Open Access

ARTICLE

Numerical Investigation on the One-Way Coupling of Gas Leakage-Explosion and a New Quantitative Overpressure Attenuation Law in Underground Culverts

Pengcheng Kang¹, Yuanyuan Tian¹, Ying Liu¹, Qian Xu¹, Yuting Chen¹, Lixin Jia², Shuge Guo², Heng Rong², Taolong Xu^2,*

1 Gathering and Transportation Engineering Technology Research Institute, PetroChina Southwest Oil & Gasfield Company, Chengdu, China
2 School of Petroleum Engineering, Southwest Petroleum University, Chengdu, China

* Corresponding Author: Taolong Xu. Email:

(This article belongs to the Special Issue: Greening the Pipes: Achieving Sustainability in Pipeline Engineering)

Structural Durability & Health Monitoring 2026, 20(3), 18 https://doi.org/10.32604/sdhm.2026.077643

Received 14 December 2025; Accepted 24 March 2026; Issue published 18 May 2026

Abstract

Accurate assessment of gas explosion risks in urban underground culverts is often hindered by the decoupling of leakage diffusion and explosion mechanics. This study develops a high-fidelity numerical framework by implementing a one-way coupling strategy, where the steady-state methane concentration field simulated in FLUENT is mapped into ANSYS/LS-DYNA as the initial material status. Unlike traditional models assuming uniform gas distribution, this approach captures the realistic impact of complex culvert geometries on explosion precursors. A multi-material coupled model involving the confined space, road surface, and surrounding air was established to investigate shock-wave propagation and structural response. The results reveal the migration laws of explosive regions in both enclosed and semi-enclosed spaces. The primary contribution is the derivation of a novel quantitative overpressure attenuation law P = A·e^Bx that explicitly incorporates the depth-to-width ratio, r. This formula enables the precise determination of damage radii for building structures and personnel. Validation against experimental benchmarks confirms the model’s reliability. The proposed framework and empirical formula provide a robust tool for urban safety distance planning and emergency risk zoning.

---

Keywords

---