On behalf of DESPE, we are carrying out a structural and vibrometric monitoring plan during the controlled explosive demolition of select tunnel lining sections.
Since the excavation of the emergency exits must be carried out with the main tunnel already constructed, the final linings along the main tunnel were demolished only in the areas where the bypass junctions need to be created.
The potentially harmful dynamic effects of the blasts on the adjacent lining not subject to demolition are monitored by GD Test through continuous vibrometric and stress monitoring during the demolition and bypass excavation phases.
For this purpose, triaxial automatic vibrometers were installed to control induced vibrations, along with strain gauge bars placed on the lining across the flat jacks previously installed to evaluate changes in the stress state before and after demolition, as well as during bypass excavation. All sensors were adequately covered with steel casings to protect them against projections caused by blasting.
 |
