The 3D laser scanning technology was introduced for the first time to acquire the global deformation of the inner surface of segmental lining during prototype loading test on the quasi-rectangular shield lining with a large crosssection. Based on the experimental data, the deformation and the effective transverse rigidity ratio of the lining structure were analyzed. The values of the deformation characteristics and the effective transverse rigidity ratios of the segmental lining in both vertical and horizontal directions in the dead weight and design state were determined as well. The variation of deformation and the effective transverse rigidity ratios with the burial depth and lateral earth pressure coefficient were obtained. The variation of deformation and effective transverse rigidity ratios with the buried depth in the limit failure state were shown to follow a doublelinear pattern. Finally, shellspring models were established to compare the similarities and differences of the deformations and effective transverse rigidity ratios between the quasirectangular and circular tunnels in detail, and the significant influence of the deadweight on the overall structural stiffness was revealed.