山岭隧道DMI精细化断面检测算法的研究及应用OA

To accurately analyze over-and under-excavation conditions in mountain tunnels constructed by the mining method,and to effectively reduce over-and under-excavation while lowering construction costs and risks,this study proposes a refined cross-section detection method based on 3D laser scanning technology and the DMI(Difference-Mean-Interpolation)algorithm.A 3D laser scanner was used to acquire tunnel point cloud data,and a mean filter denoising method,a difference-based denoising method,and an improved Kriging interpolation method(collectively referred to as the"DMI algorithm")were proposed to perform refined denoising and interpolation on the raw point clouds.This enabled more precise and accurate calculations of parameters such as over-and under-excavation values,the number of over-and under-excavation spots,over-and under-excavation areas,and average linear over-and under-excavation values.The method was applied and compared in a mountain tunnel constructed using the mining method in Guangdong Province.The results revealed that,compared with conventional cross-section detection methods,the DMI method showed significant differences in the results,particularly in the maximum under-excavation(clearance infringement)values and the number of under-excavation(clearance infringement)spots.Noise in the point cloud data caused conventional detection methods to misjudge the locations and number of under-excavation(clearance infringement).After denoising and interpolation using the DMI algorithm,these noise points were effectively removed,and point cloud data in occluded or missing areas were automatically completed,avoiding misjudgments of under-excavation(clearance infringement)and comprehensively and accurately reflecting the actual over-and under-excavation conditions of the tunnel.In terms of detection results,the excavation sections generally met the requirements,with no under-excavation observed,but notable over-excavation was present.The primary support sections generally met the requirements,but minor clearance infringement and poor flatness were observed.It is recommended to appropriately adjust the reserved deformation allowance and conduct necessary treatment on the clearance infringement areas in the primary support sections to ensure the safety and quality of the project.