Publication Date:
2021-09-08
Description:
Soil liquefaction can result in significant settlement and reduction of
load-bearing capacity. Moreover, the generation of pore pressure during
an earthquake and its post-seismic dissipation can generate permanent
deformations and settlements. The quantitative evaluation of
post-liquefaction settlements is of extreme importance for engineering
purposes, i.e. for earthquake-resistant design of new buildings and
safety evaluation of existing ones. Quantifying the extent of these
phenomena is, however, rather difficult. Uncertainties arise from the
stochastic nature of the earthquake loading, from the simplifications
of soil models, and from the difficulty in establishing correlations between
the pre-earthquake soil state and the post-seismic deformations.
Field scale liquefaction tests, under controlled conditions, are therefore
important for a correct quantification of these phenomena. Recent experiences
(e.g. New Zealand, United States) show that liquefaction
can be induced and monitored with field scale blast tests to study the
related effects on soil geotechnical properties. Within this framework
this paper introduces the preliminary results obtained from a research
project on blast-induced liquefaction at field scale. Tests were performed
at a trial site located in Mirabello (Ferrara, Italy), a village
strongly affected by liquefaction phenomena during the 2012 Emilia
Romagna earthquake. Invasive tests, such as piezocone, seismic dilatometer
and down-hole tests, and non-invasive tests were carried out
before and after the execution of two blast test sequences to study the variation in physical properties of the soils. Pore pressure transducers,
settlement profilometers and accelerometers were installed with the objective
of measuring, during and after the detonations, the generation
and subsequent dissipation of the pore pressure, the vertical deformations,
and the blast-induced ground motions respectively. Variations
in load distribution on deep foundations due to soil liquefaction were
also evaluated on a test micropile instrumented with a strain gauge
array. Topographical surveys were carried out to measure ground surface
settlements. Laboratory tests and trenches also provided increased
understanding of the site characteristics.
Description:
Published
Description:
S0556
Description:
4T. Sismologia, geofisica e geologia per l'ingegneria sismica
Description:
5T. Modelli di pericolosità sismica e da maremoto
Description:
JCR Journal
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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