Tweet Share

• Send by email

  Send by email

  

  Recommendations for Efficient Face Support in Slurry Shield Tunnelling

  In slurry shield tunnelling, a reliable face support is presumed if a support pressure is transferred and the slurry excess pressure provides efficient support pressure on the soil skeleton. To ensure face stability, the support pressure transfer needs to be provided within the theoretical sliding wedge after Horn (1961) at the tunnel face. Therefore, the penetration depth of the bentonite suspension as a support medium has to be kept within a maximum limit. On the other side, research shows that certain penetration is also required for a safe support. To describe the efficiency of the support, the stagnation gradient of bentonite suspension is used. The gradient defines the relation of the support pressure and the penetration depth of the suspension. This paper presents a detailed supplement to the DIN 4126 (2013) for a more precise observation of the stagnation gradient adapted for slurry shield tunnelling. The aim is to determine the minimum recommended stagnation gradient for which no increase of the slurry excess pressure is necessary due to too deep penetration and also safe support ensured.

  Recipient :

  Name ^* :

  E-mail address ^* :

  ^* Required fields

  Send   or  Cancel

• Print