ANALYSIS OF THERMAL INTERNAL FORCES FOR CURVED SUBMERGED FLOATING TUNNELS

Using mixed method, temperature induced internal forces of a curved submerged-floating tunnel (SFT) supported by tension legs were investigated. The analysis indicated that axial forces were far smaller than radial forces, which were produced by temperature changes, and bending moment and torsional moment of SFT were produced by thermal forces of tension legs. Numerical test for the Qian-dao Lake case gave the relation that the radial force of tension legs varied with spring constant of tension legs, flexural rigidity, curvature radius and central angle of SFT. The results showed that one of temperature induced internal forces of two groups of tension legs were increasing, but the other were decreasing when one of foregoing factors changed. In the design of curved SFT, the influence of internal forces by temperature changes needs to be considered.