Field detection and zoning method for the elastic modulus of surrounding rock while drilling

The geological conditions of deep engineering are complex and are impacted by high stress and excavation disruption, which can lead to engineering disasters like severe surrounding rock deformation and roof collapse. The real-time, accurate measurement of rock mechanical parameters is a necessary condition for analysing the stability of deep surrounding rock and preventing disasters. In this paper, drilling tests are conducted with an intelligent detection anchoring system for underground engineering. An investigation is conducted into the correlation and change law between drilling parameters and the elastic modulus E , and a testing model for E while drilling, is proposed. According to the test results, the average difference in E is 0.43 GPa, and the average error rate is 5.49%. On this basis, an in situ zoning approach for surrounding E while drilling is established, and field drilling experiments are carried out for deep surrounding rock. A three-dimensional (3D) zoning and mapping relationship model is established for the equivalent elastic modulus E eq of the surrounding rock, enabling in situ testing of the E eq of the surrounding rock and effective identification of rock interfaces and fracture zones. While constructing the boreholes for rock bolts and anchor cables, the drilling testing method established can constantly and quickly determine the E of rock in real-time. This work provides theoretical and technical support for the on-site, real-time acquisition of rock mechanical parameters required for preventing and controlling failures of surrounding rock in underground engineering.