悬浮隧道和支撑结构的响应分析

Analysis of the Responses of Submerged Floating Tunnel and Its Supporting Structure

研究目的:悬浮隧道是一种悬浮于水中的新型交通结构物。由于它直接处于波浪、水流作用的自然环境中,因此计算分析悬浮隧道结构系统在波流作用下的响应,就成为研究和设计工作中必须考虑的问题。本文将悬浮隧道结构系统简化为空间梁系有限元模型,采用梁元的CR列式法,在考虑波流与结构相互作用的条件下,计算分析了跨越长度、隧道断面形式、支撑形式等对悬浮隧道结构响应及支撑所受轴向应力的影响。研究结论:通过计算分析表明,跨越长度由2 000 m增至4 000 m时,隧道静响应位移及支撑所受轴向应力值均变化较小,而动响应位移和支撑所受轴向应力的变化幅值显著增加;椭圆断面隧道的静响应远小于圆形断面隧道,而动响应又远大于圆形断面隧道;锚链式悬浮隧道的响应远小于张力腿式悬浮隧道。

Research purposes： A Submerged Floating Tunnel （SIT） is a new type of submarine structure and is kept under the water by a series of supporting structure. As SIT is directly impacted by water, it is necessary to analyze and calculate the responses of structure system to the actions of water flow and wave. In this paper, SFT and its support system are analyzed with a finite element model of spatial beam system. By applying beam element CR formulation and considering the interaction between water and structure, the calculation and analysis are made for the influences of crossing span, the shape of tunnel cross section and form of support on the response of structure system and axial stress of the support component. Research conclusions ：The results show ： （ 1 ） The differences of the static response in displacement of the tunnel and axial stress of support component are fairly small as the crossing span increases from 2 000 m to 4 000 m, but the dynamic response increase notably. （2） The static response of tunnel with an elliptical cross section is extreme smaller than that of tunnel with a circular cross section and the dynamic response of former is extreme bigger than that of the latter. （3） The response of SFT with mooring tether anchorage is extreme smaller than that of SIT with tension leg anchorage.