穿越活动断层的隧道新型吸能材料和减震结构研究

Tunnel sections crossing active faults are the high-risk seismic damage area and vulnerable spot of aseismic design, by the review of tunnel’s seismic damage research in Wenchuan Earthquake and other earthquakes. However, a large numbers of tunnels, especially long ones in west China, may face the problem of crossing active faults. This project plans to use methods of investigation, theoretical derivation, numerical simulation and model test to study seismic failure mechanism for tunnel crossing active faults. Tunnel seismic response regularity will be analyzed, considering factors of fault geometry scale, attitude characteristic, physical and mechanical property of fracture plane and fault displacement. Traditional lining concrete possess weak energy absorption ability, easy cracking possibility and shear failure after fault displacement, relatively, new types of energy absorption material and structure are developed, assembling compression resistance and tensile material to bear load and absorb earthquake energy. Moreover, energy absorption capacity of new material and structure will be evaluate based on fault movement test, drop-weight test and numerical calculation, to give damping effect and economic indicator. All the research is aimed to provide advanced theoretical method, technical measures and calculation model for engineering design of tunnel more and more built in earthquake region.

汶川特大地震以及国内外以往大地震后的隧道震害研究表明，隧道穿越活动断层段是破坏高发区和抗减震设计薄弱环节。而目前大量隧道的建设特别是西部地区长大隧道大都面临直接穿越活动断层问题。本项目拟综合运用调查研究、理论推导、数值模拟、模型试验等方法，对穿越活动断层的隧道地震破坏机理进行深入研究，分析隧道在不同断层几何尺度、产状特征、破裂面物理力学特性、错动位移等条件下地震响应规律。针对地震中传统衬砌混凝土材料不吸能、易开裂、断层错动即剪坏的缺陷，研发新型吸能材料及结构，耦合抗压材料和抗拉材料共同承担荷载并同时吸收耗散地震能量，并分别通过断层错动试验、落锤试验和数值模拟计算等方法对其进行吸能水平评价，研究其减震效果和经济指标，为大规模建设的震区隧道的工程设计提供先进理论方法、技术对策及其计算模型。

本项目综合运用调查研究、理论推导、数值模拟、模型试验等方法，对穿越活动断层的隧道地震破坏机理进行深入研究，主要取得如下成果：（1）开展了隧道地震响应模型试验箱体设计并对合理性进行验证，采用拟静力法试验结果均在10%误差范围内；（2）进行了动静耦合剪切模型箱的设计分析及试验验证，利用该模型试验箱研究了隧道衬砌的振动响应；（3）设计了一种模拟发震断层动力特性的隧道地震试验方法，试验装置能够模拟活动断层在不同错动方向、倾角和错动量条件下自主发震，通过改变弹簧组的单个弹簧单元的刚度系数、弹簧组内弹簧单元的个数等，改变试验动力响应特征，得到振动频率-组合弹簧刚度回归公式和位移-组合弹簧刚度回归公式。