EARTHQUAKE HAZARD ASSESSMENTS FOR BUILDING CODES

The First Workshop Report

Amman – Jordan

27-30 March 2000

 

Contact:

Dr. Avi Shapira, Geophysical Institute of Israel, Seismology Division, Israel, Avi@iprg.energy.gov.il

Abdel-Qader F. Amrat, Jordan Seismological Observatory, Natural Resources Authority Amman – Jordan, jso@nic.net.jo

Dr. Jalal Al-Dabbik, The Center of Earth Sciences and Seismic Engineering of An –Najah National University, Palestinian National Authority, seiscen@najah.edu

       

Seismology Division, Natural Resources Authority

Amman, Jordan (Mar., 27-30, 2000)

 

Executive Summary

 

The workshop was held in Amman, Jordan 27 – 30 March, 2000, hosted by the Natural Resources Authority, and was sponsored by the Middle East Regional Cooperation (MERC) program, US-AID. In order to, present and discuss issues related to Seismicity, Seismic Hazard, Geology and Geophysics studies related to the Seismic Hazard Assessment, and existing Building Codes.

The purpose was to promote cooperation and acquaintance among the participants, and to be groundsel and launch of this project.

Participants were from; the Natural Resources Authority (NRA), Seismology Division and the Building research Center of the Jordanian Royal Scientific Society, Jordan, the Geophysical Institute of Israel (GII), Seismology Division, and the faculty for Civil Engineering, the Technion, Israel, the center of Earth Sciences and Seismic Engineering of An – Najah National University, Palestinian National Authority, and Dr. Walter Hays from the American Society of Civil Engineering (ASCE).

The participants reviewed  many topics related to the seismic hazard assessment  in the region through their presentations and discussions.  At the end of presentations all the participants were grouped  in the following groups: Compilation of Data (Geology, Geophysics, Seismology), Catalogs and Seismicity parameters and, Strong Motion and Buildings.

Background

 

The most populated areas of Israel, Jordan and the Palestinian National Authority are vulnerable to strong earthquakes that will most definitely occur. A full and true regional cooperation in the fields of Seismology and Engineering Seismology is essential for better quantifying the earthquake threat.

 

The documented history of the region provides a wealth of descriptions of destructive earthquakes. The Dead Sea rift is transform boundary between  the Arabian and African plates, connecting the Red Sea spreading center in the south to the Taurus-Zagros collision zone in the north. The Dead Sea transform is about 1100 km. The Jordan valley is a major part of the Dead Sea Transform, and the most seismically active region in the Middle East, which having a history of four thousand years of documented destructive earthquakes. Regional Cooperation is a basic requirement for a better assessment and, consequently, mitigation of the possible effects of earthquakes that will most definitely occur in this region.

 

The relevant governmental institutions in Israel, Jordan and Palestinian National Authority are already  in the  process of preparing and updating their building codes. A-seismic building code requirements are based on seismological assessments of the spatially distributed seismic hazard parameters. To achieve the objective of this project, a proposal was presented to the Middle East Regional Cooperation (MERC) program, US-AID in 1998, and was funded  in October 1999.

 

 The Earthquake Hazard Assessments for Building Codes  project,  is aimed to provide seismic hazard assessments in a form to be implemented in building codes and used in day-to-day engineering practice, in order, to reduce the effects of future earthquakes.

 

In order to achieve this overall aims we shall conduct the following studies and surveys to obtain:

 

 

        ·          A unified catalogue of earthquakes

        ·          Determination of seismogenic zones

        ·          Regionalization of seismogenic zones and assessment of their seismic capabilities.

        ·          Scaling lows of dynamic source parameters of local and regional earthquakes and attenuation of seismic energy across the region.

        ·          Implement state of the art procedures for earthquake hazard assessments and testing new approaches

        ·          Seismo-engineering characterization of buildings common in the region.

 

 

SUMARY OF PRESENTATION

 

STATE-OF-THE-ART FOR GROUND SHAKING HAZARD MAPS TO BE USED IN BUILDING CODES

 

Walter Hays, American Society of Civil Engineers

Reston, Virginia 20191, USA

 

SUMMARY

Seismic safety in Jordan, Israel, and the Palestinian Authority, or in any earthquake-prone region of the world, is accomplished through an effective building code process which calls for skillful integration by scientists and engineers of factors which balance the elastic demand on the structure with the elastic and inelastic capacity of the structure, as constrained by policy goals.  The goal is for the structure to resist the demand without collapsing.  The factors are:

 

1.      Accurate specification of the demand on the structure; that is, specifying in space and time the characteristics (i.e., amplitude, frequency composition, duration, directivity, and energy flux) of the actual  earthquake ground shaking, giving the greatest attention to the temporal and spatial variability of the horizontal components of ground shaking.

2.      Quantification of the characteristics of the site (i.e., the physical properties and geometry of the soil and rock columns which can increase the ground shaking for periods. 

3.      The actual structural design criteria, which give the specific structure the capacity to dissipate energy, sustaining damage that can be repaired, but not collapsing. 

4.      Analysis to determine the stiffness, strength, and ductility of the materials in a specific structure and its susceptibility to torsion, taking into account the configuration, actual construction materials, and lateral force resisting system.

5.      Detailed design requirements, based on a building code whose goal is to ensure an adequate seismic margin to prevent collapse. (Note: The conservatism in the actual design of a structure is referred to as the seismic margin.  It depends on the type of structure, the construction materials, and the detailing requirements that provide confidence that significant loss of life will not occur if actual ground motions are equal to, or, in rare cases, greater than  the design levels.

6.      Construction procedures to ensure continuity of load path and redundancy in the structure.

7.      Inspection to assure quality of construction procedures and compliance with the building code.

 

The attenuation function is still the critical unknown parameter because of the lack of strong motion data in Jordan, Israel, and the Palestinian Authority.  Other gaps in knowledge lead to uncertainty and call for conservatism in the building code process.

 

 

Seismotectonics of the East Mediterranean Region

 

Moh'd Naser, N R A, Jordan Seismological Observatory, P. O. Box 658,

Marj Al-Hamam 11732, Amman - Jordan.

 

The east Mediterranean region is the place where three major tectonic plates face each other and compose the tectonic features that bound the created Palestine - Sinai sandwiched sub-plate. The region could be affected by several seismotectonic sources distributed along the following major tectonic features of the region.

 

1-       The Dead Sea strike slip fault system that extend to about 1100 km from the Gulf of Aqaba triple junction up to the collision plate boundary between Arabia and Anatolian sub-plate.

2-       The East Anatolian fault that characterized by a left lateral movement continue to meet with the Cyprean Arc and extend approximately westward along the subduction zone between Africa and Eurasian plate southwest of Cyprus.

3-       The Carmel rupture zone that extend more than 130 km of northwestern trend. Aug. 24, 1984 a wide felt earthquake of M_L=5.3 take place at this fault zone.

4-       The Gulf of Suez that follow the same trend of the Mid Red Sea spreading ridge. According to the accumulated instrumental records seems to extend northwestern ward through the Mediterrain to meet with the subduction zone south of Cyprus and form the western plate boundary of the Palestine Sinai sub-plate.

 

Both historical and instrumental catalogues since the establishment of the seismological networks in the region, revealed that the majority of seismological activities are mainly associated to the tectonic features that compose the plate boundary of the Palestine Sinai sub-plate. Currently and since a couple of decades of instrumental recordings seems to be that the Gulf of Aqaba pull apart segments in addition to the south of Cyprus segment of the East Anatolian fault are the most active tectonic segments in the region. Seismic behavior of the East Mediterranean region after a decay of extreme seismic activities manifested by a magnitude M_w =7.1 on Nov. 22,1995 in the Gulf of Aqaba, and a magnitude M_w = 6.8 on Oct. 09, 1996 south west of Cyprus could be summarized as follows:

 

       1.  It seems that the increase of seismic activities in the Gulf of Aqaba segments that reach its maximum on Nov. 22, 1995 since is declining now in spite of Mar. 08, 2000 M = 5.0 earthquake.

       2.  The total number of subsequent shocks followed by an earthquake of certain magnitude is decreasing with time.

       3.  An indication of seismological activities migration toward the north, the Wadi Araba Oct. 28,1999 M = 4.5 earthquake at Lat. 30.39^○ N  and Lon. 35.036^○ E, and the Al-Querrah Dec. 19,1999 M = 4.3 earthquake at Lat. 29.38^○ E  and Lon. 35.17^○ north east of Aqaba.

       4.  The majority of the recent instrumental in addition to the historical seismic activities in the East Mediterranean region mainly concentrates along the plate boundary of the Palestine - Sinai sub-plate.

       5.  Apparently none of events that exceed M_L = 5.5 take place outside of the Palestine Sinai plate boundary within the plate itself.

 

 

 REVIEW OF SEISMIC HAZARD RELATED STUDIES PERFORMED IN JORDAN

Mahmoud Al-Qaryouti

Seismology Division, Natural Resource Authority

Amman, Jordan

Summary

 

         In Jordan, many studies have been conducted related to seismic hazard assessments in the two ways: Probabilistic and Deterministic methods. These studies showed that the Jordan-Dead Sea Transform and related branches are the major active zone to earthquake hazard in the region.

 

         In probabilistic method, detailed study was conducted. Al-Tarazi (1992) used historical and instrumental data until 1989 to evaluate a probabilistic seismic hazard assessment model for two cases, the point-source model and the line-source model. The iso-contour maps of ground motion resulting from both models are compared to each other in order to select the best representative seismic hazard maps for the study area. Macrozoning seismic factor (Z) is represented in probabilistic seismic hazard maps by Alzoubi (1995).

 

         Many earthquakes were recorded in many localities in Jordan especially in the Dead Sea and Aqaba areas (Al-Qaryouti and Amrat,1995). The major earthquake was recorded by the accelerograph stations is the main shock of the 22 November 1995 Aqaba earthquake sequence. The Aqaba hotel accelerograph station showed that the maximum ground acceleration is 0.156 g, while the Aqaba civil defense accelerograph station showed that the maximum ground acceleration is 0.066 g. Kablawi (1997) applied design response spectrum to locally recorded earthquakes. The response spectra to all ground motions are constructed, normalized and averaged out resulting in a design response spectrum for 50 %  and 84 %  nonexceedance probabilities.

 

         Site effects in Aqaba city were estimated using microtremor measurements (Al-Qaryouti et al., 2000). Predominant periods were conducted through more than 1200 measured sites.

Annex  A

List of Participants

 

Annex  B

WORKSHOP AGENDA

Monday   Mar., 27

                    Arrival Amman

08:00-08:30   Registration

08:30-09:30   Opening Session

                     Abdel-Qader Amrat, Head of Seismology, NRA

                     Darweesh Jaser, Director of Geology, NRA

                     Avi Shapira, Director of Seismology, GII

                     Jallal Dabbeek, Director of ESSE

                     Walter Hays, ASCE

                     Ma'in Hiyari, Director General, NRA

 

09:30-10:00    Coffee

 

10:00-10:30   Presentation of the project - objectives and general plans -

                                 Avi Shapira (GII)

10:30-11:30    State-of-the art on earthquake hazard assessments in the      USA

                            Walter Hays (USGS and   ASCE)

11:30-12:00   Current practice and basic concepts in designing a building code

                                 Jallal Dabbeek (ESSE)

12:00-12:30   Cornell-McGuire procedure for earthquake hazard assessments

                                 Eid El-Tarazi (HU)

12:30-13:00   Stochastic methods for estimating earthquake hazard (SEEH)

                                 Avi Shapira (GII)

 

13:00-14:30   Lunch

14:30-15:00    Seismotectonics of the region

                            Mohammed Naser (NRA)

15:00-15:30   Geology and tectonics related to the seismic hazard assessment

                                 Ahmed Al-Masri (NRA)

15:30-16:00   Geophysical studies related to the seismic hazard assessment

                                Awni Batayneh (NRA)

 

Wednesday   Mar., 29

08:30-09:00   Review of seismic hazard related studies performed in Jordan

                                Mahmoud Al-Qaryouti (NRA)

09:00-09:30   Review of seismic hazard related studies performed in Palestine

                                Jallal Dabbeek (ESSE)

09:30-10:00   Review of seismic hazard related studies performed in Israel

                                J. Leonov & Y. Zaslavsky (GII)

10:00-10:30   Earthquake resistance in building codes in Jordan

                               Khaled Kahhaleh (RSS)

10:30-11:00    Coffee

11:00-11:30    Earthquake resistance in building codes in Palestine

                                Abdel-Hakeem El-Jawhari ( ESSE)

11:30-12:00    Earthquake resistance in building codes in Israel

                                J. Leonov (GII)

12:00-16:00   Working groups:

               ·   Group A:   Compilation of data (Geology, Geophysics, Seismology)

               ·   Group B:   Catalogs & Seismicity parameters

               ·   Group C:   Strong motion data analysis and characteristics of buildings

13:00-14:30   Lunch

Thursday   Mar., 30

08:30-10:30   Groups presentations and final report

10:30-11:00    Coffee

 Closing session

Annex C

Report of the Working Groups

Group A

 

Chairman :  Ahmed Al-Masri (NRA)

 NRA :  Awni Batayneh, Wajdi Talib

 ESSE :  Radwan El-Kelani

 GII :  Avi Shapira

 

Title: Compilation of data (Geology, Geophysics, Seismology)

Goal: Generate a seismogenic map.

 

Methodology:

        ·          Defining the area with a suitable base map (31^o - 40 ^o E  ,  27 ^o - 37 ^o N)

        ·          Produce a simplified lithological map.

        ·          Produce a tectonic map related to seismic hazard, specially active faults

        ·          Produce seismic map

        ·          Produce magnetic map

        ·          Any data (paleoseismicity, archeo-seismicity or heat flow will be used during compilation)

        ·          Any information regarding remote sensing technique, specially for those reactivated faults.

        ·          Within three months from now, geologists and geophysicists will set together to compile what they know about tectonics and seismicity .

        ·          We have to check the instrumentation technique for producing our different maps.

 

Results: After three months from now the results from compilation will be submitted in the second workshop. The second workshop will be in Jerusalem in the second half of June 2000.

 

Group B:

 

Chairman :  Abdel-Qader Amrat (NRA)

 NRA :  Mahammed Naser, Waleed Olimat

 ESSE :  Usama Zakout

 GII :  Nitzan Rabinowitz

 

Title:   Catalogs and Seismicity Parameters.

Goal: Unified regional catalog both historical and instrumental within the area (27 ^o -37 ^o E and 31 ^o -40 ^o E) including hypocenter, epicenter and magnitude

 

 Methodology:

 

       1.         Using instrumental data such as ISE, EMSC, PDE, JSO, GII and Al-Tarazi. For historical data, collect any available sources.

       2.         To select a few reliable instrumental events to relocate and find the optimal location method that will be merge both networks ( special attention will be paid for focal depth consideration).

       3.         For the purpose of relocation we will be use several velocity models to see the best suitable velocity model, bearing in mind the goal of merging the two network records.

       4.         Evaluating unified magnitude to be used in the future:

                 ·   We will be apply several methods and compare their values. In particular we intend to compare magnitude of the two networks

                 ·   Evaluate the completeness of each catalog.

                 ·   Check the possibility of using amplitude-based magnitude from existing broad band statioms in both sides.

                 ·   The final product will be the integration of all these elements into one unified regional catalog.

 

The first meeting will be held in GII in the second half of June 2000 for 3 days (4,2,2 participants from NRA, GII, ESSE, respectively). The second face we will devoted with evaluation of statistical parameters associated with the catalog in cooperation with Group A.

This group will determine the seismogenic sources, the recurrence and (a and b) values.

Group C:

 

Chairman :  Jallal Dabbeek (ESSE)

NRA :  Mahmoud Al-Qaryouti, Omer Mayas

ESSE :  Abdel-Hakeem El-Jawhari

GII :  Yuli Zaslavsky, Joseph Leonov

 

Title: Strong Motion Data Analysis and Characteristics Buildings

Goal: Enhancing Building Codes.

 

        Objectives : 1.Analysis of strong motion accelerograms

                                2.Characterization of dynamic parameters of buildings

 

Methodology:

 

        ·          Analysis of strong motion accelerograms

        ·          Compare strong motion records obtained by Jordan and Israel.

        ·          Strong Motion Networks.

        ·          Establish acceleration attenuation relationship.

        ·          Characterization of dynamic parameters of buildings

        ·          Prepare tables of the types of existing buildings in Palestine, Jordan, and Israel.

        ·          Correlate these tables and obtain a unified classification that covers all common types in the three countries.

        ·          Instrument a number of selected buildings from those common categories.

        ·          Obtain measurements of the fundamental period of vibration of these structures and their damping characteristics.

        ·          Compare measurements with values calculated using the most recent edition of the UBC and the local national codes and make modifications the formulae as necessary.  These new empirical formulae will be the basis for future drafts of a unified building code for the region.

        ·          Define the spectral band pass and damping rations for which the acceleration response function will be computed, and consequently, the earthquake hazard maps will be prepared.

        ·          The proposed framework for action includes two training courses and joint analysis workshops.

 

Annex D

List of Abbreviations

 

ASCE          American Society of Civil Engineers.

EMSC          European-Mediterranean Seismological Center.

ESSE           Center of Earth Sciences and Seismic Engineering.

GII              Geophysical Institute of Israel.

HU              Hashemite University.

ISC             International Seismological center>

JSO           Jordan Seismological Observatory.

MERC           Middle East Regional Cooperation.

NRA            Natural Resources Authority.

PDE            Preliminary Determination of Epicenters.

RSS            Royal Scientific Society.

US-AID          U.S. Agency for International Development.

USGS          U.S. Geological Survey.