The bolt relates to a tunnel support. It is inserted into pre-drilled hole in the roof of the tunnel, of any underground cavity and supports it. General lacks of any conventional rock bolt are:

• they fail to prevent weak roof fall enough frequently; if the bolts prevent premature roof fall they use 1-3% of their bearing capacity, because they break in the point in the weakest part of their body;
• as a result, conventional bolts can not to maintain proper safety and in addition are non-economical;
• 97-99% of supporting material are wasted unused.

BRIEF DESCRIPTION
New rock bolt is a rigid rod. It almost the same by shape and by material. Its installation in a hole is almost the same as the installation of conventional bolt. Slight differences are applied in design of the bolt. These differences are the object of patenting.
    Actual measurements in-situ, physical and computer modeling have helped to discover new behavior of surrounding underground opening rock mass. New rock bolt complies with this behavior and helps to control it more effectively. Two papers have been accepted for presen-tation at the 36th American Rock Mechanics Symposium ‘NYRock’97’ in New York, Columbia University, 31 June-3 July 1997. These papers describe the new behavior in general. However there is a great number of ‘now how’ in order to understand comprehensively connection between the new bolt’s design and the new behavior of the rock.

ADVANTAGES
New bolt will cost 40-55% less than conventional rigid bolt. Its installation in a hole will be 10-15% time-consuming but will be accomplished with the same equipment + slight optional modification. The cost of conventional bolt is $5.08 in 1991 price level (Tadolini S.C., Dolinar D.R. Thrust bolting: a new innovation in coal mine roof support// 10th International Conference on Ground Control in Mining (1991). Morgantown, WV, USA. P.83). New bolt will cost $2-2.5. Positive difference will be at least $2.5. In a typical coal mine, 100,000 bolts are installed every year.
However new bolt utilizes 50-80% (theoretically 100%) of the bearing capacity of material (steel). It demonstrates average maximum resistance 1.08-1.98 times more and average bearing capacity 2.1-2.8 times more than conventional bolt.
Therefore new bolt increases essentially safety and economic efficiency other things been equal (using the same amount and quality of material).

AREA OF IMPLEMENTATION :
support in tunnels and underground workings. For instance transportation tunnels in mountainous area, heavy loaded underground (metro), hazardous waste (radioactive) underground deposits, coal mines entries. Especially it is useful in the areas where earth quakes occur;
fixing heavy loaded foundation, for instance dams.

HOW TO IMPLEMENT
New bolt has been tested in the physical models. It is expected that the efficiency of new bolts will be even more in-situ. Now two samples is being manufactured in a metallurgical plant and will be ready for the test to the end of February.
    Patent search was made in 1994 from CD and current journals being in WVU.
    The patents should be applied for the bolt design and equipment for its installation in USA, UK, Austria, Sweden, Germany, Japan, South Africa, Australia. Research should be conducted during 1-1.5 years period: to develop final design and its options, to design additional appliance for bolt’s installation, to test the bolt in laboratory and in-situ. Approximate fund should be from $300,000 to $500,000. Detail budget may be written after approval of the primary proposal.

SUGGESTIONS
To sell non-exclusive licenses to every firm.

Back to the Technologies