CEE Graduate Seminar - Ocotober 30! Dr. Steffern Leppla

Steffen Leppla, PhD Professor for Geotechnics Frankfurt University of Applied Sciences, Germany Project Leader and Scientific Consultant at Ingenieursozietaet Friday, October 30, 2026 10:00 am 319 Benedum Hall "Theoretical basics and application in engineering practice of the Combined Pile-Raft Foundation (CPRF)" Abstract: Depending on the boundary conditions, superstructures are founded on three possible foun-dation systems: raft foundation, classic pile foundation, or the Combined Pile-Raft Foundation (CPRF). In many cases the CPRF is the most efficient foundation system regarding technical, economic and environmental aspects. The target is to save material resources, money and con-struction time and to minimize the emission of greenhouse gas CO2. A CPRF combines the bear-ing capacity of the foundation raft and the bearing capacity of the piles. The regulations for the design of a CPRF are given in the International CPRF-Guideline which is published by the Inter-national Society for Soil Mechanics and Geotechnical Engineering (ISSMGE). For the design of a CPRF numerical simulations using the Finite-Element-Method (FEM) are useful. The simula-tions have to consider the initial stress state of the soil, the non-linear load-deformation be-havior of the soil and all stages of the construction time and of the service time of the structure. The contribution explains the theoretical basics of the CPRF, the design and safety concept and the application in engineering practice by several examples for high-rise structures and for en-gineering structures like street and railway bridges. The examples show the savings of material, money, time and CO2 without neglecting the requirements on the stability and the serviceabil-ity. Biographical Sketch: Prof. Dr.-Ing. Steffen Leppla, born 1979, studied civil engineering in Frankfurt am Main and in Darmstadt, Germany. From 2007 to 2017 he was a scientific research assistant at the Institute and Laboratory of Geotechnics of