| dc.description.abstract | Considering the cost, the efficiency of constructions, the restriction of geological conditions, and other issues, blasting is generally inevitable for excavation in tunnel constructions. The ground vibration induced by blasting may have some negative effects on surrounding structures and neighborhood. Therefore, understanding the impacts of ground vibration induced by blasting is important to tunnel construction.
This study performed a carefully planned field measurement for ground vibration and sound induced by blasting test, the weight of explosive was the equivalent of the latest design in “New Wu-Shan-Ling Headrace Tunnel Project”, so that the influences of this construction can be estimate. The measured data was analyzed to derive the vibration characteristics, including the velocity attenuation relation, Fourier and response spectra. Also, compared measurement results with worldwide vibration criteria.
Because of the careful planning and well organized, large amounts of data have been successfully measured. The data include the vibration at free filed, surrounding structures, slopes and the Wu-Shan-Ling headrace tunnel. From the attenuation relationship between PGV and distances, the coefficient of determinations are very high, shows consistency at both east side and west side of tunnel. Fourier spectral analysis founds that free field near by the blasting area has dominant frequency about 50 Hz, also founds the natural vibration frequency of structures. Response spectrum analysis shows that the blasting has small effect on long-period structures. After the distance is greater than 70 m, the ground vibrations are under worldwide acceptance criteria. | en_US |