My intention is to produce a video, pictorial, and oral presentation on utility blasting, primarily power pole holes and ditches. Included will be blasting for a take-off structure inside of Wanapum substation, jointly owned by BPA, PSE, and Seattle City Light, and blasting for 230kV steel tower foundations. Grant County's rock is primarily basalt, an extrusive igneous rock, with the same minerals as its intrusive equivalent, gabbro. The northern portion of the county is bordered by Grand Coulee Dam (once the world's largest dam) and the rock is primarily granite know as Grand Coulee granite. From this area south, you will find columnar basalt, diced basalt, scoria, a vesicular basalt and massive fine grained aphanitic basalt with very few fault lines to break to. The underlying geology can change from pole to pole, making a challenging situation for a utility blaster. Water in fault lines is very common, in this second largest county in Washington State. Blasting in city limits, and very close to buildings and other structures further the challenge. Also covered will be hole diameter, drill patterns, depth, power charges, initiator patterns and delays, wet/dry holes, jack hammer drilling, air trac drilling and Texoma 330 pressure auger drilling.
展开▼
