基于能量原理的隧道结构地震影响区划分及节段式衬砌响应特性

Partitions of seismic affected zone and characteristics of segmental lining based on energy principle

隧道结构从变形到失稳的整个过程与地震能量的输入、转化和耗散密切相关。本文从结构的能量响应出发,基于地震波激励建立了能量平衡方程。根据输入能量与结构固有能量之间的关系,提出了强震作用下基于结构整体破坏的稳定性判别依据。首先分析了不同断层宽度隧道能量响应特征,通过建立能量稳定函数来研究穿越不同断层宽度隧道结构的动力稳定性特征;结合能量稳定函数和结构最大变形量,验证了基于能量的结构失稳与变形之间的关系。其次,从可释放弹性应变能的角度得到了地震作用下跨断层隧道纵向影响区域。在此基础上考虑断层破碎带隧道结构的自适应变形,在结构主要影响区设置节段式衬砌。通过比较断层内部结构不同位置的能量稳定函数,得到了跨断层隧道基于能量原理的最优抗减震措施。

The whole process of tunnel structure from deformation to instability under earthquake motion is closely related to the input, transformation and dissipation of seismic energy. Based on the energy response of tunnel structure,this paper establishes an energy balanced equation under the seismic wave excitation. According to the relationship between input energy and inherent energy of structure, the instability criterion is proposed based on failure of overall structure. Firstly, the energy response characteristics of tunnels across different fault widths are analyzed under seismic excitation, and the relationship between energy-based structural instability and deformation is verified through combining the energy stability functions and structural deformation. Secondly, on the basis of releasable elastic strain energy, the longitudinal affected sections of cross-fault tunnel are divided under strong ground motion. Thus, the self-adaptability deformation characteristic of tunnel structure is studied inside the fault fracture zones during earthquake motion, and then the segmental lining is designed to adapt deformation of surrounding rock at the main influenced areas of fault belt. Lastly, the dynamic stability functions are compared and analyzed at different positions of the fault, and the optimal anti-seismic measure is proposed to improve aseismic performance of tunnel structure based on energy criterion.