Method and device for dynamically analyzing big arch springing CRD stratified excavation footage of cross-section tunnel

Abstract

The invention discloses a method and a device for dynamically analyzing the big arch springing CRD stratified excavation footage of a cross-section tunnel. The method comprises the following steps: stratified excavation: building a three-dimensional numerical model to achieve the numerical simulation during the excavation process; obtaining the deformation and the safety indexes of surrounding rocks, and forming a data sample using the mechanical parameters and the footage as the input and the deformation and the safety of the surrounding rocks as the output; building a surrounding rock parameter identifying sample set and a footage determining sample set; building a surrounding rock parameter identifying neural network model and a footage determining neural network model; performing the dynamic classification on the surrounding rocks; obtaining the deformation of the surrounding rocks of the tunnel; obtaining the distribution range of the mechanical parameters of the surrounding rocks; obtaining the mechanical parameter of the surrounding rocks; determining the neural network model through the footage to obtain the excavation footage in next-stage construction. According to the method and the device, the blindness of artificially selecting footage due to the uncertainty and the variability of a geologic body is overcome, and the method and the device have great economic and social meanings.

Description

technical field [0001] The invention relates to a dynamic analysis method and device for CRD layered footage of a large arch foot in a tunnel excavation construction section. Background technique [0002] With the progress of infrastructure construction in our country, the number of tunnel projects is increasing, especially the emergence of many long tunnels. Large-section tunnels often need to be excavated in blocks. The CRD construction method is a representative one. The CRD method is also known as "" The "intersecting middle partition construction method" is to excavate one side of the tunnel in parts in a long-span tunnel with weak surrounding rocks, construct the middle partition and diaphragm, and then excavate the other side of the tunnel and complete the construction of the diaphragm. Footage refers to the length of tunnel section excavation in blocks. The larger the footage, the higher the efficiency of tunnel construction, but the worse the stability of the surrou...

AI Technical Summary

Problems solved by technology

[0003] Due to the complexity and uncertainty of the geological conditions of the strata, many tunnels are in the condition of different geological stratifications. For example, the environment is an uneven stratum with soft top and hard bottom. Traditional CRD construction generally targets the entire soft stratum, and adopts the unified method of the entire section. The excavation efficiency is very low for the stratum with a relatively short footage, and the excavation efficiency is very low for strata that are soft at the top and hard at the bottom. Using layered and large-scale excavation can significantly improve the construction efficiency, but the geological conditions have great uncertainty, which brings great difficulties to the determination of the step distance. blindness, which brings losses in terms of safety and economy

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