Study On The Effect Of Interlayer Occurrence Characters On The Mechanical Properties Of Molded Layered Salt Rock And The Long-time Stability Of Storage

Domestic salt rock resources have many interlayers, which are often very weak andhave thin thicknes. Therefor, study on the effect of interlayer occurrence characters onthe mechanical properties of molded layered salt rock is quite an important part of thedomestic salt rock basic research. In allusion to the situation that samples which havedifferent interlay characters are not rich and difficult to obtain, this paper provides anew research method. First, the molded salt rock samples which have different interlaycharacters were made by the means of model experiment. After that, the samples weretaken to carry on the conventional mechanical test and long-time creep test in order toobtain the law of the molded salt rock’s mechanical characters. At last, with the resultsof numerical simulation, the long-time stability of a domestic salt-cavern gas storagewith dense interlays was analyzed. The main research contents and conclusions are asfollows:1. Salt rock powder or particle whose mechanical property was much more similarto salt rock crystal was taken to be the main raw material of the similar material.Modeling methods of pure salt rock, hardness interlayer, weak interlayer and layeredsalt rock was obtained through mono-factor and orthogonal experiments, and then, theinfluences of the various factors on the mechanical properties of the models wasanalyzed.2. Deformation behaviour and strength characteristics change rules of hardness andweak interlayed salt rock samples under different conditions such as different interlayerthickness ratio, interface numbers and interlay distance ratio were obtained throughmodeling tests.3. Long-time creep experiments using multistage loading were carried on toanalyze the rules of steady state creep ratio of layered salt rock with different interlayerthickness ratio, interface numbers or interlayer distance ratio on the condition ofdifferent confining pressure and different parial pressure.4. The numberical simulation of long-term rheological properties of salt cavernwith different interlayer occurrence characters during different ages was carried on byusing of the FLAC3D. According to the above, the effects of interlayer occurrencecharacters on pastic damage zone of salt rock cavern cavity and volume contractionratio of cavity were analyzed. 5. Considering the salt rock with dense thin interlays as composite rock, short-termand long-term mechanical parameters of the molded layered salt rock was obtainedthrough model tests, in order to simplify the analytical mode of the numerical modeling,so that the simulation results might be more accurate.