(1. Key Laboratory of New Technology for Construction of Cities in Mountain Area，Ministry of Education，Chongqing University，Chongqing 400045，China；2. Shanghai Shen Yuan Geotechnical Engineering Co.，Ltd.，Shanghai 200041，China；3. School of Civil Engineering，Chongqing University，Chongqing 400045，China)
Full-scale model tests are carried out to reveal the propagation mechanism of velocity waves of X- section pile in low strain dynamic testing. The velocity responses at various points are obtained by arranging measuring points at different locations at both pile top and pile bottom. The three-dimensional effect and high frequency interference of X-section pile in low strain testing are researched. The results show that the velocity responses in the direction of concave arc are similar with those in the direction of convex edge. The three- dimensional effects of incident waves on pile top are obvious；however，the reflection waves from pile bottom are almost the same. The arrival time of incident waves is increased with the increase of the distance from the pile center，while the time difference between incident and reflection waves is decreased. The high frequency interferences at the location of 0.4R to 0.5R from pile center are unobvious，while they are more significant at the edge of pile section. There are two kinds of high frequency interference waves in velocity waves of X-section pile in low strain testing.
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2017, Vol. 36 
