Integrated Analysis of the Formation Mechanism of Cracks in a Concrete Dam Using Microseismic Monitoring and Numerical Simulation

Table 1

Examples of dams with cracks [1, 2].

Projects	Status of cracks	Consequences
Single-buttress massive head dam in Xinfeng River in China	A horizontal penetration crack 82 m in length was caused by an earthquake of 6.1 magnitude on March 19, 1962.	The reservoir had to operate at a low water level because of water seepage.
Meishan multiarch dam in China	A 70 L/s sudden seepage occurred at the foundation of the right shore, and dozens of cracks appeared in the dam body, resulting in the dam being in danger.	The reservoir had to be emptied for reinforcement.
Chencun gravity arch dam in China	The dam operated at a low water level for a long time, and large horizontal cracks significantly expanded.	The dam was seriously damaged.
Revelstoke Gravity dam in Canada	Abutment cracks occurred on the upstream face of most sections of the dam. The depth of the largest crack was up to 30 m, and the water percolating capacity was 174 L/s.	The dam had to operate at and maintain a low water level.
Dworshak high gravity dam (219 m) in USA	An abutment crack appeared on the upstream face 50 m in depth and 2.5 mm in width. The water percolating capacity was 483 L/s.	The dam had to operate at and maintain a low water level.
LegGage arch dam in France	After the initial impoundment, cracks occurred in a wide area on the upstream and downstream faces of the dam and continuously developed afterwards.	The dam had to operate at and maintain a low water level.
Tona arch dam in France	During the initial impoundment, cracks occurred in a large area on the downstream face close to the skewback and continuously developed in the subsequent eight years.	Arch rings and buttresses were added to the downstream side to reinforce the original arch.
Koehibrein arch dam in Austria	After two years since the dam construction was completed, cracks with serious seepage occurred inside the foundation passage, and the uplift pressure on the whole basic plane in the dam section of the river bed reached the total head.	The operation of the dam had to be stopped for reinforcement.
Zeuzier arch dam in Switzerland	When the reservoir was about to be filled, significant displacement to the upstream occurred on the dam, and multiple cracks 15 mm in widths occurred on the downstream face.	The water level of the reservoir had to be reduced, and large-scale repair work was carried out.