In Budapest's 13th district, Hotel Astron required a 10.1m deep basement to accommodate three levels at the street front, and four levels at the back of underground parking.
Ground conditions were similar to the Elisabeth Centre, but in this case the diaphragm wall extended to 16m.
HBM jet grouted below buildings running along three sides before excavating down to the level of the uppermost slab.
Bulk excavation was painstakingly carried out through gaps left in the top slab. This was further complicated by the elaborate array of vertical load bearing steel columns plunged into the 7.9m long bored piles and intricate temporary strutting, needed because the many different property owners around the site made it impossible to gain permission to use temporary ground anchors.
Bored piles: 28, 1m diameter and 17, 1.2m diameter Diaphragm wall: 2,545m 2, up to 16m-deep Jet grouting: 320m of 'jet piles' 870m 2supporting slab 14,350m 3bulk excavation 985m 3concrete raft Three 14m deep pressure relief wells