Department of Civil and Environmental Engineering Stanford University

THE MEXICO EARTHQUAKE OF SEPTEMBER 1985, A PRELIMINARY REPORT

by

Shigeru Suzuki and

Anne Kiremidjian

Report No. 77

January 1986

The John A. Blume Earthquake Engineering Center was established to promote research and education in earthquake engineering. Through its activities our understanding of earthquakes and their effects on mankind’s facilities and structures is improving. The Center conducts research, provides instruction, publishes reports and articles, conducts seminar and conferences, and provides financial support for students. The Center is named for Dr. John A. Blume, a well-known consulting engineer and Stanford alumnus. Address: The John A. Blume Earthquake Engineering Center Department of Civil and Environmental Engineering Stanford University Stanford CA 94305-4020 (650) 723-4150 (650) 725-9755 (fax) earthquake @ce. stanford.edu http://blume.stanford.edu

©1986 The John A. Blume Earthquake Engineering Center

ACKNOWLEDGMENTTABLE OF CONTENTSLIST OF FIGURESLIST OF TABLES1. INTRODUCTION2. SEISMICITY OF SOUTHWESTERN MEXICO2.1 Tectonic Setting2.2 Seismicity2.3 Probabilities of Occurrence of the September 9, 1985 Mexico Earthquake

3. STRONG MOTION3.1 Strong Motion Records3.2 Characteristics of Strong Motions

4. DAMAGE TO BUILDINGS�4.1 Introduction4.2 Typical Failures4.3 Typical Buildings in Mexico City4.3.1 1-3 Story Buildings4.3.2 4-15 Story Buildings4.3.3 16 Story and Higher

4.4 Causes of Damge4.4.1 Total Collapse4.4.2 Upper Floor Damage4.4.3 Corner Column Failure4.4.4 Non Structural Damage4.4.5 Other Observed Damage

5. DAMAGE TO LIFELINES�5.1 Power Supply5.2 Water Supply5.3 Gas Supply5.4 Communication5.5 Transportation5.6 Airports

6. DAMAGE EVALUATION6.1 Local Soil Effect6.2 Classification of Damaged Buildings

7. SUMMARY AND CONCLUSIONSREFERENCES