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INTEGRATED METHODOLOGIES OF REPRESENTATION AND ANALYSIS OF A GREAT
MONUMENTAL STRUCTURE: SAN LORENZO MAGGIORE IN MILAN
C. Achille, S. Bozic*, R. Brumana, L. Fregonese, C. Monti, G. Monti*, C. Savi, R. Virgilio*
DIIAR, Civil and Environmental faculty, Politecnico di Milano, piazza L. Da Vinci, 32 - 20133 Milan
CIPA 2003: XIX th International Symposium - Antalya, Turkey, 30 September - 4 October
KEY WORDS: cultural heritage, survey, laser scanner, modelling, orthorectification, GIS.
ABSTRACT: San Lorenzo Maggiore in Milan: advanced survey.
San Lorenzo is a paleochristian Basilica which consists of a central tetraconical body with connected chapels. It is subject
to a series of stratigraphic, material and historical analysis to establish the dating of every part of it. The entire work is
based on a complete surveying system with the aid of the most update instruments.
This implies the planning of maps, sections, and orthophotos with the use of digital cameras, laser scanners and no
prism theodolites together with the implementation of data in a GIS.
1. MANUSCRIPT
1.1 Introduction
The Basilica of San Lorenzo Maggiore can be
considered an extract of history and a chronological
story of constructive techniques of Milan because it
represents a sort of stratified "deposit" of 1600 years
of yard activity, from its foundation occurred in late-
ancient ages to the Medieval and late-Renaissance
reconstructions, until the interventions of restoration in
the XIX and XX century.
In the Laurentian complex, from the end of the IV
century, up to the middle of the XIX century,
interventions of construction, modification,
maintenance, reconstruction and also important
enlargements for the use, have stratified.
The architectonic literature considers it one of the most
extraordinary structures of the western Mediterranean
area because it is a very articulate aggregate of
buildings, without a stylistic unity and still of difficult
interpretation and comprehension.
With the restoration yard there was the occasion to
lead a work of metric and archaeological knowledge,
with the aim to finally verify the foundation date of the
different parts of the building, the paternity of the
commission, causes and entity of the breakdowns
occurred in Medieval and Modern ages, the systems of
plans and elevation layouts linked to the dynamics of
the old yards.
The problem of the original destination has recently
been tackled with the help of the absolute dating led
with radiocarbon 14 and thermoluminescence.
Researches have allowed to set the original nucleus of
the structure to the years following the death of
Sant'Ambrogio and the emperor Teodosio, in the period
dominated by the general Stilicone, temporary regent
of the Roman Empire.
The new archaeometrical dating together with data
already known in the past has permitted to reject
previous hypothesis and in particular the ones of Aryan
church, Palatine chapel or Basilica Porziana.
The Laurentian complex constitutes the part of a
magnificent project of memorial dynastic architecture, a
heroon mausoleum designated to the new family of
Teodosii, expression of the new politic power of the city
of Milan, capital of the Roman Empire.
The private financial support has permitted the use of
leading methodologies in the survey and
archaeometrical fields (absolute dating and material
characterization).
The complexity and the quantity of data collected will
lead to the editing of an informative system that will
include data and their correlation in function of more
parameters.
1.2 Survey and knowledge
Discussing about survey implies the knowing
quantitatively the Architecture, claims understanding
the meaning of knowing.
We can speak of knowledge in general, but we can also
concentrate on what a cognitive progress expresses in
research, conceived as the approach to a pre-
established purpose, for example the knowledge of the
architecture through its measurement (survey), its
representation (views, vertical and horizontal sections),
its analysis (the archaeometrical,materials..).
What we ideally pretend from science through
knowledge is a precise representation-description of the
fundamental aspects of reality, deeply connected
between themselves. Knowledge passes through
different stages of analysis, waiting for a synthesis that
only rarely comes true. San Lorenzo is a typical
example of different doctrines converging to achieve an
analysis that leads to an explicative synthesis of the
different aspects of the Basilica.
Nevertheless the goal of the knowledge of the Basilica
in its material, historic, geometric... aspects reaches a
high level, that further knowledge developments could
even elevate, giving for uncertain what was given for
sure.
The survey progress is underlined by the reduction of
the uncertainty of measurements.
Even during Galileo's times these measurements had
much bigger uncertainties than today, but the
measured quantities were also less.
In San Lorenzo it is clear how the increasing number of
measures and the reduction of uncertainties about the
coordinates of points, due to the use of new
* Sandra Bozic, email, sandrabozic@hotmail.com
Giada Monti, email, giada.monti@polimi.it
’ Roberta Virgilio, email: pebs@softhome.net
