Arch dam: Difference between revisions

[[File:Katse Dam.jpg|thumb|300x300px|The [[Katse Dam]], a 185m185 m high concrete arch dam in [[Lesotho]].]]

The development of arch dams throughout history began with the [[Ancient Rome|Romans]] in the 1st century BC and after several designs and techniques were developed, relative uniformity was achieved in the 20th century. The first known arch dam, the [[Glanum Dam]], also known as the Vallon de Baume Dam, was built by the [[Ancient Rome|Romans]] in [[France]] and it dates back to the 1st century BC.<ref name="smith">{{Citation| last = Smith| first = Norman| title = A History of Dams| place = London| publisher = Peter Davies| year = 1971| isbn = 0-432-15090-0}}</ref><ref name="simsci">{{cite web|title=Key Developments in the History of Arch Dams |url=http://www.lassp.cornell.edu/sethna/SimScience/cracks/advanced/arch_hist1.html |work=Cracking Dams |publisher=SimScience |accessdateaccess-date=20 September 2018 |url-status=live |archiveurlarchive-url=https://web.archive.org/web/20120728110447/http://simscience.org/cracks/advanced/arch_hist1.html |archivedatearchive-date=July 28, 2012 }} from archive.org</ref><ref>{{cite web |last= D.Patrick JAMES |first= Hubert CHANSON |title= Historical Development of Arch Dams. From Cut-Stone Arches to Modern Concrete Designs |url= http://www.traianvs.net/textos/archdams_en.htm |publisher= Barrages.org |accessdateaccess-date= 18 July 2010}}</ref> The dam was about {{convert|12|m|ft}} high and {{convert|18|m|ft}} in length. Its radius was about {{cvt|14|m}}, and it consisted of two masonry walls. The Romans built it to supply nearby [[Glanum]] with water.

The Monte Novo Dam in [[Portugal]] was another early arch [[List of Roman dams and reservoirs|dam built by the Romans]] in 300 AD. It was {{convert|5.7|m}} high and {{cvt|52|m||adj=mid|long}}, with a radius of {{cvt|19|m}}. The curved ends of the dam met with two winged walls that were later supported by two buttresses. The dam also contained two water outlets to drive mills downstream.<ref>{{cite web |last= Chaason |first= Hubert |title= EXTREME RESERVOIR SEDIMENTATION IN AUSTRALIA: A REVIEW |url= http://espace.library.uq.edu.au/eserv/UQ:124112/un_watresjl_98.pdf |work= Resources Journal |accessdateaccess-date= 18 July 2010 |page=101}}</ref>

The Elche[[Tibi Dam]] in [[ElcheTibi, Alicante|Tibi]], [[Spain]] was a post-medieval arch dam built inbetween the1579 1630sand by Joanes del Temple1594 and the first in Europe since the Romans. The dam was {{convert|2642.7|m|feet}} high and {{convert|7565|m|feet}} long, and had a radius of {{convert|62|m|feet}}. This arch dam also rests on winged walls that servedthe asmountains abutmentssides.<ref name="simsci"/>

In the early 20th century, the world's first variable-radius arch dam was built on the [[Salmon Creek Dam|Salmon Creek]] near [[Juneau]], [[Alaska]]. The Salmon Creek Dam's upstream face bulged upstream, which relieved pressure on the stronger, curved lower arches near the abutments. The dam also had a larger toe, which off-set pressure on the upstream heel of the dam, which now curved more downstream. The technology and economical benefits of the Salmon Creek Dam allowed for larger and taller dam designs. The dam was, therefore, revolutionary, and similar designs were soon adopted around the world, in particular by the [[U.S. Bureau of Reclamation]].<ref name="simsci"/>

In 1920, the Swiss engineer and dam designer [[Alfred Stucky]] developed new calculation methods for arch dams,<ref>{{Cite book|url=https://books.google.chcom/books?id=SWHgCQAAQBAJ&pg=PA21&lpg=PA21&dq=montsalvens+arch+dam+stucky&source=bl&ots=insyQft63T&sig=8UOi5mS0_6XfaoD_a6unxu4waE0&hl=fr&sa=X&ved=2ahUKEwiMl-vMv97eAhVCPVAKHW32BZ0Q6AEwBnoECAUQAQ#v=onepage&q=montsalvens&fpg=falsePA21|title=Hydraulic Structures|last=Chen|first=Sheng-Hong|date=2015-06-09|publisher=Springer|isbn=9783662473313|language=en}}</ref>, introducing the concept of [[Elasticity_Elasticity (physics)|elasticity]] during the construction of the [[Lac_de_MontsalvensLac de Montsalvens|Montsalvens]] arch dam in Switzerland, thereby improving the dam profile in the vertical direction by using a parabolic arch shape instead of a circular arch shape.

[[File:Enguri Dam, Georgia.jpg|thumb|left|200px|[[Enguri Dam|The Enguri Dam]] in the CaucasasCaucasus of [[Georgia (country)|Georgia]].]]

Arch dam designs would continue to test new limits and designs such as the double- and multiple-curve. The Swiss engineer [http://www.asst.ch/PIONNIERS/02.Stucky.FR.html Alfred Stucky] and the U.S. Bureau of Reclamation would developdeveloped a method of weight and stress distribution in the 1960s, and arch dam construction in the United States would see its last surge then with dams like the 143-meter double-curved [[Morrow Point Dam]] in Colorado, completed in 1968.<ref>{{cite web|title=Arch Dam Design Concepts and Criteria|url=http://www.dur.ac.uk/~des0www4/cal/dams/conc/concf13.htm|publisher=Durham University|accessdateaccess-date=18 July 2010}}</ref> By the late 20th century, arch dam design reached a relative uniformity in design around the world.<ref name="simsci"/> Currently, the tallest arch dam in the world is the {{convert|305|m|feet}} [[Jinping-I Dam|Jingpin-I Dam]] in [[China]], which was completed in 2013.<ref>{{cite web|url=http://energy.people.com.cn/n/2013/0902/c71661-22774787.html|title=The world's highest arch dam Jinping first production unit|date=2 September 2013|publisher=Economic Times Network|language=Chinesezh|archive-url=https://archive.istoday/20130909181936/http://energy.people.com.cn/n/2013/0902/c71661-22774787.html|archive-date=9 September 2013|url-status=dead|accessdateaccess-date=9 September 2013}}</ref> The longest multiple arch with buttress dam in the world is the [[Daniel-Johnson Dam]] in [[Quebec]], [[Canada]]. It is {{convert|214| meters|feet}} high and {{convert|1314|meters|feet}} long across its crest. It was completed in 1968 and put in service in 1970.<ref>{{cite web|last=Guimont|first=Andréanne|date=3 August 2010|title=Manic 5 : colossal témoin du génie québécois en hydroélectricité|url=http://canada.suite101.fr/article.cfm/manic-5--colossal-temoin-du-genie-quebecois-en-hydroelectricite|publisher=suite101.fr|accessdateaccess-date=30 September 2010|archiveurlarchive-url=https://web.archive.org/web/20100817021129/http://canada.suite101.fr/article.cfm/manic-5--colossal-temoin-du-genie-quebecois-en-hydroelectricite|archivedatearchive-date=17 August 2010|url-status=dead}}</ref>

Other miscellaneous loads that affect a dam include: ice and silt loads, and uplift pressure.<ref name="USBR">{{Citation| last = | first = | title = Design of Arch Dams - Design Manual for Concrete Arch Dams| place = Denver Colorado| publisher = Bureau of Reclamation| year = 1977| isbn = }}</ref>

<ref name="USACE">{{Citation| last = | first = | title = Arch Dam Design - Engineering Manual EM 1110-2-2201| place = Washington DC| publisher = U.S.Army Corps of Engineers| year = 1994| isbn = }}</ref>

Most often, the arch dam is made of concrete and placed in a "V"-shaped valley. The foundation or abutments for an arch dam must be very stable and proportionate to the concrete. There are two basic designs for an arch dam: ''constant-radius dams'', which have constant radius of curvature, and ''variable-radius dams'', which have both upstream and downstream curves that systematically decrease in radius below the crest. A dam that is ''double-curved'' in both its horizontal and vertical planes may be called a '''dome dam'''. Arch dams with more than one contiguous arch or plane are described as '''multiple-arch dams'''. Early examples include the Roman [[Esparragalejo Dam]] with later examples such as the [[Daniel-Johnson Dam]] (1968) and [[Itaipu Dam]] (1982). However, as a result of the failure of the [[Gleno Dam]] shortly after it was constructed in 1923, the construction of new multiple arch dams has become less popular.<ref name="Herzog">{{Cite book |last=Herzog |first=Max A. M.|title=Practical Dam Analysis |publisher=Thomas Telford Publishing |year=1999 |location=London |pages=115, 119–126 |url=https://books.google.com/books?id=gSSEGDjakBYC|isbn=3-8041-2070-9}}</ref>

*; '''Constant Radiiradii Archarch Dam'''dam –: the upstream face of the dam has a constant radius making it a linear shape face throughout the height of the dam. But the inner curves their radius reduces as we move down from top elevation to bottom and thus in cross-section it makes a shape of the triangle.

*; '''Constant angleVariable arch dam''' –: thisthe isradius theof mostboth economicalinner inand construction.outer However,faces forof the third type ofdam arch damvaries strongerfrom foundationbottom isto requiredtop. as itThe involvesradius overhangs atof the abutmentarch sections.is greatest Theat constantthe angletop archand damlowest isat thatlower inelevations. which theThe central anglesangle of the horizontal arch ringsis arealso ofwidened theas samewe magnitudemove at all elevationsupside.

* [[Lago di Luzzone|Luzzone Dam]]