum

option, REXEL founds 4 x 2 components of motion record from 4 different earthquakes from

ESD (Figure 27a). Assigning, as tolerances for the average spectral matching, 50% lower and

50% upper in the period range 0.15s 2s and selecting the options to stop the search after

the first record is found, REXEL immediately returns the record in Figure 27b.

(a)


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(b)

Figure 27. Results of preliminary research (a) and record found for Ponticelli (b), case 5c

Case 5d: Selection of a set of 7-unscaled accelerograms using PGA asparameter for preliminary database search.

Considering again the same example in Ponticelli, lets consider selection of an individual

horizontal record using PGA as parameter for preliminary database search.

Specifying the PGA intervals to [0.3g, 0.5g] and selecting the Any site class option (for

records from ESD), REXEL founds 14 x 2 components of motion record from 13 different

earthquakes (Figure 28a). Assigning, as tolerances for the average spectral matching, 10%

lower and 30% upper in the period range 0.15s 2s and selecting the options to stop the

search after the first combination is found, REXEL immediately returns the set in Figure 28

(b).

(a)

(b)

Figure 28. Results of preliminary research (a) and records found for Ponticelli (b), case 5d


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Case 6: ASCE spectrum and SIMBAD database

Caso 6a: Selection of a set of 30-scaled accelerograms.

In the following, a set of 30-scaled accelerograms is selected starting from an ASCE design

spectrum with TL, SS and S1 parameters respectively equal to 3, 1.25 and 0.4 (further

information about ASCE spectra can be found in FEMA P -750, 2009). Chosen soil class is B

and only the horizontal component is considered.

Selecting SIMBAD as database, considering recordings on any site class with high magnitude

[6-7] and distance [0-30 km], REXEL finds 2x152 accelerograms referred to 43 different

events in the database as reported in Figure 29.



combinations of Figure 30a (1-component) and Figure 30b (2-components).

Figure 29. Design spectrum definition and result of preliminary research, case 6.


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(a) (b)

Figure 30. Found scaled sets of 30 record for 1 (a) or 2 (b) horizontal components, case 6.


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Appendix A

Epsilon is defined as the number of standard deviation by which the logarithmic ground

motion departs from the median predicted by the chosen attenuation relationship.

Analytical expression is reported here:

aS

aa SS

log

loglog

(1)

In Equation (1):a

S is the recorded spectral acceleration; a

Slog is the mean of the

logarithms ofa

S obtained from the ground motion prediction equation (GMPE); and aSlog

is the standard deviation of the logarithms ofa

S , still from the GMPE.

Used GMPE is the one provided by Ambraseys et al. (1996): it was fitted on records with

surface magnitude (Ms) from 4.0 to 7.5 and source-distance up to 200 km. Because those

intervals of magnitude and distance are not uniformly represented by the records in REXEL,

for each implemented database (ITACA, ESD and SIMBAD), mean of logarithmic differences

between recorded ground motion and predicted spectral acceleration (residual) is different

from zero (as shown in Figure 31a) and standard deviations of residuals for each structural

period are different from values reported in Ambraseys et al. (1996) (Figure 31b).

Figure 31. Average (a) and standard deviation of residuals from the horizontal GMPE.

The hypothesis of normal distribution of values seems satisfied for each database as

graphically represented in the following plots for some of the spectral periods provided by

GMPE.


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Figure 32. Distributions of values for ITACA (a), ESD (b) and SIMBAD (c) database.


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REFERENCES

Ambraseys, N.N., Simpson, K.A., Bommer, J.J. (1996). Prediction of Horizontal Response

Spectra in Europe,Earthquake Engineering and Structural Dynamics 25, 371-400.

ASCE, American Society of Civil Engineering (2006). Minimum Design Loads for Buildings and

Other Structures (7-05), Standards ASCE/SEI 7-05.

Bojrquez E., Iervolino I. (2011) Spectral shape proxies and nonlinear structural response,

Soil Dynamics and Earthquake Engineering, 31(7), 996-1008.

CEN, European Committee For Standardisation (2003). Eurocode 8: Design provisions for

earthquake resistance of structures, Part 1.1: general rules, seismic actions and rules for

buildings. Pren1998-1.

Chioccarelli E., Esposito S., Iervolino I. (2012). Implementing conditional hazard forearthquake engineering practice: the Italian example. Proceedings of 15 WCEE, Lisbon,

Portugal.

Convertito V., Iervolino I., Herrero A. (2009). The importance of mapping the design

earthquake: insights for southern Italy. Bulletin of the Seismological Society of America,

99(5), 29792991.

Cosenza E., Manfredi G. (2000). Damage Index and Damage Measures. Progress in Structural

Engineering and Materials, 2(1): 50-59.

CS.LL.PP (2008). DM 14 Gennaio 2008: Norme tecniche per le costruzioni. Gazzetta Ufficiale

della Repubblica Italiana, 29.

FEMA P-750, NEHRP Recommended Seismic Provisions for New Buildings and Other

Structure, Washington, D.C., 2009.Iervolino I., Chioccarelli E., Convertito V. (2011).

Engineering design earthquakes from multimodal hazard disaggregation, Soil Dynamics and

Earthquake Engineering, 31(9): 12121231.

Iervolino I., Galasso C., Cosenza E. (2010a). REXEL: computer aided record selection for code-

based seismic structural analysis.Bulletin of Earthquake Engineering, 8:339-362.

Iervolino I., Giorgio M., Galasso C., Manfredi G. (2010b). Conditional hazard maps for

secondary intensity measures. Bulletin of the Seismological Society of America, 100(6): 3312

3319.

Smerzini C., Paolucci R. (2011). SIMBAD: a database with Selected Input Motions for

displacement-Based Assessment and Design 1st

release. Report of DPC-ReLUIS 2010-2013

project (http://wpage.unina.it/iuniervo/SIMBAD_Database_Polimi.pdf).
http://wpage.unina.it/iuniervo/papers/Bojorquez-Iervolino_SDEE.pdfhttp://wpage.unina.it/iuniervo/papers/Bojorquez-Iervolino_SDEE.pdfhttp://wpage.unina.it/iuniervo/SIMBAD_Database_Polimi.pdfhttp://wpage.unina.it/iuniervo/SIMBAD_Database_Polimi.pdfhttp://wpage.unina.it/iuniervo/SIMBAD_Database_Polimi.pdfhttp://wpage.unina.it/iuniervo/SIMBAD_Database_Polimi.pdfhttp://wpage.unina.it/iuniervo/papers/Bojorquez-Iervolino_SDEE.pdfhttp://wpage.unina.it/iuniervo/papers/Bojorquez-Iervolino_SDEE.pdf

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