Santo Ant(o)nio Hpp River Diversion-Inovattive Solution for Cofferdam Construction to Anticipate Power Generation
Plans for the civil construction and electrical and mechanical equipment erectionactivities for Santo Ant(o)nio HPP consideredthe reservoir filling prior to the completionof all the 4 powerhouses, allowing the anticipation of commercial operation and power generationin relation to the original schedule.This special requirement was achieved with the provision of an unusual cofferdam across the riverbed, nominated LR3, to allow the reservoir filling and power generation with only partial conclusion of the river bed structures, with the powerhouses located in both abutments being able to operate and to generate energy.Its characterization as a special cofferdam or a temporary dam is justified by the factthat it was necessary to ensurethe same safety conditionsof usual dams, specially taking into considerationits location at 10 km upstream Porto Velho, a town with 500 thousand inhabitants.In addition, the typical characteristics of a cofferdam as a temporary structure that has tobe removed andbuilt very fast contrary to ausual earth dam were also preponderant.The occurrence of systems of open fractures in the rock foundation, conditioned geotechnical design, preventingthe risk of piping through the foundation.The requirementof performing the river diversion in a single dry season(6 months) demanded innovative solutions to allow the feasibility of the construction schedule.Among these were the construction of some sectors of the cofferdam in the previous dry seasonand the adoption of 90% degree of compaction in an 80 m high earth fill section.These requirements, and the compressed schedule with the power generation anticipation, the cofferdam construction, the river diversion and the LR3 embankment toreach elevation 73 in a single dry season, turned the construction a majorchallenge due to the largevolumesof the cofferdam (about 3.5 million m3) beside logistics, geotechnical-geological and hydrological adversities.This paper presents some geotechnical aspects of the design and construction and the cofferdam s monitoring after reservoir impoundment.Some construction aspects and monitoring data are described to demonstrate LR3 s good behavior, in spite of the hard and nonsingular conditions for foundation, caused by several deep channels in the river section.
Cofferdams river diversion earthfill embankment
Wilson Soares Jr Rogério Piovesan Paulo De (A)vila Pimenta Fernando Dias Resende
Intertechne Consultores Odebrecht/Andrade Gutierrez
国际会议
昆明
英文
719-729
2013-11-01（万方平台首次上网日期，不代表论文的发表时间）