7 de juny de 2010

Informe preliminar de la Unesco: " Interim ICOMOS Mission Report For the Reactive Monitoring mission to the Sagrada Familia and Casa Milà, 6-11 February 2010"

7 junio 2010

Interim ICOMOS Mission Report
For the Reactive Monitoring mission to the Sagrada Familia and Casa Milà, 6-11 February 2010, 


Carried out by Geotechnical Expert / Prof. Dr.-Ing. Rolf Katzenbach
Checking Engineer: Technische Universität Darmstadt
Robert-Bosch-Str. 9
64293 Darmstadt • Germany

Structural Expert / Prof. Dr.-Ing. Wolfram Jäger
Checking Engineer: Technische Universität Dresden
Wichernstr. 12
01445 Radebeul • Germany

1. Subject: World Heritage Property of the Works of Gaudí
(Spain)

2. Object: Cathedral Sagrada Familia and Casa Milà,
Barcelona; potential impacts of the planned AVE
tunnel on the World Heritage Property of the works
of Antoni Gaudí

3. UNESCO decision No.: 33COM 7B.121
4. Existing Documents: See Annex 2 with documents D1.1 to D17.51
5. Required Documents: See Annex 3 with documents S.1ff., T.1ff. and P.1ff.
ICOMOS
International Council on Monuments and Sites
World Heritage Unit/ Unité du patrimoine mondial
Secretariat international
49-51, rue de la Fédération
75015 Paris

6. Short description of the The Cathedral Sagrada Familia,
The Cathedral Sagrada Familia designed by Antoni Gaudí 
is the most well known building in Barcelona.
Its construction was started in 1882 and is not yet
finished.. The Cathedral was inscribed on the World
Heritage List in 2005. The columns of the Cathedral
Sagrada Familia consist of various different materials
(stones etc.) according to the loads the columns
have to carry.
The structural loads as well as the foundation design

of the Cathedral Sagrada Familia are not well

known. According to the information given by the
Junta the loads of the Gloria Façade are 250 MN.
Parts of the Cathedral Sagrada Familia are founded
on a pile foundation down to a level of about 16,9 m

underneath the ground surface which is at a level of
ca. 30,4 s.n.m at the Calle Mallorca.
The Casa Milà (La Pedrera), consisting of 6 floors,
was constructed by Antoni Gaudí between 1906 and
1910. The Casa Milà was inscribed on the World
Heritage List in 1984..

7. Underground conditions: 
Down to a level of ca. 22 s.n.m to 26 s.n.m quaternary
fillings have been explored by soil investigation
[D15.5]. Beneath these layers in some explorations
a transition level of quaternary to tertiary soils
was investigated. They consist of sand, silt and partly
clay. Up to the depth of investigation tertiary layers
(pliocene) were discovered.
The subsoil in the depth of the AVE tunnel consists
of saturated tertiary (pliocene) sand, clay and marl
which belong to the class of so called soft soils.

8. Groundwater: The groundwater level varies 
between 12,7 s.n.m and 18,1 s.n.m according to the soil 
investigation report of INTEMAC [D15.5]. The average
groundwater level was investigated in June 2009 at a
level of about 16 s.n.m, i.e. about 14 m below the
ground surface. The groundwater level varies to the
east-southeast which results in a lower groundwater
level towards the sea.

9. Short description of the
AVE Tunnel and Protection measures

for the WH Sites: The planned AVE tunnel will connect 
the stations Sants and La Sagrera. The closed tunnel excavation
starts at km 5+262 in the North-East and runs
beneath the Calle Mallorca where it passes the Cathedral
Sagrada Familia (km 3+700). While running
underneath the Carrer de Provenca the tunnel passes
the Casa Milà (km 2+200). The closed tunnel excavation
by TBM ends at km 0+408.
The change from the Calle Mallorca to the Carrer de
Provenca along the Avinguda Diagonal is realized
by two curves with a very small radius of 350 m
which causes a reduced maximum train velocity of
70 km/h.
Passing the Cathedral Sagrada Familia the crown of
the AVE tunnel is situated at a depth of about
25,7 m. The tunnel side wall is planned to be at a
distance of 4,21 m from the pile foundation of the
Cathedral Sagrada Familia [D15.5].
The diameter of the tunnel excavation by the tunnel
boring machine is 11,52 m due to the same diameter
of the EPB shield which is 12 m long. Due to conicity
of the shield its diameter reduces to 11,49 m. The
tunnel lining consists of concrete segments with a
thickness of 0,38 m [D15.5]. The outer diameter of
the tunnel lining is 11,16 m which causes a gap, between
the soil and the tunnel lining, 0,18 m wide.
In order to protect the foundations of the Cathedral
Sagrada Familia from disturbances caused by the
tunnel excavation, a bored pile wall (protection
wall) of 233 m length with a depth of 44 m and a di-
ameter of 1,5 m is under construction at a distance
of 0,81 m from the planned AVE tunnel and 1,90 m
from the foundation of the Cathedral Sagrada Familia
(see Annex 1). The horizontal distance between
the centers of the piles is 2 m. According to
[D15.5], the construction of the piles of the bored
pile wall is being carried out under the protection of
a casing to a depth of 10 m and 12m respectively.
Below that zone the stabilisation of the boreholes is
realized by bentonite suspension during the boring
process of the piles.
The piles of the protection wall are connected by a
ridgepole with a dimension of 2,0 m by 2,0 m at a
depth of 1,0 m.
The tunnel construction process is accompanied by
an extensive monitoring program consisting of extensometer,
inclinometer, micrometer and geodetical
measurements.

10. Interim Results of the
ICOMOS Mission and
recommendations: 
I.
Up to now there do not exist any transparent and

checkable structural analysis with qualified

specifications for the
- geometry and construction epochs,
- materials used,
- type and amount of reinforcement,
- loads,
- safety factors applied and
- foundation systems
of the Cathedral Sagrada Familia and the Casa Milà.
So it is necessary that an independent structural

analysis of these World Heritage properties of the
works of Antoni Gaudí is undertaken in order to be
able to judge the permissible settlements and especially
the permissible differential settlements of the
structures, before an tunnel boring commences.


II.
The preferable solution would be to change the route

of the AVE tunnel to an area where it would not
have the potential to impact on World Heritage
properties of Antoni Gaudí. If that is not possible,
then it is necessary, following the structural analysis
outlined above, and to apply a special design in the

sense of “Disaster Prevention” against worst case

scenarios by devising
a) special technical solutions with a level higher

than conventional design procedures and
b) organisational procedures, including the presence

of independent Experts from the early

beginning of the driving of the tunnel boring

machine, due to the responsibilities arising

from WH status

III.
Up until now, the tunnel and the additional measures
have been obviously designed in accordance with
national and European standards; whether that is the
case in reality should be finally checked by independent
experts based on the relevant documents.
Such checks would include the quality of the relevant
materials, i.e. the masonry and the concrete of
the Cathedral Sagrada Familia and the Casa Milà,
through independent concrete and soil tests. There
would also be a need for an independent engineering
group to carry out sampling and soil investigation
works in-situ.
However, such a conventional design is obviously

not able to avoid with an absolute safety unforeseen
disasters and sudden collapses of structures close the

tunnel, especially during the construction process of
the tunnel using a tunnel boring machine (TBM)
even if the design fulfills all conventional standards
(Eurocode, National Codes etc.); this has been learnt
from several unforeseen and prominent disasters in
the recent past.
Reflecting on this problem and on the duty to guarantee
that there will not be any negative impact on
the World Heritage properties of the works of An-
toni Gaudí it is considered necessary with respect to
Result No. II to change the classical design methodology
and to build a fully redundant system.
A possible solution for such a redundant system is
shown in Annex 1. The designed frame, consisting
of the protection walls left and right of the AVE
tunnel and of horizontal beams (reinforced concrete
at the top, soilcrete in the deeper layers), is able to
prevent damages to the Cathedral Sagrada Familia
and the Casa Milà independent of the functionality
and serviceability of the EBP tunnel boring machine.
The gaps between the piles of the protection walls
would need to be made water-tight during the tunneling
process, for example by soil freezing.
IV.
In summary we consider that it is essential that the
following further work should be undertaken before
any tunnel boring work commences:
i) Undertake structural analysis of the World Heritage
properties of Sagrada Familia and Casa Mila
ii) Undertake independent concrete and soil tests of the
masonry and the concrete of the Cathedral Sagrada
Familia and the Casa Milà, and independent engineering
sampling and soil investigation works
Devise
a) special technical solutions with a level higher

than conventional design procedures and
b) stronger organisational procedures, including

the presence of independent Experts from the

early beginning of the driving of the tunnel

boring machine,

V.
Additionally we recommend that the final monitoring
program should be beveled and calibrated before
the TBM is passing the Cathedral. The monitoring
program will be checked by us after we have re-
ceived all required information; this includes certainly
all aspects regarding the Casa Milà.
The monitoring program should be widened by electronically
recording measurement equipment like
inductive displacement transducers. The done crack
mapping has to be completed by the crack width and
the course of the width otherwise any conservation
of evidence is impossible if the crack width is missing.

VI.
It is recommended that the tunnel driving process by

the TBM does not start until the necessary steps outlined

above are undertaken   


VII.
ICOMOS considers that in the light of the urgency
to address these issues, with respect to the programme
of works for the proposed tunnel, the matters
raised in this interim report should be considered
at a meeting with the State Party, ICOMOS and
UNESCO in advance of the final Mission report being
produced.
Such a meeting could consider the recommendations
and how they might be implemented, in order to
take all possible measures to protect the World Heritage
property. In particular it would be necessary to
consider how the necessary data could be provided,
how independent analysis, supervision and checking
might be carried out and whether special technical
and organisation procedures could be developed.


The following people contributed to this report:
Execution: Dr.-Ing. Matthias Vogler
Dipl.-Ing. Isabel M. Wagner
Dipl.-Ing. Robert Dunaevskiy
Dipl.-Ing. Matthias Seip
Dipl.-Ing. Jörg Gutwald
Dipl.-Ing. Christiane Bergmann
Arley Aristizabal Berrio B.Sc.
Dr.-Ing. Toralf Burkert
Dipl.-Ing. Peter Schöps
Prof. Dr.-Ing. Rolf Katzenbach Prof. Dr.-Ing. Wolfram Jäger
Publicly Certified Expert for
Geotechnics and Tunneling
Publicly Certified Checking Engineer
for Masonry, Concrete and Composite
Structures, Expert in Structural Rehabilitation
of Architectural Heritage
Member ISCARSAH
Annex:
- Annex 1: Cross section Cathedral Sagrada Familia 
and AVE tunnel including protection system

- Annex 2: list of existing documents

- Annex 3: list of documents that would be needed 
for further analysis and checking

Annex 1: Cross section Cathedral Sagrada Familia 
and AVE tunnel including protection system

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