SAFETY PERFORMANCE OF DAMS IN CHILE’S HIGHLY SEISMIC ENVIRONMENT In summary the study of dams built from 1853 up to 2015 showed that:


• No concrete dams (built between 1910 and 2012) have suffered significant damage. • Only two relatively small earth dams, built in the 1920s by private agricultural associations, have suffered serious damage. Other private irrigation small earth dams have suffered some reparable damage.


• No major earth dam, rockfill dam or gravel dam has suffered significant damage, except Cogotí rockfill dam and Coihueco earth dam which suffered reparable damage. • No large tailings dam built after 1965 have failed or suffered meaningful damage.


The notably successful performance of dams of all types under the extreme conditions imposed by the high seismicity of Chile could be explained by the empirical experience developed inside the country, in government institutions, individual professionals and engineering companies always conscious of foreign experience and the recommendations and guidelines of international institutions like ICOLD.


It is important to mention that in the particular case of tailings dams, after the collapse or flow failure of El Cobre dam which occurred in 1965, the upstream method of construction, as was applied by Chilean practice, was banned by law in 1970. There have been no upstream tailings dams approved and built in Chile after 1965. The tailings dams that have failed after 1965 are mostly relatively small upstream tailings dams built before 1965. The Chilean experience can be used as empirical evidence showing that all types of dams – including tailings dams – are safe structures if designed and constructed according to sound engineering concepts, and following the recommendations of the best available practice. It is worth noting that during the last 40-50 years Chilean dam engineers have developed considerable knowledge and experience, especially with two types of dams, which have performed successfully under the seismic conditions of the country: concrete face gravel fill dams founded on alluvial soils including a diaphragm wall connected to the concrete plinth, and downstream sand tailings dams reaching heights over 200m.


(1)Heights in the ICOLD register are measured between the crest elevation and the lower point of the downstream slope. In most other references it is measured as the difference between crest elevation and foundation elevation in the vertical at the centre of the crest. Heights not registered by ICOLD are noted as m*.


Vol XXXI Issue 3 DAM ENGINEERING 231


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