Geokon 4910, Инструкция по эксплуатации

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1. INTRODUCTION
1.1 Theory of Operation
The Geokon Model 4910 Instrumented Rockbolt is made by inserting a vibrating wire strain
gauge inside a short length of standard threaded rockbolt or rebar. This short length is then
connected to a longer length of the same bolt material by means of a coupler. The full rockbolt
assembly is then installed in the normal manner, making sure that the strain gauged portion of
the bolt remains located in the loaded section of the bolt.
The Instrumented Rockbolt is frequently used:
• To confirm the load as determined by the torque applied to the rockbolt nut, or to the
hydraulic pressure exerted by a jack, during installation
• To provide a permanent means of monitoring the load throughout the life of the rockbolt.
The Instrumented Rockbolt is read out by means of a hand-held Readout Probe that is used to
contact an electrode in the end of the bolt. The probe is shown in Figure 1. The probe is
connected to a readout box and then the tip of the probe is pushed against the electrode recessed
in the end of the rockbolt. This method of readout eliminates the need for cables and connectors,
which could be damaged during installation or later.
Figure 1 - The 4910 Readout Probe used with the GK-404 Readout.
Figure 2 on the following page shows a typical installation.