PSI - Issue 32

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A.K. Fedoseev et al. / Procedia Structural Integrity 32 (2021) 202–208 A. K. Fedoseev/ StructuralIntegrity Procedia 00 (2021) 000 – 000

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Fig.6. Fault areas distribution in WPS for pumping pressure 2 MPa when maximum pressure is maintained over the whole length of flaw zone and infiltration of grouting material takes place If the infiltration of grouting material into the crumbling part in WPS top takes place while pumping pressure is kept under 1 MPa only slight growth of the fault zone is observed. When pressure reaches 1.5 MPa significant intensification of failure processes in salt bed occurs (Fig.5). Fault zone width at the border with SMO increases by 20% which could lead to the necessity of additional boreholes drilling. With the pumping pressure around 2 MPa the distance from extensive fault zone in the upper layers of WPS to crumbling area in its lower part is less than 3 m (Fig.6) which is equivalent to formation of continuous failure area through whole WPS; fault zone width at the border with SMO in this case increases by factor 1.5 compared to the state before grouting solution pumping.Thus, only pumping pressures under 1 MPa can be considered safe enough for creating antileakage screen without incurring negative impact on already disturbed state of WPS. Conclusion The proposed methodical approach gives a foundation for a quick estimation of impact from grouting on already disturbed salt strata. Using this approach, it was demonstrated that within hazardous area at the site of exploration well number 492 (BKRU- 4 mine) only when pumping pressure doesn’t exceed 1 MPa there is still a possibility to make antileakage screen in salt-marl overburden. Acknowledgements The work was supported by the state task N 0422-2019-0148-C-01. References Amusin B.Z., Linkov A.M. (1973). Primenenie metoda peremennyh modulej dlja reshenija zadach linejnoj nasledstvennoj polzuchesti [Application of a method of variable modules for the solution of problems of linear hereditary creep]. Works of the All-Russian Research Institute of Dairy Industry, Vol. 88. pp. 180-184.