In a river valley with extremely steep slopes a 160 m high and about 1.7 km long Motorway bridge is to be built. By the use of the observational method, relevant downhill orientated slope displacements have been detected with inclinometers. To secure the overall stability of the bridge piers and of the slope challenging stabilization measures become necessary. Due to the extremely complicated local conditions a new technical method for slope stabilization has been developed. Therefore about 45 m deep shafts with a diameter of 6.6 m are constructed. For the load transfer the shafts are connected with a 4.2 m x 6.3 m thick and 32 m long strongly reinforced head board and tied back with up to 55 m long permanent anchors. This new developed slope stabilization construction will be used in combination with permanent groundwater lowering. To analyse the applicability of the construction, a nonlinear 3D-Finite-Element-Model of the steep slope with the anchored shafts was developed and a parameter study has been conducted.
In this paper the risk analysis, the risk assessment and the new developed slope stabilization scheme using the anchored shafts as well as the 3D-FE-Analysis will be described in detail.
Subjects: Natural Hazards, Slope Stability, Observational Method, Landslides
Author: Professor Dr.-Ing. Rolf Katzenbach and Dipl.-Ing. Christiane Bergmann
Publisher: DFI