FOR 1136:  Simulation of Geotechnical Construction Processes with Holistic Consideration of Constitutive Lows in Soils

• Subject Area: Construction Engineering and Architecture
• Term: from 2009 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 76838227

Construction in urban environment requires frequently excavation pits. The shoring of these pits have to be constructed in such a manner that its serviceability and the respective of the nearby structures are assured. Within the Research Unit it is expected to consider the overall changes of the soil conditions throughout the entire process of one or of diverse geotechnical construction processes using non-linear, robust, realistic and modern constitutive laws for soils and powerful, stable numerical modelling strategies for the geotechnical problems associated with.
Due to the fact that geotechnical methods and construction processes are diverse and manifold, the intention of the Research Unit is not to consider all possible variations of those construction processes. Furthermore, the Research Unit will concentrate the efforts on selected geotechnical problems. For the description of the selected processes it is, on one hand, necessary to implement static, cyclic and dynamic simulation strategies and, on the other hand, the soil has to be regarded as a mixture of grain skeleton with water and air contents. Besides of these fundamental considerations are also further effects related to the contact between soil and structure, which have to be taken into account. Some of the fundamental questions to be answered are: (1) Is there any significant influence of the construction process on the design of the elements to be installed or on the serviceability of already nearby existing structures? If so, under which conditions are these influences significant and in which simplified manner can these be implemented in the design process? (2) May existing constitutive laws be improved for a realistic description of repeated loading and unloading? (3) Can the dynamic installation of piles (installation by vibration or dynamic impact) and the holistic consideration of the stress-strain paths throughout the entire construction process in soil be analysed with a dynamic coupling of the solid and fluid material phases according to the p-u or u-p-U-formulation in order to obtain realistic results? How can the numerical stability of the chosen algorithms and methods be obtained? The answer of the above and further questions are the scope of work of the Research Unit.

• DFG Programme: Research Units

Projects

• Central project of the researchers group FOR 1136 with demonstrator experiments (Applicant Triantafyllidis, Theodoros )
• Contact models and -discretizations for dry and saturated soils within dynamical applications (Applicant Wriggers, Peter )
• Dynamic Loading of Partially-Saturated Soil: an investigation in the framework of numerical mechanics of strongly coupled problems (Applicant Ehlers, Wolfgang )
• Incremental stress-strain-behaviour of sand at low-cycle loading and application on excavation models (Applicant Hettler, Achim )
• Neo-Hypoplasticity (Applicant Niemunis, Andrzej )
• Numerical modeling of vibro-injection pile installation (Applicant Savidis, Stavros A. )
• Soil deformations close to retaining walls due to vibration excitations (Applicant Triantafyllidis, Theodoros )

• Spokesperson: Professor Dr.-Ing. Theodoros Triantafyllidis