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ROADS & MOTORWAYS
Certaldo
Variant of State Highway S.S. 429 "Val
d’Elsa"
:
Section
Poggibonsi -
Empoli - Italy
Client:
ANAS (State Highway Authority) – Department of Tuscany
Services: Detailed
design and environmental impact assessment
Period: 1999-2000
Construction cost:
€
72,820,422
The Project:
Detailed design and environmental impact assessment study in
relation to the new section of the state highway SS 429 of the
«Val d’Elsa». The new alignment, which connects the two Tuscan
towns of Poggibonsi and Empoli, lies within the municipal
area of Certaldo and is known as the « Certaldo variant ».
The project entrusted to Technital by ANAS consists in the
detailed design and environmental impact assessment of the
variant alignment for the SS 429 between the towns of
Poggibonsi and Empoli in the municipal area of Certaldo.
In the central part of the alignment, the true variant, which
runs south-north for some 5 km west of the town of Certaldo
several major structures are foreseen, including three tunnels
(for a total of over 1800 m) and four viaducts with
steel-concrete decks.
The other two parts of the alignment consit in the connections
to the existing road. These are achieved eastward (at the
southern end of the variant), by means of a roundabout feeding
off to two provincial roads (to San Gimignano and Piano d’Elsa)
as well as to the existing SS 429 to Poggibonsi, and westward
(at the northern end) exploiting and widening the existing
municipal road of Pian di Sotto to rejoin the existing
highway.
Since the project area is subject to flooding by the river
Elsa, various techniques have been adopted to protect the
road :
-
protection of the road embankments against erosion for a
height of 1.50 m,
-
design height of the roadway 2.50 m above the level of the
surrounding land
-
placement of culverts (diameter = 1500 mm) at 50 m intervals
to allow the runoff of the floodwaters.
The environmental impact study led to the inclusion in the
design of measures to counteract the acoustic and atmospheric
pollution. These include the use of natural barriers
consisting of trees and shrubs to absorb both noise and the
atmospheric pollution of the industrial area.
The negative impacts of the road on the environment will be
reduced by the masking effect of trees and shrubs planted
along the alignment and by landscaping works at the
interchanges (with lawns, groups of trees and shrubs) and by
planting vegetation along the embankments. These works will
not only mitigate the visual impact of the road but also
favour spontaneous colonisation by both flora and fauna.
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