摘要
通过三轴卸荷试验,系统分析了卸荷速率对卸荷过程中岩石力学特性的影响,研究了岩体的应力应变特征、卸载变形特征和破环特征,得到卸荷速率与变形模量及峰值围压的关系。结果表明,当卸荷速率小于0.02 MPa/s时,卸荷破坏变形模量随卸荷速率的增大呈非线性增长,破坏时的围压随卸荷速率增加呈非线性递减;当卸荷速率大于0.02 MPa/s时,变形模量呈线性增长,破坏时围压呈线性递减,但当卸荷速率增大到一定值时,变形模量将趋于稳定;不同卸荷速率与峰值围压的二次多项式拟合,相关系数都在0.90左右,说明采用二次多项式进行拟合是可行的。
The influence of unloading ratio on mechanical properties of water-bearing sandstone was analyzed systematically by triaxial unloading tests.The relationship between unloading ratio and deformation modulus and peak confining pressure can be obtained by discussing the stress-strain characteristics,unloading deformation characteristics and failure characteristics of rock.The results show that the deformation modulus is nonlinear growth and confining pressure is nonlinear decreasing as unloading ratio increases when unloading ratio is less than 0.02MPa/s;deformation modulus is linear growth and confining pressure is linear decreasing as unloading ratio increases when unloading ratio is more than 0.02MPa/s.When unloading ratio reaches a certain value,the deformation modulus is stable.Correlation coefficient of quadratic polynomial fit between different unloading ratio and the peak confining pressure is 0.90.It shows that quadratic polynomial fit is feasible.
出处
《水电能源科学》
北大核心
2016年第7期120-123,137,共5页
Water Resources and Power
关键词
含水砂岩
卸荷速率
变形模量
力学特性
water-bearing sandstone
unloading ratio
deformation modulus
mechanical properties
