With the acceleration of urbanization, deep foundation projects are increasing. Faced with complex geological conditions, especially silty clay layers, traditional anchor support methods have exposed many limitations and are difficult to meet the stability requirements of the project. Moreover, in the actual construction process, the low porosity formed by the traditional method has brought great pressure to the subsequent grouting and anchoring process, which not only greatly increases the difficulty of construction, but also significantly increases the cost of the project. So, how to solve this problem? This article will introduce the clay bit in detail to help solve the support problem of silty clay.
What is silty clay？
First, let’s understand what silty clay is. Silty clay is a common soil in geotechnical engineering. It has a fine appearance and a slightly sticky touch, which is significantly different from ordinary soil. Its composition endows it with some special physical properties. In a dry state, silty clay has certain strength and stability and can maintain its own structure. However, once it encounters water, its “true nature” will change significantly. Due to the presence of clay particles, silty clay easily absorbs water when wet, causing it to swell. Its volume increases, and its originally relatively stable structure becomes loose and unstable.
Why is it Difficult to Support Silty Clay?
The characteristics and structure of silty clay are important reasons for the difficulty in supporting it.
Prone to Swelling When Exposed to Water
Firstly, when self-drilling anchor bolts are used in the silty clay stratum, the swelling property of silty clay becomes a major obstacle when it meets water. As the drilling progresses, the surrounding silty clay swells due to contact with the water generated during the drilling process, and it is easy to squeeze into the self-drilling hollow anchor bolt, causing blockages. Once such blockages occur, subsequent operations will become extremely complicated. Not only will it take a lot of time and effort to clear the blockages, but it may also prevent the self-drilling hollow anchor bolt from being smoothly installed in the reserved position, seriously affecting the construction efficiency.
Located in a Complex Environment
Secondly, in projects such as coal mining, the environment where silty clay is located is often complex, and its strength is low, making it difficult to withstand large external forces. This requires the support structure to have higher stability and load-bearing capacity. However, traditional support methods often have unsatisfactory effects when dealing with this special soil of silty clay.
Likely to Delay the Project Construction Progress
In addition, if sticky mud is encountered during the drilling process, it will further increase the difficulty of drilling, making it difficult to drive the self-drilling hollow anchor bolt in smoothly, thus delaying the construction progress of the entire project and increasing the project cost and time cost.
Introduction to the Clay Bit
The self-drilling anchor bolt is an efficient support material that integrates drilling, grouting, and anchoring. With this unique advantage, it is widely used in complex geological conditions such as weak surrounding rocks, fault-fractured zones, high in-situ stress, and large deformations. We previously introduced how to choose the drill bit of the self-drilling anchor bolt, which can be chosen according to different geological conditions.
When designing the Clay Bit, Sinorock has always adhered to the concept of pursuing excellence. To improve the drilling efficiency and bit quality, through multiple experimental summaries, it has finally designed a suitable structure and size. This enables the self-drilling hollow anchor bolt to increase the drilling speed while drilling, effectively reducing the wear of the bit during high-intensity work and greatly extending its service life.
Features
Unique Structural Design with Integrated Wing Plates
The clay bit is characterized by a distinctive design featuring four large wing plates integrated with the main body, a structural configuration that effectively minimizes its overall weight.
Specialized Water Hole Engineering for Debris Evacuation
The dimensions and placement of its specialized water holes are meticulously engineered to satisfy specific criteria for debris evacuation during operation.
Reinforcing Rib Design for Wing Plate Robustness
To enhance the robustness of the wing plates, reinforcing ribs are strategically incorporated into their design, fortifying their mechanical strength.
Heat Treatment for Elevated Wing Plate Hardness
Additionally, the entire clay bit undergoes a heat-treatment process, a procedure that elevates the hardness of the wing plates for improved durability and performance.
Applicable geological conditions
Clay Bit is applicable to geological conditions such as sand, chalk, alluvial sand, silt, chalky clay, gravelly sand, fill, dry loess, gravelly loess, and gravelly hard soil.However, it performs optimally in geological conditions such as clay, soft soil, sand, gravel, and mixed fill.
The Clay Bit, with its unique design, is naturally suitable for silty clay geology. Then, apart from these unique designs, what other reasons for choosing the Clay Bit?
Why Choose the Clay Bit?
In geotechnical engineering construction, silty clay presents numerous challenges to engineering projects due to its characteristics such as swelling when exposed to water and low strength. The clay bit, with its innovative design and working principle, demonstrates remarkable advantages in silty clay construction. It effectively addresses the traditional support problems and improves the efficiency and quality of engineering projects.
Unique Crushing Method to Avoid Swelling and Adhesion
Driven by a drilling rig, the Sinorock clay bit crushes rocks and soil through a rotary-impact method. Without tungsten carbide teeth, it relies on its hardened material and the energy provided by the drilling rig to advance the borehole. This crushing method can effectively avoid the swelling and adhesion problems of silty clay when it comes into contact with water, ensuring a stable drilling process and laying a good foundation for subsequent construction.
Optimized Flushing Hole Design to Protect the Borehole Wall
The clay bit is equipped with flushing holes, allowing the selection of water, cement slurry, or compressed air as the flushing medium according to the geological and construction requirements. In silty clay rich in clay content, the cement slurry penetrates the soil through the flushing holes. It not only protects the borehole wall but also plays an excellent role in chip removal during drilling. This reduces the soil pressure changes caused by chip accumulation, prevents the swollen clay from squeezing into the self-drilling hollow anchor bar, and regulates the water content inside the hole to prevent excessive clay swelling, creating favorable conditions for the drilling and installation of the self-drilling hollow anchor bar.
Integrated Grouting and Positioning Function to Enhance Anchoring Effect
During grouting, the cement slurry flows from the bottom of the hole to the hole mouth through the water holes on the clay bit, achieving uniform distribution. At the same time, the bit can keep the self-drilling hollow anchor bar in the center of the borehole, maintaining a consistent thickness of the cement slurry. This function is highly suitable for the low-strength characteristics of silty clay. After the cement slurry solidifies, the clay bit is tightly bonded to the surrounding rock and soil, significantly enhancing the overall anchoring effect, improving the stability of the building, and effectively solving the support problems of silty clay.
Large Wing Structure to Improve Construction Efficiency
In complex engineering projects in silty clay environments such as coal mines, the large wing structure of the self-drilling anchor bolt clay bit has significant advantages. Four large wings at the body part reduce the weight of the bit, making it more flexible when drilling in silty clay and better able to adapt to soil property differences in different areas. Meanwhile, the enhanced chip-removal performance can quickly discharge the cuttings, greatly improving the drilling efficiency and shortening the construction period.
Reinforced Structural Design to Ensure Durability and Stability
The Sinorock clay bit adopts a reinforced rib design and an overall heat-treatment process. The reinforced ribs enhance the strength of the wings, making the drill bit more robust in complex silty clay environments and reducing the risk of wing damage. The overall heat-treatment process increases the hardness of the wings, enabling more efficient cutting and reducing wear, prolonging the service life, and ensuring a stable and reliable construction process.
Conclusion
In conclusion, through its exquisite design, the Clay Bit can comprehensively improve the construction performance in the silty clay stratum and solve the support problems. It is undoubtedly the ideal choice for supporting the silty clay stratum and can provide a reliable and efficient solution for geotechnical engineering, effectively promoting the smooth progress of projects.
