It could be the largest concrete pour since the Third Powerhouse project in the 1970s.
An official from Wilson Construction, Gerald Turner, said that pours in late spring on the six towers in the Bonneville Power Administration powerline replacement project will require continuous pours on each footing under the new 300- 350-foot towers.
Turner said each leg of each tower will require a hole eight feet across and from 46 to 50 feet deep, filled with steel and concrete to support the tower. Once the pour is started on a hole, the pour will be continuous until finished. Turner said each leg of the foundation will require 150-200 cubic yards of concrete, or a total in the entire project of approximately 2,640 cubic yards.
“It wlll take a lot of concrete trucks running continuously to fill a hole that size,” Turner stated.
Workers drilled test holes last summer to determine what type of soil and rock is below the surface where the towers will be located.
“They took three-inch bore samples from the various places and determined that they were dealing with dirt, sand, clay and fractured rock,” Turner stated.
“I don’t think the concrete trucks will be fully loaded due to the makeup of the road and how steep it will be,” Turner added. He expected trucks will be partially loaded with six to eight cubic yards.
The six new towers will require the construction company to locate some 750 tons of steel on site.