FIELD MONITORING AND SURVEYS Microtremor measurements
Site response surveys (HVSR, SSR, GIS) 100 200 300 400 500 600 700 800
Promygdonian system
160m
225m 260m 287m
GPS 370m
sensor
Phase velocity dispersion curve of Rayleigh waves
1
1
10
SSR on earthquake/NS & EW components 10
Bedrock
408m
Survey deployment (circular array)
10
Frequency (Hz)
Amplification
recorder
HVSR ambient noise /NS component
Vs (m/sec)
Amplification
Mygdonian system
0m 35m
S-wave velocity profile with comparison to stratigraphy of the site
Down-hole and Cross-hole surveys
Resonant frequency (Hz)
1
0.1
1
Frequency (Hz)
Survey deployement
0.30 - 0.39 Hz 0.40 - 0.50 Hz
S-part / EW component Coda part / EW component S-part / NS component Coda part / NS component
0.51 - 0.59 Hz 0.60 - 0.75 Hz 0.76 - 0.90 Hz 0.91 - 1.20 Hz 1.21 - 1.75 Hz > 1.75 Hz
10
Spatial variation of the resonant frequency in Euroseistest
Site response surveys (HVSR, SSR, GIS) Profitis
Stivos
P-w s
Survey deployment
ave
Source (hammer)
Recordings and dromochromic diagram of P- and S-waves, and Vp and Vs velocities Vs velocity (km/sec) 0.5 1.0 1.5 2.0
1.0
0.02
0.9
0.04
0.8
0.06
0.7
0.08
Depth (km)
Phase velocity (km/sec)
Multichannel Analysis of Surface Waves
0.6 0.5 0.4
0.16
0.2
Survey deployment
10
0.12 0.14
0.3
10-1
0.10
Period (sec)
100
Phase velocity dispersion curve of Rayleigh waves
0.18
S-wave velocity profile
Selected projects:
EUROSEISTEST • EUROSEISMOD • EUROSEISRISK • MERP • SRM-DGC • XSOILS
Selected publications:
• Raptakis D, Chávez-García FJ, Makra K, Pitilakis K, 2000. Site effects at Euroseistest Part I. Determination of the valley structure and confrontation of observations with 1D analysis, Soil Dyn. & Earthq. Eng., 19:1-22. • Manakou M, Raptakis D, Chavez-Garcia FJ, Apostolidis P, Pitilakis K, 2010. 3D soil structure of the Mygdonian basin for site response analysis. Soil Dyn. & Earthq. Eng., 30: 1198-1211.
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