Face stability of microtunnelling TBMs is an important aspect for a safe and controlled project execution. Lack of proper face support can lead to sudden collapse with resulting large settlements. Guidelines for minimal and maximal support pressures in most codes do not take the infiltration of bentonite suspension in coarser soils into account. Infiltration lowers the effectiveness of the face support. In loose sands infiltration can lead to excess pore pressures and induce liquefaction, with possible catastrophic consequences. This paper investigates the influence of infiltration and gives guidelines for a proper selection of bentonite suspensions based on soil gradation.
|Title of host publication||2013 International No-Dig Downunder|
|Publisher||International Society for Trenchless Technology|
|Publication status||Published - 1 Jan 2013|
|Event||31st ISTT International No-Dig Downunder - Sydney, Australia|
Duration: 1 Sep 2013 → 4 Sep 2013
|Conference||31st ISTT International No-Dig Downunder|
|Period||1/09/13 → 4/09/13|