Numerical Analysis of the Hydraulic Fracturing of Pressure Tunnel Lining Based on the 2P-IKSPH Method

Abstract

In order to investigate the fracture mechanisms of the pressure tunnel lining under water-stress coupling, based on the traditional smoothed particle hydrodynamics (SPH) method, the solid-water particle interaction method, and the particle damage conversion algorithm are proposed to realize the hydraulic fracturing process, which is called the 2P-IKSPH method. The “particle domain searching method,” the “birth-and-death particle method,” and the “group discrimination searching method” have also been proposed to realize the simulations of complex processes of excavation, lining, and operation of the hydraulic tunnel. Taking the Guzeng hydraulic tunnel as an engineering example, the hydraulic fracturing of tunnel lining under different conditions is numerically simulated. Results show the following: (1) the 2P-IKSPH method can dynamically reflect the stress wave propagation processes of surrounding rock and the damage process of tunnel lining. (2) The lining damage mainly occurs on the vault and the arch foot. (3) The critical internal water pressure increases with the increase of the tunnel buried depth and the thickness of lining, but increases first and then decreases with the increase of the surrounding rock mass grade. The research results can provide some references for the optimization designs of tunnel lining and reinforcement of similar projects. Meanwhile, developing 3D parallelization program based on 2P-IKSPH will be the future research directions.

An integrated underwater structural multi-defects automatic identification and quantification framework for hydraulic tunnel via machine vision and deep learning

“…2 Under the action of high-speed water flow and high ground stress, these projects suffer from various structural defects after long-term service periods. 3 The occurrence of structural damage will significantly deteriorate the durability, impermeability, and integrity Visual inspection implemented by human inspectors walking along the tunnel has been a practical strategy. 4 However, manual inspection is high-risk, labor-intensive, and time-consuming, especially for long-distance tunnel inspection.…”

“…2 Under the action of high-speed water flow and high ground stress, these projects suffer from various structural defects after long-term service periods. 3 The occurrence of structural damage will significantly deteriorate the durability, impermeability, and integrity of tunnel structures, further affecting the structural stability.…”