斜入射地震波下单层球面网壳土-结构相互作用及其地震响应分析

Soil-structure interaction and seismic response analysis of single-layerreticulated dome under oblique incidence seismic wave

为分析斜入射地震波下单层球面网壳土-结构相互作用及其地震响应,采用等效节点力实现地震波输入,通过黏弹性人工边界处理无穷远辐射条件,分析了地震波类型、土体参数、入射角度等因素对单层球面网壳结构的土-结构相互作用及其地震响应影响。结果表明:单层球面网壳结构在地震波入射一侧出现翘起,网壳总体沿入射方向发生旋转,当P波斜入射时支座位移差最大达0.514 m,为网壳跨度的1/250。当P波斜入射时,软弱土情况下网壳顶点位移比中硬土和中软土大,顶点位移随入射角增大呈现先增大后减小的趋势;当SV波入射时,中软土情况下网壳顶点位移比中硬土和软弱土大,顶点位移随入射角增大而增大。斜入射地震波下,考虑土-结构相互作用后网壳顶点位移增幅最大达5.5倍,网壳外圈位移增幅大于网壳跨中增幅。

Here,to analyze soil-structure interaction(SSI)and seismic response of single-layer reticulated dome under oblique incidence seismic wave,equivalent nodal forces were used to realize seismic wave input.Infinity radiation condition was processed using viscoelastic artificial boundary.Effects of seismic wave type,soil parameters,incidence angle,and other factors on SSI and seismic response of single-layer reticulated dome were analyzed.The results showed that single-layer reticulated dome structure has upwarping on incident side of seismic wave,and the overall shell rotates along incident direction;when primary wave(P-wave)is obliquely incident,the maximum displacement difference between supports is 0.514 m,it is 1/250 of shell span;when P-wave is obliquely incident,top displacement of the shell in soft soil is larger than that in medium-hard soil and medium-soft soil,and shell top displacement firstly increases and then decreases with increase in incident angle;when SV wave is incident,shell top displacement in medium-soft soil is larger than that in medium-hard soil and soft soil,and shell top displacement increases with increase in incident angle;under oblique incident seismic wave,after considering SSI,the maximum increase in shell top displacement reaches 5.5 times,increases in displacements at shell outer ring are larger than those at shell mid-span.