Pile Foundation Functions


When the soil beneath the level at which a footing or raft would normally be established is too weak or too compressible to provide adequate support, the loads are transferred to more suitable material at a greater depth by means of piles or piers. The distinction between the two is somewhat arbitrary.

Piles

Piles are the structural members of small cross-sectional area compared to their length, and are usually instated by a driver consisting of a hammer or a vibrator. They are often grouped into clusters or rows, each containing enough piles to support the load delivered by a single column or wall.

Pile Foundation Functions   Why Piles Are Used ase129

Important Factors To Consider During Pile Design

A lightly loaded column may, in some instances, require only a single pile. However, since under field conditions the actual position of a pile may be  as much as several inches from its planned location, an eccentric loading can hardly be avoided. Consequently, the heads of single piles are usually braced in two directions by grade beams. If only two piles are needed, their heads may be connected by a concrete cap braced by grade means in only one direction, perpendicular to the line joining the two piles Fig.1(b). Clusters containing three or more piles are provided with reinforced concrete caps, as shown in Fig.1(c), and are considered stable without support by grade beams.

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Vertical piles may also be used to resist lateral loads as for example, beneath a tall chimney subject to wind. Compared to their axial capacity, the lateral capacity is usually small. Where large lateral loads are to be used (Fig.1d.) Batters of 4 horizontal : 12 vertical represent about the greatest inclination that can be achieved with ordinary driving equipment. Economy usually favors smaller inclinations even if more piles have to be battered.

Functions of Pile Foundation

Piles are used if the bearing capacity of soil at shallow depth is not enough to withstand the structural load. So the piles are driven  to transfer the loads from the structure to the high bearing capacity soil/rock stratum. The main functions of using pile foundations are listed below in short.

  • To transfer the load from the structure to the foundation at a greater depth where the \bearing capacity of soil is efficient to withhold the structure loads.
  • Pile controls the soil settlement which can be accompanied by surface foundations.
  • Piles are used to increase the safety factor for high loaded structures.
  • Piles enable the scope of construction in very low bearing capacity soils

Note : Article Courtesy : http://civilengineersforum.com/function-of-pile-foundation/

25 Tallest Dams In The World


Throughout history man has been building dams for various reasons, whether it was to prevent floods, generate electricity, or create a water supply. Starting thousands of years ago in the middle east as small walls, today dams are immensely huge power generation facilities that fulfill a number of tasks and take years to build. So, whether you recognize the impact these architectural wonders have had on your life or not, these are the 25 tallest dams in the world. (courtesy: http://list25.com)

25  Toktogul Dam

A hydroelectric and irrigation dam on the Naryn River in the Jalal-Abad Province of Kyrgyzstan, this dam is the shortest on our list at 215 meters high.

Toktogul Dam

24  Longtan Dam

Longtan DamLongtan Dam is a large roller-compacted concrete gravity dam on the Hongshui River in China. It stands at 216.5 meters.

23  Glen Canyon Dam

Glen Canyon DamNamed for Glen Canyon, a colorful series of gorges most of which now lies under the reservoir, the dam created the second largest artificial lake in the United States.

22 Dworshak Dam

Dworshak DamAt 219 meters, Dworshak is the third tallest dam in the United States and the tallest straight-axis concrete dam in the Western Hemisphere.

21 Contra Dam, Switzerland

Contra DamCommonly known as the Verzasca Dam and the Locarno Dam, the Contra is an arch dam on the Verzasca River in Switzerland.

20  Hoover Dam, Arizona

Hoover DamOnce known as Boulder Dam, the Hoover 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.

19  Luzzone Dam, Switzerland

Luzzone DamFeaturing the world’s highest artificial climbing wall on one of its sides, this dam stands at 225 meters.

18  Bhakra Dam, India 

Bhakra DamThis is a concrete gravity dam across the Sutlej River near the border between Punjab and Himachal Pradesh in northern India.

17  Karun-4 Dam, Iran

Karun-4 DamAn arch dam on the Karun River in Iran its primary objectives are electric power supply and flood control.

16  Shuibuya Dam, China

Shuibuya DamBuilt not just for power but also to promote flood control, navigation, tourism and fishery, the Shuibuya Dam is 233 meters tall.

15  Chirkey Dam, Russia

Chirkey DamThis arch dam on the Sulak River is the tallest arch dam in Russia at 232.5 meters.

14  El Cajón Dam, Honduras

El Cajón DamOfficially known as Central Hidroeléctrica Francisco Morazán, this dam is a hydroelectric power plant located in Western Honduras.

13  Oroville Dam, California

Oroville DamAt 230 meters high this earthfill embankment dam on the Feather River in California is the tallest in the United States.

12  Ertan Dam, China

Ertan DamThis 240 meter high arch dam can be found on the Yalong River, a tributary of the Yangtze River in Sichuan Province, southwest China

11  Sayano–Shushenskaya Dam, Russia

Sayano–Shushenskaya DamLocated on the Yenisei River, near Sayanogorsk in Russia, this dam is the largest power plant in the country and the sixth-largest hydroelectric plant in the world.

10  Mica Dam, Canada

Mica DamThis 243 meter high dam spans the Colombia River 135 kilometres north of Revelstoke, Canada.

9  Deriner Dam, Turkey

Deriner DamNamed after İbrahim Deriner, who died while serving as the Chief Engineer of its research team, the dam is located on the Çoruh River 3 miles east of Artvin, Turkey.

8  Laxiwa Dam, China

Laxiwa DamThe Laxiwa Dam is a 250 meter high arch dam on the Yellow River in Qinghai Province, northwest China.

7  Mauvoisin Dam, Switzerland

Mauvoisin DamWith Mont Blanc de Cheilon in the background the Mauvoisin Dam creates the Lac de Mauvoisin in the Swiss alps.

6  Tehri Dam, India

Tehri DamThis multi-purpose rock and earth-fill embankment dam on the Bhagirathi River near Tehri in Uttarakhand, India is 261 meters high.

5  Vajont Dam, Italy

Vajont DamA disused dam north of Venice, Italy, in 1963 a landslide caused the overtopping of the dam and around 2,000 deaths.

4  Inguri Dam, Georgia

Inguri DamThis hydroelectric dam on the Inguri River in Georgia is the second highest concrete arch dam in the world.

3  Grande Dixence Dam, Switzerland

Grande Dixence DamA concrete gravity dam on the Dixence River in Switzerland, at 285 meters it is the tallest of its kind in the world.

2  Xiaowan Dam, China

Xiaowan DamAn arch dam on the Lancang (Mekong) River in China, its primary purpose is to provide hydroelectric power.

1  Nurek Dam, Tajikistan

Nurek DamThis earth fill embankment dam on the Vakhsh River in Tajikistan is currently the tallest dam in the world at 300 meters.

Beirut Terraces by Herzog & de Meuron


Herzog & de Meuron Beirut Terraces

Swiss architects Herzog and de Meuron have designed this apartment tower with overhanging floor plates and terraces for Beirut, Lebanon.

Herzog & de Meuron Beirut Terraces

Created as part of a wider masterplan to regenerate this area of the city that includes a marina, the building will comprise five different modular floor slabs used in varying combinations to create a mixture of overhangs and terraces.

Herzog & de Meuron Beirut Terraces

The building will have vegetation on the terraces to provide privacy and in the main entrance space to act as continuation of the neighbouring green boulevard.

Herzog & de Meuron Beirut Terraces

The 116 metre-high structure will be supported by columns on a 14.7 metre regular grid, with each floor plate overhanging the glazing by at least 60 centimetres.

Beirut Terraces Herzog & de Meuron

129 single, duplex and townhouse apartments will be available, arranged in different clusters throughout the tower.

Herzog & de Meuron Beirut Terraces

The project is due for completion in 2013.

Herzog & de Meuron Beirut Terraces

NOTE:
Courtesy: http://www.dezeen.com/2010/07/27/beirut-terraces-by-herzog-de-meuron/