Abstract
Grouting is a common technical measure to improve the mechanical properties of broken rock mass and ensure the stability of underground excavation. The strength characteristics of reinforced broken rock mass are important parameters in geotechnical engineering design. However, due to the complex structure of broken rock mass, the strength characteristics of reinforced broken rock mass are influenced by various factors, making quantitative studies of its strength extremely complex. To establish a reasonable approach for predicting the compressive strength of reinforced broken rock mass, this paper examines how various properties of broken rock mass (i.e., strength, volumetric block proportion, degree of fragmentation, shape, and angle) and the characteristics of cement stone body (i.e., cement stone body strength and interface strength) influence the reinforcement strength, and quantifies these effects. It reveals the mechanisms by which these factors influence the reinforcement strength. Considering factors such as rock shape, orientation, and intrinsic angle, a dimensionless quantitative method to describe rock structure is proposed. On this basis, a prediction model for the compressive strength of reinforced broken rock mass is established by comprehensively considering the properties of both the broken rock mass and the grout stone body. The prediction equation is validated using data from the literature, confirming the accuracy of the prediction model. The research findings provide a valuable reference for refining the reinforcement theory of broken rock mass.
Full Text
An Approach to Predicting the Compressive Strength of Reinforced Broken Rock Mass
Yanxu Guo¹, Jinlong Wang¹, Baohui Wang¹, Chune Wang¹, Ying Zhou¹, Shujing Chen¹, Hongbo Wang², Qingsong Zhang³
¹ Weifang University, Weifang 261061, China
² Shandong University of Science and Technology, Qingdao 266590, China
³ Institute of Geotechnical and Underground Engineering, Shandong University, Jinan 250061, China
Abstract
Grouting is a common technical measure for improving the mechanical properties of broken rock mass and ensuring the stability of underground excavations. The strength characteristics of reinforced broken rock mass represent critical parameters in geotechnical engineering design. However, due to the complex structure of broken rock mass, its reinforced strength is influenced by numerous factors, rendering quantitative investigations extremely challenging. To establish a rational methodology for predicting the compressive strength of reinforced broken rock mass, this study systematically examines the influence of various rock mass properties—including rock strength, volumetric block proportion, degree of fragmentation, shape, and orientation—as well as grout stone body characteristics such as grout strength and interface bond strength. The underlying mechanisms through which these factors affect reinforcement strength are elucidated. Furthermore, considering rock block geometry, orientation, and intrinsic angle, a dimensionless quantitative method for characterizing rock structure is proposed. Based on this framework, a comprehensive prediction model for the compressive strength of reinforced broken rock mass is developed, integrating both rock mass and grout stone body properties. The predictive equation is validated against published experimental data, confirming the model's accuracy. The research findings provide a valuable reference for advancing the reinforcement theory of broken rock mass.
Keywords: Broken rock mass; Grouting reinforcement; Compressive strength; Prediction equation