Experiment Studies On Time And Temperature Effect Of Mechanical Properties And Constitutive Relation Of Rock Salt

Nowadays, energy conjuncture is obviously, energy storage become more and more vital. There are many advantaged factors such as high safety on deeply space as a medium for energy storage. Rock salt as ideal medium for energy storage or high radioactive wastes permanent disposal is recognized because rock salt have especial characteristic such as well creep deformation, low permeability ,damage recovery. Studies on time and temperature effect of mechanical properties and constitutive relation of rock salt under high temperature become more and more important.Systemic experimental investigation and theoretic analysis on the mechanical aspects of jintan`s rock salt have been conducted in the dissertation. Testing studies is made on the mechanical properties of rock salt under different deviatoric stress and different high temperature, through the data which achieved, the mechanical model and one dimensional TM coupled damage constitutive equation are established, this constitutive equation are in agreement with the experiment result. The mechanical parameter is availability while the rock salt as a deposited medium. Experimental studies mostly are static experimental studies of rock salt. Include uniaxial and triaxial compress experiments, uniaxial and triaxial creep experiments under different deviatoric stress and different high temperature. Theoretic analysis of rock salt includes compress mechanism analysis and creep mechanism analysis under high temperature. Through the test results, damage constitutive equation is established by using damage mechanical.There are two aspects for experimental studies and theoretic analysis of the rock salt:Firstly, uniaxial and triaxial compress experiment are made on the mechanical properties of rock salt after undergoing different high temperatures, the mechanical properties include stress–strain curve, peak stress, peak strain, modulus of elasticity. This paper researches the strength and time dependent properties of rock salt. Through the experimental curves of uniaxial and triaxial complete stress—strain of rock salt, based on the relation of elastic modulus and temperatures for rock salt, the thermal damage evolution and one dimensional TM coupled damage constitutive equation are established.Secondly, creep mechanical properties are analyzed to uniaxial and triaxial creep of rock salt; through uniaxial and triaxial creep experiment result of rock salt under different deviatoric stress and different temperature, research the effect of stress level and temperature on creep of rock salt. the damage constitutive equation of steady creep rate is recomposed basis on creep results and damage characteristics of rock salt, the creep characteristic curves and parameters are obtained by regressed .The results indicate that this constitutive equation are in agreement with the experiment result. Based on the relation of creep modulus and creep time for rock salt, the creep damage evolution and creep damage constitutive equation are established. Through creep mechanism analysis of solid materials, the creep mechanism of rock salt has achieved, a creep constitutive model of rock salt is made by using visco-elastic-plastic theory. Finally, the parameters of constitutive equation are obtained by fitting test data, the theoretic results is proved well by comparison with the experimental results.