Increasing climatic stresses accelerate the degradation of highly organic soils, like peats, by increasing their drying rate above the water table and their decomposition rate under water. Recent experimental studies are providing evidence of the consequences of these processes on the hydro-mechanical properties of peats. However, modelling the experimental evidence in a comprehensive framework remains challenging, especially in the case of anaerobic degradation, which is accompanied by gas generation, exsolution and expansion into an initially saturated matrix of soil. In this work, experimental results from undrained isotropic unloading on artificially gas charged peat samples are combined with data form drying tests on the same peat, in an attempt to develop a unified framework encompassing the two desaturation processes. As a first approximation, simple compression laws depending on the average stress acting on the soil skeleton are used to simulate the experimental results. The comparison between experimental data and model simulations suggests the possibility of modelling gas expansion similarly to the gas invasion process occurring upon drying. The modelling approach, stemming from unsaturated soil mechanics, is meant to offer a possible framework to include the hydro-mechanical consequences of the effects of degradation of peats in the engineering analysis.

中文翻译：

---

泥炭中的瓦斯释放和瓦斯入侵：拟议综合模型框架

气候压力的增加通过增加其在地下水位以上的干燥速率和在水中的分解速率，加快了泥炭等高度有机土壤的降解。最近的实验研究提供了这些过程对泥炭的水力机械性能的影响的证据。但是，在一个综合的框架中对实验证据进行建模仍然具有挑战性，特别是在厌氧降解的情况下，厌氧降解伴随着气体的产生，释放和膨胀成最初饱和的土壤基质。在这项工作中，在人工充气的泥炭样品上进行不排水的各向同性卸载实验结果与同一泥炭上的干燥试验数据相结合，以试图建立一个涵盖两个脱饱和过程的统一框架。作为第一近似值，根据作用在土壤骨架上的平均应力，使用简单的压缩定律来模拟实验结果。实验数据与模型模拟之间的比较表明，可以对气体膨胀进行建模，类似于干燥时发生的气体入侵过程。基于非饱和土壤力学的建模方法旨在提供一个可能的框架，以便在工程分析中包括泥炭退化影响的水力机械后果。