T.R. ISTANBUL METROPOLITAN MUNICIPALTY DEPARTMENT OF EARTHQUAKE RISK MANAGEMENT AND URBAN DEVELOPMENT DIRECTORATE OF EARTHQUAKE AND GROUND ANALYSIS PRODUCTION OF MICROZONATION REPORT AND MAPS EUROPEAN SIDE (SOUTH) GEOLOGICAL – GEOTECHNICAL STUDY REPORT ACCORDING TO THE CONSTRUCTION PLANS AS A RESULT OF SETTLEMENT PURPOSED MICROZONATION WORKS FINAL REPORT (SUMMARY REPORT) OCTOBER 2007 ISTANBUL OYO INTERNATIONAL CORPORATION TABLE OF CONTENTS 1 OBJECTIVE AND SCOPE …………………………………………………………… 1 1.1 Objective of the Work ……………………………..………………………………… 1 1.2 Scope of the Work …………………………………………………………………… 1 1.3 Work Organization …………………………………………………………….......... 2 2 INTRODUCTION OF THE WORK AREA AND WORKING METHODS………… 3 2.1 Location of the Work Area ………………………………………………………… 3 2.2 Database, Mapping and Working Methods …………………………………………. 5 2.3 Summary of the Work ..……………………………………………………………. 6 3 GEOGRAPHICAL LOCATION AND GEOMORPHOLOGY…………………….. 7 3.1 Geographical Location ……………………………………………………….......... 7 3.2 Geomorphology ……………………………………………………..….................. 7 4 CONSTRUCTION PLAN ……………………………………….……………….…… 9 5 GEOLOGY…………………………………………………………….…………..…... 10 5.1 General Geology ………………………..……........................................................... 10 5.2 Geology of the Project Area……................................................................................ 13 5.3 Structural Geology ……………….............................................................................. 15 5.4 Historical Geology ……………….............................................................................. 16 6 GEOLOGICAL WORKS, GEOPHYSICAL MEASUREMENTS AND IN-SITU TESTS …………………………………………………………………….… 17 6.1 Geological Works ……………………………………………………….………….. 17 6.2 Geophysical Measurements…………………………………………………………. 17 6.3 Local Soil Characteristics ……………………………………………....................... 18 7 LABORATORY TESTS ………………………………………………………………. 24 7.1 Contents of Laboratory Tests ………………………………………………………… 24 7.2 Results of Laboratory Tests …………………………………………………………. 24 8 HAZARD ANALYSIS AND MAPPING ……………………………………………… 26 8.1 Earthquake Hazard Analysis ………………………………………………………… 26 8.2 Surface Ground Motion Analysis……………………………………………….......... 37 8.3 Liquefaction Hazard Analysis……………………………………………………….. 48 8.4 Mass Movements (Slope Instability)………………………………………………... 53 9 WATER STATUS ……………………………………………………………………… 58 9.1 Groundwater Levels …………………………………..…………………................... 58 9.2 Flooding Hazard Analysis ………………………..………………….......................... 61 9.3 Tsunami Hazard Analysis …......…………………………..…………………............. 67 10 ASSESSMENT OF SUITABILITY FOR SETTLEMENT ………………….…….... 78 10.1 Technical and Legal Criteria of the Evaluation …………….………………….……. 78 10.2 Evaluation of Hazards in Terms of Settlement Suitability………………….……….. 78 10.3 Suitable Areas (UA) …………………………………………………..……….......... 78 10.4 Precautionary Areas (ÖA) …………………………………………………………… 79 10.5 Unsuitable Areas (UOA) …………………………………………………………….. 82 11 RESULTS AND SUGGESTIONS ………………….…………………………….….... 84 1 OBJECTIVE AND SCOPE This Report describes the summary of contents, methods and results of “PRODUCTION OF MICROZONATION REPORT AND MAPS – EUROPEAN SIDE (SOUTH)” (hereinafter referred to as “the Work”), prepared by OYO International Corporation (OIC), and submitted to Istanbul Metropolitan Municipality (IMM). 1.1 Objective of the Work The objective of the Work is to identify separate areas which have different potentials for hazardous earthquake effects and to produce the seismic microzonation report and maps which can serve as the basis for “hazard-related land use management and city planning” within the boundary of Istanbul Metropolitan Municipality. In order to assess these earthquake effects, detailed geological, geophysical, geotechnical, and seismological investigations and study were conducted. 1.2 Scope of the Work The flow of whole Work is shown in Fig. 1.2.1. (1) Planning and Organization for the Work (2) Site Investigations and Data Collections (3) Data Input and Evaluation (4) Data Analysis and Processing (5) Microzonation Mapping and Reporting Fig. 1.2.1 Flow of the Work 1 1.3 Work Organization The Work organization is shown in Fig. 1.3.1. Istanbul Metropolitan Municipality Technical Department of Committee Earthquake and Soil Research OYO International Corporation Project Team Project Manager Geological Seismological City Planning, Microzonation and and Geomorphology, Evaluation Geotechnical Geophysical and GIS Work Group Work group Work Group Work Group Fig. 1.3.1 Work organization 2 2 INTRODUNTION OF THE WORK AREA AND WORKING METHODS 2.1 Location of the Work Area The location of the Work area is shown in Fig. 2.1.1. Fig. 2.1.1 Location of the Work area Fig. 2.1.1 Location of the Work area The Work area, shown in Fig. 2.1.2, is the land portion surrounded with the following coordinates: 1) X: 388,598.72 Y: 4,547,051.31 2) X: 388,430.19 Y: 4,535,945.17 3) X: 407,375.58 Y: 4,535,681.75 4) X: 415,860.39 Y: 4,541,134.16 5) X: 415,892.19 Y: 4,543,910.66 6) X: 411,720.15 Y: 4,546,736.56 The total area is approximately 182 km2. The Work period is between 18.01.2006 – 19.10.2007 and this final report has been prepared in October 2007. 3 Proje İçi Gridler Proje Dışı Gridler Proje Alanı Fig. 2.1.2 Work area grid map (250 x 250 m. European Side (South), İstanbul) 4 2.2 Database, Mapping and Work Methods Data and maps are prepared in ArcInfo1 environment, after an agreement with the Municipality. National geodetic coordinate systems are used to produce data and maps. 1/1000 scale DGN files of year 1999 are mainly used as base map. 1/5000 scale DGN and GEO-TIFF files of year 2005 are used as assistant base map. Geological legends are based on MTA’s geological mapping standard, and updated for Istanbul based on the comments of control engineers, professors and other high engineers. The datum of “1/1000 scale DGN files of year 1999“ is “European Datum 1950”. The datum is pre-defined by ArcGIS 9.1. Major database systems developed in this project are listed in Table 2.2.1. Table 2.2.1 Major database systems Name Path Description Borehole Log I:/Project2006/ This is a borehole log system and data, including systems drilling data/ to draw the N chart and lithology in borehole logs in log excel/ Excel format. GeoDB I:/Project2006/ This is a system to combine the data files of field survey GeoDB result into one GIS database, including systems to import borehole logs, laboratory test result, CPT field test result, ground water monitoring result, PS logging result, ReMi field survey result, array microtremor field survey result, resistivity field survey result. The system also include the control system of elevation value of field survey locations with DEM data, and the liquefaction potential calculation system. Building Extraction I:/Project2006/ This is a system to extract building boundary polyline Tools from all 1/5000 base maps of year 2005, and convert to building polygon. The output of this system is used for Tsunami Simulation. 1/1000 base map file I:/Project2006/ This is a system to convert all 3D-Spline of DGN files conversion Tools into polyline, and then convert into shapefiles. Both of Microstation/J 7.1J BASIC environment and ArcGIS 9.1 VBA are used for system development. PDF Export I:/Project2006/ This is a system to shift map extent and export PDF files. Tools 1 Version 9.1 5 2.3 Summary of the Work Total amount of 2,830 normal drillings with 30m depth, 27 deep drillings, 764 liquefaction drillings, 608 landslide drillings, 100 drillings with differant depths to determine baserock depth and thickness of some formations and also 35 drillings to determine some structural features like faults and alluvium thickness as a total number of 4,364 mechanical drillings were conducted in 2,912 grids (250x250) within the context of project. Total drilling depth was 125,578.90 m. Beside SPT tests which were conducted in the site, 636 CPT tests were also conducted. Total 2,762 Seismic Refraction – ReMi measurements, 2,625 Electric Resistivity measurements, 201 PS Logging tests, Array Microtremor measurement in 30 points and 20km lenght Seismic Reflection measurement were conducted within the context of geophysical studies. These studies that conducted in field were supported with laborary tests and complied in office work with grouping recent and possible hazards by conducting necessery analiysis. Consequently, Microzonation maps were produced regarding to the studies which were mentioned above and settlement suitability map were created from these maps. 6 3 GEOGRAPHICAL LOCATION AND GEOMORPHOLOGY 3.1 Geographical Location In the general view of Istanbul area, the Bosphorus, a narrow straight, links the Marmara Sea to the Black Sea, and divides Istanbul into two main parts: European side and Asian side. The European side of Istanbul is split in historical areas and modern areas by the Golden Horn, a narrow channel off the Bosphorus. The Work Area includes west part of the Golden Horn and it is bounded by the Golden Horn and the Marmara Sea enterance of the Bosphorus in east, the Marmara Sea in south, east slopes of Yakuplu district (west slopes of Haramidere) in west and TEM highway (South) in north. 3.2 Geomorphology Fig. 3.2.1 shows the topography in the project area. The project area, facing the Marmara Sea to south, lays east and west. Lots of hills divided by valleys along north to south are observed. The Küçükçekmece Lake divides the project area into the west part and east-middle parts. There are several rivers such as Harami Dere, Karagos