为防止埋地燃气管道与电力通道邻近敷设条件下，因燃气泄漏进入电缆通道并在其中积聚，进而引发爆炸事故，该文基于Fluent软件建立了邻近敷设下电缆通道燃气积聚模型，并对电缆通道内燃气积聚过程展开数值模拟，系统研究了不同坡度及不同通风换气次数对通道内燃气积聚规律的影响。研究结果表明：电缆通道坡度对甲烷扩散路径、积聚位置及浓度场分布具有显著影响：无坡度时，甲烷于100 s内围绕渗漏口均匀分布；存在坡度时，甲烷受坡度作用发生扩散偏移，且积聚效应随坡度的增大而显著增强，易在电缆通道底部支架下方形成高浓度聚集区。机械通风可有效降低电缆通道内甲烷积聚浓度并改变甲烷扩散方向，其抑制效果受通风次数及通道坡度的协同作用影响；通风次数增加可提升通道整体换气效率，使积聚区域由无风状态下的顶部向出风口侧底部迁移。该文可为预防和控制复合敷设区域的燃气安全事故提供技术支撑，并为工程实践中电缆通道的安全设计、监测点布置及风险管控策略优化提供科学依据。

Objective: As China's urbanization continues to accelerate, cities are expanding in size, populations are becoming increasingly concentrated, and the demand for energy is growing. Consequently, the construction of underground natural gas pipeline networks continues to advance, with steadily expanding coverage and increasing pipeline density. However, safety incidents have become more frequent during the construction and operation of gas pipeline networks, resulting in serious casualties, property damage, and the disruption of urban production and daily life activities. Urban gas pipelines traverse the underground space of cities, making it difficult to avoid intersections with or co-location alongside other municipal pipelines, such as those for water supply and drainage, district heating, and electricity. This is primarily due to limited underground space and a lack of unified planning and coordination among various municipal construction projects, which often leads to mutual interference between different pipeline systems during construction. This complex underground pipeline layout exposes gas pipeline networks to numerous safety risks. Methods: A model for gas accumulation in cable ducts with adjacent cable runs is established using Fluent, a powerful computational fluid dynamics software package with a rich set of physical models that enables high-precision numerical simulations of complex fluid flow and mass transfer processes. Model development considered various factors, including the actual structure of the cable duct, location and intensity of gas leaks, and ventilation conditions within the duct. Through reasonable simplifications and assumptions, a mathematical model was constructed that accurately simulated the real-world conditions. Subsequently, numerical simulations of gas accumulation within the cable duct were performed, and different operating conditions were included to systematically investigate the effects of varying the slope and ventilation rate on the patterns of gas accumulation within the duct. Results: The results indicate that the slope of a cable duct substantially affects the methane diffusion path, accumulation locations, and concentration field distribution. In the absence of a slope, methane is distributed uniformly around the leak point within 100 s. When a slope is present, methane diffusion is deflected by the slope, and the accumulation effect increases significantly as the slope steepens, making it likely for high-concentration accumulation zones to form beneath the supports at the bottom of the cable duct. Mechanical ventilation effectively reduces methane accumulation concentrations within cable ducts and alters the direction of methane diffusion; its suppression effect is influenced by the synergistic interaction between ventilation frequency and duct slope. Increasing the ventilation frequency improves the overall air exchange efficiency of the duct, causing the accumulation zone to shift from the top (under nonventilated conditions) to the bottom near the exhaust outlet. Conclusions: This study provides multidimensional technical support for the prevention and control of gas safety accidents in areas with overlapping utility lines, including real-time gas leak monitoring, intelligent hazard detection, and emergency response technologies, thereby effectively enhancing the precision and efficiency of gas safety management. In addition, it provides a comprehensive and in-depth scientific basis for the safe design of cable ducts, the layout of monitoring points, and the optimization of risk management strategies in engineering applications, thereby facilitating the development of safer and more reliable urban underground pipeline networks to ensure the stable operation of urban infrastructure and reduce risks to people's lives and property.