【摘要】 采用中国矿业大学的20 MN高温高压岩体三轴试验机进行了高温三维应力下大尺寸Φ200 mm×400 mm鲁灰花岗岩蠕变特性的实验研究,温度最高达到了600℃,轴向应力最高达到了175 MPa。通过对实验数据的分析,发现高温三维应力条件下静水应力引发鲁灰花岗岩发生蠕变变形,提出了考虑静水应力作用时稳态蠕变率的本构方程,得到了鲁灰花岗岩蠕变本构方程的参数A1,A2,?Q,m,n。研究还发现静水应力下的蠕变和差应力下的蠕变曲线特征相同,同样可以划分为初始蠕变阶段、稳态蠕变阶段和加速蠕变阶段三个阶段,鲁灰花岗岩的蠕变变形是温度,差应力和静水应力的函数,温度、差应力和静水应力的升高都会加速鲁灰花岗岩的蠕变变形。更多还原

【Abstract】 By use of the 20 MN servo-controlled triaxial rock testing machine with high temperature and high pressure in China University of Mining and Technology,an experimental study is carried out on creep properties of large size granite specimens of Φ200 mm×400 mm with temperature up to 600℃ and axial stress up to 175 MPa.Through the analysis of experimental data,it is discovered that hydrostatic stress can cause creep formulation of lu gray granite.A constitutive equation of stable-state creep rate considering hydrostatic stress is thus proposed.The creep constitutive equation parameters of lu gray granite A1,A2,ΔQ,m,n are obtained.It is discovered that the creep properties caused by hydrostatic stress are the same as those caused by the differential stress in lu gray granite.It can also be divided into three stages: transient creep,stable-state creep and accerlerating creep.The creep formulation of lu gray granite is a function of temperature,differential stress and hydrostatic stress.Increase of temperature,differential stress and hydrostatic stress can accerlerate the creep formulation of lu gray granite.更多还原