TITLE:
Non-Linear Analysis of Masonry Structures Subjected to External Settlements
AUTHORS:
Stefano Galassi, Michele Paradiso, Giacomo Tempesta
KEYWORDS:
Masonry; Arches; Walls; Ruins; Settlements; Internal Distortions; Non-Linear Analysis
JOURNAL NAME:
Open Journal of Civil Engineering,
Vol.3 No.2A,
June
17,
2013
ABSTRACT:
This
article describes a methodology for the non-linear analysis of existing masonry
structures subjected to external yielding constraints, with particular
attention to the historical and cultural heritage constructions. It is well
known, indeed, that most of the arch and wall damages
are often due to settlement of abutments, in the former case, and to settlement of foundations, in the latter one. The
ability to observe and correctly analyze the cracking failure pattern, visible
on such structures, is the main “diagnostic tool” for identifying its origin:
the modification of load conditions over time, foundation settlements and
earthquakes. The objective of this work is to identify a
numeric modelling of masonry structures
(such as walls, arches, vaults, ruins) under any load condition and subjected
to inelastic settlements impressed to some external constraints. The purpose of
the numerical procedure is to interpret the behaviour of such structures in order
to assess both the peak settlement value and their specific failure mode in
correspondence to a geometry which is very often compromised. Therefore, this
procedure allows one to estimate the degree of the structures’ vulnerability,
in order to prevent any future damage, both local and global. The iterative algorithm proposed in this
article, developed in a calculation software, processes the structure
considering, not only the properties of constitutive material, non-homogeneous
and anisotropic, but also the change of the structure’s shape during the
settlements increase. In this way a non-linear analysis is performed both
materically and geometrically. Through a
direct comparison between numerical and experimental results, obtained by
testing some simple structural models in a laboratory, it was ascertained, both
from a qualitative and quantitative point of view, the correctness and the
efficacy of the proposed procedure, which will be explained below. Therefore, this numerical procedure
demonstrates to be a useful “diagnostic
tool” by which, starting from the input of the masonry structure to be studied and
simulating a presumable event, one can trace the source of the causes that have
generated a certain failure, comparing the cracking pattern of real structure
with that plotted by the software.