Analysis of Stress and Deformation of High-Pressure Jet Grouting Piles Reinforcing Loess Tunnels

DOI

10.2991/978-94-6463-902-5_17How to use a DOI?

Keywords

Lanzhou; High pressure jet grouting pile; Loess tunnel; Force and deformation; numerical simulation; Tunnel monitoring

Abstract

The Lanzhou area’s loess is loosely structured, has a high pore ratio, is weak, and is extremely collapsible. These features result in the loess tunnel basement’s inadequate bearing capacity, which makes it simple for the tunnel basement to undergo severe deformation during excavation. High pressure jet grouting pile was chosen as the reinforcement technique to address the issue of excessive deformation of the tunnel basement of a large section of a loess tunnel on a Lanzhou highway. Three-dimensional numerical simulation and on-site monitoring were used to examine the deformation and stress characteristics of the tunnel basement. According to the results, the uplift of the surrounding rock of the tunnel bottom can be effectively restrained by using a high-pressure rotary jet grouting pile to reinforce the tunnel bottom. The soil stress between the piles is also lower than it would be without the high-pressure rotary jet grouting, meaning that the pile is bearing more stress. The lateral distribution of uplift is greatest at the center of the invert and decreases to the foot of both sides of the arch. The rotary jet pile can withstand the initial uplift and distortion of the rock surrounding the tunnel bottom as well as the subsequent settlement and deformation of the same rock after the tunnel is finished. In both the three-step and seven-step methods, the displacement at the tunnel bottom decreases by 10%, despite a time delay compared to the tunnel bottom uplift. Compared to the unreinforced section, the equivalent strain around the tunnel is reduced by 14%, with the reinforcement effect primarily observed on the side walls and beneath the tunnel. According to the measurements, the radial earth pressure of the surrounding rock gradually increases over time until it stabilizes. Although there is some discrepancy between the measured data and the numerical simulation results, it remains within an acceptable range, and the fundamental behavior aligns, indicating that the calculated results are reliable.

Copyright

© 2025 The Author(s)

Open Access

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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TY  - CONF
AU  - Xincheng Tian
AU  - Qian Zhao
AU  - Hao Liu
AU  - Rong Li
AU  - Jinpeng Dai
AU  - Qicai Wang
PY  - 2025
DA  - 2025/12/16
TI  - Analysis of Stress and Deformation of High-Pressure Jet Grouting Piles Reinforcing Loess Tunnels
BT  - Proceedings of the 2025 7th International Conference on Civil Engineering, Environment Resources and Energy Materials (CCESEM 2025)
PB  - Atlantis Press
SP  - 169
EP  - 182
SN  - 2352-5401
UR  - https://doi.org/10.2991/978-94-6463-902-5_17
DO  - 10.2991/978-94-6463-902-5_17
ID  - Tian2025
ER  -