DEFORMATION MONITORING AND MECHANICAL BEHAVIORS OF PIPE-ROOF IN SHALLOW TUNNELS
浅埋暗挖隧道管棚变形监测及受力机制分析

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.