数字图像测量技术及在隧道室内模型试验中的应用

Digital Image Measurement Technology and Its Application in Tunnel Indoor Model Test

摘要:

首先按照数字图像技术分析基本原理差异，对数字图像相关（DIC）、粒子图像测速（PIV）等二维数字图像测量方法在隧道模型试验中的应用现状、技术发展以及基本原理进行梳理。进一步，对三维测量方法的原理及在隧道模型试验中的应用潜力进行分析。最后，通过黄土地层盾构隧道的掘进模拟试验，对数字图像测量技术在隧道模型试验中的应用进行示范。结果表明：DIC、数字照相变形量测（DPDM）等非接触测量方法以照片上点的相关性判断各点的位移，使用场景更偏向于室内试验道路、桥梁、隧道、基础、河坝、钢结构、钢混结构等土建结构的变形监测中；而PIV分析可测量流体中流动的大小和方向，被广泛运用于浆液、泥石流、喷泉等流体运动的研究中。此外，基于黄土地层盾构隧道室内模型试验方案发现，低含水率黄土地层盾构掘进8环管片距离时，围岩的扰动范围为盾构掘进中轴线两侧1 D（管片外径）左右和盾构上方1 D范围内。

Abstract:

Based on the difference in basic principles of digital image technology， the application status， technical development， and basic principles of two-dimensional digital image measurement methods such as digital image correlation （DIC） and particle image velocimetry （PIV） in tunnel model test are summarized. Moreover， the principle of the three-dimensional measurement method and its application potential in tunnel model tests are analyzed. Furthermore， the application of digital image measurement technology in the tunnel model test is demonstrated through the tunneling simulation test of the shield tunnel in the loess stratum. The results show that DIC， digital photogrammetry for deformation measurement（DPDM）， and other non-contact measurement methods judge the displacement of each point by the correlation of points on the photo， and the use scenarios are more inclined to the deformation monitoring of civil structures such as indoor test roads， bridges， tunnels， foundations， dams， steel structures， and steel-concrete structures. PIV analysis can measure the size and direction of the fluid flow and is widely used in the study of fluid motion， such as slurry， debris flow， and fountains. Based on the indoor model test scheme of the shield tunnel in the loess stratum， it is found that the disturbance range of surrounding rock is about 1D on both sides of the central axis of shield tunneling and 1D above the shield when the shield tunneling is eight-ring segment distance in low water content loess stratum.