Civil Engineering VSU “Lyuben Karavelov”, Sofia, May 15, 2007
Engineering challenge in safeguarding and sustainability of architectural heritage
Miloš F. Drdácký
Institute of Theoretical & Applied Mechanics
of the Academy of Sciences of the Czech Republic, v.v.i.
ARCCHIP Centre of Excellence
(Advanced Research Centre for Cultural Heritage Interdisciplinary Projects)
Civil Engineering VSU “Lyuben Karavelov”, Sofia, May 15, 2007
Safeguarding of architectural heritage Important European Issue Science Engineering Social & Political Matter Environment & Sustainability
Civil Engineering VSU “Lyuben Karavelov”, Sofia, May 15, 2007
Structural heritage values
Failure of a Gothic vault of St.Francesco church in Assisi (I)
Diamond vault in Franciscan Monastery in Kadaň (CZ)
Civil Engineering VSU “Lyuben Karavelov”, Sofia, May 15, 2007
Integrated qualities Aesthetic Functional Technological
Civil Engineering VSU “Lyuben Karavelov”, Sofia, May 15, 2007
National Theatre in Prague
St.Trinity Column Olomouc
Testing of stress distribution in bronze sculpture & inner iron frame
Civil Engineering VSU “Lyuben Karavelov”, Sofia, May 15, 2007
Structural craft lessons
Carpentry door frame with locked corner stiffeners (rigid corner)
Forged hinges with distributed nails & screws (distributed & reduced reaction forces)
Civil Engineering VSU “Lyuben Karavelov”, Sofia, May 15, 2007
Traces by left handed carpenter worked above the waist level on a horizontally oriented hewn log
left handed carpenter
Log squaring traces
right handed
Origin of traces
High work Broad axe
Transparent plastic sheet for trace analysis (below)
Examples of carpentry technological traces
Low work Long felling axe
Civil Engineering VSU “Lyuben Karavelov”, Sofia, May 15, 2007
Proof load tests of timber crane replicas
Two way moveable crane for lifting sculptures
Rotating crane for roof repair on medieval castle
Civil Engineering VSU “Lyuben Karavelov”, Sofia, May 15, 2007
Diagnostics & Damage Analysis
sound wood
Imager plate
X-ray source
Resistance drilling
cracks decayed area
X-ray
Discovered wood decay & nails, hidden details & fasteners
Videoscopy
Driven rod penetration
Ultrasonics
Civil Engineering VSU “Lyuben Karavelov”, Sofia, May 15, 2007
Wood
Non-standard specimen small sample testing of material characteristics
Cutting out wood strands
7x7mm rect. triangle
Tension test
4.5 mm Core drilling
Compression test Bending test - mortar
Stone & Mortar
Compression test Splitting test
Shear test
Civil Engineering VSU “Lyuben Karavelov”, Sofia, May 15, 2007
X-ray Micro-tomography
Medipix detector
Calibration carousel
X-ray source
Concrete specimen (2x7x13 mm)
Turntable with loading device
Principle & set up
Civil Engineering VSU “Lyuben Karavelov”, Sofia, May 15, 2007
Modeling & testing of climate effects
Environmental fatigue Failure analysis Stresses in St. Vitus tracery during warming Simplified FEM Model Process of warming from 5°C to 15°C – surface temperature after 2 hours of heating
Temperature differences on wet surface during cycling
wind rain
SP01 SP02 SP03 SP04
3D laser scanning
Civil Engineering VSU “Lyuben Karavelov”, Sofia, May 15, 2007
Lessons from historic materials & development of compatible restoration materials
Mortars with fibres
Study of effective stresses in noncompatible filling & original material exposed to real temperature changes
Pozzolanic mortars
Distribution of stresses inside and around filling shaped as truncated pyramid & truncated cone 75 mm thick (above) and as truncated pyramid 15 mm thick (left)
Civil Engineering VSU “Lyuben Karavelov”, Sofia, May 15, 2007
Testing & modeling of air flow around complex architectural forms
Wind tunnel test models & CFD computed velocity streamlines around the tower
Civil Engineering VSU “Lyuben Karavelov”, Sofia, May 15, 2007
Thank you for your attention