基于分数阶微积分的岩石硬性结构面蠕变本构模型  

Constitutive Model of Creeping at Joints of Hard Rock Based on Fractional Calculus

作　　者：李任杰 吉锋[1] 张津铭 潘勇杰 熊朝正 LI Ren-jie;JI Feng;ZHANG Jin-ming;PAN Yong-jie;XIONG Chao-zheng(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,成都610059

出　　处：《科学技术与工程》2020年第11期4501-4506,共6页Science Technology and Engineering

基　　金：国家重点研发计划(2017YFC1501000);四川省科技计划(2018JY0471);四川省教育厅重点基金(15A0075)。

摘　　要：结构面普遍存在于工程岩体中,影响工程安全。对含结构面岩体的蠕变特性及本构模型的研究对揭示岩质边坡蠕变机制及边坡失稳预测具有较大的意义。利用水泥砂浆制作非贯通硬性结构面试样,进行剪切蠕变试验,并对蠕变特性进行分析。将整数阶黏壶元件改进为分数阶微积分软体元件,并替换Kelvin模型中整数阶黏壶元件,同时引入能够模拟结构面加速蠕变过程的非线性黏性元件并将其非定常化,采用元件组合方式,构建基于分数阶微积分的岩石硬性结构面蠕变本构模型。以非贯通硬性结构面和贯通型硬性结构面试样剪切蠕变试验数据为基础,分别对本构模型进行验证并对待定参数进行辨识。结果证明,试验值和预测值之间相关性程度R^2均较高,非贯通硬性结构面和贯通型硬性结构面相关性R^2分别达0.94和0.97,表明该模型能较好地模拟非贯通硬性结构面和贯通型硬性结构面岩体蠕变特性,对揭示岩质边坡蠕变机制和时效演化有重要意义。Joints of rock mass are very common in engineering and affect the engineering operation and safety. Therefore, study of creep characteristics and constitutive model of joints of hard rock mass is of great significance for revealing creep mechanism of rock slope and predicting slope instability. Non-persistent hard-joint samples were made from cement mortar, to which shear creep test was carried out, and the creep properties were analyzed. The integer-order viscous pot element was improved to a fractional-order calculus software element, and the integer-order viscous pot element in the Kelvin model was replaced. At the same time, a non-linear viscous element with which the accelerated creep process of joints can be simulated was introduced and denormalized. The creep constitutive model of rock hard joints based on fractional calculus was constructed by means of component combination. The constitutive model was validated and the parameters to be determined were identified based on the shear creep test data of non-penetrating and penetrating hard structures. Results show that the correlation degree between the experimental value and the predicted value was high, and the R^2 values of the non-persistent hard joints and the persistent hard joints are 0.94 and 0.97, respectively. It shows that the model can simulate the creep characteristics of rock mass with non-persistent and persistent hard joints, and is of great significance for revealing the creep mechanism and time evolution of rock slope.

关 键 词：硬性结构面蠕变 分数阶微积分 加速元件 本构模型 

分 类 号：TU454[建筑科学—岩土工程]