Abstract:

To avoid the jamming phenomenon encountered by fullface tunnel boring machines caused by the difficulty in predicting the surrounding rock states on the tunnel face and untimely advance support, statistical analysis is conducted on the tunneling and surrounding rock parameters of the Songhua river and the Hanjiang riverWeihe river water diversion projects. A regression relationship between the field penetration index, specific energy index of the tunnel boring machine, and total score of the tunnel′s surrounding rock is established. The results show the following: The field penetration index has an exponential relationship to the total score of the tunnel′s surrounding rock, while the specific energy index has a logarithmic relationship to the total score of the surrounding rock. A stability identification method for a tunnel′s surrounding rock based on field penetration and specific energy indices is proposed, and the identification results of the surrounding rock′s classification using this method are validated according to the field′s surrounding rock conditions. Verification results show that the classification of the surrounding rock is consistent with the actual situation, indicating the effectiveness and accuracy of the recommended identification method.

Key words: tunnel boring machine, tunneling parameters, surrounding rock stability, identification method, field penetration index, specific energy index