Abstract：博士学位论文摘要 The rheo logical behavio r of rock salt is impo rtant fo r many engineering app licat ions1Th is dissertat ion repo rt s on experiment s and model analyses of rock salt1 A n in- dep th study is p resented of the t ime - dependent p ropert ies of rock salt1 It consist s of two part s1 The f irst part is the experimental invest igat ion, w h ich is aimed at imp roving the understanding of the rheo logical behavio r of rock salt1U niaxial and t rtaxial creep and relaxat ion experiment s have been perfo rmed to further th is goal1 The second part is the analysis of const itut ive models of the mechanical behavio r of rock salt and the evaluat ion of their p redict ive capability1 The object ive of th is research is to upgrade the understanding of the t ime- dependent p ropert ies of rock salt and to develop a mo re reasonable damage const itut ive theo ry to describe the comp lete mechanical response of rock salt1 In the f irst part , besides convent ional creep and relaxat ion test s , stepw ise , loadins and reloading , and alternat ing relaxat ion and creep test s are described1 Tw elve test s have been perfo rmed, rangig in durat ion f rom a few hours to 4 month s1 The axial st ress ranges f rom 13 to 43M Pa1 Conf ining p ressure ranges f rom 0 to 111 2M Pa1The conf inins p ressure effect , the st ress level , and the load path effect on the creep and st ress relaxat ion of rock salt are analyzed th rough the experimental invest igat ion1 The p re - creep effect on st ress relaxat ion is obtained1 The experimental invest igat ions reveal that the conf ining p ressure effect on the creep is signif icant only in the low - p ressure range (0～ 3M Pa) 1 Steady state st rain rate is independent of the load path1 The p re- creep st rain and the conf ining p ressure affect the st ress relaxat ion signif icant ly1 The existence of a t ransient st rain lim it and of a low er creep lim it is conf irmed by the experimental result s p resented in th is dissertat ion1 The second part of th is study review s const itut ive theo ry equat ions current ly used in rock salt mechanics research and suggest s a new const itut ive equat ion in o rder to rep resent the test ing data obtained1 A n endoch ronic model is developed in o rder to model the temperature effect s on the material response1 A new damage const itut ive equat ion is p ropo sed in o rder to rep resent the ent ire creep behavio r1 A comparison of theo ret icaliy calculated result sw ith experimental result s is given1Based on thermodynam ic theo ry and damage mechanics , an evo lut ion equat ion of creep damage of rock salt is p ropo sed1A new creep const itut ive equat ion is derived f rom th is evo lut ion equat ion1 The new model p redict s the damage behavio r induced by the creep usins only a few material parameters , w h ich have obvious physical meaning1
YangChunhe. T IM E- DEPENDEN T BEHAV IOR O F ROCK SAL T EXPER IM EN TAL INV EST IGA T ION AND THEORET ICAL ANAL YS IS[J]. 岩石力学与工程学报, 2000, 19(05): 687-687.
