Open pit protection – Hotel Plat, Dubrovnik
The site is located in the area of today’s hotel complex Plat in Župa Dubrovacka, on the mild peninsula of Plat, on the eastern coast of the spacious bay, situated between the main road and the sea. For the construction of the new hotel Sensatori, which is being built by reconstruction of the existing Hotel Ambasador within the existing Plat complex, a construction pit of a maximum height of about 30.0 m is planned, whose bottom will reach about +20.00 m above sea level. The hotel building has 242 accommodation units. The terrain is mostly made of breccia and marl, and along their contact, it is occasionally seated on clay gray to darker gray color and clay yellow to brown. Sides and bottom of the construction pit and part of the foundation of the building will be in clay and marl, but also in the breccia, which should be considered when designing and performing.
The upper part of the construction pit will be provided by installing rods of self-drying anchor length L = 6.0, 9.0 and 12.0 m on, shotcrete in two layers with reinforcing mesh. For the purpose of water drainage, a minimum diameter of 50.0 mm, length L = 2.0 m, is required. The lower part of the construction pit will be provided by the execution of a pilot rock of reinforced concrete drilled piles with nominal diameter D = 1200.0 mm, length L = 15.0 and 20.0 m and installation of geotechnical anchors and shotcrete in two layers with reinforcing mesh. For the drainage of water, the cut of the least diameter of 50,0 mm, length L = 2,0 m and of self-drying drainage length L = 12,0 m is foreseen. For the need to transfer seismic forces from the structure to the ground floor, anchoring beam, geotechnical anchors, and self-drilling anchors are provided.