Based on the analysis of main causes of rockburst,the compressive strength,tensile strength,elastic energy index of rock and the maximum tangential stress of the cavern wall are chosen as the criterion indexes for roc...Based on the analysis of main causes of rockburst,the compressive strength,tensile strength,elastic energy index of rock and the maximum tangential stress of the cavern wall are chosen as the criterion indexes for rockburst prediction.A new approach using neural method is proposed to predict rockburst occurrence and its intensity.The prediction results show that it is feasible and appropriate to use artificial neural network model for rockburst prediction.展开更多
The problems existing in the present sampling method for weak layers in exploratory adits are discussed. At present, the confining pressure effect on engineering properties of weak layers is often neglected, but the a...The problems existing in the present sampling method for weak layers in exploratory adits are discussed. At present, the confining pressure effect on engineering properties of weak layers is often neglected, but the argillizational effect under ground water is emphasized. Ordinarily, samples of weak layers are obtained in exploratory adits. But the weak layers are easily affected by the stress relaxation after the excavation of exploratory adits. So the engineering properties of weak layers, based on laboratory or in-situ tests, are very poor. Obviously, the test results of samples from exploratory adits cannot reflect their engineering properties under natural ground stresses. To avoid the effect of stress relaxation on weak layers, a special sampling method in exploratory adits is adopted, which reveals that weak layers are of good engineering properties under confining pressure. Taking the weak intercalations at a giant hydroelectric station on Jinshajiang River as an example, the correlations between physical and mechanical indices and confining pressure indicate that confining pressure is the most important environmental factor to control the engineering properties of weak layers.展开更多
基金Supported by Chinese National Natural Science Foundaion(49972091)
文摘Based on the analysis of main causes of rockburst,the compressive strength,tensile strength,elastic energy index of rock and the maximum tangential stress of the cavern wall are chosen as the criterion indexes for rockburst prediction.A new approach using neural method is proposed to predict rockburst occurrence and its intensity.The prediction results show that it is feasible and appropriate to use artificial neural network model for rockburst prediction.
文摘The problems existing in the present sampling method for weak layers in exploratory adits are discussed. At present, the confining pressure effect on engineering properties of weak layers is often neglected, but the argillizational effect under ground water is emphasized. Ordinarily, samples of weak layers are obtained in exploratory adits. But the weak layers are easily affected by the stress relaxation after the excavation of exploratory adits. So the engineering properties of weak layers, based on laboratory or in-situ tests, are very poor. Obviously, the test results of samples from exploratory adits cannot reflect their engineering properties under natural ground stresses. To avoid the effect of stress relaxation on weak layers, a special sampling method in exploratory adits is adopted, which reveals that weak layers are of good engineering properties under confining pressure. Taking the weak intercalations at a giant hydroelectric station on Jinshajiang River as an example, the correlations between physical and mechanical indices and confining pressure indicate that confining pressure is the most important environmental factor to control the engineering properties of weak layers.
