摘要
基于低频三轴循环加卸载试验得到盐岩轴向初始衰减和稳态蠕变变形规律,以及卸载模量随着循环周次的增加呈现负指数型弱化趋势。以弹性模量的折减表征循环荷载下盐岩损伤劣化,考虑损伤因子的频率和时间效应,得到统一损伤演化方程,建立考虑频率影响的变参数Burgers蠕变损伤模型。对比分析表明,该模型能够准确描述不同频率循环荷载作用下盐岩蠕变变形特征和损伤演化过程,为盐岩地下储气库注采运营稳定性分析提供更为合理的分析模型和力学参数。
Based on the low-frequency triaxial cyclic loading tests on rock salt,the axial creep deformation law of rock salt in the initial and the steady phases were obtained. The test results show that the unloading modulus negative exponentially decreases with loading cycles. The degradation of rock salt was characterized by the reduction of its elatsic modulus. Taking into account the frequency and the time effect on damage factor,a united damage evolution equation was presented. Then a variable parameters-based creep damage model considering the effect of frequency was proposed. A comparative analysis shows that the proposed creep damage model can accurately decribe the creep deformation law and damage evolution for rock salt under different loading frequencies. It can provide a more reasonable constitutive model and related parameters for the stability analysis of natural gas storage in rock salt.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2015年第S1期93-99,共7页
Journal of China Coal Society
基金
中国矿业大学深部岩土与地下工程国家重点实验室开放基金资助项目(SKLGDUEK1403)
国家自然科学青年基金资助项目(51309234)
江苏省自然科学青年基金资助项目(BK20130065)
关键词
频率
变参数
循环加载
卸载模量
损伤演化
Burgers体
frequency
variable parameter
cyclic loading
unloading modulus
damage evolution
Burgers model
