Classification model of surrounding rock of underground oil storage caverns based on weights back analysis method and efficacy coefficient method and its application

Based on weights back analysis and efficiency coefficient method, a new surrounding rock classification model of underground oil storage caverns is put forward. And rock compressive strength, integrated coefficient, character of discontinuity, groundwater, the angle between tunnel axis and soft surface are selected as key factors of surrounding rock stability. Then using weights back analysis method to determine the weights of factors, after which the model of the surrounding rock classification can be established based on weights back analysis method and efficacy coefficient method. Finally, the established classification of surrounding rocks model is used in practice; and the results show that the outcomes of stability analysis match the actual surrounding rock classification. It proves that the method used in surrounding rock classification of underground oil storage caverns is rational and effective, so as to provide a new idea to predict surrounding rock criterion for underground oil storage caverns stability.