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As we all know, bolt support needs to adopt different support methods according to different geology. Silty clay belongs to cohesive soil, which is relatively hard when dry and relatively sticky when wet. Silty clay will absorb immediately when it comes into contact with water, so there are problems such as serious material consumption in bolt support. Below, Sinorock will answer the question of whether silty clay can be bolted for support. this question.

Difficulties of silty clay support

The soil is viscous

Silty clay is generally brownish-yellow, hard plastic, with small soil particles, low moisture content, and high water absorption. In the support process, it is necessary to consider the difference between the actual pull-out force and the design pull-out force to see whether the tensile strength of the bolt can meet the pull-out force requirements.

Large pulp consumption

Since the silty clay has strong water absorption, and the soil will become viscous after absorbing water, in order for the bolt to be smoothly drilled into a hole, it is necessary to use the method of drilling, then pulling out, and then drilling. This will lead to long construction time, more slurry outflow, material loss, and large slurry consumption.

The water outlet is blocked

During the drilling process, because the clay will stick to the drill bit, it is easy to block the hole. Especially when the drilling depth is deep, this problem may not be obvious at the beginning, but as the drilling deepens, there may be a problem that the grouting pressure is insufficient and the grouting cannot be smoothly returned, which will lead to hole plugging.

Self-drilling bolt support solution

The self-drilling bolt has the functions of drilling and grouting at the same time, which can well solve the support problems of different complex geology. Let's take a look at how the self-drilling bolt solves the silty clay support.

Drilling method

Since the silty clay is easy to form agglomeration, it will stick to the rod body, connecting sleeve, drill bit and adapter of the self-drilling bolt, so it is necessary to slow down the drilling speed, let the slurry discharge the clay, and then drill deeply.

Slurry ratio

For the preparation of the water-cement ratio of the slurry, it is necessary to pay attention to the principle of thinning first and then thickening. First, use the slurry with a relatively large water-cement ratio, and inject a slurry with a relatively small water-cement ratio after drilling. And add a centralizer to make the hollow bolt body in the middle of the borehole to ensure that the slurry can wrap the rod body more evenly.

Power of grouting machine

In the early stage of drilling, it is necessary to pay attention to clearing the hole. While drilling, the hole should be cleaned with water, and the long anchor rod should be connected and sleeved in time, and the power of the grouting machine should be increased at the same time. Self-drilling rock bolts are drill rods, which do not need to be pulled out after drilling, so there is no problem of not forming holes, reducing the possibility of hole plugging and reducing slurry consumption.

Anchoring support has been increasingly used in tunnel construction with the rapid development of China's economy. Ordinary mortar anchors and hollow grouting anchors are commonly used in tunnel arches in the past years. The grouting fullness cannot be detected since the grouting process is poured from bottom to top, which leads to the hidden danger to the construction and operation of railway tunnels. Compared with other bolts, the self-drilling anchors improve the grouting process and effectively solve the practical problem of insufficient grouting. Self-drilling anchors have been widely used in railway tunnel construction in recent years.

Self-drilling bolt support is the form of tunnel construction support. It can effectively control rock loosening caused by blasting and excavation and improve the surrounding rock stability. Jiaozhou Bay Subsea Tunnel In Qingdao connection line passes through Yunnan Road and Sichuan Road. It is in a built-up area, surrounded by numerous military and civil facilities and densely distributed pipelines. During the tunnel construction, the safety of the above-ground facilities should be ensured, but the above-ground buildings are mainly multi-layered, which puts forward high requirements on the excavation and support of the surrounding rock. After forming an underground cavern by blasting or other means during construction, the rock's force status has changed, and some surrounding rocks formed a loose circle (Picture 9). The rock's self-stability was very poor in the loose zone, which caused adverse effects for cavern lining structure. To solve these problems, the construction party used self-drilling anchors to reinforce the loose circle and restore stability after releasing the stress. Self-drilling anchors have the following characteristics: 1) Self-drilling anchor bar is made of high-strength steel, and continuous-wave thread conforms to international standards. Anchor bars can be cut and lengthened on request, and they can be used in a narrow space.

2) Self-drilling anchors combine drilling, grouting, and anchoring functions, which improves the anchoring efficiency. It does not need to take out after drilling, which solves the problem of hole collapse in unusual geology.

3) The hole collar plug makes the grouting pressure higher, and the slurry fully contacts the rock, which ensures reliable anchoring quality.

Sinorock is a market-leading manufacturer of anchor bolt support solutions, rock drilling tools, and custom fabricated products. Sinorock has been supplying the underground mining sector for ten years and has adopted quality, safety, innovation, and manufacturing flexibility as its core strategic imperatives.

As the largest Chinese provider of rock bolt support solutions, Sinorock’s vision is to meet the needs of a growing number of clients, by focusing on innovation, strategic alliances, and industry-leading expertise. Sinorock completes technology assists miners in ensuring rapid, safe advances through even the most difficult ground conditions.

Sinorock knows well the complexity of mining in varying ground conditions and challenges. We know the importance of being responsive and proactive in order to achieve maximum results and efficiencies for our customers. We have the inventory and personnel to support your operations, including responsive customer service personnel who will streamline your materials acquisition process. Our technical specialists work directly with your technical and operations teams to make sure that challenges are addressed; quickly with the right solutions, ensuring safety and productivity at the lowest possible costs.

As an important transportation infrastructure, expressways have developed rapidly in recent years. Various problems appeared in the process of highway construction due to geology, materials, climate, construction technology, etc. How to solve these problems? It is an important issue for builders

 Yexin Expressway in Henan Province, is a major transportation road and plays a vital role in the development of Henan's economy. However, during the construction process, there were many problems, such as damage to the outer drum on both sides of the bridge abutment, leading to road settlement; overpass slope bulged causing road subsidence. In this situation, self-drilling anchor system was adopted to reinforce the road, which solved the potential safety hazards of the expressway.

 Self-drilling anchors were drilled directly on both sides of the vertical walls. Utilizing the integrated function of drilling, injection, and anchoring, making the cement slurry entered through the hollow pipe of the anchor bar, which ensured the anchor bar consolidated with the rock and soil. Combined with the equal-pressure compaction grouting process, the flow direction and volume of the mud were controlled, and the sinking road near the abutment was contained and restored. It not only solved the problem of external drums on the wall but also achieved a good anchoring effect.

A concrete anchor bolt is needed when you are building a wood structure on top of a concrete foundation. The concrete anchor bolt helps to evenly distribute the weight from the rest of the structure. The information that follows will show you how to install a concrete anchor bolt in bother wet and dry concrete.

Firstly, board support. Read the instructions on the bag of concrete and mix it with the appropriate amount of water. When it is pourable consistency fill the area that needs the concrete. If you place the concrete anchor bolt in the cement at this point it will sink to the bottom. In order to properly install a concrete anchor bolt you need a way to support it and a 2 by 4 is that way. Measure the area where the concrete is and cut a piece of 2 by 4 to slightly larger than that size. Determine where you want the concrete anchor bolt to be placed and drill a hole in the 2 by 4 at that distance.

Secondly, setting the concrete anchor bolt. The board is what is going to stop you from losing the concrete anchor bolt. Install the bolt to the 2 by 4 where you determined it needs to go. Make sure that it is tightly fastened to the wood. Place the 2 by 4 across the wet concrete. Just set it on top. Be careful to not damage or ruin the concrete. You can adjust the bolt so that at least half of it is in the concrete.

Thirdly, finishing up. Wet concrete can harden in a day but will not fully cure for another two days. It is possible that it could take longer depending on the climate and weather conditions of your area. At this point the concrete anchor bolt is in place and will be very secure. There is one problem though: the board. You do not want to keep the 2 by 4 hanging around and you can't remove the concrete anchor bolt. The only solution is to cut the 2 by 4. Use the saw and carefully position it close to the bolt. Score the 2 by 4 so it is cut through about half the thickness. Use the hammer and strike the wood. The force will cause the wood to splinter and break away from the bolt.

Fourthly, dried concrete. It is a better idea to install a concrete anchor bolt to concrete that is wet but it can still be done on dried concrete. You'll need a special concrete drill which you can usually rent. You will also need a concrete drill bit. Determine where you want to place the concrete anchor bolt and mark the area with an "X". Drill a hole through the concrete and gently hammer the bolt.

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