The creep model is the main form used to describe the creep behavior of weakly cemented soft rock (WCSR). To investigate the creep behavior of weakly cemented soft rock, multi-stage loading creep tests were performed by using GDS HPTAS creep triaxial apparatus. The creep curves, creep rates, and creep failure modes of weakly cemented soft rock under different water contents were obtained. A novel four-element fractional-order creep model to describe the three-stage creep behavior of weakly cemented soft rock was proposed using the Abel dashpot basing on the creep test results and fractional calculus theory. The formula of this model was developed according to the H-Fox special function. The trust-region method was used to obtain the model parameters, and the parameters were optimized using the ant colony optimization approach. The creep curves of weakly cemented soft rock under different water contents were calculated and compared with the experimental results, verifying the superiority of the four-element fractional-order creep model in describing the creep characteristics of weakly cemented soft rock. The calculated results were also in good agreement with the experimental results, which confirms that the four-element fractional order creep model can accurately reflect the complete creep behavior of weakly cemented soft rock.

蠕变模型是用于描述弱胶结软岩（WCSR）蠕变行为的主要形式。为了研究弱胶结软岩的蠕变行为，使用GDS HPTAS蠕变三轴仪进行了多阶段载荷蠕变试验。得到了不同含水量下弱胶结软岩的蠕变曲线，蠕变速率和蠕变破坏模式。基于蠕变试验结果和分数演算理论，利用阿贝尔阻尼器提出了一种新型的四元素分数阶蠕变模型，用于描述弱胶结软岩的三阶段蠕变行为。根据H-Fox特殊函数开发了该模型的公式。使用信赖域方法获得模型参数，并采用蚁群优化方法对参数进行优化。计算了不同含水量条件下的弱胶结软岩的蠕变曲线，并与实验结果进行了比较，验证了四元分数阶蠕变模型在描述弱胶结软岩的蠕变特征方面的优越性。计算结果也与实验结果吻合良好，证实了四元分数阶蠕变模型可以准确反映弱胶结软岩的完整蠕变行为。