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Settlement Monitoring of Embankment Dams: Case Study of Gurara Dam, North Central Nigeria

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Abstract (2. Language): 
Embankment Settlement in earth dam is common at post construction. Settlement also occurs during construction where compaction of fill materials is below optimum level specified in the design. This study analysed post Settlement of Gurara Multipurpose Dam built on the Gurara River near Abuja, the capital of Nigeria. Seven monitoring devices such as Electrical Vibrating Wire Piezometers (EVW), Standpipe Piezometers, Relief Wells, Finger Drains, Differential Settlement Monitoring (DSM), V-notch and Concrete Block Tape Extensometer were used in Gurara Multipurpose dam. Data obtained from DSM devices was used in the settlement analysis. Ten year (2004-2014) data were obtained at seven control stations of the crest settlement data of the embankment. There are seven sections and each section comprises of three DSM devices, except section 22 which has only two. The dimensionless parameter known as settlement index (Si) and the percentage of the dam elevation P (%) that settled at each section were calculated for each of the seven sections. The measured difference in relative height P(field) and the calculated percentage of the dam elevation P(%) that settled at each section were plotted to ascertain the deviation limit of the dam crest. The study showed that the maximum value of the settlement index (Si) for each set of measurements at all sections was significantly lower than the threshold value of 0.02. Also the P (%) was less than 1% in all the sections indicating absence of creep or secondary consolidation of the embankment material.
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REFERENCES

References: 

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