非一致激励下长距离输水隧道地震响应分析

近年长隧道结构震害频发，随着调水工程大规模建设，长距离输水隧道抗震性能的重要性愈加突出。在隧道传统抗震分析方法的基础上，针对非一致地震动作用下地基土－长距离输水隧道体系的地震响应问题，建立了非一致激励下长距离输水隧道的大规模地震响应分析方法，并以上海市某重点工程中的长距离输水隧道为工程应用，计算模型中不仅考虑了土体的动力滞回非线性、土体与隧道之间的接触非线性等因素，而且引入“附加质量法”来考虑了地震作用下输水隧道内水体的动水压力作用。通过与一致激励的计算结果对比，表明非一致地震激励会显著增加输水隧道结构的内力和变形响应，从而对隧道抗震产生不利影响。研究结论可为长输水隧道结构的抗震设计和分析提供科学依据。

Effect of Non-uniform Excitation on Seismic Response of Long-distance Water-conveyance Tunnel

Long tunnels suffered great damages in recent earthquakes frequently. With the increasing of large amount of water conveying engineering under construction, the seismic performance of long-distance water-conveying tunnels is significant. Based on the deficiency of traditional method for large-scale seismic computation, a large-scale analysis method is proposed to solve the non-uniform seismic response problems of the complex soil-long tunnel-water system. As an application, the presented method is used in an existing long-distance water tunnel, which is one of key projects in Shanghai. Both the nonlinear hysteretic constitutive model of soil and nonlinear contact behaviors between soil and tunnel are considered in the established numerical model. Furthermore, the added mass method is introduced to simplify the effect of dynamic water pressure on the tunnel liner when subjected to seismic loadings. Two seismic input modes, the uniform and non-uniform excitations, are involved in the seismic analyses of the long water tunnel system. Results show, compared with the uniform seismic input, the non-uniform excitation can remarkably increase both stress and deformation responses of the long tunnel, which makes adverse influence on the seismic performance of the tunnel. The research conclusions are beneficial to proving theoretical criterions for seismic design and analysis of long water-conveying tunnels.