2014年12月11日星期四

self drilling rock bolt

rock bolt are used for rock bolting and grouting in softer rocks, especially the loose ground and sections prone to collapse. rock bolt stabilises the slopes which are highly weathered or broken. rock bolt can also be used for rock pinning and rock dowel applications where localized reinforcing of the rock face is required. rock bolts are typically regarded as lightly loaded, full bonded installations, for low risk applications.

Stabilisation of tunneling
rock bolt is usually used in mining, hydroelectric, and tunneling projects.
Sinorock rock bolt is used extensively for the stabilization of tunnel portals. The ability of rock bolt accommodate a range of different ground conditions make them a popular choice for tunneling works. Spiles are used to form a protective canopy for tunneling in areas of loose ground. When rock bolt is used as spiles, the bolt can be drilled into place using rotary percussion and then grouted through the hollow core to consolidate the heading.

rock bolt can also be used in mining applications. In mining applications, rock bolt is used for the bolting of pillars, the injections of resins or waterproofing agents as well as for general reinforcement applications.


Friction anchor bolt

Friction anchor bolt is one kind of anchor bolt. This kind of anchor bolt improves rock stability and safety factors by tightening as lateral strata movement occurs. Friction anchor bolt is primarily used in metalliferous mining operations, but is also well suited for rib support in coal operations. Friction anchor bolt is available in two sizes: 33 mm and 39 mm. Strength and Versatility anchor bolt is manufactured from highstrength steel. For increased protection against corrosion, the anchor bolt is available in galvanized and stainless steel.

Installation process of anchor bolt:
1. The first step, drilling hole at proper diameter and depth. Diameter is determined by on-site testing.
2. Insert anchor bolt into the hole. A driving tool is fitted into the rock drill’s chuck. Place anchor bolt and plate onto the installation tool.
3. Using percussion and thrust, fully drive the anchor bolt into the hole until the anchor plate is tight against the rock surface.

Application of anchor bolt
This kind of anchor bolt can be used in tunneling, mining, hydroelectric station and civil construction. Sinorock anchor bolt has been exported to many countries and used to many construction projects. Due to the strict quality control system, Sinorock anchor bolt wins great reputation from our customers. 

Application of self drilling rock bolt

rock bolt is an efficient solution for ground anchoring. It can be used in various kinds of ground conditions. Here is the illustration of rock bolts' applications.

Slope stabilization
rock bolt is used to stabilize unstable rock formations. Compared to the traditional methods, the rock bolt is a fast and simpler method of installation. The unconsolidated or weathered ground conditions favor the rock bolt technique.

Foundations with micropiles
Micropiles can be also regarded as drilled piles, composed of injected grout with the rock bolt as steel reinforcement. rock bolt can be installed in sites with limited space. With a light drilling equipment, rock bolt can be installed into most ground conditions including rock. rock bolts are also suitable for tension and compression loads. The big advantage of rock bolt is the combination of drilling and grouting gprocess which makes high piling outputs possible.

Tunneling
rock bolt is the most economical solution for the reinforcement of the tunnel circumference. It is also suitable for advanced roof support for tunnel excavation in overburdened and soft fractured rock conditions.

rock bolt system

Sinorock rock bolt system is a kind of fully threaded steel bar. rock bolt system can be drilled and grouted into loose or collapsing soils without a casing. The feature of the rock bolt system is that there is a hollow center in the middle of the bar. The hollow center is designed for simultaneous drilling and grouting and a rope thread for connection to standard drill tooling. rock bolt system is manufactured by cold rolling heavy wall steel tubing. Sinorock rock bolt system has a standard rope thread profile, which has all sizes include R thread from R25 to R51, T thread from T30 to T130. The rolling process refines the grain structure of the steel, increasing the yield strength and producing a durable drill rod suitable for a range of applications. Sinorock rock bolt system can be installed into a variety of different soils and ground conditions ranging from sand and gravel to inconsistent fill, boulders, rubble and weathered rock, as well as through footings and base slabs.

Here are the installation advantages of rock bolt system
1. rock bolt system is used with small drill rigs without casing in narrow spaces
2. It has the similar installation methods for all ground conditions, so it is convenient to use.
3. Simultaneous Drill and Grout Installation: anchor bolt system combines drilling and grouting into a single process. Thus, it improves the work efficiency greatly. 
4. No Casing Required: rock bolt system can be installed into loose or collapsing soils without the need for a temporary casing to support the borehole.
5. Rotary Percussive Drilling: Allows quick rates of installation, good directional stability and assists in the consolidation of the grout within the borehole.


Sinorock rock bolt system

Sinorock drill rock bolt is a kind of self-drilling rock bolt system that is fully threaded on the surface. rock bolt can be simultaneously drilled and grouted into loose or collapsing soils and brittle rock, but the casing is not necessary. The feature of the rock bolt is that it has left-thread for standard rotary percussive drilling.

rock bolt system is manufactured from high grade steel tubing. The standard rope thread can be formed after the cold rolled process. The rolling process refines the grain structure of the steel. The structure increases the yield strength and produces a robust drill steel that is suitable for a range of drilling and grouting applications.

rock bolt system is consist of a various kind of drill bit, adapter sleeves, couplers, nuts and bearing plates. With the injection adapters and drill tooling, the rock bolt can be used with many types of drilling equipment. 

Features of rock bolt system

1. Casing is not necessary. rock bolt can be drilled into loose or collapsing soils without the need for a casing to support the borehole.

2. Simultaneous drill and grout installation. Grout is injected at all points of the borehole as drilling is advanced, permeating the local strata for increased bond performance and producing bulbing between the strata and the rock bolt in the softer sections of the soil.

3. Rotary percussive drilling
This drilling technique is highly efficient, ensures fast progress of drilling as well as good directional stability of the drill string and helps to consolidate the grout within the borehole.

rock bolt

    rock bolt has many features. It has a hollow hole in the middle of the bar that is designed for flushing. The drilling and grouting process can be combined into single operation. There is left-hand thread on the surface which is designed for connection to standard drill tooling. rock bolt is manufactured from thick wall steel tubing, and then cold rolled to rope thread. The rolling process of rock bolt refines the crystaline structure of the steel, increasing the yield strength and producing a durable drill rod suitable for a wide range of applications.
    rock bolt is always used with many accessories, such as extension coupling, bear plate, hex nut, gap spacer and drill bit. rock bolt also can be galvanized to against the corrosion.
    Corrosion is a very complex process, it is hard to predict the corrosion rates accurately. However, analytical evaluations can be helpful to recommend the need for corrosion protected rock bolts. For this reason, Sinorock has developed a hot dip galvanizing corrosion protection. The full range of rock bolts and accessories is available with his corrosion protection.