# Analytical dataset to determine squeezing potential of deep tunnels

## TL;DR

This paper introduces a dataset and analytical method to assess and mitigate squeezing risks in deep tunnel construction using ground reaction curves and strain data.

## Contribution

The novel contribution is the development of a dataset and analytical framework using ground reaction curves to estimate support pressure for deep tunnel stability.

## Key findings

- 480 ground reaction curves were developed and analyzed for various tunnel radii and depths.
- Strain and stability factors were classified to estimate the minimum internal pressure ratio for tunnel stability.
- A graph was created to determine optimal support pressure for different rock mass conditions.

## Abstract

This article presents a dataset that consists of historical strain data from deep tunnel construction and an analytical study that uses the ground reaction curve (GRC) to calculate the support pressure required to lower the risk of squeezing potential. In deep tunnel excavation, high in-situ stress conditions can cause an instability phenomenon known as squeezing. Historical tunnel strain data are classified into categories based on the percentage of tunnel convergence observed. Furthermore, 480 ground reaction curves (GRC) were developed and analyzed: 5280 calculations were performed with tunnel radii of 3, 4, and 5 m, depths ranging from 100 to 1000 m (in increments of 100 m), uniaxial compressive strength (σci) values of 30 and 50 MPa, and Geological Strength Index (GSI) values from 20 to 90 (in increments of 10). Three primary factors were used to estimate support capacity: the reduction of internal pressure relative to in-situ stress (pi/po), strain (%ε), and the stability factor (σcm/po). Strain (%ε) and the stability factor (σcm/po) were classified based on the resulting pi/po (0–0.9). A graph was obtained to determine the minimum pi/po that reflects all rock mass class conditions in deep tunnel construction in an effort to avoid squeezing at specific limits.

Image, graphical abstract