土性参数纵向不均匀对盾构隧道地震响应影响的初步分析

目前一般将土体假设为匀质单层模型或匀质分层模型进行研究,不考虑土性参数沿纵向的不均匀分布对隧道等地下结构地震响应的影响。通过某具体工程,建立均匀土体-隧道模型和纵向不均匀土体-隧道模型,计算并对比分析两种工况时结构的相对变形及受力。结果表明:在给定的计算工况下,土性参数纵向不均匀时对隧道结构变形与受力有一定的影响,但影响程度不大,主要原因可能是隧道尺寸较小、地震动幅值较小以及场地条件较好。今后还需进行广泛的参数分析以探讨一般性的规律。

Preliminary Analysis of the Influence of Longitudinal Non-uniform Distribution of Soil Parameterson the Seismic Response of a Shield Tunnel

Soil is generally simplified as a uniform one-layer model or uniform multi-layer model in present research works, and the influence of soil parameters that may change along the longitudinal direction during seismic responses is usually neglected. With a focus on a practical engineering, a uniform soil-tunnel model and non-uniform soil-tunnel model were established and the internal structural forces and deformations were calculated and compared. The results showed that soil parameters that changed along the longitudinal direction had some influence on internal structural forces and deformation, but the degree of influence was not significant. The reasons were attributed to the small sizes of the tunnels, the small seismic wave amplitude, and the good soil conditions. The results of this study showed that more general seismic response laws should be discussed in future works, based on extensive parameter analyses.