Créer mon blog M'identifier

SDA bolt integrates drilling and grouting in the construction

Le 21 juin 2017, 12:24 dans Humeurs 0

The general requirements of self drilling rock bolt design in underground projects are reliable technology and reasonable economy. So, there are some points in both engineering design and construction.

1. During site selection, design and construction, methods should be chosen to ensure rock body not loose.

2. Adjusting and controlling rock body’s deformation rationally and effectively to develop self supporting capacity and self drilling rock bolt’s bearing capacity.

3. During design and construction, self drilling rock bolt should be unified as a whole with rock body to play the common function of both.

4. Confirming the class level of rock body, obtaining its mechanical parameters to guide design and construction.

5. Under different geological structure, rock mass classification and mechanical property, different supporting ways should be chosen according to different calculation and design methods.

6. Combining geological exploration, design, construction and monitoring together, adjusting design parameter to make structural form accord with actual construction.

SDA bolt integrates drilling and grouting in the construction. After the hollow bar is installed, it’ll be grouted with cement slurry without casing and meanwhile it can avoid the gap in the cement.

The use of grouting pipe for continuous grouting can ensure 100% coverage rate and achieve a good anti-corrosion effect as same as the concrete reinforcing rebar. The cement slurry covering layer around the permanent anti corrosion SDA bolt can provide permanent anti-corrosion function.

Operational Principle and construction technology of Rock Anchor

Le 20 juin 2017, 09:46 dans Humeurs 0

The Sinorock Rock Anchor System is a fully threaded steel bar which can be drilled and grouted into loose or collapsing soils without a casing. The bar features a hollow bore for simultaneous drilling and grouting and a left hand rope thread for connection to standard drill tooling. Manufactured from heavy wall steel tubing, Sinorock Rock Anchor is cold rolled to form a standard rope thread profile (R25-R51). 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. The standard rope thread of Sinorock Rock Anchor produces an excellent bond between the bar and grout as well as enabling connection to all conventional drill rigs and the use with a wide range of drill steel accessories and bits.

Sinorock Rock Anchor 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. Applications include: soil nails for road widening and railway embankments, ground anchors for temporary works and sheet pile tie back, mini piles for stabilisation of footings and underpinning, and roof bolts or spiles for tunnelling.

The construction technology of self drilling rock bolt

1. Arranging position of holes

Arrange holes on the surface of the initial shotcrete according to the requirements of design drawings.

 

2. Drilling hole and installing self drilling rock bolt

After excavation and initial shotcrete, the drilling should be started with the artificial hand-held pneumatic drill as soon as possible in the simple bench. When the drilling is finished, the self drilling rock bolt should be installed in time. In the plugging process, the anchor bar should be kept in the center of the hole. The length of the self drilling rock bolt exposed should not be greater than the thickness of the shotcrete. Then spray the concrete again to thickness designed on the drawings. In the watery region, the water in the hole should be cleaned or drilling should be operated in the near site. Finally, install the self drilling rock bolt.

3. Grouting

The injection pump was adopted for grouting. The grouting pressure is 1.0Mpa~1.5Mpa. When grouting quantity in the single pipe reaches to the requirements of drawings, the grouting should be over.

 

Efficient supporting methods - Self drilling rock anchor system from Sinorock

Le 9 mars 2017, 10:49 dans Humeurs 0

Self drilling rock bolt support has many advantages, such as instant bearing, large pretension force, good support effect, low labor strength and low cost, etc.Nowadays, self drilling rock bolt technology has become an effective way to realize high efficiency and production. 

Self drilling rock anchor system, one of efficient supporting methods, has played important role in reinforcing and supporting engineering. As for underground engineering, such as metro station and foundation pit supporting, self drilling anchor system can bond itself to soil and ground, which can enhance integrity and cohesiveness, avoid deformation and collapse. 

Self drilling anchor of Sinorock is a kind of prestressed anchor, which combines drilling, grouting and anchoring together.Self drilling anchor bolt in slope treatment were able to achieve the ideal effect in improving the surrounding rock, which nicely solves the problem of drilling difficult in anchoring construction, it is an economic, safe and highly effective geotechnical reinforcement technology and now is widely used in tunneling, mining and slope works.The self drilling anchor bolt system are used widely to improve the stability and load bearing characteristics of a rock mass. 

Often they are used to stabilize relatively small blocks of rocks in cuttings, slopes and underground excavations such as tunnels, caverns and mines. They can be used on their own or in conjunction with other support systems such as ground anchorages.

 

Voir la suite ≫