基于扰动状态概念的软岩蠕变本构模型与试验验证  

Identification of the Creep Model and Its Parameters of Soft Rock on the Basis of Disturbed State Concept

作　　者：黄明[1] 蒋宇静[1,2] 王少杰 邓涛[1] Ming Huang;Yujing Jiang;Shaojie Wang;Tao Deng(College of Civil Engineering, Fuzhou University, Fuzhou,350108;Department of Civil Engineering, Nagasaki University, Nagasaki 852-8521, Japan)

机构地区：[1]福州大学土木工程学院,福州350108 [2]国立长崎大学土木工程系

出　　处：《固体力学学报》2017年第6期570-578,共9页Chinese Journal of Solid Mechanics

基　　金：国家自然科学基金项目(41672290);福建省自然科学基金项目(2016J01189)资助

摘　　要：软岩材料的蠕变过程从初始加载阶段开始即容易产生塑性变形,这与硬岩存在较大差异,而传统的元件模型仅在应力超过某一阈值后才开始描述其粘塑性行为.通过分析岩石加卸载时效变形过程中弹塑性状态的演变规律,以扰动状态理论为基础,确定了以塑性变形为变量的扰动因子函数,并通过塑性变形随时间的变化特征进一步建立了以时间为自变量的蠕变扰动因子演化方程.在此基础上,针对泥质页岩的蠕变变形过程,选取Burgers和Bingham模型分别描述扰动状态理论中的相对完整状态和完全调整状态,并选取蠕变扰动因子为权重函数建立了基于扰动状态理论的蠕变本构模型.通过泥质页岩的室内蠕变特性试验对模型进行有效性检验表明,理论曲线与实测曲线的逼近程度较高,蠕变扰动函数能随时间的发展持续调整相对完整状态向完全调整状态转换的过程,较高应力状态下软岩进入完全调整状态的速率较快,相对传统模型该模型具有更好的非线性及阶段协调性,可较好地描述软岩的初始、稳定和加速蠕变阶段.Contrary to hard rocks,the plastic deformation of soft rocks during the initial creep stage occurs more obviously.The traditional component models can be used to describe the visco-plastic behavior of geomaterials,but only when the stress value is beyond the yield point.This paper proposes the plastic deformation as a variable in the disturbance function,in the framework of the Disturbed State Concept,to describe the evolution characteristics of elasto-plastic states during loading and unloading.In addition,the evolution of the disturbance equation with time is further investigated and analyzed according to the relationship between plastic deformation and time.The Burgers model is applied to the relative intact state;while the Bingham model is employed to describe the fully adjusted state.The disturbance function is utilized to combine the two states.Following this approach,the creep constitutive model for soft rocks is presented.Comparison with the creep test results of argillaceous shale indicates that the proposed disturbance state constitutive model accurately captures the temporal evolution of the transformation process from the relative intact state to the fully adjusted state.Furthermore,the proposed model can better handle both nonlinearity and stage coordination,and provides a more profound description of the initial,stable and accelerating creep stages of soft rock.

关 键 词：扰动状态理论 软岩 蠕变方程 元件模型 

分 类 号：O344.6[理学—固体力学]