Work

A safety-critical component for large-scale underground hydrogen storage: The role of concrete sealing plug

Year: 2026

Type: article

Abstract: Underground hydrogen storage (UHS) is a cornerstone technology for enabling a reliable and large-scale hydrogen economy. However, the high diffusivity and cyclic storage pressure of hydrogen pose significant challenges to the long-term integrity of storage caverns. The concrete sealing plug, as a primary barrier against hydrogen escape at the cavern mouth, is a safety-critical component. This study addresses this energy storage challenge by developing a comprehensive mechanical model to guide the optimized design of a wedge-shaped plug for a UHS project in Daye, China. The model's accuracy was validated through laboratory shear tests on a limestone-concrete interface with joints. Furthermore, a high-fidelity 3D (three-dimensional) numerical model was established to simulate the complex geological conditions. The key findings are: (1) The proposed wedge-shaped design not only ensures stability but also minimizes excavation volume, thereby reducing the construction cost and environmental footprint of UHS facilities—a crucial factor for their economic viability. (2) The plug's key dimensions, determined via limit equilibrium analysis, are governed by the cavern diameter, rock mass strength, joint properties, internal pressure, and manhole diameter. (3) Numerical simulations reveal that internal pressure induces tensile debonding at the rock-concrete interface, with the maximum compressive stress located at the plug base, pinpointing a potential failure initiation zone. The result provides essential theoretical foundations and practical guidelines for designing robust concrete seals, contributing to the safe and efficient deployment of underground hydrogen storage systems.

Source: Journal of Rock Mechanics and Geotechnical Engineering

DOI: 10.1016/j.jrmge.2026.01.008

Authors: Xinyu Liu, Jianping Yang, Weizhong Chen

Institutions: Chinese Academy of Sciences, Institute of Rock and Soil Mechanics, University of Chinese Academy of Sciences, State Key Laboratory of Geomechanics and Geotechnical Engineering

Language: English

Topic: Rock Mechanics and Modeling

Subfield: Mechanics of Materials

Field: Engineering

Domain: Physical Sciences

SDGs: Industry, innovation and infrastructure, Affordable and clean energy

Open Access status: diamond

Funders: National Natural Science Foundation of China, National Key Research and Development Program of China