Monitoring of the vibration induced on the Arno masonry embankment wall by the conservation works after the May 25, 2016 riverbank landslide

Abstract

Background: The concepts of disaster risk reduction and disaster risk management involve the development, improvement, and application of policies, strategies, and practices to minimize disaster risks throughout society. Nowadays, preserving architectural heritage and ancient monuments from disasters is an important issue in the cultural life of modern societies. The "health" of a building/structure may be evaluate by its deterioration or damage level: monitor the aging and promptly detect relevant damages, play a central role, and structure dynamic characterization and microtremor analysis are considered powerful techniques in this field. A wide bibliography about structures/ buildings seismic dynamic characterization is counterpoised to a missing one about their seismic response during conservation/safety works. This paper focus on the seismic response and monitoring of a historical masonry embankment wall during the conservation works carried out after a riverbank landslide that seriously damaged it. Results: The H/V results of the acquired traces show that main resonance frequency of the masonry embankment wall is between 4 Hz and 15 Hz, in agreement with the frequency range of roughly 10-meters-high, squat and monolithic structure. The whole monitoring period can be divided into three intervals corresponding to three different kind of workings: i) piling work; ii) parapet breakdown, excavation, embankment arrangement and foot wall consolidation; iii) backfill and restoring of the original condition, ordinary construction activities. The maximum peak component particle velocity substantial increase during the second period. All the stations have a higher energy content in the 10-20 Hz frequency range, but the spectra analysis clearly shows that the NS component, perpendicular to the wall, is the most stressed one. Moreover, despite the considerable distance from the August 24 Central Italy earthquake epicentre, the earthquake waveform is clearly recognizable at each station. In fact, the energy is focused around 2 Hz and the signals show directivity neither for the spectrum nor for the H/V. Conclusion: This work may contribute to characterize the vibrations induced by piling work at close range, and help to define the maximum acceptable vibration pattern for such structures, since literature is missing of such case studies. The maximum peak component particle velocity values clearly showed the work advancement. This paper also shows how the H/V technique is a valuable method to estimate the resonant frequency not only of buildings, but also of a squat and monolithic structure like the Lungarno Torrigiani masonry embankment wall.

Assessing subsoil void hazards along a road system using H/V measurements, ERTs and IPTs to support local decision makers

“…Moreover, the porosity and soil density values reported in the literature (Reynolds ) were used to obtain the profile that best fit the experimental data. Additionally, the directionalities of each spectral peak (Del Gaudio et al ; Pazzi et al ) were calculated by means of the same software. As shown in Pazzi et al.…”

“…Moreover, the porosity and soil density values reported in the literature (Reynolds 2011) were used to obtain the V s profile that best fit the experimental data. Additionally, the directionalities of each spectral peak (Del Gaudio et al 2008;Pazzi et al 2017a) were calculated by means of the same software. As shown in Pazzi et al (2017b) and the reference therein, the dataset of the deepest impedance contrast depths and amplitudes was spatially interpolated in a GIS environment using the IDW geostatistical method to generate the thickness and peak amplitude maps.…”

A Sensor Network with Embedded Data Processing and Data-to-Cloud Capabilities for Vibration-Based Real-Time SHM

“…Among the variety of monitoring approaches, techniques based on the changes of structural natural frequencies and modes shapes have been largely investigated and adopted in the civil engineering field spanning from historical buildings [2][3][4][5] to more modern long-span bridges [6][7][8][9]. The continuous analysis of vibration features, in fact, can provide extremely useful information about possible changes in the structural properties and in turn on the overall state of the structure.…”

Kinematic Reconstruction of a Deep-Seated Gravitational Slope Deformation by Geomorphic Analyses

“…Geosciences 2018, 8,26 4 of 24 related structural constraint contributed to develop the current amphitheatre shape of the DSGSD and influenced the deformational character of the entire slope. On the basis of the geomorphological analysis, the whole DSGSD can be divided into two main zones ( Figure 1A): (i) an upper detachment sector (mean slope of approximately 30°), which develops large extensional forms that reduce the average slope inclinations, and (ii) a lower dismantling or bulging sector (mean angle of approximately 34°) that includes high-angle slopes with compressive arched forms [15].…”

“…Therefore, advanced remote sensing methodologies that are chiefly based on satellite, aerial and terrestrial technologies have gained widespread recognition as efficient tools for characterizing and monitoring landslide-affected areas in terms of resolution, accuracy, data visualization, management, and reproducibility [14,[23][24][25][26]. Among all the terrestrial and aerial remote sensing technologies applied in landslide analysis, those that are more effective for DSGSD studies are ground-based interferometric radar (GB-InSAR, [21,24,25,27]), and light detection and ranging (LiDAR, [19,28]).…”