考虑边界土体性质悬浮隧道地震响应分析

悬浮隧道地震响应研究是确保该新型交通结构物安全的重要内容,现有的研究往往忽视了驳岸结构的影响,将其简化为铰支、固支等简单约束形式。考虑了悬浮隧道驳岸结构周围岩土性质对其边界条件的影响,研究在横向地震作用下悬浮隧道的地震响应特性；采用大质量法,以Messina海峡悬浮隧道方案为基本模型,结合我国东部海域海床岩土性质,计算得到了地震作用下悬浮隧道管体位移、弯矩、扭矩和锚索索力,并对驳岸段长度Lsh和粘性土剪切模量G进行了参数分析。研究表明,悬浮隧道管体最大位移和弯矩出现于跨中、最大扭矩出现于两端、索力增量最大值出现于短索；弹性支撑有利于管体受力,但不利于锚索索力控制；驳岸段计算长度和粘土剪切模量的变化会对悬浮隧道地震响应特性带来显著影响,且影响规律较为复杂,可能与悬浮隧道结构动力特性、地震波的特性等相关参数具有耦合关系,需要进一步的研究探索。

Seismic Response of Submerged Floating Tunnel Considering Boundary Soil Property

The research of seismic response of submerged floating tunnel（SFT）is important for ensuring the safety of this new traffic structure,but the revetment structures are neglected which are often reduced to simple constraint forms in the existing researches.In this paper,the seismic response characteristics of SFT in the lateral earthquake were researched,considering the impact of the geotechnical properties around the revetment structures to the boundary conditions.The displacement,bending moment and torque of tube and cables tension were calculated combined with the seabed geotechnical nature in the eastern ocean,by using large mass method,based on the Messina Strait SFT option.And some parametric analysis were done for the revetment structure length Lsh and cohesive soil shear modulus G.The results showed that the maximum displacement and bending moment of tube appeared at the mid-span,the maximum torque arised at both ends,and the maximum incremental tension of cable occurred in the shortest cables;the elastic support was conducive to the tube,but not conducive to the control of cables tension;the seismic response characteristics of SFT were significantly influenced by the revetment structure length Lsh and cohesive soil shear modulus G,but the impact was complicated which might be related to the structure dynamic characteristics and seismic waves parameters.