Effect on Municipal Pipeline under Subway Tunnel Excavation in Drill-Blasting

Drill-blasting method is used in Qingdao subway tunnel excavation, because of soil-stone assorted strata. But study on stress and strain of municipal pipeline is not enough now, because drill-blasting method is not widely used in subway tunnel excavation. Stress and displacement of municipal pipeline are studied, when blasting load is considered in subway tunnel excavation in the research. It shows that :(1) When the position of municipal pipeline and subway tunnel is vertical, displacement of pipeline less than horizontal, but the stress of pipeline is opposite. (2) The blasting load effect on stress and displacement of pipeline dramatically. (3)Stress and displacement of pipeline dive, when the distance from medium weathered granite to tunnel vault increases. And downtrend slows down when the distance reaches 2m. (4) With the increase of elasticity modulus of covering soil, the stress and displacement of pipeline decreased.