Tunnel excavation auxiliary method "Slit Injection Fore-Polling"

Reduce surface spalling from the top through construction from within the cross-section! Achieve reliable injection through leak suppression.

The "Slit Injection Forepoling" is a tunnel excavation auxiliary method that allows for the insertion of a cuttable bolt at a low angle from beneath the support structure into areas of concern for rockfall, such as uncemented ground. By performing construction from within the cross-section, it reduces the skin fall that occurs from the top and achieves reliable injection through leak suppression. It is highly effective for ground improvement. 【Features】 ■ The slit processing of the bolt allows for the removal of the bolt's end. ■ It enables insertion from beneath the support structure, proving particularly effective in uncemented ground such as sandy hills, demonstrating higher effectiveness than conventional methods. ■ Since it involves pouring from beneath the support structure, it suppresses leaks caused by roughness in the boreholes through pouring from the position of the sprayed concrete, allowing for reliable injection. *For more details, please refer to the PDF document or feel free to contact us.

Tunnel constructionCivil Engineering Method