Rock bolts are one of the support systems, that are widely used support systems in mining and various civil engineering operations. Rock bolts or anchors play a very important role as systematic support during the excavation stage of tunneling or mining work, the bolts can go into the roof of underground mines or the walls of tunnels to prevent caving. The anchor bolts reinforce the loose and weak strata to make them, self-supportive by enhancing their inherent strength. Anchoring of the rock bolt plays an important role when the deformation or movement of the layers in the rock mass induces axial tensile load in the installed rock bolts. Their purpose is to improve the resistance of the ground. Bolts will fail if the applied or induced axial load to the bolt exceeds the anchorage strength. Anchorage strength depends on many factors such as type of bolt, annular space, grouting media, shear behavior at the bolt-grout interface, surface profile, installation mechanism and position. The stability of structures in any tunneling and mining excavation is critical and roof rock stability has long been the primary concern in all underground excavations. Rock bolting has been successfully utilized worldwide for excavation support and slope stabilization and its use continues to grow rapidly. A single use drill bit, selected to suit the ground condition, is fitted to the leading end of the hollow bar ( also called Self-Drilling Anchors)with an anchor plate and anchor nut fitted on the trailing end. Couplings can be used to combine hollow bar sections for extension bolting. What are purposes of Rock bolts installed? 1. Provide pre-tension in fragile geology conditions;2. Serves as a mortar bolt for passive loading. For the pre-tension purpose, immediate anchoring of rock bolts with loose rock geology is necessary. Rock bolting carries the tension and shear forces to prevent the displacements of rock mass, There are three kinds of anchoring material to fulfill the pre-tension purpose within 2-3 hours at most which are liquid accelerator cartridge, two-component resin cartridge, and mechanical expansion shell. Friction force from the grout body also enables rock bolts to prevent the loosening of different geology layers. It also prevents rusting by covering the metal parts eliminating the chance of water getting into the connection. Based on different geology conditions and physical performances of tunneling rock bolts, there are different designs of rock bolts including the following: Fully threaded rock bolts: for cost-effectiveness, greater loading capacity, and easy connection on site Self-drilling anchor: for extremely fragile geology to reduce the installation time Friction swell rock bolt: for applying pre-force to surrounding geology and achieving quick installation What are Rock bolts Applications? Dams Tunnels Mines Stabilization of excavations Embankment stabilization Stabilization and renovation of landslips Road construction Renovation of retaining walls foundation work, and other subsurface projects… Advantages of Using Rock Bolts Anchor Systems Improves stability for various wall heights and depths Spreads ceiling loads across the surface minimizing the impact on one specific point Versatile option for dam building Correct design

A: Enough space for cuttings to evacuate the hole efficiently; B: High-performance design for harsh and abrasive conditions formations; C: Components Replace Easy to Save Drill Cost; D: Choose Right DTH Drill Rods; E: Choose Right Friction-welded joints; A: Enough space for cuttings to evacuate the hole efficiently: As experienced, the smallest hole diameter a DTH hammer can drill is its nominal size. i.e. standard 102 mm (4 inches) hammer will drill a hole down to a minimum diameter of 102 mm (4 inches). The limiting factor is the outside diameter of the hammer dth, because as the hole diameter reduces due to diameter wear of the dth hammer bit, airflow is restricted. Maximum hole size for production drilling is the nominal hammer size plus 25 mm (1 inch), so for a 102 mm (4 inches) hammer the maximum hole size is 127-130 mm (5 inches). The right drill bits are determined by the type of application, hole size, and type of rock formation, the size of the hammer DTH should match the required hole dimension as closely as possible, leaving just enough space for cuttings to evacuate the hole efficiently. B: High-performance designed DTH Rock Tools for harsh and abrasive conditions formations: VD DRILL DTH hammers are purpose-matched for all rock types and applications where high performance and low total cost per drill meter are the main criteria. ) VD Drill’s DTH Hammer with a common design is a suitable choice for dth drilling in quarries, shallow water well drilling, and underground blast hole drilling. ) VD Drill’s standard DTH hammer is the optimum selection for demanding conditions in abrasive formations. It has the same internal components as the common design, but with larger OD of the drive chuck and wear sleeve. These also protect the top sub from excessive wear when rotating out of the hole through broken rock. Each hole hammer is made from quality alloy steel and has been precision machined to produce a perfect body, heat treated to the required hardness, given surface compression for fatigue resistance, and the head of DTH Hammer is fitted with a top sub-fitted with tungsten carbide buttons for wear protection in harsh and abrasive conditions. Each DTH hammer can be quickly and easily adjusted to different compressor air pressures and air volumes, making our hammers fit all drill rigs, operating at different altitudes and climates. C: Components Replace Easy to Save Drill Cost: DTH drilling to greater depths with Higher penetration rates (More efficient) and lower fuel consumption (cost-effective). As experienced, a hole hammer used in dth hammer drilling should be replaced when it has lost 10% in net penetration rate. The total drilling cost per meter increases drastically when productivity drops. All VD hole hammers have the rebuild option with components, components consisting of external and internal wear parts. This is a valuable option particularly in abrasive to medium abrasive formations. With a unique combination of the highest quality in design, production, and material, the hole hammers can

Operation Instruction Put DTH Hammer on the Bench Adjust the position of DTH Hammer and wrench; use a wrench to block the top subside of the hammer; let the wrench and jack in the same face. Fix K-Shaped base with a nut. Fix wrench with nuts. Shake handle of Jack slowly till the top sub away from hammer After the top sub is dismantled, release hydraulic oil pressure in the jack, release nuts, discharge the K-shaped base and turn around the Hammer. The part of the external cylinder thread is prohibited to wrap by the jaw to avoid any damage to the hammer dth. Adjust the position of hammer and wrench; use a wrench to block the drive bit of the hammer; let the wrench and jack in the same face. Fix hammer Fix K-Shaped base and the wrench with the nut. Shake handle of Jack slowly till dive chuck away from hammer dth.     For more about DTH Hammer Hydraulic Manual Breakout Bench Please read How to avoid DTH Bits loss in the hole with DTH Hammer Hydraulic Manual Breakout Bench : https://drillbitsupplier.com/how-to-avoid-dth-bits-loss-in-the-hole/   More information please contact our Expert or ask for a quote.