‘Standing’ full-scale loading tests on the mechanical behavior of a special-shape shield lining under shallowly-buried conditions

• Published in: Tunnelling and underground space technology Vol. 86; pp. 34 - 50
• Main Authors: Zhang, Zixin, Zhu, Yeting, Huang, Xin, Zhu, Yanfei, Liu, Wei
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.04.2019; Elsevier BV
• Subjects: Deformation; Earth pressure; Full-scale test; Internal forces; Mechanical properties; Plates (structural members); Rigidity; Rubber; Special-shape shield; Stiffness; Testing; Water pressure; Deformation; Rigidity; Full-scale test; Special-shape shield
• ISSN: 0886-7798; 1878-4364
• DOI: 10.1016/j.tust.2019.01.010

•‘Standing’ full-scale loading tests were performed on a special-shape tunnel lining.•The structural response under the self-weight condition was obtained.•The influence of different factors on the structural behavior was explored.•The structural response depended on the joint location. A reconfigurable loading and data acquisition platform was developed for the first time to perform ‘standing’ prototype loading tests on a special-shape segmental lining. The testing lining was seated on rubber bearing plates installed at the invert region to simulate the structure-subgrade interaction. The mechanical characteristics of the testing lining under the deadweight condition and subject to different shallow overburden conditions were examined. The influences of lateral earth pressure and soil reaction pressure on the structural performance of the testing lining were investigated. The testing results showed that the distributions of internal forces and deformation under the deadweight condition differed greatly from that obtained in earth-and-water pressure loading tests. Although the contribution of deadweight to the internal forces was small, its influence on deformation was significant for shallowly-buried cases. The structural response of the lining in current ‘standing’ loading tests was different from that observed in conventional ‘lying’ loading tests. In ‘standing’ loading tests, the internal forces and deformation at the invert region were smaller than that at the crown area. Increasing lateral earth pressure and soil reaction pressure were beneficial for enhancing the overall rigidity of the lining structure. The testing results also indicated that the structural responses (rotational stiffness, effective rigidity ratio and moment transferring coefficient) of the lining structure depended on the joint locations, and evolved during loading.