The Hoover Dam By SYED ALMAS ALI B.TECH,CIVIL ENGG. VIT UNIVERSITY
Hoover Dam, once known as Boulder Dam, is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the US states of Arizona and Nevada. It was constructed between 1931 and 1936 during the Great Depression and was dedicated on September 30, 1935, by President Franklin D. Roosevelt
Construction of the Hoover dam At the time the dam cost 49$ million to construct. The dam is 726 feet high, 660 ft thick, and is 1244 ft long. Hoover Dam required over 3,250,000 cubic yards of concrete plus another million for the power plant, intake towers and other support structures. With the dams building complete, in 1935 Hoover Dam became the largest dam in the world.
About the Construction of the Hoover Dam Geological specialists inspected the volcanic bedrock and found fault lines that were solid enough to support the structure. Also they sent out surveying parties to make contour maps showing that the area would hold 31 million acre feet of water. The office engineering staff was busy making system analyses, drawings, specifications, schedules, and cost estimates. The work on the Dam was finished in the late 1930’s which was six months ahead of the projected time.
DIVERSION TUNNELS Two 50-foot diameter tunnels drilled into the canyon. The tunnels diverted the water around the dam while it was being constructed The tunnels area combined 3 miles in length
The Canyon The river over millions of years sunk down into the canyon This created many crevasses and loose rocks, which had to be removed
Building Materials Use of quick-dry concrete This called for the concrete to be required to be moved quickly from the production plant to the dam site. . If it was not moved quickly enough it would set, and had to be scraped out by hand
One of the biggest challenges that theengineers faced in construction ofthe dam was pouringthe concrete. With 4.36 million cubicyards of concrete this became aproblem fast. The material used forconcrete would create internal heatingwhen mixed with water. The internalheat became a problem, because itwould form cracks, which wouldweaken the structure and causethe curing process to slow down. Toresolve the problem the dam wasbuilt in a series of interlocking blocks.The blocks were connected by coolingpipes, which cooled the concrete as itwas poured into the blocks. The coolingof the concrete did not allow heat todevelop and the curing process wasable to proceed faster.
Need for the Hoover DamThe Colorado River was growing out of control Flooding increased rapidly The surrounding states needed water to support people • Arizona • Wyoming • Colorado • New Mexico • Utah
Serving the Public Electricity –Supplies 1.3 million people with electricity Water –Supplies surrounding states with drinking water Flood Prevention –Prevents floods by holding water back
Disservice to the Public Releases Methane –Still water causes organic matter to die, releasing methane. River bed Lowering –The pressure of the still water is digging into the river bed Destroys Natural ecosystems –Many animals lose their shelters Water Quality is disturbed
Water Quality The amount of dissolved oxygen is lowered because the water is still. The temperature is cooler than the normal river.
River bed Lowering The river bed is lowering due to the water building up In 9 years , the water table sank 4 meters.