Abstract: For a high concrete face rockfill dam (CFRD) under strong ground motions, the middle and upper parts of its face slabs usually produce high tensile stress along the slope, possibly resulting in horizontal cracks and leakage. It has been proved that setting permanent horizontal joints in the areas prone to high tensile stress can reduce the stress effectively. However, most of the previous studies on the effect of anti-seismic measures used a single ground motion for deterministic analysis, lacking consideration of the randomness of ground motions. This paper presents a stochastic dynamic method for determining along slope zones with high stress of the face slab, together with a discussion on the length of horizontal joints and an application to a 300 m high dam. The area influenced by horizontal joints and their effect of stress reduction are investigated by using the generalized probability density evolution method and focusing on a specific direction and typical elements, which shows the effectiveness of horizontal joints serving as a new measure for anti-seismic protection from the perspective of probability.

Key words: concrete face rockfill dam (CFRD), along slope tensile stress, anti-seismic measure, stochastic dynamic method, generalized probability density evolution method