Brittleness is of great significance for evaluating the mechanical properties of the slope rock in reservoir area and revealing the brittle failure mechanism of the rocks.Although a series of definitions of the brittl...Brittleness is of great significance for evaluating the mechanical properties of the slope rock in reservoir area and revealing the brittle failure mechanism of the rocks.Although a series of definitions of the brittleness and evaluation methods of brittleness index have been proposed,there is still lack of a widely recognized and remarkable standards in these aspects due to the differences in diagenetic process,depositional environment and mineral composition.The previous methods to quantitively estimate the rock brittleness based on energy balance analysis are summarized,which neglect multiple influencing factors of the rock brittleness,such as the weight of pre-peak or post-peak mechanical behaviors on the prediction performance of the brittleness index.Based on the typical curves about stress and strain,the relationships between the brittle failure behaviors and the energy evolutions are comprehensively analyzed,then a new method for assessing the brittleness is proposed.Based on prepeak brittleness index to represent brittle property at pre-peak stage and post-peak brittleness index to determine brittle characteristic at post-peak stage,a new brittleness index is established by additive synthesis method in consideration of the weight of brittleness indexes before and after peak strength,and either of the two brittleness indexes can be punished or compensated by setting different parameter values.The results indicate that the proposed brittleness index can represent the brittle change laws for different rock types whenα≤0.5,β≥0.5.When evaluating the brittleness of the slope rock in Three Gorges Reservoir(TGR)area,the results show that the rock brittleness in the slope affects the stability of the slope.Therefore,the novel evaluation method can provide reliable results,and the proposed brittleness index considering the energy evolution can be applied to assess the brittle property in the reservoir bank project.展开更多
基金funded by the National Natural Science Foundation of China(No.42477174,42002268)the Science and Technology Program of the Tibet Autonomous Region(Nos.XZ202301YD0034C,XZ202202YD0007C,XZ202402 ZD0001)+1 种基金the Open Fund of Anhui Intelligent Underground Detection Technology Research Institute(No.AHZT2023KF03)the Qinghai Province Basic Research Program Project(No.2024-ZJ-904)。
文摘Brittleness is of great significance for evaluating the mechanical properties of the slope rock in reservoir area and revealing the brittle failure mechanism of the rocks.Although a series of definitions of the brittleness and evaluation methods of brittleness index have been proposed,there is still lack of a widely recognized and remarkable standards in these aspects due to the differences in diagenetic process,depositional environment and mineral composition.The previous methods to quantitively estimate the rock brittleness based on energy balance analysis are summarized,which neglect multiple influencing factors of the rock brittleness,such as the weight of pre-peak or post-peak mechanical behaviors on the prediction performance of the brittleness index.Based on the typical curves about stress and strain,the relationships between the brittle failure behaviors and the energy evolutions are comprehensively analyzed,then a new method for assessing the brittleness is proposed.Based on prepeak brittleness index to represent brittle property at pre-peak stage and post-peak brittleness index to determine brittle characteristic at post-peak stage,a new brittleness index is established by additive synthesis method in consideration of the weight of brittleness indexes before and after peak strength,and either of the two brittleness indexes can be punished or compensated by setting different parameter values.The results indicate that the proposed brittleness index can represent the brittle change laws for different rock types whenα≤0.5,β≥0.5.When evaluating the brittleness of the slope rock in Three Gorges Reservoir(TGR)area,the results show that the rock brittleness in the slope affects the stability of the slope.Therefore,the novel evaluation method can provide reliable results,and the proposed brittleness index considering the energy evolution can be applied to assess the brittle property in the reservoir bank project.
