First Sections of Variante di Valico to Open SoonThe upgrading project of the Apennine section between Sasso Marconi and Barberino di Mugello, first designed in 1993 and revised in 1999, goes from chainage 199+520 to chainage 255+593. The variante di valico bypass itself is a new route that will reduce the altimetric difference by about 40% with respect to the present alignment. For further information, click here, here, it/21 and visit www.osservatoriovariantedivalico.itContracts 1 and 2Between 17th June and 9th July, 2006 the first structures of the road bypass will open: the Sasso Marconi junction connecting with the new toll plaza replacing the ongoing toll booth and the north and south roadways through the Monte Mario tunnel.Contracts 3 and 4The structures built as part of these contracts should open by the summer. One of the structures within contract 4 (section Sasso Marconi-La Quercia) is the Gardeletta artificial tunnel (840 m), a twin tube structure built by Tensiter. GP 16-type prefabricated articulated elements mounted on walls have been used. Its width is 16.05 m.The nominal concrete strength of the prefabricated elements is 40 MPa, the nominal concrete strength of the cast seals between the prefabricated parts is 35 Mpa, while the nominal concrete strength of the other seals of the structure (slab and interstices between the upper prefabricated elements on the walls and the slab) is 30 MPa. FeB44K-type steel reinforcements with improved adhesion have been used.The main technical characteristics of this prefabricated structure are the covering slab, designed to handle first category loads, with cover and paving up to 3 m to 8 m above, according to the width; the inside width that can vary from 8 m to 25 m, without intermediate supports; and the consistency of the temporary supporting walls at the face designed to withstand an inside friction angle of 33°, a specific ground weight of 1.8 t/cu m and a maximum overload of the ground surrounding the walls of 1 t/sq m. Visit www.tensiter.it/A_Gardelletta/pag_Gardelletta2.htm 23/06.