The rock mass rating(RMR)system is one of the most commonly used methods for classifying rock masses in underground engineering.Uncertainty of RMR values can signifi cantly aff ect the safety of underground projects.I...The rock mass rating(RMR)system is one of the most commonly used methods for classifying rock masses in underground engineering.Uncertainty of RMR values can signifi cantly aff ect the safety of underground projects.In this regard,we proposed a reliable rating approach for classifying rock masses based on the reliability theory.This theory was incorporated into the RMR system to establish the functions of rock masses of different classifications.By analyzing the probability distribution patterns of various parameters used in the RMR system and using the Monte Carlo method to calculate the reliability probability of surrounding rock belonging to each classifi cation,reliable RMR values for the rock mass to be excavated can be obtained.The results demonstrate that it is feasible to adopt the reliability theory in classifi cation tasks considering the randomness characteristics of rock and soil.As verified through a case study of the Lushan Tunnel project,the proposed approach can be used to obtain the probability of the uncertainty of the calculated RMR values of underground engineering rock masses,and the calculation results are consistent with reality.The proposed approach can serve as a reference for studies in other fi elds and also applies to other rock mass classifi cation methods.展开更多
Rapid acquisition of rock structure information during tunnel construction is crucial for optimizing subsequent construction strategies and avoiding engineering rock disasters.In this regard,this study proposes the be...Rapid acquisition of rock structure information during tunnel construction is crucial for optimizing subsequent construction strategies and avoiding engineering rock disasters.In this regard,this study proposes the best time to obtain rock structure information on the tunnel face during the construction period.By summarizing relevant studies on rock information acquisition locally and abroad and combining them with the actual situation during the construction of the Lushan Tunnel,this study analyzed the factors affecting the quality of rock information acquisition during the construction period and the approximate range of the optimal timing of acquisition.We also conducted experiments on the concentration of respiratory dust and the concentration of total dust on each section of the Lushan Tunnel construction site and explored the optimal timing of acquiring rock information on the tunnel face by conducting several dust experiments at the construction site.The results showed that the best time to obtain information was before the erection of the steel arch,which was also the best time for the engineers to conduct mechanical characterization of the tunnel face and the lining inspection of the tunnel.The optimal acquisition timing identified in this study is crucial for improving the accuracy of rock information acquisition and guiding subsequent construction programs.展开更多
基金supported by the National Natural Science Foundation of China [Grant No.52079077]China Postdoctoral Science Foundation (Grant No. 2022M711962)。
文摘The rock mass rating(RMR)system is one of the most commonly used methods for classifying rock masses in underground engineering.Uncertainty of RMR values can signifi cantly aff ect the safety of underground projects.In this regard,we proposed a reliable rating approach for classifying rock masses based on the reliability theory.This theory was incorporated into the RMR system to establish the functions of rock masses of different classifications.By analyzing the probability distribution patterns of various parameters used in the RMR system and using the Monte Carlo method to calculate the reliability probability of surrounding rock belonging to each classifi cation,reliable RMR values for the rock mass to be excavated can be obtained.The results demonstrate that it is feasible to adopt the reliability theory in classifi cation tasks considering the randomness characteristics of rock and soil.As verified through a case study of the Lushan Tunnel project,the proposed approach can be used to obtain the probability of the uncertainty of the calculated RMR values of underground engineering rock masses,and the calculation results are consistent with reality.The proposed approach can serve as a reference for studies in other fi elds and also applies to other rock mass classifi cation methods.
基金supported by the National Natural Science Foundation of China[Grant No.52079077]China Postdoctoral Science Foundation(Grant No.2022M711962)。
文摘Rapid acquisition of rock structure information during tunnel construction is crucial for optimizing subsequent construction strategies and avoiding engineering rock disasters.In this regard,this study proposes the best time to obtain rock structure information on the tunnel face during the construction period.By summarizing relevant studies on rock information acquisition locally and abroad and combining them with the actual situation during the construction of the Lushan Tunnel,this study analyzed the factors affecting the quality of rock information acquisition during the construction period and the approximate range of the optimal timing of acquisition.We also conducted experiments on the concentration of respiratory dust and the concentration of total dust on each section of the Lushan Tunnel construction site and explored the optimal timing of acquiring rock information on the tunnel face by conducting several dust experiments at the construction site.The results showed that the best time to obtain information was before the erection of the steel arch,which was also the best time for the engineers to conduct mechanical characterization of the tunnel face and the lining inspection of the tunnel.The optimal acquisition timing identified in this study is crucial for improving the accuracy of rock information acquisition and guiding subsequent construction programs.
