Pressure monitor for cement injection point behind tunnelling machine - by extrapolating from pressure differences measured at points along cement delivery pipe

摘要

A method monitors the filling pressure of a filling compound (pref. cement) conveyed via a pipe line (40,32) to an injection point (34) leading into a circular space (30) behind a funnelling machine (10) in a funnel. Pressure differences for the viscous filling compound are measured inside the pipe line at several places (42) at a distance from the injection point (34) and lying along a given measurement path. To determine the filling pressure prevailing at the injection point, a value dependent on the measured pressure difference is taken as a measure of the pressure drop between the pressure-measuring point (42) and the injection point (34) and is subtracted from the pressure measured at the pressure-measuring point (42). ADVANTAGE - Precise pressure measured independently of viscosity and flow.