Portugues Dam
Encyclopedia
The Portugués Dam is a roller-compacted concrete
thick arch dam
that is currently (October 2011) under construction on the Portugués River, three miles (5 km) northwest of the city Ponce
, in Barrio Tibes
, Ponce, Puerto Rico
. Construction on the dam began in April 2008, soon after the U.S. Army Corps of Engineers, Jacksonville District awarded the Spanish
firm Dragados USA with a $180 million contract in March 2008 to build the dam.
The primary purpose of the dam is flood control
and when completed, it will provide flood protection for 40,000 people and over 13,000 residential structures. The dam is the final component of the Portugues and Bucana Flood Protection Project and the first dam of its type constructed by the U.S. Army Corps of Engineers in the United States
or Caribbean
. The final cost of the dam is estimated at $375 million; 75% is funded by the U.S. Government and 25% by the Government of Puerto Rico
.
ing and foundation curtain grouting
along with the excavation of 350000 cubic yards (267,594.2 m³) of material for the left and right abutment
s took place.
When the dam was advertised for construction in 2000, only one proposal that was above government budget was received. To reduce costs, a five-year technical review program was developed in order to investigate new, cheaper designs for the dam. The program resulted in a lower cost design, switching from the double-curvature thin arch to a single-centered roller-compacted concrete thick arch. Proposals for the dam were requested in 2007 and Dragados USA was awarded with a $180 million contract in March 2008 to finish the dam project.
Construction on the dam began in April 2008 and will consist of five-phases:
As of March 2011, Phase 3 work underway and the project is 48% complete. The rolled-compacted concrete production facilities have been completed, 700,500 tons of aggregate
(for use in concrete) has been produced while foundation preparation continues. RCC placement has been placed in 47 ft (14 m) of dam. Construction is expected to be completed by 2012.
center-left side, over the river bed; 21 ft (6.4 m). below the dams crest of 534.6 ft (162.9 m). above sea level . The center of the dam will straddler an intake and outlet structure which will draw water from behind the dam and discharge it into the river valley.
ceremonial plaza, "batey
" or ball court used by the ancient Taino
s was discovered at a disposable site for the Portugues Dam's construction. A 60 ft (18.3 m). long row of intricately carved stones bearing petroglyph
s that appeared to date to the 11th or 12th Century was also discovered. Additionally, a burial ground containing 40 well-preserved sets of human remains was discovered. 15% percent of the site is believed to be discovered and as many as 400 bodies may be buried. The site had been initially marked during a cultural resource survey in 1979 but excavation work in 2007 prompted the major discovery.
The USACE found an alternate disposal site and performed mitigation work in order to preserve the site, adding $3 million in additional project costs. Despite objections of locals, the USACE was bound by federal law and had to transport artifacts and human remains to a federally-approved laboratory in Georgia
. The artifacts and human remains will be returned to Puerto Rico
when the investigation is complete. The site is covered and awaiting future excavation.
Roller-compacted concrete
Roller-compacted concrete or rolled concrete is a special blend of concrete that has essentially the same ingredients as conventional concrete but in different ratios, and increasingly with partial substitution of fly ash for Portland cement. RCC is a mix of cement/fly ash, water, sand, aggregate...
thick arch dam
Arch dam
An arch dam is a type of dam that is curved and commonly built with concrete. The arch dam is a structure that is designed to curve upstream so that the force of the water against it, known as hydrostatic pressure, presses against the arch, compressing and strengthening the structure as it pushes...
that is currently (October 2011) under construction on the Portugués River, three miles (5 km) northwest of the city Ponce
Ponce, Puerto Rico
Ponce is both a city and a municipality in the southern part of Puerto Rico. The city is the seat of the municipal government.The city of Ponce, the fourth most populated in Puerto Rico, and the most populated outside of the San Juan metropolitan area, is named for Juan Ponce de León y Loayza, the...
, in Barrio Tibes
Tibes
Tibes is one of the 31 barrios in the municipality of Ponce, Puerto Rico. Together with Magueyes, Portugues, Monte Llano, Maragüez, Machuelo Arriba, Sabanetas, and Cerrillos, Tibes is one of the municipality's eight rural interior barrios...
, Ponce, Puerto Rico
Ponce, Puerto Rico
Ponce is both a city and a municipality in the southern part of Puerto Rico. The city is the seat of the municipal government.The city of Ponce, the fourth most populated in Puerto Rico, and the most populated outside of the San Juan metropolitan area, is named for Juan Ponce de León y Loayza, the...
. Construction on the dam began in April 2008, soon after the U.S. Army Corps of Engineers, Jacksonville District awarded the Spanish
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
firm Dragados USA with a $180 million contract in March 2008 to build the dam.
The primary purpose of the dam is flood control
Flood control
In communications, flood control is a feature of many communication protocols designed to prevent overwhelming of a destination receiver. Such controls can be implemented either in software or in hardware, and will often request that the message be resent after the receiver has finished...
and when completed, it will provide flood protection for 40,000 people and over 13,000 residential structures. The dam is the final component of the Portugues and Bucana Flood Protection Project and the first dam of its type constructed by the U.S. Army Corps of Engineers in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
or Caribbean
Caribbean
The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...
. The final cost of the dam is estimated at $375 million; 75% is funded by the U.S. Government and 25% by the Government of Puerto Rico
Government of Puerto Rico
The Government of Puerto Rico is a republican form of government subject to U.S. jurisdiction and sovereignty. Its current powers are all delegated by the United States Congress and lack full protection under the United States Constitution...
.
History & construction
Since the 1970s, The U.S. Army Corps of Engineers (USACE) had been investigating a site to build the Portugues Dam. Despite the many different geographic challenges, the USACE was able to choose a suitable dam location and double-curvature thin arch dam design in the 1980s. In the 1990s, foundation test groutGrout
Grout is a construction material used to embed rebars in masonry walls, connect sections of pre-cast concrete, fill voids, and seal joints . Grout is generally composed of a mixture of water, cement, sand, often color tint, and sometimes fine gravel...
ing and foundation curtain grouting
Grout curtain
Grout curtains are barriers that protect a dam from seepage and can be used in initial construction or repair. Additionally, they can be used to strengthen foundations and contain spills.-Characteristics:...
along with the excavation of 350000 cubic yards (267,594.2 m³) of material for the left and right abutment
Abutment
An abutment is, generally, the point where two structures or objects meet. This word comes from the verb abut, which means adjoin or having common boundary. An abutment is an engineering term that describes a structure located at the ends of a bridge, where the bridge slab adjoins the approaching...
s took place.
When the dam was advertised for construction in 2000, only one proposal that was above government budget was received. To reduce costs, a five-year technical review program was developed in order to investigate new, cheaper designs for the dam. The program resulted in a lower cost design, switching from the double-curvature thin arch to a single-centered roller-compacted concrete thick arch. Proposals for the dam were requested in 2007 and Dragados USA was awarded with a $180 million contract in March 2008 to finish the dam project.
Construction on the dam began in April 2008 and will consist of five-phases:
- Phase 1 – $24.5 M - Mobilization, clearing, quarry overburden excavation, power-line relocation
- Phase 2 – $47.6 M - Foundation excavation, aggregate Production, dental Concrete
- Phase 3 – $37.3 M - Aggregate production, ½ dam RCC placement
- Phase 4 – $41.1 M - Final dam RCC placement, spillway, intake structure
- Phase 5 – $29.7 M - Remaining items, valve house, access road, mechanical, electrical.
As of March 2011, Phase 3 work underway and the project is 48% complete. The rolled-compacted concrete production facilities have been completed, 700,500 tons of aggregate
Aggregate (composite)
Aggregate is the component of a composite material that resists compressive stress and provides bulk to the composite material. For efficient filling, aggregate should be much smaller than the finished item, but have a wide variety of sizes...
(for use in concrete) has been produced while foundation preparation continues. RCC placement has been placed in 47 ft (14 m) of dam. Construction is expected to be completed by 2012.
Dam characteristics
When completed, the Portugues Dam will be a 220 feet (67.1 m) high and 1230 feet (374.9 m) long single-centered roller-compacted concrete thick arch. Containing 367000 cubic yards (280,591.6 m³) of roller-compacted concrete, it will be 110 feet (33.5 m) thick at its base and 35 feet (10.7 m) thick at its crest. The dam will have an uncontrolled spillwaySpillway
A spillway is a structure used to provide the controlled release of flows from a dam or levee into a downstream area, typically being the river that was dammed. In the UK they may be known as overflow channels. Spillways release floods so that the water does not overtop and damage or even destroy...
center-left side, over the river bed; 21 ft (6.4 m). below the dams crest of 534.6 ft (162.9 m). above sea level . The center of the dam will straddler an intake and outlet structure which will draw water from behind the dam and discharge it into the river valley.
Archeological findings
During excavation, a 130 x 160 ft (48.8 m). Pre-Columbian eraPre-Columbian era
The pre-Columbian era incorporates all period subdivisions in the history and prehistory of the Americas before the appearance of significant European influences on the American continents, spanning the time of the original settlement in the Upper Paleolithic period to European colonization during...
ceremonial plaza, "batey
Batey (game)
batey was the name given to a special plaza around which the native Caribbean Taino Indians built their settlements. It was usually a rectangular area surrounded by stones with carved symbols known as petroglyphs....
" or ball court used by the ancient Taino
Taíno people
The Taínos were pre-Columbian inhabitants of the Bahamas, Greater Antilles, and the northern Lesser Antilles. It is thought that the seafaring Taínos are relatives of the Arawak people of South America...
s was discovered at a disposable site for the Portugues Dam's construction. A 60 ft (18.3 m). long row of intricately carved stones bearing petroglyph
Petroglyph
Petroglyphs are pictogram and logogram images created by removing part of a rock surface by incising, picking, carving, and abrading. Outside North America, scholars often use terms such as "carving", "engraving", or other descriptions of the technique to refer to such images...
s that appeared to date to the 11th or 12th Century was also discovered. Additionally, a burial ground containing 40 well-preserved sets of human remains was discovered. 15% percent of the site is believed to be discovered and as many as 400 bodies may be buried. The site had been initially marked during a cultural resource survey in 1979 but excavation work in 2007 prompted the major discovery.
The USACE found an alternate disposal site and performed mitigation work in order to preserve the site, adding $3 million in additional project costs. Despite objections of locals, the USACE was bound by federal law and had to transport artifacts and human remains to a federally-approved laboratory in Georgia
Georgia (U.S. state)
Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
. The artifacts and human remains will be returned to Puerto Rico
Puerto Rico
Puerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...
when the investigation is complete. The site is covered and awaiting future excavation.