Type of work

Hydraulic works

Franca de Xira

Portugal

Implementation of the adductor of Vila Franca de Xira / Telheiras - Recovery of stretches of 2 and 3

Implementation of the adductor of Vila Franca de Xira / Telheiras - Recovery of stretches of 2 and 3

Description

This project aims to recover 2 sections, belonging to the Vila Franca de Xira Aductor - Telheiras, identified as:

  • Section of 2 slopes of the Bairro da Mata and the Alhandra Tunnel;
  • Section 3-Slope of São João dos Montes;

SECTION 2-SIDE OF THE BAIRRO DA MATA AND ALHANDRA TUNNEL

This section has a total length of 1,600 m divided into 1,380 m to be developed within a gallery and 220m in an open conduit supported by concrete blocks.

This section currently suffers from two types of pathologies, one at the level of concrete degradation (tunnel lining and foundations) and another at the level of corrosion existing in the DN 1500 mm steel pipe.
We highlight the following main activities to develop in Section 2:
 

Inside the Alhandra tunnel:

  • Repair and painting of the conduit steel pipe, inside the tunnel;
  • Replacement of accessories;
  • Rehabilitation of the concrete lining structure of the gallery, solid and slab filling;
  • Waterproofing and drainage of the gallery;

Slope of the Bairro da Mata:

  • Replacement of accessories and repair and exterior painting of the pipe.
  • Rehabilitation of 3 boxes (Box 56, 57 and 58);
  • Implementation of a sectioning valve box upstream of the tunnel;
  • Demolition and reconstruction of the retaining wall of the existing land, with structural reinforcement of foundations with the execution of micropiles.

SECTION 3-SÃO JOÃO DOS MONTES STREET:

This section has a total length of 620m, currently consisting of a DN 1500 mm conduit in prestressed reinforced concrete. The duct crosses two differentiated zones, a gutter zone (with a visible part and another buried) and a buried duct zone. The stabilization of the gutter is ensured through anchors.
However, due to the pathologies that the concrete pipe presents (reduction of coating, efflorescence, oxidation) and the instability of the land in the area of ​​the ditch due to the slope of the slope on which it is located, greater than 20%, the The project considered the replacement of the existing pipeline and the passive stabilization of slopes using micropiles.

Highlights

We highlight the following main activities to develop in Section 3:

  • Removal of slabs from the gutter cover, length 300 m;
  • Opening and lining of a trench in the buried section of about 300 m;
  • Removal of the entire existing reinforced concrete conduit, length of 600 m;
  • Repair of reinforced concrete in the gutter;
  • Supply and application of DN 1,500 steel pipe, in an extension of 600 m;
  • Reinforcement of the gutter foundations with micropiles;
  • Rehabilitation of boxes (Boxes 60,61,62,63,65 and 66);
  • Demolition of Cx.64;
  • Replacement of all existing steel equipment and accessories in Boxes 65 and 66 (Dn1200 disassembly valve and gasket).