Segmental Bridge Construction

Segmental bridges are made from precast concrete units stressed together with strand or bars. They are generally box girders with a widened top flange, that will form the full width of the carriageway on completion of the bridge. Because of the size of the units they are usually cast on or very close to the construction site in purpose-built plant.

So that there is a good fit when they are joined together in their final position units are normally counter-cast (units are cast against the end of the previous unit, with a suitable bond breaker between the old and the new concrete) . The units are lifted into position and stressed back to the previously installed unit, with a thin layer of epoxy mortar between the two to form a water-tight joint.

Units are built out from the abutments of the bridge or from the piers; in the latter case the units are generally cantilevered in either direction so that the sections under construction balance each other.

Segmental Bridges Construction 3D Animation

This animation shows all major processes involved in construction of a concrete bridge made of concrete segments in a method called “balanced cantilever”. This medium was used as a learning material for contractor’s staff who were new to this technology. Many university teachers also have used this animation to teach their students about this kind of bridge.

Bridge to Russky Island in Vladivostok

The Russky Island Bridge in Russia connects the city of Vladivostok to Russky Island across the Eastern Bosphorus Strait and was built in preparation for the 2012 Asia-Pacific Economic Cooperation Summit held on Russky Island.

The construction project was a collaboration between Russian industrial group USK Most and French company Freyssinet and it was completed in an impressive time of 43 months.

The bridge was officially opened by the Russian Prime Ministr Dmitry Mededev in July 2012.

The Russky Island Bridge is the longest cable-stayed suspension bridge in the world with a total length of 3,100m (10,200 ft). A concrete and steel construction it is 25.5m (97 ft) wide and carries four lanes of traffic on a deck 70m (230 ft) above the water.

There are 11 spans in total with the main central one being 1,104m (3,622 ft) in length. The two A-shaped anchor pylons are 325m (1,066 ft) tall, the second tallest in the world after those on the Millau Viaduct.

The bridge was designed to cope with the area’s extreme climatic conditions of temperature variances of between the -30s and +30s degrees centigrade, storm winds and thick icy layers in winter.

The need for such an expensive and large scale bridge project to the sparsely populated Russky Island was questioned at the time and many feel that it was undertaken in advance of the Summit as a demonstration to its APEC partners of Russia’s industrial might.

It is estimated that the bridge cost in excess of $1 billion.

Beautiful and scary 99 Bending Road in Tianmen Mountain- Zhangjiajie, China

https://www.youtube.com/watch?v=HxzZaOt-1_k&feature=youtu.be

Tianmen Mountain National Forest Park is located in Zhangjiajie, about 8 kilometers from the urban district.

It is approved to be National Forest Park in 1992, boasting abundant up-to- 90% vegetation.

On the mountain there are a wealth of rare species of plant. Old trees grow very high to the sky. A 7.2-km long cable car was constructed in the park, which is said to be the longest of the same type in the world.

With profound cultural background, Tianmen Mountain is always considered as the holy mountain by locals.

A 500-year-old Buddhist temple is nestled in the mountain attracting thousands of prayers every year.

Many legends and stories about the mountain were inherited from generation to generation, which are widely spread in the west of Hunan Province.

Railway Tunnel with China’s Biggest Cross Section Completed in NW China

https://www.youtube.com/watch?v=_cHXjRIwgbo&feature=youtu.be

A railway tunnel with the largest cross sectional area in China was completed Tuesday in the country’s northwest Gansu Province after more than seven years of construction.

Its maximum cross sectional area is 350 square meters, or 2.5 times the size of common railway tunnels, making it the largest ever constructed in China.

The 9,164-meter Xinchengzi tunnel is part of the railway line connecting the province’s capital of Lanzhou with Chongqing Municipality in southwest China.

The complex geological structure on the northeast edge of the Qinghai-Tibet Plateau where the tunnel stands make the excavation work extremely difficult, according to the tunnel’s contractor, China Railway 11th Group Co., Ltd.

The completion of the tunnel will greatly facilitate the operation of the Lanzhou-Chongqing railway line stretching 915 kilometers, said the contractor.