浅埋暗挖隧道管棚变形监测及受力机制分析

在土江冲隧道进口段采用应变计对管棚纵向变形进行监测，根据现场测试结果分析管棚在隧道开挖过程中的受力特性，讨论管棚的作用机制。对管棚的刚性固定端Winkler弹性地基梁模型进行改进，建立浅埋暗挖隧道管棚受力的弹性固定端双参数弹性地基梁模型，推导出管棚的扰度方程及应力、应变计算公式，提出求解方法。将弹性固定端双参数弹性地基梁模型应用于土江冲隧道管棚作用机制的分析，计算结果与实测结果吻合较好，说明采用弹性固定端双参数弹性地基梁模型分析管棚受力特征是可行的。

DEFORMATION MONITORING AND MECHANICAL BEHAVIORS OF PIPE-ROOF IN SHALLOW TUNNELS

The longitudinal deformations of the pipe-roofs in the entrance of Tujiangchong tunnel are monitored by installation of a series of strain gauges to investigate the mechanical behaviors of the pipe-roofs during the tunnel excavation; and the working mechanism of pipe-roofs in shallow tunnels is discussed. The rigid joint Winkler elastic foundation beam model is revised; and a new double-parameter elastic foundation beam model for pipe-roof in shallow tunnels is put forward. The corresponding deformation equations, stress and strain formula are deduced; and the solutions of this model are given. The proposed elastic joint double-parameter elastic foundation beam model has been used successfully in the evaluation of mechanical behaviors of the pipe-roofs in Tujiangchong tunnel. It shows that the calculation results agree well with the measured values; and the elastic joint double-parameter elastic foundation beam model is reasonable in the analysis of the mechanical behaviors of pipe-roofs in shallow tunnels.