Luzhniki Metro Bridge (Russian

Russian language

Russian is a Slavic language used primarily in Russia, Belarus, Uzbekistan, Kazakhstan, Tajikistan and Kyrgyzstan. It is an unofficial but widely spoken language in Ukraine, Moldova, Latvia, Turkmenistan and Estonia and, to a lesser extent, the other countries that were once constituent republics...

: Лужнецкий метромост), also known as Metromost (Метромост), is a concrete two-level arch bridge

Arch bridge

An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side...

 carrying road and subway over the Moskva River

Moskva River

The Moskva River is a river that flows through the Moscow and Smolensk Oblasts in Russia, and is a tributary of the Oka River.-Etymology:...

 in Moscow

Moscow

Moscow is the capital, the most populous city, and the most populous federal subject of Russia. The city is a major political, economic, cultural, scientific, religious, financial, educational, and transportation centre of Russia and the continent...

, Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

, connecting the city center with Sparrow Hills

Sparrow Hills

Sparrow Hills, Vorobyovy Gory is a hill on the right bank of the Moskva River and one of highest points in Moscow with an altitude up to 220 m ....

. The bridge houses Vorobyovy Gory, the only station of Moscow Metro

Moscow Metro

The Moscow Metro is a rapid transit system serving Moscow and the neighbouring town of Krasnogorsk. Opened in 1935 with one line and 13 stations, it was the first underground railway system in the Soviet Union. As of 2011, the Moscow Metro has 182 stations and its route length is . The system is...

 located above water. Originally built in 1958 by V.G. Andreyev and N.N. Rudomasin (structural engineering

Structural engineering

Structural engineering is a field of engineering dealing with the analysis and design of structures that support or resist loads. Structural engineering is usually considered a specialty within civil engineering, but it can also be studied in its own right....

), the
bridge rapidly decayed and was rebuilt in 1997-2002.

Metro Bridge (1958)

The bridge was officially opened January 12, 1959. Total length with ramps 1,179 meters, arch spans 45 - 108 - 45 meters. The upper deck, 25.8 meters wide, carried 6 lanes of traffic, the lower deck housed Vorobyovy Gory metro station. The bridge was completed in 19 months . The bridge builders used salt to speed up concrete hydration

Mineral hydration

Mineral hydration is an inorganic chemical reaction where water is added to the crystal structure of a mineral, usually creating a new mineral, usually called a hydrate....

; in 1959, it was commissioned with incomplete moisture protection . This caused rapid corrosion

Corrosion

Corrosion is the disintegration of an engineered material into its constituent atoms due to chemical reactions with its surroundings. In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen...

 of rebars and tension cables

Wire rope

thumb|Steel wire rope Wire rope is a type of rope which consists of several strands of metal wire laid into a helix. Initially wrought iron wires were used, but today steel is the main material used for wire ropes....

.

Decay (1958-1997)

July 8, 1959, rain water broke through the station hall roofing and flooded the tracks. In the next years, aluminium and steel parts of the station hall were falling apart, hiding far worse corrosion processes inside the concrete structure. As soon as 1963, examinations signalled imminent danger . By 1983, the bridge lost 60% of its structural load capacity. In 1983, the station was closed, in 1986-87 the subway tracks diverted to temporary steel box girder bridge

Box girder bridge

A box girder bridge is a bridge in which the main beams comprise girders in the shape of a hollow box. The box girder normally comprises either prestressed concrete, structural steel, or a composite of steel and reinforced concrete. The box is typically rectangular or trapezoidal in cross-section...

s (29 meters left and 29 meters right from the main bridge axis).

Reconstruction (1997-2002)

Reconstruction began with the demolition of the station hall, opening access to the main arches. The inner arches remained standing; their concrete bowstring was replaced with a steel tie. Once the arch was reinforced, in 1999, the builders demolished the automobile road deck and the columns that carried it. The new concrete deck was commissioned for automobile traffic in 2000. In July-August 2001, subway traffic returned to the main bridge tracks, the temporary bridges were removed; the restored subway station reopened on December 14th, 2002.

External links

• Russian: Photo gallery www.metromost.com
• Russian: Images of construction and reconstruction metro.molot.ru