<p><p><h2> Commentary</h2>Typical contract pay items and units of measurement used for blast densification include:<br><ul> <li>Drilling and casing blast holes by the lineal foot.</li> <li>Explosives by the pound.</li> <li>Exploratory drilling by the lineal foot.</li> <li>Mobilization by the lump sum.</li></ul><h2> Cost Information Summary</h2>Very little historical cost information exists for blast densification; the Washington Department of Transportation reported two projects circa 1994 which had total costs of $1.91 per cubic yard and $2.66 per cubic yard of improved soil. Drilling and blasting costs can vary widely depending upon geologic conditions, proximity to structures, and other factors. This variability in cost is demonstrated by the bid tabulation data shown in the table below. Specific project inquiries regarding the cost of blast densification should be made to experienced drilling and blasting contractors.</p><p><table class='tablepress' id='tablepress-64'><thead><th>Pay Item Description</th><th>Quantity</th><th>Unit</th><th>Low Unit Price</th><th>High Unit Price</th><th>Average Unit Price</th><th>No. of Bids</th><th>Bid Date</th><th>Source/Agency</th></thead><tbody><tr><td >Rock
Excavation
(Controlled
Blasting)</td><td >27,486F</td><td >CY</td><td >$15.29</td><td >$25.99</td><td >$19.88</td><td >6</td><td >4/13/2010</td><td >California DOT</td></tr><tr><td >Rock
Excavation
(Controlled
Blasting)</td><td >9,620</td><td >CY</td><td >$80.00</td><td >$137.00</td><td >$110.88</td><td >6</td><td >9/29/2010</td><td >California DOT</td></tr></tbody></table><h2>Conceptual Cost Estimating Tool</h2>No cost estimating tool is provided for this technology.</p></p>