ABSTRACT
The evaluation of construction processes regarding environmental aspects is becoming more important and is of particular interest for the construction business. An evaluation method for stone columns using vibro replacement technique (VRSC) and dynamic compaction with execution of large stone pillars, called dynamic replacement (DR), is presented. The analysis includes both technical and environmental criteria. Life cycle assessment (LCA) is used to evaluate the environmental criteria. The global warming potential (GWP) is considered as relevant indicator because of its informative value regarding climate change. The result of the two analysed ground improvement methods considered here are columns consisting of granular material. With DR an additional improvement can be obtained in the underlying layers through the transmission of the energy of the weight at depth. The results of a logistic centre case study show advantages of DR in terms of environmental impact. With the defined maximum settlement of 1.5 cm, the DR pillars can save approx. 60 % of the GWP compared to the VRSC technique. If larger settlements are allowed, the environmental impacts of both methods can be further reduced. In the future, this decision will have to be made by the investors. In the present example of a so-called “positive footprint building”, the multiobjective optimisation for the ground improvement is carried out with the criteria of minimising the settlement as well as the GWP to reach both targets.
