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Pine Valley Creek Bridge
The Pine Valley Creek Bridge, officially named the Nello Irwin Greer Memorial Bridge, is a reinforced concrete box girder bridge in San Diego County, California near the town of Pine Valley. The bridge was built in 1974 as part of the Interstate 8 (I-8) freeway system. At the time of its construction, it was the first bridge constructed in the United States using the segmental balanced cantilever method. The northern span is long while the southern span is long. The two spans rise above the valley floor, placing Pine Valley Creek Bridge among the highest bridges in the United States. Originally known unofficially as the Pine Valley Creek Bridge, a California State Senate concurrent resolution (SCR-33) officially named the bridge in honor of the project engineer, Nello Irwin Greer, responsible for designing the section of I-8 known as the "Pine Valley Project". In the original design, the freeway's routing followed the old U.S. Route 80 (US 80) path through ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Diego County, California
San Diego County (), officially the County of San Diego, is a county in the southwestern corner of the U.S. state of California. As of the 2020 census, the population was 3,298,634, making it California's second-most populous county and the fifth-most populous in the United States. Its county seat is San Diego, the second-most populous city in California and the eighth-most populous city in the United States. It is the southwesternmost county in the 48 contiguous United States, and is a border county. It is also home to 18 Native American tribal reservations, the most of any county in the United States. San Diego County comprises the San Diego-Chula Vista-Carlsbad, CA Metropolitan Statistical Area, which is the 17th most populous metropolitan statistical area and the 18th most populous primary statistical area of the United States as of July 1, 2012. San Diego County is also part of the San Diego–Tijuana transborder metropolitan area, the largest metropolitan area s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reinforced Concrete
Reinforced concrete (RC), also called reinforced cement concrete (RCC) and ferroconcrete, is a composite material in which concrete's relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel bars (rebar) and is usually embedded passively in the concrete before the concrete sets. However, post-tensioning is also employed as a technique to reinforce the concrete. In terms of volume used annually, it is one of the most common engineering materials. In corrosion engineering terms, when designed correctly, the alkalinity of the concrete protects the steel rebar from corrosion. Description Reinforcing schemes are generally designed to resist tensile stresses in particular regions of the concrete that might cause unacceptable cracking and/or structural failure. Modern reinforced concrete can contain varied reinforcing materials made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Box Girder Bridge
A box girder bridge, or box section bridge, is a bridge in which the main beams comprise girders in the shape of a hollow box. The box girder normally comprises prestressed concrete, structural steel, or a composite of steel and reinforced concrete. The box is typically rectangular or trapezoidal in cross-section. Box girder bridges are commonly used for highway flyovers and for modern elevated structures of light rail transport. Although the box girder bridge is normally a form of beam bridge, box girders may also be used on cable-stayed and other bridges. Development of steel box girders In 1919, Major Gifford Martel was appointed head of the Experimental Bridging Establishment at Christchurch, Hampshire, which researched the possibilities of using tanks for battlefield engineering purposes such as bridge-laying and mine-clearing. Here he continued trials on modified Mark V tanks. The bridging component involved an assault bridge, designed by Major Cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the most populated subnational entity in North America and the 34th most populous in the world. The Greater Los Angeles area and the San Francisco Bay Area are the nation's second and fifth most populous urban regions respectively, with the former having more than 18.7million residents and the latter having over 9.6million. Sacramento is the state's capital, while Los Angeles is the most populous city in the state and the second most populous city in the country. San Francisco is the second most densely populated major city in the country. Los Angeles County is the country's most populous, while San Bernardino County is the largest county by area in the country. California borders Oregon to the north, Nevada and Arizona to the ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pine Valley, California
Pine Valley is a community and census-designated place (CDP) in the Cuyamaca Mountains of the Mountain Empire area, in southeastern San Diego County, California. The population was 1,510 at the 2010 census, up from 1,501 at the 2000 census. Geography Pine Valley is named for the locally unique strand of Jeffrey pine (Pinus jeffreyi) found along Pine Valley Creek, a seasonal drainage in the foothills of the Laguna Mountains in central San Diego County. According to the United States Geological Survey, Pine Valley is located 3,736 feet (1,139 m) above sea level, at . Interstate 8 passes east-to-west along the southern border of Pine Valley, and crosses Laguna Summit (altitude ) just to the east of the town. The Sunrise Highway marks the eastern border of the town. According to the United States Census Bureau Pine Valley is located at (32.828184, -116.526583), which is near the center of the Pine Valley census-designated place (CDP). The Pine Valley CDP has a total area of , all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interstate 8 In California
Interstate 8 (I-8) is an Interstate Highway in the southwestern United States. It runs from the southern edge of Mission Bay at Sunset Cliffs Boulevard in San Diego, California, almost at the Pacific Ocean, to the junction with I-10, just southeast of Casa Grande, Arizona. In California, the freeway travels through the San Diego metropolitan area as the Ocean Beach Freeway and the Mission Valley Freeway before traversing the Cuyamaca Mountains and providing access through the Imperial Valley, including the city of El Centro. Crossing the Colorado River into Arizona, I-8 continues through the city of Yuma across the Sonoran Desert to Casa Grande, in between the cities of Phoenix and Tucson. The first route over the Cuyamaca Mountains was dedicated in 1912, and a plank road served as the first road across the Imperial Valley to Yuma; east of there, the Gila Trail continued east to Gila Bend. These were later replaced by U.S. Route 80 (US 80) across Californi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Bridges In The United States By Height
This is a list of the highest bridges in the United States by height over land or water. ''Height'' in this list refers to the distance from the bridge deck to the lowest point on the land, or the water surface, directly below. A bridge's deck height is greater than its ''clearance below'', which is measured from the bottom of the deck structure, with the difference being equal to the thickness of the deck structure at the point with the greatest clearance below. Official figures for a bridge's height are often provided only for the clearance below, so those figures may be used instead of actual deck height measurements. For bridges that span tidal water, the clearance below is measured at the average high water level. The minimum height for inclusion in this list is ', which may be either the ''deck height'' or the ''clearance below'' depending on available references. Note that the following types of bridges are not included in this list: demolished high bridges; historic high b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bridges In San Diego County, California
A bridge is a structure built to span a physical obstacle (such as a body of water, valley, road, or rail) without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually something that is otherwise difficult or impossible to cross. There are many different designs of bridges, each serving a particular purpose and applicable to different situations. Designs of bridges vary depending on factors such as the function of the bridge, the nature of the terrain where the bridge is constructed and anchored, and the material used to make it, and the funds available to build it. The earliest bridges were likely made with fallen trees and stepping stones. The Neolithic people built boardwalk bridges across marshland. The Arkadiko Bridge (dating from the 13th century BC, in the Peloponnese) is one of the oldest arch bridges still in existence and use. Etymology The '' Oxford English Dictionary'' traces the origin of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concrete Bridges In California
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most widely used building material. Its usage worldwide, ton for ton, is twice that of steel, wood, plastics, and aluminum combined. Globally, the ready-mix concrete industry, the largest segment of the concrete market, is projected to exceed $600 billion in revenue by 2025. This widespread use results in a number of environmental impacts. Most notably, the production process for cement produces large volumes of greenhouse gas emissions, leading to net 8% of global emissions. Other environmental concerns include widespread illegal sand mining, impacts on the surrounding environment such as increased surface runoff or urban heat island effect, and potential public health implications from toxic ingredients. Significant research and development is b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Road Bridges In California
A road is a linear way for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets, the main function of roads is transportation. There are many types of roads, including parkways, avenues, controlled-access highways (freeways, motorways, and expressways), tollways, interstates, highways, thoroughfares, and local roads. The primary features of roads include lanes, sidewalks (pavement), roadways (carriageways), medians, shoulders, verges, bike paths (cycle paths), and shared-use paths. Definitions Historically many roads were simply recognizable routes without any formal construction or some maintenance. The Organization for Economic Co-operation and Development (OECD) defines a road as "a line of communication (travelled way) using a stabilized base other than rails or air strips open to public traffic, primarily for the use of road motor vehicles running on their own wheels", whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interstate 8
Interstate 8 (I-8) is an Interstate Highway in the southwestern United States. It runs from the southern edge of Mission Bay at Sunset Cliffs Boulevard in San Diego, California, almost at the Pacific Ocean, to the junction with I-10, just southeast of Casa Grande, Arizona. In California, the freeway travels through the San Diego metropolitan area as the Ocean Beach Freeway and the Mission Valley Freeway before traversing the Cuyamaca Mountains and providing access through the Imperial Valley, including the city of El Centro. Crossing the Colorado River into Arizona, I-8 continues through the city of Yuma across the Sonoran Desert to Casa Grande, in between the cities of Phoenix and Tucson. The first route over the Cuyamaca Mountains was dedicated in 1912, and a plank road served as the first road across the Imperial Valley to Yuma; east of there, the Gila Trail continued east to Gila Bend. These were later replaced by U.S. Route 80 (US 80) across Californi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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