Description
The Swellex bolt, also known as the hydraulic expansion bolt, represents a friction-based support system extensively utilized in underground engineering projects such as mining and tunneling operations. Constructed from high-strength welded pipes, its design features a pipe body that is longitudinally folded along its entire length, with both ends seamlessly welded and hermetically sealed.
Upon deployment, the bolt is inserted into a pre-drilled borehole, where it is then pressurized by injecting water via a high-pressure pump. Under the specified pressure, the pipe expands radially, creating frictional contact with the surrounding rock along its full length. This mechanism delivers immediate stabilization, ensuring robust and prompt support.
The Swellex bolt boasts several notable advantages: rapid installation, eliminating the need for resin or grouting; resilience to blasting vibrations; and an evenly distributed load-bearing capacity. Typically fabricated from high-strength steel materials—such as S355M or Q345—the bolts are commonly available in diameters of 27/28mm and 36/37mm. Their versatility makes them indispensable for providing stable reinforcement for surrounding rocks in underground mines, tunnels, and slopes
This system not only enhances operational efficiency but also significantly contributes to the safety and durability of underground structures. Its widespread adoption underscores its effectiveness and reliability in demanding engineering environments.
