Examples of Testing and Monitoring Programs - Rock Mechanics Based on an Anisotropic Jointed Rock Model - page 607

19 Examples of Testing and Monitoring Programs

19.1 Introduction

The setup of a testing and monitoring program for rock engineering structures requires,
for each individual case, the selection of suitable and adequate investigation methods
that were described in Chapters 13 to 17. Testing and monitoring programs depend on
the project and the encountered rock mass, that is the parameters that are important
for the particular case. The economic performance of an investigation program also
depends on the experience of geologists, engineers, geotechnical specialists as well as the
companies and authorities that are involved in the project.

The author of this topic and his colleagues, have gained experience over several decades
with rock mass formations and strata occurring in the city of Stuttgart and the sur-
rounding area. Therefore two testing and monitoring programs carried out in Stuttgart
are subsequently described as examples.

19.2 Urban Railway Stuttgart, Hasenberg Tunnel, Construction Lot 15,

Exploration Shaft and Adits

The Hasenberg tunnel was constructed as an underground connection between two
stations of the urban railway in Stuttgart. For this project a testing and monitoring
program was carried out in an exploration shaft and two adits, which were constructed
as an advanced building measure for the tunnel.

During the sinking of the ca. 32 m deep shaft with a diameter of 5.8 m, the walls were
mapped, and the relative displacements of the walls due to excavation were measured
by means of four convergence measurement cross-sections (C1 to C4 in Fig. 19.1). The
shaft is located not far from the construction pit for the Station University described in
Section 16.7.2. The rock mass thus consists of the same formations already described,
namely the Lias , comprising claystone with single horizontal sandy limestone layers,

the Rhaetian and the Knollenmergel. In these formations dilatometer tests, LFJ tests,
in-situ stress measurements and ultrasonic logs were conducted (Fig. 19.1).
In the Lias

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and the Knollenmergel, crosscuts were excavated serving as exploration
adits in which the displacements due to excavation were monitored using convergence
measurement devices (C5 to C8 in Fig. 19.1) and multiple-point rod extensometers (EI
to EVI in Fig. 19.1). The latter were installed in vertical boreholes sunk from the ground
surface before the excavation of the adits was carried out.

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