P-Wave Velocity and Quality of Building Materials
Professor Basile Christaras
Aristotle University, School of Geology, Lab. Engineering Geology &
Hydrogeology, 54006 Thessaloniki, Greece.
Abstract: The investigation of the physical and mechanical properties of stones in
monuments needs non-destructive methods and small quantity of testing
material. In this framework, P & S waves ultrasonic velocities can be used
for both in situ and laboratory measurements. These methods are used
for studying properties such as the mechanical anisotropy, and the modulus
of elasticity of the materials. In this paper, the P-wave velocities were
used for the estimation of the depth of weathered or artificially
consolidated layers as well as the depth of cracks at the surface of the
building stone. This estimation was performed in relation to the lithology
and texture of the materials, given that in many cases different
lithological data create similar diagrams. All tests were performed on
representative monuments in Greece.
Biography of the speaker:
Professor Basile Christaras was born in 1954, in Thessaloniki.
He is a) Professor of Engineering Geology b) Director of the Geological
Department and c) President of the Postgraduate Course on “Applied &
Environmental Geology” in the School of Geology, of the Aristotle University
of Thessaloniki (AUTH). He is also Chairman of the Join Technical Committee
on “Ancient Monuments/Historic Sites” of the Federation of the International
Geo-engineering Societies (IAEG, ISSMGE & ISRM).
He studied in the Aristotle University of Thessaloniki and the University P.
et M. Curie of Paris. He has a very good knowledge of English and French
languages and quite good knowledge of the Italian one, additionally to his
Greek mother tongue.
During his carrier, he was President of the Board of Directors of the Greek
Geological Survey (IGME), member of the Greek National Advisory Council of
Research and Technology, member of the Boards of Directors of several
National Institutions and member of European and international committees of
experts. Scientifically, he is President of the Commission 16, for the
protection of monuments, of the International Association of Engineering
He is responsible for the courses of soil mechanics, at graduate and
postgraduate level, in the School of Geology of AUTH.
His research concerns geotechnical aspects related to a) the construction of
public works, b) natural hazards c) environmental management, d) natural
building stones and protection of monuments, especially with the use of
In this framework, he performed (and continues to coordinate) research
projects, in Greece and abroad. Apart from Greece, his research is related
to studies of St. Sophia church in Istanbul, the Cathedrals of Bari and
Cadiz, small churches in Malta, the orthodox rock-hewn churches of Lalibela,
in Ethiopia, fieldwork related Tree Gorges Dam in China, in collaboration
with the Chinese Academy of Sciences, deep drilling construction in the
Pacific Ocean and other geotechnical activities.
He is author of two books on soil mechanics, published by the Aristotle
University of Thessaloniki and the Technical Chamber of Greece, and 120
scientific papers, published in international scientific journals.
Furthermore, he participated in numerous international congresses (in many
of them as invited speaker).