Design, Construction and Performance of ... - Geosystems, LP

The two-row grout curtain featured holes drilled 15º off vertical in order to ensure
that vertical joints were intersected (Figure 2). Construction began with the coring of 34
“superprimaries” to further explore the foundation. These holes were subject to
geophysical logging, optical televiewing and multipressure Lugeon testing, prior to
grouting. Thereafter, the intermediate Primaries, Secondaries and Tertiaries (where
deemed necessary) were drilled with rotary percussion and water flush. A Drilling
Parameter Recorder was used to record the drilling characteristics of each hole, thereby
contributing greatly to the pool of knowledge on the variability of the rock mass, both
laterally and vertically.
Photograph 1. Irregular packstone surface detected in seismic refraction survey.
Photograph 2. Weathered zones mapped in Bangor Shale Unit C beneath historic Bear Creek
channel.
Photograph 3. Cherty limestone and packstone contact.
Photograph 4. Cleaning of N30E features.
28