Time-dependent lateral pressure of the filling barricade for roadway cemented backfill mining technology

The filling barricade is one of the key components of roadway cemented backfill systems and this research focuses on critical factors influencing the performance of these systems, particularly the lateral stress characteristics and the stability of the filling barricade. In this paper, a theoretical model is presented and applied to obtain and calculate the lateral pressures exerted on the filling barricade and to understand the effects of the filling process. It is found that the yield stress of cemented backfill increases with curing time and this relationship can be described as an increasing power function. The lateral stresses exerted on the filling barricade increase over time during the filling period but decrease over time during the waiting period. Both the maximum lateral stress exerted on the filling barricade and the decreasing amplitude decrease as the number of filling rounds increases. In the calculation case, the maximum lateral stress declines from 0.161 MPa to 0.0148 MPa when the number of filling rounds increases from one to six. From these results, the filling process with three rounds is determined to be the optimal process scheme. In the first round, the lateral stress increases to 0.0369 MPa during the filling period and decreases to 0.0146 MPa during the waiting period; In the second round, the lateral stress increases to 0.0368 MPa then decreases to 0 MPa; in the third round, the lateral stress of the filling barricade stays at 0 MPa.