Abstract: An optimised and safe design of foundation systems for high-rise buildings in difficult soil and groundwater conditions is based on a reduction of construction material used, construction time spent, energy consumed and the adequate consideration of the soil-structure interaction. For high-rise buildings the following aspects are the basis for an environment friendly and safe design:

- adequate soil investigation
- in-situ load tests of (deep) foundation elements
- advanced foundation systems like the Combined Pile-Raft Foundation (CPRF)
- non-linear numerical simulations (e.g. Finite-Element-Method)
- observational method including in-time detection
- independent peer review (4-eye-principle)

Considering these aspects, the planning, design and construction of the highest high-rise buildings in the world have been successful, e.g. the Jeddah Tower in Jeddah in Saudi Arabia (1,007 m high), the Federation Tower in Moscow in Russia (360 m high) and the Commerzbank in Frankfurt am Main in Germany (299 m high). Figure 1 shows the three high-rise buildings.

Fig. 1. Jeddah Tower (left), Federation Tower (middle), Commerzbank (right).

Biography: Professor Dr.-Ing. Rolf Katzenbach was from 1993 until 2018 Director of the Institute and Laboratory of Geotechnics of Technische Universität Darmstadt, Germany, and is CEO of his Consulting Office "Ingenieursozietät Professor Dr.-Ing. Katzenbach GmbH". He is Past-Chairman of TC 212 Deep Foundations of the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE) and Board Member of several other international and national organizations.

He is member of the Chamber of Engineers and publicly certified official Expert of Geotechnics and Independent Checking Engineer working with his expertise for national and international courts of justice, the International Chamber of Commerce (ICC, Paris) arbitration committees, insurance companies, state ministries, building authorities and big national and international financial institutions and investors.

Professor Katzenbach is involved in a lot of national and international projects, regarding value engineering and the safety and serviceability of buildings and structures. Due to his outstanding expertise and knowledge Professor Katzenbach was appointed by the Building and Construction Authority (BCA) Singapore to carry out the independent Peer Review for the new Metro Line DLH3 in Singapore. The Kingdom of Saudi Arabia appointed Professor Katzenbach to check the safety of the foundation of the 1,007 m high Jeddah Tower (former name: Kingdom Tower) in Jeddah which is currently the highest high-rise building of the world.

Professor Katzenbach is responsible for the successful application of the Combined Pile-Raft Foundation (CPRF) at important projects all over the world and is a respected specialist for soil and rock mechanics, retaining systems, slope stability and underground constructions, including tunnels for railway lines and metro systems.