EVALUATION OF THE LOAD ON SHIELD TUNNEL LINING IN GRAVEL

It is important to evaluate accurately the load acting on a shield tunnel lining to facilitate its economical and rational design. In Japan, the load calculated by Terzaghi's formula, or overburden load, is generally adopted for the design of tunnel segments. However, some previous field measurements have shown that the actual load acting on the shield tunnel lining could be much smaller than that adopted for the design in the case of good ground conditions. In this study, field measurements at two shield tunnel construction sites in gravel were carried out, and the load acting on the shield tunnel lining was evaluated by analyzing the field data to establish the rational design of the shield tunnel segments. The method of treating the dead load of segments in the design was also investigated.