列车振动荷载下海底盾构隧道交叉结构动力特性及车致损伤机理研究

With the rapid development of construction technology on underwater railway tunnels in China, large subsea railway tunnel will inevitably become an important means to pass through the channels or bays, and the construction of world-class large undersea railway tunnels will come up in near future,such as Qiongzhou channel tunnel, Bohai channel tunnel. Combined with the characteristics of offshore marine geological body，marine abrasion and high-speed，heavy freight train, aimed at a large number of space cross structures in large subsea railway shield tunnels formed by the intersection of the fire fighting and operating ancillary facilities such as connected cross aisle and shaft with the main tunnel,the research includes: spectrum characteristics of train vibration load caused by diferent running speed and weight, dynamic analysis models and vibration effect of space cross structure under vibration load, damage mechanism of space cross structure, damage evolution law as well as engineering control technology of train vibration damage. The results are expected to reveal spectrum characteristics of train vibration load under different condition, prove up train vibration response law of space cross structure, build train vibration dynamic damage evolution model and evaluation method of space cross structure,announce dynamic damage mechanism of space cross structure, construct the partition standard of train vibration influence, propose engineering measures to reduce and resist train vibration damage of space cross structure, in order to offer theory and technology help for the durability design and long-term operation safety of space cross structure in a lot of large subsea railway tunnels that will be built in the future.

随着我国铁路水下隧道建设技术的快速发展，大型海底铁路隧道必将成为今后海湾海峡跨越水域分割的重要手段，琼州海峡通道、渤海海峡通道等世界级铁路海底隧道的建设已然临近。本项研究结合近海海洋地质体、海洋海蚀和高速、重载列车的特点，针对大型海底铁路盾构隧道联络横通道或竖井等消防运营附属设施与主体隧道形成的大量空间交叉结构，研究不同行车速度和列车载荷下车辆振动荷载频谱特性、振动荷载下空间交叉结构动力分析模型及其振动效应、空间交叉结构车致损伤机理、损伤演化规律以及损伤的工程控制技术措施等，以期揭示不同条件下列车振动荷载的频谱特性、探明空间交叉结构的车辆振动响应规律，建立交叉结构车辆振动动力损伤演化模型及其评估方法，揭示交叉结构动力损伤机理，构建交叉结构列车振动影响的分区标准，提出交叉结构消减和抵御列车振动损伤的工程技术措施，为今后大量海底铁路隧道空间交叉结构的耐久性设计和长期运营安全提供理论和技术支撑。

随着我国高速铁路的快速发展，越来越多的铁路隧道穿越江河湖海。出于通风和防灾救援的需要，长大隧道中往往需要设置一定数目的横通道，形成了大量由盾构隧道与联络横通道相互连接形成的交叉结构。这种交叉结构由于刚度差异大，极易造成应力集中，在列车振动荷载的长期作用下，极易出现疲劳损伤导致结构开裂甚至垮塌，并进一步引发洞内水灾等重大事故。由此，本课题结合理论分析、数值模拟以及模型试验等研究手段，着力研究列车振动荷载作用下海底盾构隧道交叉结构动力响应及其影响因素。通过研究，拟合出了列车振动荷载时程拟合公式，获得了列车不同行驶速度下的振动荷载；建立了带联络横通道的交叉盾构隧道和近距离空间交叉盾构隧道模型，分析了列车振动荷载作用下海底盾构隧道交叉结构动力响应及其影响因素；探明了控制海底盾构隧道交叉结构列车振动损伤的工程控制技术措施；揭示了混凝土腐蚀后海底盾构隧道交叉结构车振损伤机理及其损伤演化规律；提出了考虑混凝土在列车振动荷载下疲劳损伤表现的混凝土疲劳本构模型；研究了列车振动荷载作用下海底盾构隧道交叉结构动力响应与疲劳累积损伤；进行了交叉隧道结构的室内模型试验分析，验证了数值分析结果的正确性。成果可为海底盾构隧道空间交叉结构的设计和运营安全提供一定的参考。