Application of Relationship model for the Measurement While Drilling Data to Predict Rock Uniaxial Compressive Strength for Tunneling

The rock uniaxial compressive strength (UCS) has significant implications for underground engineering support design. Traditional methods mainly rely on laboratory tests, which are costly, time-consuming, and unable to meet the real-time adjustment of underground engineering support plans and construction safety requirements. To address the real-time acquisition issue of rock UCS in tunnel engineering sites, this paper proposes a method for predicting the rock UCS based on computer drilling jumbo measurement while drilling (MWD) data. First, by applying the principle of energy conservation and the Hertzian contact theory, a theoretical relationship between MWD data and the rock UCS is established. Second, a method for filtering MWD data was proposed, determining energy transfer efficiencies for percussion (η_P), rotation (η_R), and feed (η_F) are 51%, 41%, and 42%, respectively. The proposed relationship model was validated using a dataset of 398 experimental samples, resulting in an R² of 0.92 and an RMSE of 5.76 MPa, demonstrating the correctness of the model and its applicability for predicting the rock UCS. Finally, the relationship model is applied to the Xiwuling Tunnel, forming a three-dimensional visualization evaluation method for the tunnel rock UCS based on MWD data. The results of 6 sets of samples in the DK42+253 section demonstrated an R² of 0.91 and an RMSE of 4.12MPa between predicted UCS and laboratory-measured UCS. These findings affirm the reliability of the method, providing valuable support for tunnel construction and design.