Device and method for determining material strength in situ
OwnerCarel J. H. Brest van Kempeninventor
Life of this patent
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Abstract
A device and method for determining compressive strength of solid matter in situ. One embodiment is particularly advantageous in underground mine roof bolting, where the device can be used to indicate the compressive strength of the rock immediately surrounding the roof bolt anchor. Such compressive strength indication is developed for each bolt installed as it is installed using no machine operator time or effort beyond the time and effort normally used already. The compressive strength indication is developed by monitoring rate of bolt head torque increase with respect to bolt head rotation and relating these to anchor tooth penetration parameters and hence rock compressive strength.
Claims37
A method for determining the compressive strength of solid matter, comprising the steps of:
- drilling a hole in said solid matter for access to the region to be measured;
- inserting an expanding toothed anchor means in such drilled hole;
- measuring the rate of increase in applied force to the anchor teeth per unit distance of anchor tooth penetration into said solid matter;
- and
- calculating said compressive strength from said movement.
A device for determining the compressive strength of solid matter, comprising in combination:
- an expanding toothed anchor means with matching headed bolt;
- bolt tightening means;
- bolt head torque measurement means;
- bolt head rotation measurement means;
- means to synchronize and relate said torque measurement with said rotation measurement;
- and
- means to convert said synchronized and related torque and rotation measurements to an indication of compressive strength.
Dependencies are inferred from the claim text.