Analysis of jacking force data for microtunnels in glacial till at Kilcock, Ireland

Abstract

Although the application of microtunnelling to pipeline construction has grown considerably in Ireland in recent times, there is very little published guidance on the jacking forces that might be expected in Irish ground conditions. In this paper, relevant experience from jacking records for a Sewerage Improvement Scheme project in Kilcock, Co. Kildare, Ireland is presented. Data from almost 0.9km of pipe-jacked tunnels constructed below the water table at depths between 2.4m and 4.4m in largely greenfield conditions are examined. Topics discussed in this paper include the separation of jacking force into friction and face components, lubrication and stoppages.