Design and construction of the shoring for the underground parking lots of the Courts of Justice of Concepción

Abstract

Geotechnical conditions of the soil for an uderground parking project of ho levels are described. The project is located in the center of the city of Concepción and the total parking area to be built was 10423 m2 The excavation support design has to avoid any damage of the historic building Tribunals of Justice and the surrounding buildings, which have between four and nine floors. In addition, another building next 10 the parking project is classified as a historical building too. Any interference with facilities and services such as water, sewage, gas and electricity had to be avoided. For the 8.1 m depth excavation the retaining solution adopted was an anchored soldier pile wall, where the soldier piles (H section steel piles) were driven into semi dense sand. Two lines of anchors were designed separated vertically and horizontally 3 m and 3.2 m respectively. The design loads for the anchors were calculated between 300 and 520 KN. In particular, the anchors installation and placement were studied in order to not disturb the different stages of construction. The project included 3596 m2 of anchored soldier pile wall with 314 post-stressed anchors and 300 soldier piles totalling 3200 m. 1t can be concluded that the temporary retaining solution adopted performed adequately.