Four (4) different shoring systems of Zorlu Levent Project with 20 m to 27 m excavation depth were designed by KASKTAŞ. In order to perform the excavation in dry condition and safely without causing any hazard to surrounding structures and roads; topographic properties of project site and soil conditions consisted of available artificial fill layer, weathered greywacke and fissured claystone were taken into account for design. The structure had a footprint area of 11,300 m² and the dimensions of the excavation pit in the plan were 260 m x 43 m.
Inclinometers and optic reading points were placed for deformation control. Since there was a reinforced concrete retaining wall from the previous works at north side of site, deformations on this region were controlled by optical readings. Shoring system was verified by comparing calculated and measured deformations for 4 different sides during excavation.
- This deep excavation work with a maximum depth of 27 m in the city center was completed safely without damaging the surrounding structures and roads. It was observed that the calculated and measured deformations in the design phase were quite compatible with each other
- All these different shoring systems designed for this deep excavation project in Istanbul greywacke were observed the expected performance as a result of quality control studies.