Rock Bolt installation involves a complex process of drilling into rock, inserting a steel bar, and filling the void with grout. These steel bars are then connected to the structure or fastened to a horizontal whaler, in the case of an earth retention system this whaler bar combination provides lateral support. This process is used as an uplift restraint system, earth retention system, or a variety of other applications.
A rock bolt is used in tunnels or rock cuts. It transfers load from the unstable exterior to the confined (and much stronger) interior of the rock mass. Rock bolts are almost always installed in a pattern, the design of which depends on the rock quality designation and the type of excavation.There are many types of rock bolts, including self drilling rock bolt, expansion shell rock bolt, friction rock bolt and fiberglass rock bolt, etc. Every kind of rock bolt has its own method to finish installation.Here is the installation instruction of Sinorock expansion shell rock bolt:
1. Drilling and cleaning the hole. In order to have a straight and accurate hole, please use cross-cut drill bit.
2. Putting the anchor bar which has installed expansion shell into the bottom of the hole.
3. Giving prestressing force to the Self drilling anchor bolt and making sure the expansion shell fully opened by using specialized tools reach the design requirement.
2013年6月21日星期五
2013年6月5日星期三
How to remove rock bolts
Concrete anchors are available in a wide variety of styles. The majority of concrete rock bolts remove easily and often come with removal instructions. There is one type of concrete Rock Bolt that is not meant to be removed, but can be removed with the proper tools. Wedge anchors or expansion bolts lock into the concrete and are difficult, if not impossible to remove. Special concrete anchor extractors have been designed that allow you to removed broken or damaged expansion rock bolts.
1. Put on your hearing protection and safety glasses.
2. Select a socket from the socket set that matches the size of the hex nut tightened to the expansion bolt and place the socket onto the 3/8-inch ratchet.
3. Place the socket onto the expansion bolt hex nut and turn the ratchet handle counterclockwise to loosen the hex nut.
4. Remove the hex nut from the threads of the expansion rock bolt supplier.
5. Secure the expansion self drilling anchor bolt into the chuck of the hammer drill. Refer to the operating manual for the hammer drill to determine the proper procedure for securing the expansion bolt extractor.
6. Fill the hand-pressurized water tank with water and pump the handle of the water tank to pressurize the water.
7. Slide the expansion rock bolt extractor over the expansion bolt and press the trigger of the hammer drill to start drilling around the expansion bolt.
8. Spray water onto the expansion rock bolt extractor as you drill around the concrete anchor.
9. Pull the hammer drill toward you to remove the expansion rock bolt extractor from the concrete.
10. Remove the loose expansion rock bolt from the concrete.
11. Wipe the area around the expansion rock bolt with clean rags to clean the surface of the concrete.
1. Put on your hearing protection and safety glasses.
2. Select a socket from the socket set that matches the size of the hex nut tightened to the expansion bolt and place the socket onto the 3/8-inch ratchet.
3. Place the socket onto the expansion bolt hex nut and turn the ratchet handle counterclockwise to loosen the hex nut.
4. Remove the hex nut from the threads of the expansion rock bolt supplier.
5. Secure the expansion self drilling anchor bolt into the chuck of the hammer drill. Refer to the operating manual for the hammer drill to determine the proper procedure for securing the expansion bolt extractor.
6. Fill the hand-pressurized water tank with water and pump the handle of the water tank to pressurize the water.
7. Slide the expansion rock bolt extractor over the expansion bolt and press the trigger of the hammer drill to start drilling around the expansion bolt.
8. Spray water onto the expansion rock bolt extractor as you drill around the concrete anchor.
9. Pull the hammer drill toward you to remove the expansion rock bolt extractor from the concrete.
10. Remove the loose expansion rock bolt from the concrete.
11. Wipe the area around the expansion rock bolt with clean rags to clean the surface of the concrete.
2013年5月29日星期三
New developments in self drilling rock bolt technology
The mining industry is continually striving to develop more effcient methods to support the roof and walls of roadways and tunnels, and rock bolting has proven to be one of the most significant improvements in ground support over the last 50 years. Rock Bolt is now almost universally used in the underground mining industry worldwide, and there are many different rock bolts available.
Rock bolts are traditionally made from steel or fiberglass and are anchored into a borehole with a friction-anchor device, such as an expansion shell mechanism; cement grout; or chemical resin. Friction-anchored bolts are widely used in the Australian metal mining industry, predominantly as short-term support. They are used in conjunction with resin-anchored bolts where there is a requirement for longer life. Resin-anchored bolts are used in the coal mining industry.
Friction-anchored bolts provide immediate rock support, but their load transfer capacity is poor compared to resin or cement anchor bolts. In addition, friction-anchored bolts are more susceptible to corrosion than resin or cement self drilling anchor bolt.
Resin-anchored bolts typically use a plastic resin cartridge that contains mastic and catalyst components that are separated by a thin plastic film within the resin cartridge. The resin cartridge is insertd into the bolt hole before the rock bolt, and the rock bolt is pushed into the bolt hole to push the resin cartridge to the back of the hole. Then, the bolt breaks the plastics cartridge, and the bolt is rotated to thoroughly mix the mastic and catalyst components together. The mixed resin then flows down around the bolt and cures and hardens to anchor the bolt in the hole. These resin-anchored solid bolts work well and provide immediate roof support because the mixed resin typically cures and hardens in less than 60 seconds; it often cures in less than 15 seconds when resin capsules are used. However, bolts and anchored with resin cartridges have a significant disadvantage in that they require considerable manual handlingand several process steps to install, such as hangling drill steels, bolts, and resin cartridges http://www.sinorockco.com/.
Rock bolts are traditionally made from steel or fiberglass and are anchored into a borehole with a friction-anchor device, such as an expansion shell mechanism; cement grout; or chemical resin. Friction-anchored bolts are widely used in the Australian metal mining industry, predominantly as short-term support. They are used in conjunction with resin-anchored bolts where there is a requirement for longer life. Resin-anchored bolts are used in the coal mining industry.
Friction-anchored bolts provide immediate rock support, but their load transfer capacity is poor compared to resin or cement anchor bolts. In addition, friction-anchored bolts are more susceptible to corrosion than resin or cement self drilling anchor bolt.
Resin-anchored bolts typically use a plastic resin cartridge that contains mastic and catalyst components that are separated by a thin plastic film within the resin cartridge. The resin cartridge is insertd into the bolt hole before the rock bolt, and the rock bolt is pushed into the bolt hole to push the resin cartridge to the back of the hole. Then, the bolt breaks the plastics cartridge, and the bolt is rotated to thoroughly mix the mastic and catalyst components together. The mixed resin then flows down around the bolt and cures and hardens to anchor the bolt in the hole. These resin-anchored solid bolts work well and provide immediate roof support because the mixed resin typically cures and hardens in less than 60 seconds; it often cures in less than 15 seconds when resin capsules are used. However, bolts and anchored with resin cartridges have a significant disadvantage in that they require considerable manual handlingand several process steps to install, such as hangling drill steels, bolts, and resin cartridges http://www.sinorockco.com/.
2013年5月20日星期一
Sinorock®-Rock Bolt,Self Drilling Anchor Bolt,Soil Nail China Rock Bolts Suppliers & Manufacturer
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