Yang Hui, Yin Jun, Jiang Xueliang, Shen Bo, Wang Haodong, Wei Zhenzhen
Guangdong Provincial Key Laboratory of Green Construction and Intelligent Operation & Maintenance for Offshore Infrastructure, Guangzhou Maritime University, Guangzhou, 510725, China.
school of civil engineering, Central South University of Forestry and Technology, Changsha, 410004, China.
Sci Rep. 2024 Oct 10;14(1):23748. doi: 10.1038/s41598-024-75676-8.
A large-scale shaking table test of a living stump slope with a geometric similarity ratio of 1:7 was designed and completed. The peak acceleration, acceleration amplification factor, and displacement response patterns of living stumps slopes under different types of seismic waves and excitation intensities were obtained. The time-frequency and energy variation characteristics were analyzed using the Hilbert-Huang Transform (HHT). The results showed that: (1) Regardless of the type of seismic wave, the peak acceleration and acceleration amplification factor of the living stumps slope surface are positively correlated with relative height and seismic excitation intensity. When the excitation intensity is ≤ 0.4 g, the acceleration amplification effect is more pronounced; when the excitation intensity is > 0.4 g, the acceleration amplification effect weakens. (2) Under the action of different seismic waves, the peak displacement of slope surface shows amplification effect along the elevation, and increases with the increase of excitation intensity. In addition, the incremental displacement gradually decreases from the toe to the top of the slope, which is expressed as D2 > D3 > D1 > D4 > D5. The peak displacement at the top of the slope is the greatest, but the incremental displacement is the smallest; the peak displacement at the toe of the slope is the smallest, but the incremental displacement is relatively large. (3) Regardless of the type of seismic wave, living stumps slope shows the characteristics of filtering the low-frequency components of the seismic waves and amplifying their high-frequency components. At the same time, the seismic Hilbert energy gradually accumulates along the elevation. PSHEA and PMSA significantly increase with elevation and excitation intensity, and they reach the maximum at the top of the slope. (4) The seismic Hilbert energy is positively correlated with the relative height and excitation intensity, and reaches the maximum at the top of the slope. With the accumulation of seismic Hilbert energy increases, the dynamic response parameters such as peak acceleration, acceleration amplification coefficient and displacement also increase synchronously, reaching the maximum at the top of the slope. The research conclusions can provide an experimental basis for the seismic design of living stumps slopes.
设计并完成了几何相似比为1:7的活树桩边坡大型振动台试验。得到了不同类型地震波和激励强度作用下活树桩边坡的峰值加速度、加速度放大系数及位移响应规律。采用希尔伯特-黄变换(HHT)分析了其时频和能量变化特征。结果表明:(1)无论地震波类型如何,活树桩边坡坡面的峰值加速度和加速度放大系数与相对高度和地震激励强度呈正相关。当激励强度≤0.4g时,加速度放大效应更明显;当激励强度>0.4g时,加速度放大效应减弱。(2)在不同地震波作用下,坡面峰值位移沿高程呈现放大效应,并随激励强度的增加而增大。此外,增量位移从坡脚到坡顶逐渐减小,表现为D2>D3>D1>D4>D5。坡面顶部的峰值位移最大,但增量位移最小;坡面坡脚的峰值位移最小,但增量位移相对较大。(3)无论地震波类型如何,活树桩边坡均表现出过滤地震波低频成分并放大其高频成分的特征。同时,地震希尔伯特能量沿高程逐渐积累。PSHEA和PMSA随高程和激励强度显著增加,并在坡面顶部达到最大值。(4)地震希尔伯特能量与相对高度和激励强度呈正相关,并在坡面顶部达到最大值。随着地震希尔伯特能量增加而积累,峰值加速度、加速度放大系数和位移等动力响应参数也同步增加,在坡面顶部达到最大值。研究结论可为活树桩边坡的抗震设计提供试验依据。