Piled foundations are commonly thought to create preferential pathways for ground gas migration. This view is often held without consideration of site-specific ground conditions, pile type or source of gas. There are currently no published data that quantify the effects of piles on gas flow from the ground. Both contaminated water and gas are fluids that for the purposes of this paper can be modelled using the standard equations of fluid flow. Therefore, the available research on the risk of piles increasing the permeability of the surrounding ground with respect to contaminated water can also be applied to gas flow. This paper discusses the different types of pile construction commonly used in the UK and how each may, or may not, influence gas migration. Understanding ground conditions is critical to assessing whether a preferential pathway will form. This paper looks at the available evidence on the influence of piles on the permeability of the surrounding ground. Even if it is considered possible that a preferential pathway could develop, the influence on the gas risk will depend on the number of piles, gas pressure and horizontal permeability. A significant effect is possible only where gas is under pressure and/or the piles are very closely spaced.

中文翻译：

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英国地下气体迁移的基础和途径堆积如山

通常认为桩基会为地下气体的迁移创造优先途径。通常不考虑特定地点的地面条件，桩类型或气源而持有该视图。当前没有公开的数据可以量化桩对地面气体流动的影响。受污染的水和气体都是流体，就本文而言，可以使用流体流动的标准方程式进行建模。因此，关于桩增加受污染水的周围地面渗透性的风险的现有研究也可以应用于气流。本文讨论了英国通常使用的不同类型的桩结构，以及每种桩如何影响或不影响气体迁移。了解地面条件对于评估是否会形成优惠途径至关重要。本文研究了有关桩对周围地面渗透性影响的现有证据。即使认为可能会形成一条优先通道，对瓦斯风险的影响也将取决于桩数，瓦斯压力和水平渗透率。仅在气体处于压力下和/或桩之间的距离非常近的情况下，才可能产生明显的效果。