Deep excavation solutions in an urban environment - Distrikt residential project, Lisbon
Deep excavation solutions in an urban environment - Distrikt residential project, Lisbon
This paper describes the main design and execution criteria adopted for the peripheral earth retaining solutions, required for the construction of three underground floors for the Distrikt Residential Buildings, located in the south of Parque das Nações, in Lisbon. The excavation, with 11 m of maximum depth, mainly intersected landfill layers and Lisbon Miocene soils (Areolas do Cabo Ruivo e Areolas do Braço de Prata). The excavation site is confined by several underground infrastructures, which are mostly inside a technical gallery, close to the excavation pit boundaries. It is also noteworthy the proximity to two buildings with several basements, as well as the possibility that the excavation can coexist with the construction of an underground car park, under Rua Mário Botas. To minimize the ground disturbance, as well as the deformations of the mentioned structures, a reinforced concrete bored pile wall with 600mm diameter was defined, braced in general by steel props and temporary ground anchors. In the elevations where the neighbourhood conditions didn’t allow the execution of ground anchors, the retaining wall was braced by concrete slab’s strips, which were connected to pile buttresses and supported by HEB200 micropiles. The main results of the monitoring plan are drawn and presented, including the analyses and comparison with the estimated values from the design phase.