An all-round monitoring method for tunnels deformation based on tilt inversion
The tilt sensor,with its compact size,user-friendly interface,and continuous monitoring capability,holds immense promise within the realm of tunnel deformation assessment.Yet,existing monitoring approaches reliant on tilt sensors often only capture deformation at specific monitoring points,leading to limitations in precisely gauging overall tunnel cross-sectional deformations.Thus,a novel comprehensive monitoring technique was proposed to assess tunnel cross-section deformations based on tilt measurements at monitoring points derived from the distinct shape characteristics of its cross-sectional curve.This innovative method constructed a segmented deformation interpolation function for the tunnel.By establishing a mathematical model correlating tunnel tilt angles and polar radius in polar coordinates,a segmented analytical approach formed the basis of the tunnel tilt-deformation model.Additionally,leveraging the co-deformation assumption,the method calculated tunnel tilt-deformation by adjusting the polar angle of tunnel measuring points.Subsequently,a three-dimensional numerical model of the tunnel was formulated.The efficacy of the method was evaluated across three distinct loading conditions:uniform load,symmetric non-uniform load,and asymmetric load,employing an error analysis approach.The results show that the method has adaptability for typical three-centered circular cross-sections of railway tunnels under these conditions,with deformation calculation errors consistently below 1 mm and average relative errors under 7%.Indoor tests further corroborate these findings,showcasing less than 8%monitoring error for vault settlement and no more than 5%error for horizontal convergence.These results affirm the accuracy and reliability of this monitoring method in practical applications.
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维普
