# A Study on the Creep Characteristics of Gassy Clay Mixed with Silt
## 1 Introduction  
Gassy soil primarily contains CH\({}_{4}\), N\({}_{2}\), CO\({}_{2}\), etc., collectively referred to as shallow gas. Shallow gas represents a natural gas resource and a geological hazard, especially in oceanic environments. In China, shallow gas is widely dispersed along the southeastern coast, the middle and lower reaches of the Yangtze River, the Sichuan Basin, and the Bohai Bay Basin, with an even broader presence on the seabed. Its impact on the construction of foundation engineering projects is often considerable [1, 2, 3]. Scholars both domestically and internationally have conducted extensive studies on the mechanical properties of gassy sands and gassy soils: [PERSON] et al. [4] conducted triaxial tests on saturated sand and gas-bearing sand and established a constitutive model of gas-bearing sand and a static liquefaction criterion for gas-bearing sand. [PERSON] et al. [5] conducted triaxial tests on Hangzhou Bay gas storage sand under four stress paths of active and passive compression and elongation and demonstrated the influence of stress path on the deformation and strength characteristics of unsaturated sand. [PERSON] et al. [6] conducted field tests and indoor tests to compare the bearing capacity of sand before and after biogas release and found that the slow release of biogas can improve the bearing capacity ofsand. [PERSON] et al. [7] conducted single and cyclic triaxial tests on medium-density gas-bearing sand and found that even the presence of a small amount of gas makes the soil more easily compressed and limits the accumulation of excess pore water pressure. [PERSON] et al. [8] found that the occurrence and configuration characteristics of sand in the shallow gas-rich zone of a reservoir were similar to those of ordinary unsaturated soil, but its pore gas pressure was several times that of the atmospheric pressure. During the gas release process, the deformation of the reservoir sand caused only by a reduction in suction was negligible, and the main deformation was attributed to the increase in net average stress caused by a reduction in gas pressure in the reservoir. [PERSON] et al. [9] studied the influence of temperature on the shear behavior of gas-bearing sand and found that, under undrained shear conditions, the shear strength of loose gas-bearing sand increased with increasing temperature, while the opposite was true for dense gas-bearing sand, and the higher the gas content, the more obvious the phenomenon. The aforementioned research on the mechanical properties of gassy sands is relatively complete. However, due to the differences in particle size, structure and mineral composition, the mechanical properties of gassy soils are also different to those of gassy sands: [PERSON] et al. [10] conducted a \(K_{0}\) consolidation test on gas-bearing soil prepared by zeolite and found that the compression coefficient of gas-bearing soil was negatively correlated with the load, and the compression coefficient and rebound coefficient were both positively correlated with the load and gas content. [PERSON] et al. [11] studied the pore pressure dissipation and settlement development law of fine-grained gas-bearing soil and found that the instantaneous settlement was negatively correlated with saturation, the instantaneous settlement was positively correlated with pore pressure, and the final settlement of gas-bearing soil was greater than that of saturated soil. [PERSON] et al. [12] conducted indoor tests to study the distribution of water vapor pressure and saturation changes in the aeration zone of shallow gas reservoirs and their effects on soil deformation under controlled degassing measures. [PERSON] et al. [13] conducted undrained triaxial compression tests on gas-bearing soil and found that the presence of bubbles increased the undrained shear strength of loose sand but reduced the shear strength of dense sand. [PERSON] et al. [14] prepared gas-bearing clay using the zeolite method and conducted triaxial and one-dimensional consolidation tests.