The Gleno Dam was a multiple arch buttress dam on the Gleno Creek in the Valle di Scalve, northern Province of Bergamo, Italy. The dam was built between 1916 and 1923 with the purpose of producing hydroelectric power. The middle section of the dam collapsed on 1 December 1923, forty days after the reservoir was filled, causing widespread flooding that killed at least 356 people.[1]
Gleno Dam
The Gleno Dam in 1923, shortly before its partial collapse
The dam was proposed and constructed by the Viganò company. A request to construct it was submitted in 1907 and construction began in 1916. In 1920, construction began on the foundation. In September of that year, local officials were warned that contractors were not using proper cement mortar. In 1921, because of lack of funding, the project design was changed from a gravity dam to a multiple-arch type. The revised design was approved: the multiple arch dam would be constructed on top of the gravity dam foundation.
By January 1923, the dam was 80% complete and by October that same year, it was fully complete and its reservoir full after heavy rains.[1] The dam's power plant had an installed capacity of 3,728 kW (3.7 MW).[2]
Failureedit
The dam after the failure, showing the collapsed section
At 6:30 am on 1 December 1923, a buttress on the dam cracked and subsequently failed. Within minutes, an estimated 4,500,000 m3 (3,648 acre⋅ft)[3] of water gushed from the reservoir at an elevation of 1,535 m (5,036 ft) to the valley below. The village of Bueggio was flooded first, followed by a partial flooding of Dezzo, part of the municipality of Azzone, and complete flooding of Dezzo, a frazione of Colere and Corna di Darfo. The flood waters stopped when they reached Lake Iseo, which lies at an elevation of 186 m (610 ft). At least 356 people were killed in the disaster.[1][2]
Investigationedit
The dam was originally permitted as a gravity dam with a slight curvature, but was changed to a multiple arch dam by the client to save money.[4]
The permit was not revised for this change until after the dam was completed. The failure of the multiple arch dam was attributed to many aspects of its construction, ultimately poor workmanship. The concrete in the arches was of a poor quality and it was reinforced with anti-grenade scrap netting that had been used during World War I.
There were also indications that the dam was poorly joined with its foundation.[3] Additionally, the concrete was believed not to be completely cured when the reservoir was filling. Reportedly, workers who complained about the construction techniques were fired.[citation needed]
Legacyedit
The ruins of the dam in 2019, with the new, smaller dam bridging the gap left by the collapse
The dam's failure was influential in the development of Italian dam design and risk assessment.[5] As a result of the accident, multiple arch dams fell out of favour.[4]
A much smaller dam was built spanning the gap left by the collapse, and is still in use today, creating a minor reservoir. A memorial at the site commemorates the tragedy.[1]
Referencesedit
^ abcd"The Curious Traveler: Ride II The Ruins of Gleno Dam" (in Italian). Biblioteca Italia Grassi. Retrieved 10 March 2011.
^ ab"La diga Gleno" (in Italian). Scalve.it. Retrieved 10 March 2011.
^ abRatnayaka, Don D.; Brandt, Malcolm J.; Johnson, K. Michael (2009). Twort's water supply (6th ed.). Oxford: Butterworth-Heinemann. p. 191. ISBN978-0-7506-6843-9.
^ abHerzog, Max A. M. (1999). Practical Dam Analysis. London: Thomas Telford Publishing. pp. 115, 119–126. ISBN3-8041-2070-9 – via Google Books.
^Marco Pilotti; Andrea Maranzoni; Massimo Tomirotti; Giulia Valerio. "The 1923 Gleno Dam‐Break: Case Study and Numerical Modelling". American Society of Civil Engineers: Journal of Hydraulic Engineering. Retrieved 10 March 2011.
External linksedit
Media related to Gleno Dam at Wikimedia Commons
Gleno Dam History at Scalve.it (Italian and English)
gleno, multiple, arch, buttress, gleno, creek, valle, scalve, northern, province, bergamo, italy, built, between, 1916, 1923, with, purpose, producing, hydroelectric, power, middle, section, collapsed, december, 1923, forty, days, after, reservoir, filled, cau. The Gleno Dam was a multiple arch buttress dam on the Gleno Creek in the Valle di Scalve northern Province of Bergamo Italy The dam was built between 1916 and 1923 with the purpose of producing hydroelectric power The middle section of the dam collapsed on 1 December 1923 forty days after the reservoir was filled causing widespread flooding that killed at least 356 people 1 Gleno DamThe Gleno Dam in 1923 shortly before its partial collapseLocation of Gleno Dam in ItalyOfficial nameDiga del GlenoCountryItalyCoordinates46 00 59 N 10 04 30 E 46 01639 N 10 07500 E 46 01639 10 07500StatusFailed surviving structure standingConstruction began1916Opening date1923Demolition date1 December 1923Dam and spillwaysImpoundsGleno RiverHeight43 m 141 ft ReservoirCreatesGleno ReservoirTotal capacity4 500 000 m3 3 648 acre ft Power StationCommission date1923Decommission date1923Installed capacity3 728 kW Contents 1 Construction 2 Failure 3 Investigation 4 Legacy 5 References 6 External linksConstruction editThe dam was proposed and constructed by the Vigano company A request to construct it was submitted in 1907 and construction began in 1916 In 1920 construction began on the foundation In September of that year local officials were warned that contractors were not using proper cement mortar In 1921 because of lack of funding the project design was changed from a gravity dam to a multiple arch type The revised design was approved the multiple arch dam would be constructed on top of the gravity dam foundation By January 1923 the dam was 80 complete and by October that same year it was fully complete and its reservoir full after heavy rains 1 The dam s power plant had an installed capacity of 3 728 kW 3 7 MW 2 Failure edit nbsp The dam after the failure showing the collapsed section At 6 30 am on 1 December 1923 a buttress on the dam cracked and subsequently failed Within minutes an estimated 4 500 000 m3 3 648 acre ft 3 of water gushed from the reservoir at an elevation of 1 535 m 5 036 ft to the valley below The village of Bueggio was flooded first followed by a partial flooding of Dezzo part of the municipality of Azzone and complete flooding of Dezzo a frazione of Colere and Corna di Darfo The flood waters stopped when they reached Lake Iseo which lies at an elevation of 186 m 610 ft At least 356 people were killed in the disaster 1 2 Investigation editThe dam was originally permitted as a gravity dam with a slight curvature but was changed to a multiple arch dam by the client to save money 4 The permit was not revised for this change until after the dam was completed The failure of the multiple arch dam was attributed to many aspects of its construction ultimately poor workmanship The concrete in the arches was of a poor quality and it was reinforced with anti grenade scrap netting that had been used during World War I There were also indications that the dam was poorly joined with its foundation 3 Additionally the concrete was believed not to be completely cured when the reservoir was filling Reportedly workers who complained about the construction techniques were fired citation needed Legacy edit nbsp The ruins of the dam in 2019 with the new smaller dam bridging the gap left by the collapse The dam s failure was influential in the development of Italian dam design and risk assessment 5 As a result of the accident multiple arch dams fell out of favour 4 A much smaller dam was built spanning the gap left by the collapse and is still in use today creating a minor reservoir A memorial at the site commemorates the tragedy 1 References edit a b c d The Curious Traveler Ride II The Ruins of Gleno Dam in Italian Biblioteca Italia Grassi Retrieved 10 March 2011 a b La diga Gleno in Italian Scalve it Retrieved 10 March 2011 a b Ratnayaka Don D Brandt Malcolm J Johnson K Michael 2009 Twort s water supply 6th ed Oxford Butterworth Heinemann p 191 ISBN 978 0 7506 6843 9 a b Herzog Max A M 1999 Practical Dam Analysis London Thomas Telford Publishing pp 115 119 126 ISBN 3 8041 2070 9 via Google Books Marco Pilotti Andrea Maranzoni Massimo Tomirotti Giulia Valerio The 1923 Gleno Dam Break Case Study and Numerical Modelling American Society of Civil Engineers Journal of Hydraulic Engineering Retrieved 10 March 2011 External links edit nbsp Media related to Gleno Dam at Wikimedia Commons Gleno Dam History at Scalve it Italian and English Portals nbsp Italy nbsp Water nbsp Renewable energy Retrieved from https en wikipedia org w index php title Gleno Dam amp oldid 1187798643, wikipedia, wiki, book, books, library,
