Effect of cement content on the static and dynamic liquefaction resistance of fine tailing

Abstract

Cement tailings storage (CTS) in goaf may experience static and dynamic loading, such as rock stress, mine earthquake and blasting stress. When subject to dynamic loading, the risk for liquefaction of CTS may cause goaf barricade instability. To better understand the effect of cement content on CTS liquefaction resistance. Static and cyclic triaxial tests were conducted to determine the parameters required for the dynamic response analysis of CTS storage. A finite element analysis using LS-DYNA carried out to study the blasting response of CTS storage. The results indicated that the liquefaction resistance of CTS significantly improved with the cement content increased. The CTS exhibited near-static liquefaction when cement content was less than 2.42%. However, CTS cement content greater than 2.93% exhibited strain hardening or weak strain softening with low liquefaction index. The CTS with cement content 0–2.93% initial liquefaction less than 38 cyclic loading. Dynamic response analyzed showed liquefaction risk decreases as blasting distance and cement content increased. For blasting distances greater than 30 m, the CTS cement content of 3% is sufficient to resist liquefaction under blasting. The findings are conducive to the design of appropriate CTS underground storage parameters.

Keywords

• Cement tailings
• Consolidated undrained experiment
• Liquefaction resistance
• Dynamic response
• Blasting distance