Optimal tunneling speed control method for built tunnel shield driving

Abstract

The invention discloses an optimal tunneling speed control method for built tunnel shield driving, which is characterized in that the optimal tunneling speed of the built tunnel shield driving is calculated on the basis of an optimal control principle so that the turbulence intensity and time of the built tunnel shield driving can be controlled. The optimal tunneling speed control method is realized by the following main steps of: (1) selecting a region with geological conditions similar to those of a driving point by comparison; (2) building an optimal flyover crossing tunnel system stability control model based on the optimal control principle; (3) deducing the quantitative expression of the optimal tunneling speed at the driving point; (4) drawing a turbulence intensity and time curve; and (5) combining the actual conditions (construction conditions, cost of a construction project and a construction period) of the project to determine the optimal tunneling speed of the built tunnel shield driving. The optimal tunneling speed control method for the built tunnel shield driving has the advantages that: a shield driving speed control method which takes the turbulence intensity and the time into consideration is provided and has a strict theoretic basis; the reliability estimation and risk evaluation of the shield driving are made in advance; and thus, the risks of the built tunnel shield driving are reduced.

Description

technical field [0001] The invention belongs to the technical field of tunnels and underground engineering, and provides an optimal tunneling speed control method for a shield tunneling under an existing tunnel. Disturbance intensity and aging through the built tunnel. technical background [0002] The rapid development of subway projects in recent years has formed a large-scale urban underground transportation network structure, which makes shield tunneling more and more close-distance tunnels, which also makes the stability control of existing tunnels more difficult and risky. Among them, the excavation speed of the shield passing through the existing tunnel is one of the decisive factors affecting its stability. Therefore, in the process of shield tunneling under the existing tunnel, the excavation speed must be strictly controlled to avoid large fluctuations in speed. If the speed is too fast, the superposition of stress and displacement in front of the face of the tun...

AI Technical Summary

Problems solved by technology

If the speed is too fast, the superposition of stress and displacement in front of the face of the tunnel will be too fast, and the disturbance will increase, which will easily cause the increase of soil pressure, increase the difficulty of stability control, and cause a series of problems such as insufficient grouting; if the speed is too slow, the Prolong the disturbance time of the formation, thereby prolonging the stability control time during its crossing process, which may promote the creep of surrounding rock

However, in current actual projects, the optimal tunneling speed of shield tunneling is generally determined based on experience, or with a small amount of numerical simulation analysis, which lacks scientific basis, has certain limitations and risks, and is difficult to fully meet the actual needs of the project.

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