Ba-Phu Nguyen

Project title: Investigation of soil-foundation interaction behaviour in sensitive soft soil considering installation effects

Host Institution: Technical University of Munich (TUM)

Host Supervisor: Prof. Roberto Cudmani

Co-host Institution: Technical University of Denmark (DTU)

Co-host Supervisor: Prof. Irene Rocchi

Summary project: The installation of foundations and ground improvement systems can alter soil properties (e.g., soil structure, permeability and stiffness) and stress distribution, affecting their soil-structure interaction and the entire bearing capacity. The installation effects of foundation systems are considerable for sensitive soft soil which is often found in the lake and marine deposits (e.g., Starnberg, Lindau and around Rosenheim in Germany). Although this topic is very important as it can significantly affect the quality of designs and sustainability in construction, it has not received appropriate attention in the past years. This research proposal aims to investigate performance of several foundation types (i.e., gravel columns, micro piles, atlas piles, controlled modulus columns, reinforced concrete piles and shallow foundation) on the thick soft deposits considering the soil disturbance due to their installation. This includes the following tasks: (1) investigate changes in key properties of sensitive soft soil namely physical, hydraulic conductivity, shear strength, compressibility, anisotropic, small strain stiffness in the laboratory and in situ; (2) analyse valuable monitoring data from field tests for various foundations and soil improvement at a location with the same subsoil and test conditions; (3) examination of the suitability of existing advanced material models for describing the behaviour of soil-foundation interaction in soft soil; (4) develop and validate a numerical model to predict the foundation behaviour in sensitive soft soil considering the effects of installation. Based on the results from experiment, field data, numerical investigations, recommendations can be drawn for the soil investigation and practical foundation design.