Abstract: To promote digital designing in shield tunnel construction and improve structural calculation efficiency, a parametric calculation method for longitudinal structures of shield tunnels based on geological drilling data is proposed. The method considers geological uncertainties and the threedimensional (3D) spatial linearity of the tunnel longitudinal structure, uses KNearest Neighbor and Ordinary Kriging algorithms to establish a strata database. Then, the reference relation to the structure′s space information of the tunnel axis is created to output load and constraint conditions of the structure. Finally, the equivalent stiffness beam method is employed to conduct longitudinal structure calculation. The method was applied to the QXK6+300~+400 section of the east lake section of the Lianghu tunnel in Wuhan, China. The comparative analytical results between the method proposed and the existing one indicate that the constraint conditions of the method proposed can be automatically calculated through programming without relying on conservative evaluation by humans. In addition, the parametric process meets the subsequent calculation requirements on various sections and can reflect the results of internal force analysis in 3D stress nephogram. Therefore, the proposed method can improve the design efficiency.

Key words: geological drilling, shield tunnel, longitudinal structure, parametric design, equivalent stiffness beam model