Environmental Engineering Reference
In-Depth Information
Treatment n
ame
Description
Type of check to be performed
1-a
Resin injections from the inside
Test area of 2 m
2
Type 1
1-B
Fiberglass bolting
3 bolts including their injection and
load test
2-a
Micro-seaming of blocks
5 bolts spaced differently at various
depths of 1 to 1.5
Type 2
2-B
chemical welding of smaller blocks
Test area of 1 m
2
Type 3
superficial solutions using
binders and polyurethane membranes
Test area of 2 m
2
Type 4
solutions for existing anthropic
actions
in two existing actions
the stage. in these cases the project planned surface
and isolated treatments based on paper pulp poul-
tices. as such, it was recommended to plan a treat-
ment that would cut the origin of the salts reaching
the Jameos, although this treatment was not by any
means the purpose of the project.
another limit of the treatment refers to the
edges which are already beginning to detach with
open micro-fissures greater than 50-100 µm which
cannot be treated with ethyl silicate due to very low
viscosity hindering its penetration. For these edges
the recommendable treatment is their elimination
prior to treatment by thoroughly cleaning using
compressed air. afterwards, and as an additional
measure to guarantee the effectiveness of the treat-
ment, a second cleaning is proposed once the com-
paction treatment has been carried out.
as a complementary treatment directed at
creating a film which could stabilise some edges
superficially the spraying of a liquid polyurethane
membrane was planned. in some ways this treat-
ment would aim to perform a function similar to a
very fine mesh since the largest sizes of stone will
be stable due to the serious of actions at different
levels already considered. This membrane has a
resistance to traction of approx. 3.5 MPa which
allows fixing edges which have already started
to detach or those areas in which it is necessary
to create “bridges” for micro-fissures of greater
importance of 50-100 µm.
some of these last surface treatments were
modified on site for aesthetic reasons in some cases
(shine in the polyurethane membrane) or due to
the use of replacement techniques such as hydro
demolition.
sections of each treatment along with the system-
atic supervision of the work. The following areas
were proposed for the test sections.
supervision and control actions were also recom-
mended which had to be documented and system-
ised. The supervision team (geotechnical engineer
and restorer) will be responsible for confirming on
site the treatment to be applied in each case and for
checking the final outcome of each one.
The working methodology planned was as
follows:
- Division of the auditorium into “treatment
rings” of 2 meters of treatment with a geotech-
nical survey and a photographic report of each
one using cards or a dossier. This survey was to
be detailed enough so as to enable a compari-
son to be made of the current condition and the
final one.
- on site decision regarding the treatments to be
used in each ring. in those considered systematic
there will be an indication of the ideal areas for
carrying out each one (holes, anchoring, etc).
- supervision of the execution of each ring by
carrying out a survey upon completion of work
in order to verify the effect of the treatment
applied, as well as the starting point for system-
atic maintenance during the operational phase.
- check of the inal treatment of each ring by stat-
ing whether new actions are required.
as a conclusion to this process it was planned to
create a final report on the condition of the action
in order to apply it to subsequent phases and to
each of the sections.
as auscultation measures during the work a
detailed topographical control was planned using
keystone levelling and recording convergences in
keystone and shoulders using prisms in each treat-
ment ring. likewise, in the area of the upper slab-
stratum a network of levelling reference marks
was planned with a measurement frequency every
12 hours after removing the provisional propping
of the arch.
6
RecoMMenDeD conTRol
anD sUPeRVision oF The WoRk
in The PRoJecT
The auscultation and supervision programme of
the work was proposed as part of a series of test
