Monitoring - Rock Mechanics Based on an Anisotropic Jointed Rock Model - page 585

Surface measuring points were arranged at anchor plates located at the berms and tied
to benchmarks at the slope's crest. The position of the benchmarks was controlled by
GPS measurements. On the heads of 24 tendons, anchor load cells were mounted (Sec-
tion 17.7). Three-point to five-point rod extensometers (Section 17.4.1) were installed in
six horizontal drillings. Thirteen further vertical drillings, 19 m to 29.5 m deep, served
for inclinometer measurements. Probe inclinometers (Section 17.4.2) measured the in-
clination along these boreholes in two orthogonal directions.
To monitor the effectiveness of the 35 to 60 m long drainage drillings, which were ar-
ranged at the intermediate and lower berm, a total of 18 drillings were equipped with
piezometers (Fig. 17.31).
The stability of the cut has been assessed on the basis of the monitoring results and the
results of back analyses of measured displacements and anchor forces (Chapter 25).