Geotechnical field measurements applied to a 240 m high office tower constructed by top/down methods in Frankfurt Clay

摘要

The design and construction of deep excavations and heavily loaded foundations in urban environment is a very demanding geotechnical task which has always to be accompanied by a consequent application of the observational method. On the example of the MAIN TOWER-project the specification and implementation of a large-scale geotechnical and geodetic field measurement program is presented. The MAIN TOWER is a new office tower with a total height of 240 m and five basement levels. The deisgn of the 21 m ddep excavation and the foundation in the high plastic Frankfurt Clay bases on a modified top/down construction in conjunction with a piled raft. All construction activities for the excavation and the foundation as well as the longterm safety of the tower have been carefully monitored with about 1.000 sensors installed in the supporting system, the piled raft and in the soil. All sensors are linked to an automatically operating monitoring network.