人工冻结软岩粒子群塑性强化开尔文蠕变模型

Kelvin Creep Model of Artificial Frozen Deep Soft Rock Based on Particle Swarm Plasticity Strengthening

随着地下的利用和研究往深处发展,冻结法施工越来越多,蠕变是冻土的显著特点之一,为确保工程安全,冻土蠕变成为重点研究对象。根据损伤理论,材料硬化状态的变化将导致材料变形行为的改变,因此研究人工冻结软岩的蠕变应充分考虑塑性强化的影响。基于塑性强化的蠕变模型在岩土工程中比较少见,为了更好的模拟蠕变过程,引入与时间有关的塑性强化函数,与开尔文模型串联,最后得到塑性强化开尔文蠕变模型,对圆柱形试样进行单轴蠕变试验,运用粒子群优化方法,通过对建立的蠕变模型进行识别,得到蠕变模型的参数,对比塑性强化开尔文蠕变模型计算值与试验结果,发现塑性强化开尔文模型能很好模拟深部人工冻结软岩的蠕变。

With the development of utilization and research of underground,the freezing construction method is widely used,creep is one of the significant characteristics of frozen soil,in order to ensure the engineering safety,the creep of frozen soil has become the focus of the research object.Based on damage theory,the change of material hardening state will lead to the change of the deformation behavior,the creep of materials should be considered for the hardening effect,thus the time dependent plasticity strengthening function was introduced in to series with the Kelvin model,to get the plasticity strengthening Kelvin creep model.Based on the uniaxial creep tests on cylindrical specimens,with Particle Swarm Optimization method,to indentify the established model,for obtaining the parameters of the model.Through comparing the calculation value of plasticity strengthening Kelvin creep model with the test value,it is found that the plasticity strengthening Kelvin creep model can well simulate the creep laws of artificial frozen deep soft rock.