A comparison of two numerical models for modeling a twin tunnel in a saturated half-space

Abstract

In this work an analytical as well as a numerical model are established for computing vibrations induced by a twin tunnel buried in a saturated poroelastic half-space. In the analytical solution the mechanical response for the half-space ground is expressed as a superposition of planar waves from the ground surface and cylindrical waves from two tunnel-soil interfaces. While in the numerical solution, three-dimensional saturated poroelastic finite element and multi-transmitting formula are formulated. The comparisons are made between the two methodologies, and the advantages and disadvantages of the two models are highlighted. Using the analytical one, the influence of the fluid in the soils, the reflection effect of the ground surface and the existence of a neighboring tunnel with or without a source on the mechanical response is investigated. By using the three-dimensional numerical model, the influence of various irregular tunnels on the surface vibration is investigated. The results suggest that: for the displacement and pore pressure response, the difference between one source tunnel and twin source tunnel can be up to 20 dB; the rectangular tunnels lead to the largest response followed by horseshoes and circular ones.

Keywords:

• Poroelasticity
• half-space
• analytical modelling
• numerical simulations
• comparative verification
• irregular tunnels

Authors contributions

Li Shi: Plan as a whole, Methodology, Writing-original draft, Software, Formal analysis. Zonghao Yuan: Methodology, Writing-original draft, Software, Formal analysis. Yuyu Zheng: Review & editing. Jie He: Review & editing, Data collection. Zhigang Cao: Methodology. Tingyu Wu and Honglei Sun: Resources.

Disclosure statement

The authors declare that have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Data availability statement

The data that support the findings of this study are available on request from the corresponding author.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (Nos. 52078462, 52378376) and the Fundamental Research Funds for the Provincial Universities of Zhejiang (No. RF-B2023007).