In order to evaluate the load acting on segments based on in-situ measurements, it is necessary to understand the relation between the deformation of segments, the deformation of ground, the measured earth pressure and the geometry of the segments. Up to now, because of the difficulty to conduct an in-situ measurement on the ring deformation and the joint deformation of the segments, few researches about the ring deformation and the joint behavior during tunneling are reported. In this paper, the relation between the observed load and segment deformation is examined based on the data measured at the three sites.
Furthermore, the effect of jack strength under 3-dimensional stress condition of the segments is investigated based on the data measured with the strain gauges installed on shield tunnelling segments.