Ebook: Increasing Seismic Safety by Combining Engineering Technologies and Seismological Data

The current state-of-the-art allows seismologists to give statistical estimates of the probability of a large earthquake striking a given region, identifying the areas in which the seismic hazard is the highest. However, the usefulness of these estimates is limited, without information about local subsoil conditions and the vulnerability of buildings. Identifying the sites where a local ampli?cation of seismic shaking will occur, and identifying the buildings that will be the weakest under the seismic shaking is the only strategy that allows effective defence against earthquake damage at an affordable cost, by applying selective reinforcement only to the structures that need it. Unfortunately, too often the Earth’s surface acted as a divide between seism- ogists and engineers. Now it is becoming clear that the building behaviour largely depends on the seismic input and the buildings on their turn act as seismic sources, in an intricate interplay that non-linear phenomena make even more complex. These phenomena are often the cause of observed damage enhancement during past ear- quakes. While research may pursue complex models to fully understand soil dyn- ics under seismic loading, we need, at the same time, simple models valid on average, whose results can be easily transferred to end users without prohibitive expenditure. Very complex models require a large amount of data that can only be obtained at a very high cost or may be impossible to get at all.

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Too often the Earth’s surface acted as a divide between seismologists and engineers. Now it is becoming clear that the building behaviour largely depends on the seismic input and the buildings on their turn act as seismic sources, in an intricate interplay that non-linear phenomena make even more complex. These phenomena are often the cause of observed damage enhancement during past earthquakes. While research may pursue complex models to fully understand soil dynamics under seismic loading, we need also simple models valid on average, whose results can be easily transferred to end users.

Under the title “Increasing Seismic Safety by Combining Engineering Technologies and Seismological Data”, we grouped several topics to be discussed together by engineers and seismologists: (1) Can we use ambient noise building and soil characterisation to extract useful information for engineers? (2) How we can tell apart a frequency decrease due to distributed damage, concentrated damage, time- varying building and soil behaviour? (3) Which is the role of transients in ambient noise analysis? (4) Can we quantify the influence of existing buildings on ground-motion recordings? (5) To which extent soil-building resonance is a cause of damage enhancement? (6) How to couple soil and building non-linear behaviour?

On most questions there is an unanimous answer, but in some cases different views are present and the disagreement is faithfully reported.

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Too often the Earth’s surface acted as a divide between seismologists and engineers. Now it is becoming clear that the building behaviour largely depends on the seismic input and the buildings on their turn act as seismic sources, in an intricate interplay that non-linear phenomena make even more complex. These phenomena are often the cause of observed damage enhancement during past earthquakes. While research may pursue complex models to fully understand soil dynamics under seismic loading, we need also simple models valid on average, whose results can be easily transferred to end users.

Under the title “Increasing Seismic Safety by Combining Engineering Technologies and Seismological Data”, we grouped several topics to be discussed together by engineers and seismologists: (1) Can we use ambient noise building and soil characterisation to extract useful information for engineers? (2) How we can tell apart a frequency decrease due to distributed damage, concentrated damage, time- varying building and soil behaviour? (3) Which is the role of transients in ambient noise analysis? (4) Can we quantify the influence of existing buildings on ground-motion recordings? (5) To which extent soil-building resonance is a cause of damage enhancement? (6) How to couple soil and building non-linear behaviour?

On most questions there is an unanimous answer, but in some cases different views are present and the disagreement is faithfully reported.

Content:
Front Matter....Pages i-xvii
The Use of Ambient Noise for Building and Soil Characterisation....Pages 1-2
The Need for Standardized Approach for Estimating the Local Site Effects Based on Ambient Noise Recordings....Pages 3-15
Are Transients Carrying Useful Information for Estimating H/V Spectral Ratios?....Pages 17-31
Basic Structure of QTS (HVSR) and Examples of Applications....Pages 33-51
Ambient Noise and Site Response: From Estimation of Site Effects to Determination of the Subsoil Structure....Pages 53-71
Estimates of Vs30 Based on Constrained H/V Ratio Measurements Alone....Pages 73-84
Comparison of Recorded Dynamic Characteristics of Structures and Ground During Strong and Weak Shaking....Pages 85-97
HVSR Technique Improvement Using Redundant Wavelet Transform....Pages 99-115
Effect of Buildings on Free-Field Ground Motion....Pages 117-137
Effect of Building-Building Interaction on “Free-Field” Ground Motion....Pages 139-140
Role of Dynamic Properties on Building Vulnerability....Pages 141-146
How Far Ambient Noise Measurement May Help to Assess Building Vulnerability?....Pages 147-149
Assessment of Seismic Capacity of Existing Buildings – Effects of Uncertainties....Pages 151-180
Estimation of the Period of Vibration of Existing RC Building Types Based on Experimental Data and Numerical Results....Pages 181-206
Retrofitting and Strengthening Evaluation from Stiffness Variations of a Damaged Building from Ambient Vibration Recordings....Pages 207-225
State-of-the-Art – Recent Advances and Applications....Pages 227-238
Microtremor Soil-Structure Resonance Study in the Bovec Basin (NW Slovenia) Related to 1998 and 2004 Damaging Earthquakes....Pages 239-240
Recent Earthquake Site Response Studies in Canada....Pages 241-255
Recent Applications of Ambient Vibration Measurements in Croatia....Pages 257-279
Applications to World Heritage Sites....Pages 281-292
Two Applications of the HVSR Technique to Cultural Heritage and Historical Masonry....Pages 293-324
Overview of Seismic Hazard Studies in Tunis City....Pages 325-335
An Empirical Geotechnical Seismic Site Response Procedure....Pages 337-351
Back Matter....Pages 353-380
....Pages 381-382