Siesmic analysis |
repaired immediately after the earthquake. A damaged vertical joint is shown in Figure. 4. Among seismologists there was speculation that
the Wenchuan earthquake may have been a reservoir- triggered event. This is not correct, as since 2008, when this earthquake happened, no observational evidence has been found that supports this claim. Eleven months after the Wenchuan earthquake 13 international dam and earthquake engineering experts participated in a joint ICOLD- CHINCOLD mission and visited several damaged dams, including the Zipingpu CFRD. The issue of reservoir-triggered seismicity was also discussed as such hypothetical theories appeared in the international press shortly after the earthquake. The Zipingpu CFRD and Wenchuan County are close to Chengdu where the 28th ICOLD Congress was held.
ICOLD Congress in Chengdu During the recent ICOLD Congress in Chengdu, China,
dams, run-of-river power plants, power plants and
Above and below – Figure 4: Damage of the 156 m high Zipingpu concrete faced rockfill dam caused by the magnitude 7.9 Wenchuan Earthquake in China on May 12, 2008: Repaired vertical joint of face slab with joint sealing (above) and details of damaged vertical joint (below)
reservoirs, most of them in Sichuan Province. A special feature of this earthquake was the large number of rockfalls, rockslides and landslides in the epicentral region, which also affected dams and reservoirs. This is a hazard, which up to now has not received adequate attention in dam projects as the focus on the seismic safety of dams is still ground shaking. But it is very important to note that for large dam projects, the seismic hazard is a multi-hazard that includes ground shaking, fault movements in the footprint of the dam and/or the reservoir, mass movements at the dam site and the reservoir banks and even in the catchment, ground movements, liquefaction, etc. All these hazards must be considered. The Wenchuan earthquake has also damaged the
face slab of the 156m high Zipingpu concrete face rockfill dam (Figure 3). As the reservoir was only 30% full at the time of the earthquake, the damaged dam was safe and mass movements into the reservoir did not cause any dangerous impulse waves. It would still be difficult to assess the behaviour of this large dam if the reservoir were full. The damaged joints were
from 16-23 May 2025, four technical questions were discussed, with Earthquake Performance and Safety of Dams being one of them. The General Reporter and the President for this question are the authors of this paper. The last time an earthquake question was discussed was at the ICOLD Congress in Montreal, Canada, in 2003. Since then new experience has been gained on the seismic performance of dams and new seismic design and safety criteria were published by ICOLD.
During the Congress the General Report of Question 111 was presented by the General Reporter Trevor Matuschka from New Zealand, a country that is also prone to earthquakes. The General Report provides an overview and discussion of the papers submitted to the ICOLD Congress, summarises earthquake publications and ongoing work of the ICOLD Committee on Seismic Aspects of Dam Design, and presents on the main changes and developments in seismic design and safety evaluation of large dams since 2003. Topics covered include seismic hazards, significant earthquakes since 2003, dam safety and seismic safety criteria, dam risk classification and seismic design criteria, structures and elements that need to be designed for earthquake effects, safety evaluation of existing dams, dynamic properties of mass concrete and rockfill, shaking table tests, numerical analysis, new types of dams, developments for tailings dams, and the outlook on future developments. The sub-themes discussed at the Congress are as follows:
Seismic Design of Dams. Earthquake Performance and Safety Evaluation of Existing Dams.
Seismic Design and Safety of Concrete Dams. Seismic Design and Safety of Embankment Dams.
Separate sessions were held for each sub-theme with presentations selected from submitted papers along with invited presentations from eminent industry experts. The highlights of the discussions were presentations on the effects on dams caused by: The Mw 7.7 earthquake in Myanmar of 28 March 2025. The Mw 7.8 and 7.7 earthquakes in the Turkey- Syrian border region of 6.2.2023.
24 | June 2025 |
www.waterpowermagazine.com
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
