Study on characteristics of grease flow resistance by element test

摘要

Recently, stresses in segments during construction tend to increase and therefore the segmentrndamage during construction has increased. One of the predominant components of construction loads is forcernacting around a shield tail, which is composed of the force caused by the wire brushes, the force due to the greasernflow resistance, and the force due to the contact between skin plate and segment. In this study, to make clearrnthe flow resistance characteristics of grease filled up in-between wire brushes quantitatively, the element testsrnusing grease and wire brush were carried out, using a test equipment which can press grease in front of the wirernbrush and apply water pressure behind the wire brush. As a result, it was found that the excess grease pressurernappears under the conditions of small tail clearance and large decrement rate of grease volume.