中文摘要：

基于量纲分析理论,建立了钢悬链线立管（SCR）触地段的结构循环应变响应的相似准则。设计SCR立管触地段与土体相互作用装置,实验研究了典型工况下触地段床面形状变化对结构应变响应的影响。实验结果表明：水流载荷可使立管触地段下方土体局部冲刷的范围增大,立管结构应变幅值也相应增大;随着管土循环拍击作用和局部冲刷变形的发展,钢悬链线立管触地段的循环应变幅值逐渐增大并趋于稳定值;在立管脱离床面的瞬间,可观测到立管上缘拉应变突增的现象。拉应变突增幅度随着床面变形的发展逐渐增大,进而导致循环应变幅值的增加。

英文摘要：

Based on dimensional analyses,the similarity criteria are derived for the strain responses of the Steel Catenary Riser（ SCR）at its touch-down zone（ TDZ）. A series of flume experiments have been conducted to investigate the cyclic strain responses at TDZ by utilizing the specially-designed facility for SCR riser-soil interaction. Experimental results indicate that superimposing a current promotes the local scour and further induces an increase of the strain amplitude of the SCR. With the development of cyclic interactions of the SCR with the sand-bed and the corresponding local scour,the strain amplitude of the SCR in TDZ increases and gradually approaches a critical value. An abrupt-increase of the tensile strain at the upper surface of the SCR has been observed while the SCR was being detached from the seabed. The abrupt-increase of the tensile strain increases with the development of the sand-bed deformation,and meanwhile the cyclic-strain amplitude increases gradually.