The execution of deep basement excavations under narrow conditions is one of the most challenging
tasks in geotechnics. The vicinity of neighbouring buildings, roads, and underground structures such as
sewers or power lines, quite often prohibits the application of standard solutions. In addition, legal
considerations in the use of adjacent properties is becoming increasingly difficult. This paper will
present some innovative approaches to overcome the above-mentioned challenges based on several case
studies from central Europe. For every project the design approach as well as the techniques used for
execution will be explained, detailing both the advantages and the limitations of the applications. One
case study shows a deep basement excavation (approx. 17m) in the centre of Prague, Czech Republic.
This project featured many challenging boundary conditions (narrow construction area, high ground
water table, jet grouting column embedment into bedrock, constraints regarding use of ground anchors
due to property rights, etc). The realisation of the complex design is described and illustrated in detail.
Other case studies will show the combined application of bored piles with jet grouting and also explain
the design of vertical prestressed anchors for retaining walls.
Subjects: innovative, deep excavation, boundary conditions
Author: Dr. Alexander Zöhrer and Clifford Taylor
Publisher: DFI and PFSF