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Engineering Projects: Excavació Nova Seu del Consell General

Geology and geotechnical


Andorra la Vella (Principat d'Andorra)

Date: 2004-2007
Excavació Nova Seu del Consell General, Engineering (Principality of Andorra)

Excavació Nova Seu del Consell General

This project is about the excavation and stabilization that were performed for the construction of the new seat of the Parliament of Andorra.
The excavation was carried out over a rocky substrate consists of granodiorites in the majority of its entire surface, as well as compact material and some metamorphic rocks.

The excavation in the plot involved the removal of a volume of 41,000 m3 of rock with mechanical means and blasting and the compact material.

There was made a micro screen piles and a support wall along Molines chalet house.

There were placed temporary anchors MKY type 9 meters with a density of 6.25 m2 tensioned to 65.2 tons, north-facing slopes south.

There were placed gewi type bolts or similar with a grade of steel from 500 to 550 N/mm2 with a diameter of 32 mm and a length of 6 meters.

There were placed temporary anchors gewi type quality steel with a 500 to 550 N/mm2 with a diameter of 32 mm and a length of 8 meters.

Phases d'excavation:

Phase 1: Perform column micro piles, in the areas that you can work without removing the underpinning beams of the wall and then build a short shotcrete wall.

Beams were removed and micro piles were completed and the wall of Casa Molines.

Phase 2: Three teams were worked simultaneously respecting the area near the prison on both platforms located on the north side. Two teams were on the upper platform and one team was on the lower platform.

Phase 3: The stabilization of the slope was made simultaneously with the execution of excavation works.

The anchors were run by benches unable to continue lowering the level of excavation without stabilizing the upper level.

Phase 4: Demolition of part of the prison and the walls and the infrastructures in the area and the excavation of the southwest.