Giancarlo Dal Moro

The Czech Academy of Sciences | AVCR · Department of Seismotectonics

• Generalità: onde di Rayleigh e Love, P e S, velocità di fase e gruppo • Sezioni 2D oltre la rifrazione: 2D-SuPPSALA (e non solo) • HVSR: identificazione e rimozione di segnali industriali • Amplificazioni e rimozione di segnali industriali • Amplificazioni: HVSR versus SSR e SSRn • Esempi di analisi Holisurface®, ESAC multi-componente con array l...

A series of reclamation works that took place during the twentieth century, almost completely destroyed the dune system that characterized the eastern part of the Grado-Marano perilagoonal area (NE Italy). Because of the limited data available, so far very little was known about the local subsurface conditions and the present paper presents the mai...

Gli sviluppi nel campo dell’acquisizione e analisi delle onde di superficie, hanno di fatto reso privo di un chiaro ed univoco significato il noto acronimo MASW (Multichannel Analysis of Surface Waves). Tale acronimo, infatti, non risulta più in grado di definire nulla di puntale: che genere di (combinazione di) geofoni connettiamo ai canali (M)? C...

In the last decade, the analysis of surface-wave propagation has become extremely popular especially in the framework of seismic-hazard studies although, as a matter of fact, the determination of the shear-wave velocity (VS) profile is useful for any geotechnical or geological application that requires the knowledge of the subsurface conditions. I...

The Horizontal-to-Vertical Spectral Ratio (HVSR) obtained from microtremor data recorded at three test sites are analyzed in order to highlight some issues related to the computation of the SESAME criteria that define the statistical robustness of possible peaks. In case of multiple-peak HVSR curves, it is shown that to properly assess the statisti...

Sinkholes and cavities can represent serious hazards to human safety, urban infrastructures, roadbed subsidence and so on. It is therefore essential to evaluate various sinkholes in different depths and sizes to assess the risk of collapse. This paper intends to evaluate the effect of different cavities on Rayleigh-wave propagation and body (P) wav...

SOFTWARE FOR THE ANALYSIS OF DOWNHOLE SEISMIC DATA Joint modeling of P and SH-wave travel times [considering the actual ray paths] also jointly with the HVSR curve (Horizontal-to-Vertical Spectral Ratio) ELIOVSP also processes the data recorded by a twin borehole geophone (i.e. a borehole geophone with two sensors placed at two different positio...

Manuale ELIOVSP - software per l'elaborazione di dati di sismica di pozzo (onde P e SH) e la loro analisi anche congiuntamente alla curva HVSR [release 2021.1]

In seismic hazard studies, the Horizontal-to-Vertical Spectral Ratio (HVSR) is nowadays routinely considered as a quick way to assess possible amplification effects. However, because of several issues that can affect the data, the HVSR cannot be considered as valid per se, and a careful data evaluation is necessary. In this study, a series of HVSR...

On the Identification of Industrial Components in the Horizontal-to-Vertical Spectral Ratio (HVSR) from Microtremors (Giancarlo Dal Moro) - Pure and Applied Geophysics (2020) Abstract In seismic hazard studies, the Horizontal-to-Vertical Spectral Ratio (HVSR) is nowadays routinely considered as a quick way to assess possible amplification effects...

Since vibration data can be recorded with the same field equipment used to collect seismic data and several national and international building codes require the identification of the eigenmodes of the existing structures, we decided to include a chapter aimed at introducing the Earth scientist/professional to vibration analysis. The chapter cannot...

The FVS (Full Velocity Spectrum) approach is a way to analyze the dispersion of surface waves recorded according to active methodologies. The goal is go beyond the classical and problematic approach based on the (interpreted) modal dispersion curves that, in some cases, can be difficult or impossible to be defined. In the classical approach, the ve...

This chapter focuses on two state-of-the-art techniques for the analysis of surface wave dispersion: HS (Holistic analysis of Surface waves) and MAAM (Miniature Array Analysis of Microtremors). HS is based on the analysis of active data recorded by a single 3-component (3C) geophone deployed at a fixed distance (offset) from the source. MAAM is a p...

This chapter discusses some points regarding two classical passive techniques more and more popular in seismic micro-zonation studies: the Horizontal-to-Vertical Spectral Ratio (HVSR) and the ESAC (Extended Spatial AutoCorrelation), a sort of “generalized” SPAC (SPatial AutoCorrelation). The influence of industrial components on the HVSR, the role...

In the final chapter are summarized a series of practical advices about the efficient acquisition of field data. A general discussion about the joint analysis of several observables is provided together with a few more comparative examples and, in the very end, a synthetic list of the main facts illustrated in the book.

This first chapter could be considered as a sort of warm up section aimed at clarifying a series of general issues that are often misunderstood or not sufficiently clear. Through a series of theoretical considerations and practical examples are illustrated a series of problems associated to the ambiguities inherently present in the data, the non-un...

In the last decades, surface wave analysis has become a standard tool for an increasingly large number of geotechnical applications that require the determination of the subsurface shear-wave velocity (Vs) profile. In the present paper, we investigate the role of a shallow stiff layer on Rayleigh and Love wave propagation. Multi-component synthetic...

Giancarlo Dal Moro - www.holisurface.com (Palmanova-UD) Federico Bridi (Altopiano della Vigolana-TN) RAPPORTO TECNICO - Kaiserjagerstrasse (Trentino Alto Adige) Determinazione del profilo Vs da analisi congiunta delle velocità di gruppo delle componenti R e T e della curva HVSR Il presente caso studio rappresenta una sorta di trait d'union tra...

Esempio di analisi congiunta degli spettri di velocità di gruppo delle componenti Z e T e del rapporto spettrale HVSR svolta tramite approccio HoliSurface (HS). La dispersione delle onde di superficie (Rayleigh e Love) è trattata secondo l'approccio FVS (Full Velocity Spectrum).

Seismic multi-component field data (vertical, radial and transversal components) described in the paper "Multi-component analysis of surface wave propagation: the magnifying effect of a thin surficial stiff layer on Love waves" (Scientific Reports - spring 2020).

Determinazione del profilo Vs dall'analisi congiunta delle velocità di gruppo delle componenti Z e R (HoliSurface®) e HVSR: caso studio con commenti

This book bridges the gap between theory and practice, showing how a detailed definition of the shear-wave velocity (VS) profile can be efficiently obtained using limited field equipment and following simple acquisition procedures. It demonstrates how surface waves (used to define the VS profile) and vibration data (used to describe the dynamic beh...

Joint analysis of the Z (vertical) and R (radial) group-velocity spectra jointly with the HVSR (Horizontal-to-Vertical Spectral Ratio) via HoliSurface® Italian and English www.holisurface.com

The knowledge of bedrock topography of glacially overdeepend Quaternary valleys provides important constraints to the layout of geological repositories for radioactive waste materials in Switzerland (Nagra, 2008). For this reason Nagra currently investigates these valleys at various locations including the Lower Aare Valley around the village of Ge...

The present study illustrates a series of technical aspects regarding the holistic acquisition and analysis of Rayleigh waves acquired by a single multi-component geophone. Compared with the common multi-channel and multi-offset active and passive methodologies, this approach requires simple and straightforward acquisition procedures and takes adva...

Surface wave propagation can be exploited to investigate subsurface conditions in terms of shear wave velocities in a number of possible applications (geotechnical site characterisation, seismic-risk assessment, crustal studies and non-destructive testing). Nowadays, one of the most common methods adopted to analyse the dispersion of surface waves...

An efficient system for the joint acquisition and analysis of multi-component active and passive seismic data is presented. It is shown how, in spite of the limited field equipment (the system requires just a 4-channel seismograph, one 3-component and four vertical-component geophones), it is nevertheless possible to define up to seven different (b...

Il libro Acquisizione e analisi di dati sismici e vibrazionali per studi di caratterizzazione sismica e geotecnica (interamente stampato a colori) illustra i principi e la pratica utili a svolgere correttamente tutte le operazioni di acquisizione e analisi dei dati sismici necessarie per la corretta definizione del profilo delle velocità di taglio...

La determinazione della vulnerabilità degli edifici passa attraverso il filtro della modellazione numerica. Il modello è, per definizione, una rappresentazione semplificata della realtà, che ci permette di descrivere in forma controllabile i fenomeni che caratterizzano un sistema complesso. L’onere computazionale è sempre da tenere in considerazion...

We present the results of 3-D monitoring of strain along active faults outcropping in the central Apennines, where recent and historical strong earthquakes occurred, using TM-71 extensometers during the period 2002–2017. We discuss the fault slip development as well as kinematics particularly in the light of local recent seismicity. The recorded fa...

It is often assumed that, in order to identify flexural and torsional vibration modes of a building, it is necessary to record synchronous data from a series of sensors deployed at different points. In the present paper, we present a simple and straightforward methodology to unambiguously identify flexural and torsional modes through the analysis o...

Rayleigh waves often propagate according to complex mode excitation so that the proper identification and separation of specific modes can be quite difficult or, in some cases, just impossible. Furthermore, the analysis of a single component (i.e., an inversion procedure based on just one objective function) necessarily prevents solving the problem...

Rayleigh wave propagation can occur according to complex mode excitation such that the interpretation of the phase or group velocity spectra can be erroneous thus leading to wrong reconstruction of the subsurface shear-wave velocity profile. In this paper, we present a case study solved by considering the holistic analysis of the Rayleigh waves rec...

Software for Surface-Wave analysis (MASW, ReMi, ESAC, MFA and RPM), modelling and inversion of Rayleigh and Love waves dispersion, analysis of Rayleigh–wave attenuation for the estimation of QS quality factors, determination of the resonance frequency from microtremor analyses (HVSR, Nakamura’s method) and modelling of the H/V spectral ratio for im...

Back-azimuth analysis is a classical method used in seismological studies for the determination of the direction (azimuth) of an otherwise-unknown seismic source. This is accomplished through the analysis of three-component (3C) data according to a procedure based on the evaluation of Rayleigh-wave polarity and is typically accomplished by assuming...

Joint Acquisition, Processing and Inversion of Passive (ESAC + HVSR) data for the determination of the vertical Vs (shear-wave velocity) profile

The paper intends to compare three different methodologies which can be used to analyze surface-wave propagation, thus eventually obtaining the vertical shear-wave velocity (Vs) profile. The three presented methods (currently still quite unconventional) are characterized by different field procedures and data processing. The first methodology is a...

Through a case study, the paper presents an example of application of surface-wave analysis for the assessment of the ground compaction process accomplished in order to stabilize a harbour bank. After briefly recalling the fundamental points characterizing the adopted technique, seismic data acquired before and after the soil compaction are analyze...

Surface waves propagate according to several modes and the dominating ones depends both on the site (the local stratigraphy), the acquisition geometry (i.e., the distance between source and receiver(s), and the considered components (Rayleigh waves have both a vertical and a radial component) and source. The way modes interlace and manifest in the...

This chapter presents the fundamental aspects related to the computation of the horizontal-to-vertical spectral ratio, especially in light of its use (and abuse) for the determination of the vertical shear-wave velocity profile. Proper data acquisition and processing are described also with respect to the evaluation of the meaningfulness of the cur...

An introduction to unconventional approaches to surface-wave analysis of complex dataset that cannot be solved via modal dispersion curve analysis: effective dispersion curves, Full Waveform inversion, and Full Velocity Spectrum inversion.

In this first chapter, we introduce basic aspects regarding surface wave generation and propagation. The comprehension of these facts will be crucial to then carry out the analysis of their dispersion (and attenuation) and, consequently, define a good subsurface model.

In this final chapter, we will consider few further facts useful to master surface-wave analysis and have a final holistic overview on the main topics and evidences illustrated in the previous chapters, thus being able to properly plan a survey and analyze the data in a way to obtain a robust and consistent subsurface model not affected or biased b...

In this chapter, the fundamental concepts of inversion and joint inversion will be introduced, also putting in evidence the conceptual relationships between (automatic) inversion and (direct) modeling.

Surface-wave analysis is nowadays widely considered for a number of goals ranging from geotechnical investigations to seismic-hazard studies. The most common approach is surely represented by the analysis of active or passive multi-channel data used to depict the phase velocity spectrum from which dispersion curves are then depicted and inverted. T...

A comprehensive seismic survey was conducted with the aim of characterising one of the Swiss Digital Seismic Network stations in northern Switzerland. Both active (P- and S-wave refraction tomography, surface-wave analysis, vertical seismic profiling) and passive methodologies (wavelet decomposition, Horizontal-to-Vertical Spectral Ratio, three-com...

Die Erdbebensicherheit eines Gebäudes bestimmt sich allgemein durch die regionale Erdbebengefährdung, den Baugrund, die Bauwerksklasse sowie durch die gebäudespezifische Tragwerksdynamik und den Tragwiderstand. Häufig wird eine Verbesserung der Erdbebensicherheit im Hochbau nur durch Verstärkung der Tragstruktur vorgenommen. Solche Massnahmen sind...

Implementation of a system (acquisition and processing procedures) aimed at determining robust near-surface 2D shear-wave velocity (Vs) sections through the multi-component joint analysis of surface waves via Full Velocity Spectra (FVS) joint inversion.

Surface wave analysis is nowadays routinely adopted for the exploration of large areas from the geotechnical point of view. This is usually accomplished by inverting the modal dispersion curves of successive shot gathers, therefore depicting the 2D subsurface structures in terms of shear-wave velocities. Such a classical approach (typically perform...

Propagation of surface waves can occur with complex energy distribution amongst the various modes. It is shown that even simple VS (shear-wave velocity) profiles can generate velocity spectra that, because of a complex mode excitation, can be quite difficult to interpret in terms of modal dispersion curves. In some cases, Rayleigh waves show releva...

Das präsentierte Mess- und Auswerteverfahren am Beispiel der Untersuchungen bei einer 700 Jährigen Klosterkirche zeigt, dass auch ohne aufwändige und kostspielige Crosshole-Tests relativ einfach belastbare Scherwellen-Geschwindigkeitsmessungen bis in über 50 m Tiefe möglich sind. Zudem ist es auch in schwer zugänglicher Umgebung anwendbar.

http://authors.elsevier.com/a/1QS48_L4yDsMBa (free access till March 2015 - courtesy of Elsevier) In order to investigate the sedimentary cover of a vast perilagoon area from the geotechnical point of view and test different possible and unconventional approaches to surface-wave analysis, a series of different acquisitions and analysis procedures...

Surface Wave Analysis for Near Surface Applications presents the foundational tools and techniques necessary to properly analyze surface-wave propagation nowadays performed for a number of applications. In the last decades, surface-wave analysis has in fact become critical to near-surface geophysics both for geotechnical goals, seismic-hazard asses...

In site characterisation studies, the unambiguous determination of the shear-wave velocity (VS) vertical profile is a crucial point often accomplished via surface-wave analysis. The determination of the dispersive properties eventually inverted for the determination of the VS vertical profile, can be performed both via active and passive methodolog...

The determination of the shear-wave velocity profile is a major request in site characterisation studies for geotechnical and seismic-hazard studies and it is often accomplished via surface-wave analysis according to Multichannel Analysis of Surface Waves (MASW). In order to overcome non-uniqueness of the solution and possible interpretative issues...

Understanding the near-surface structure of the Moon is important not only for scientific reasons, but for possible future technological applications related to mining, geotechnical activities, oxygen production etc. The Lunar regolith is represented by a layer of unconsolidated debris constituted by fine soil (average density around 1.5-1.8 gr/cm3...

Due to non-linear phenomena and coupling problems, Vibroseis acquisitions often suffer from source signal distortion that can cause a remarkable decrease of the signal-to-noise ratio. Such phenomenon can become particularly problematic when slip-sweep techniques are adopted in order to improve acquisition productivity. In such conditions harmonic d...

Joint analysis of Rayleigh- and Love-wave dispersion is performed with the aim of evaluating how their joint use can improve retrieved vertical VS profiles. In fact, non-uniqueness of the solution and complex energy distribution among different modes represent problems which, if not properly considered, can eventually lead to ambiguous or erroneous...

The paper deals with some often poorly considered aspects related to data interpretation (and inversion) and non-uniqueness of the solution while analysing seismic data according to methodologies based on surface wave propagation. Critical aspects are highlighted by presenting both synthetic and field datasets. A case study is presented with the ai...

Surface Wave (SW) dispersion and Horizontal-to-Vertical Spectral Ratio (HVSR) are known as tools able to provide possibly complementary information useful to depict the vertical shear-wave velocity profile. Their joint analysis might then be able to overcome the limits which inevitably affect such methodologies when they are singularly considered....

Rayleigh wave dispersion curves and refraction travel times are jointly inverted through a procedure based on a Multi-Objective Evolutionary Algorithm (MOEA) technique. The proposed procedure aims at improving the reconstruction of subsurface structure by exploiting the complementary information attainable by refraction seismics and surface-wave di...

Any sort of data is able to cast light only onto a specific aspect of the investigated problem. The implementation of a joint inversion scheme is meant to proficiently integrate the information that can be extracted from one dataset with those coming from another one. If the two objectives depend upon the same variables we can obtain a better-focus...

This study focuses on the integration of linear multi-fold GPR techniques and High- Resolution Seismics to study the Cheko Lake area (101 o E 62 o N). Primary objectives of the study are acoustic and electromagnetic subsurface imaging in the offshore area and in the southern coastal sector and characterization of subsurface properties of the materi...

In the framework of a land cover study of a reclamation area, a high‐resolution IKONOS scene characterized by an extremely non‐homogenous haze cover was processed in order to reduce haze and calculate some vegetation indices (VIs). Haze removal was performed by means of a technique based on the haze optimized transform (HOT). As HOT is also sensiti...

Surface wave dispersion curve inversion is a challenging problem for linear inversion procedures due to its highly non-linear nature and to the large numbers of local minima and maxima of the objective function (multi-modality). In order to improve the reliability of the inversion results, we implemented and tested a two-step inversion scheme based...

Due to the character of seismic energy generation and propagation, shallow high-resolution seismic-reflection surveys often fail in the identification of the shallowest horizons and, due to the limited offsets, accuracy of velocity analyses is often not very high.In recent years, Rayleigh wave dispersion analysis have proved to have good potential...

Rayleigh‐wave dispersion is observed every time acoustic‐impedance stratification occurs, and its analysis is suitable for vertical shear‐wave profile reconstruction. Accurate dispersion‐curve identification is essential in order to properly determine the shear‐wave velocity distribution of a medium. Data sets characterized by several events genera...

We performed an integrated Multi-Fold GPR and resistivity survey in a coastal area in the northern part of Italy (Adriatic coast) to reconstruct 3D stratigraphy to localize vadose zone and water table and to identify possible man-made structures and excavations. The spatial sampling was sufficiently dense to perform 3-D interpretation of radar data...

We performed an integrated remote-sensing and geophysical study of a sector of the Aquileia Archaeological Park (NE Italy). The objective of the study was to improve the performance of non-invasive methods in the identification of archaeological targets. We implemented an integrated methodology (IREGA) that aims at identifying micro-areas of intere...

In this study we apply multi-fold (MF) techniques to image and characterize layered sediments and rocks. We exploit macro-model dependent and independent imaging methods to achieve enhanced imaging. Depth converted time-domain RMS velocity maps and V-Z macro models provide further information about physical properties of the sediments and rocks and...

We exploit a combination of transmission and reflection Ground Penetrating Radar (GPR) techniques to characterize limestone at different scales (from sub-metric/metric to decametric). The integrated method is based on Multi-Fold (MF) GPR techniques to obtain radar response at different offsets (source-receiver separation) corresponding to different...

An overview is given of the imaging and resolution enhancement of ground-penetrating radar (GPR) multifold records from shallow, unconsolidated sediments. Results obtained on a fluvial terrace of the Isonzo River that are characterized by a complete alluvial sequence including a range of sediments and range of stratigraphic structures are discussed...

Velocity model refinement by a combination of Deregowsky and focusing techniques is an effective solution to image complex shallow subsurface conditions by means of GPR. Including geological knowledge in the velocity analysis of CRP gather considerably reduces costs and uncertainties of the final velocity model and allows rapid convergence to the c...

Non-invasive characterization of contaminated sites and brownfields is being used to support planning and correlation of sampling and in decision-making and monitoring of rehabilitation procedures. We exploit a combination of surface (linear/azimuthal multi-fold) and borehole [vertical radar profiling (VRP)] techniques for an integrated and constra...

In time-lapse analysis, we have to distinguish the seismic response changes due to oil and gas production at a reservoir over the years from several other causes, such as the recording signature and random noise. In this paper, we focus our attention on the velocity macromodel provided by seismic tomography, which is a basic tool for the data regul...

In time-lapse analysis, we have to distinguish the seismic response changes due to oil and gas production at a reservoir over the years from several other causes, such as the recording signature and random noise. In this paper, we focus our attention on the velocity macromodel provided by seismic tomography, which is a basic tool for the data regul...

Usually, in the conventional processing of marine data, the velocity variations of the sea water are not considered because their effects have no influence on the imaging reconstruction, especially at large depths; but in the time-lapse monitoring of hydrocarbon reservoirs, the velocity time-variations in the seawater should be measured and compens...