The so-called cone bolt may be the first energy absorbing device designed to counteract rock burst problems and was invented in South Africa .
This kind of bolt realizes energy absorbing function by the special physical construction (classified as structural deformation), for example, cone bolt  and Roofex bolt .
Simser, "Modified Cone Bolt Static and Dynamic Tests," Noranta Technology Centre Internal Report, Noranta Technology Centre, Quebec, Canada, 2002.
Description Peak load Displacement Energy (kN) limit (mm) absorption (kJ) 19 mm resin- grouted rebar 120-170 010-030 01-04 46 mm split set bolt (FS-46) 090-140 080-200 05-15 16 mm modified cone bolt 050-100 100-200 10-25 16 mm cable bolt 160-240 020-040 02-06 #4 gauge welded 034-042 150-225 3-6 per wire mesh [m.sup.2] Shotcrete and welded wire mesh 2 x mesh < mesh 3-5 x mesh * * at displacements under 100-150 mm.
* Walls: 1.95-m-long FS-46 split sets on a 1.2- x 0.75-m pattern with 4-gauge welded wire mesh, followed by a minimum 76-mm-thick layer of plain shotcrete, and 2.3-m-long modified cone bolts on a 1.2- x 1.8-m pattern with 0-gauge mesh straps.