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Proceedings of the International Conference on
Advances and New Challenges in Earthquake
Engineering Research, Hong Kong Volume
SEISMIC RESPONSE OF ARCH DAMS INCLUDING
STRAIN-RATE EFFECTS
Gao Lin and Shi-yun Xiao
Department of Civil Engineering, Dalian University of Technology,
Dalian 116024, China
ABSTRACT
Most of the experimental studies on concrete have shown that it is sensitive to the rate of loading.
The material strength, stiffness and ductility are rate-dependent. When a dam is subjected to the
earthquake excitation, the stress-strain relationship in different parts of the structure at different
instant will be different due to different rate of strain it experiences. Based on the concept of
viscoplastic consistency model, a modified three-parameter William-Warnke viscoplastic model is
developed to take account of the rate-dependent behaviour of concrete. The seismic response of a
27 8 m high arch dam is analyzed as an example. It is shown that the strain rate affects the
displacement and stress distribution of the dam response, it plays an important role in the safety
assessment of arch dams located in earthquake active area.
INTRODUCTION
Many high arch dams have been built and will be built in high seismic area in China. The highest of
them reaches 300 m . The safety of these structures against earthquake shocks is of great concern.
During the past two or three decades, our ability to analyze mathematical models of dam structures
subjected to earthquake ground motions has improved dramatically. Sophisticated computer
programs have been developed and used for numerical analysis of the arch dams. Nevertheless, the
current design practice in the seismic design of arch dams is still based on the linear elastic
assumption. The key property which determines the capacity of arch dams to withstand earthquakes
is the tensile strength of concrete. However, the design criteria for tensile stress is still a problem at
issue. A widely accepted standard is not available. As a consequence of this, there has not been a
corresponding improvement in the earthquake resistant design. Therefore, improvement of the