It’s reported that on March 22, Asian Development Bank would provide 123 million dollars loan for MWSS to construct the No.4 water-conveying tunnel, which aimed to improve water supply system and reduce risks of water shortage.
One expect expressed that current Angat water supply system had provided over 95% water for Manila, but the service life of water-conveying tunnel reached 75 years, aging seriously and power severed easily. This assistance would help to construct a 6-kilometer water-conveying tunnel, upgrade and transform current tunnel, then improve water supply service to large extent.
As for projects needed to upgrade, except increasing functions, reinforcement and extending service life are also very important work. So the supporting effect of self drilling rock bolt is reflected.
Adopting self drilling bolt to reinforce water-conveying tunnel is the application of geotechnical engineering technology in the aspect of tunnel project, which transmits structures’ tension by using surrounding rocks’ shearing strength or keeps self-stability of excavation face.
The usage of self drilling bolt can form compound between structure and stratum, produce compressive stress areas, which can enhance stratum’s strength, improve stratum’s mechanical property and bear tensile force and shearing force, resist deformation and displacement. That’s the mechanical function other retaining structures don’t have.
This technology has largely relieved structures’ self-gravity, saves engineering materials, ensured projects’ security and stability, with prominent economical and social benefit, so it has been widely used in projects at present.