Investigation of the fissure propagation mechanism of fracture grouting in the Balasu Coal Mine

Liang Xiangyang; Fang Gang; Wu Yiqiang; Wang Fuyu; Liu Yang; Zhang Jiafan

doi:10.16186/j.cnki.1673-9787.2024010021

Abstract：Objectives Grouting modification is an effective technique for preventing and controlling water-related disasters in coal mines.This study investigates the fracture grouting effects on coal under high-pressure,water-rich conditions,which is of great practical significance for engineering applications.Meth-ods Based on a fluid-solid coupling mechanism in discrete element modeling,the concepts of"domain"and"pipeline"are introduced to simulate the coupling process during fracture grouting.The fluid"do-main,"considered as a water reservoir,consists of triangular regions formed by connecting particle centers.The"pipeline"represents fluid migration paths connecting these domains,modeled using smooth parallel plate structures.The meso-parameters of the numerical model are calibrated using uniaxial compression and Brazilian splitting tests.A numerical model of fracture grouting is established to simulate force chain distri-butions after coal fracturing and to analyze the influence of grouting pressure and lateral pressure coeffi-cients on fissure propagation.Results The results show that without confining pressure,the contact force be-tween particles around the borehole ranges from 0.02 to 0.10 MPa,while under confining pressure,it ranges from 0.06 to 0.12 MPa.Under equal confining pressure,higher confining pressure leads to wider stress concentration zones but shorter fracture propagation distances.At the same confining pressure,in-creasing grouting pressure extends the fracture propagation range.Under unequal confining pressure,frac-tures tend to develop parallel to the direction of the maximum principal stress.Conclusions Higher grouting pressure can effectively displace water and air from coal seam fissures,reduce the number of boreholes re-quired,and lower operational costs.The results provide valuable guidance for the selection of grouting pa-rameters and offer technical support for similar engineering applications.