Impact Degree Zoning of Large Shield Parallel Construction on Pile-plate Structure Roadbed of Adjacent High-speed Railway

Abstract

Objective When a large-diameter shield is used for parallel tunnel construction adjacent to high-speed railway with long and small clear distances, it has extremely strict requirements for the deformation of the existing structure and the surrounding environment. There is the need to zone the affected area according to the influence degree, protect and reinforce the area that may be greatly affected. Method Based on the shield construction project of Shanghai Airport Link running in parallel with the roadbed section of Shanghai-Hangzhou High-speed Railway, a model is established by FLAC3D finite difference software to analyze the effect of parallel shield construction on the deformation of the pile-plate structure roadbed of the high-speed railway, determine the safe distances between the tunnel and the existing high-speed railway under different construction conditions, and zone the area based on the influence degree of parallel shield construction. Result & Conclusion Increasing the buried depth of the tunnel, the pile length of the high- speed railway pile-plate structure and the horizontal distance between the tunnel and the roadbed can reduce the horizontal displacement of the roadbed caused by the parallel construction. Increasing the tunnel buried depth will increase the vertical displacement of the roadbed, but the roadbed settlement may reduce as the buried depth of the tunnel increases under the influence of geological factors. The safety distance meeting the deformation control index under different construction conditions and the zoning of different influence degrees when shield tunnel runs in parallel with the existing high-speed railway pile-plate structure roadbed are obtained.

Keywords

• shield construction
• high-speed railway pile-plate structure roadbed
• finite difference method
• deformation law
• impact degree zoning