Abstract: According to the actual engineering of oil storage caverns， the orthogonal experiments were conducted. Four factors were selected， including the bolt length， the bolt spacing， the thickness of shotcrete and steel arch spacing， and three levels were set for each factor so that nine test schemes were performed. Then the corresponding numerical simulation by using FLAC^3D was conducted in order to optimize the supporting scheme. The key point displacement and plastic zone volume were taken as the evaluating index. Results showed that the steel arch spacing was the key parameter for supporting other than the bolt length and bolt spacing. An optimized supporting scheme of 5m bolt length with bolt spacing of 2m × 2m， a shotcrete thickness of 120mm and a steel arch spacing of 1.5m were adopted， which could control the stability of the surrounding rock of these caverns effectively and give some references to similar projects.

Key words: underground oil storage caverns, supporting optimization, orthogonal design, FLAC^3D, stability of surrounding rock