LUIS VALENZUELA P, RAMON VERDUGO A, JOSE CAMPANA Z & CARMEN G OPAZO A
3. Earth Dams in Chile
Although there are references to some water dams being built between 1838 and 1853, the first dam to be registered in Chile is one commissioned in 1853. The history associated with some older dams built before 1953 is confused since after the destruction of some dams (by a mudflow in 1877 and the 1928 earthquake for example), quite frequently the replacement dams were given the same name.
The comments on earth dams will be separated into three periods: the first covers the
period 1853-1928 with dams built mainly by private agricultural associations; a second period from 1930 to 1950 where dams were built mainly by the Chilean State (and some agriculture associations); and finally a third period from 1950 to present day, considering that after 1950 geotechnical and seismic engineering had been developed and was constantly evolving and improving. In the last decades dams have started to be built higher and, consequently, have become more relevant in terms of the importance of their safety.
3.1 Earth dams built between 1853 and 1928
Between 1853 and 1928 many earth dams were built and owned privately, and usually operated by irrigation associations. These facts have made it difficult to obtain details of the operation, seismic performance, and present condition of many of these dams. Many are of modest height, <15m. In this paper only dams with a height of 15m or more have been considered, in accordance with the dam register published by ICOLD Chile in 1996[1]. The dams built during the period 1853-1928, in the Central region of Chile, have been subjected to the impact of several strong earthquakes with magnitude M ≥ 7.5, at relatively short distances from the epicentres – typically in the order of 100-150km – so even if there is no detailed report on earthquake damage to these dams most probably many of them needed some repair work during their life period.
This register mentions eleven earth dams built in this period with heights(1) varying from 14m to 28m, including Catapilco, a 15m high earth dam commissioned in 1853, being the first dam registered in Chile for which information is available. With the creation in 1887 of the Ministry of Industry & Public Works (now the Ministry of Public Works (MOP)), the first dam commissioned by the Chilean State is the 22m high Peñuelas dam with construction completed in 1900 which is operated until now as part of the water supply system of the city of Valparaiso. It is not a typical earth dam but one with a complex zoned cross-section formed by bricks and clay covered by rockfill shoulders on both slopes (1V:2.5H upstream and 1V:2.0H downstream). There are no reports of any significant damage during earthquakes to either of these two dams[8].
It has been reported that Llui Lliu dam (20m high) and Las Palmas de Quilpué dam (16m high) suffered significant damage during the earthquakes of March 1965 and July 1971[9]. The 1985 earthquake of M = 8.0 caused significant damage to Lliu Lliu dam, and provoked the failure of Las Palmas de Quilpue dam and La Marquesa (10m high) dam. The failure of these last two was induced by liquefaction of the sandy soil foundation[10]. It should be
194 DAM ENGINEERING Vol XXXI Issue 3
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95
