Open AccessInternal force – deformation and corresponding control measures of shield tunnel with a 5.8m diameter under lateral pressure loss conditions
Author(s) -
Hongxia Peng,
Qiang Zheng,
Wenlong Zhang,
Xiaohui Zhang
Publication year - 2021
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/2029/1/012025
Subject(s) - shield , deformation (meteorology) , stiffness , structural engineering , geotechnical engineering , stress (linguistics) , materials science , lateral earth pressure , geology , internal pressure , mechanics , engineering , composite material , physics , petrology , linguistics , philosophy
In consideration of the deformation reservation, treatment and repair of the shield tunnel structure in the 100-year service life, the designed inner diameter of the shield tunnel structure tends to increase. However, the increase in the diameter will reduce the overall stiffness of the structure and reduce the shield tunnel’s mechanical properties under load changing conditions. Taking the 5.8m-inner-diameter shield tunnel in Nanjing as an example, this paper establishes a refined three-dimensional numerical model of the shield tunnel and validates the model with the results from a full-scale experimental test. Mechanical responses of the shield tunnel under the influence of the surrounding engineering activities are analyzed, and the structural maintenance and deformation control strategy are also discussed. The research shows that as the lateral pressure coefficient decreases (i.e. when unloading occurs around the tunnel structure), the stress and deformation curves of the structure have a strong nonlinear characteristic: when the lateral earth pressure loss is about 0% to 21%, the structure is in a near-elastic state, and the deformation and internal force response are not sensitive to load-changing conditions; when the lateral earth pressure loss is 21%∼43%, the damage, stress and deformation of the tunnel structure will increase rapidly, indicating that the structure is in the stage of plasticity, which is the critical interval for structural maintenance; when the lateral pressure loss exceeds 43%, the structure reaches total yielding stage. Therefore, the corresponding maintenance and control measures of shield tunnel segment structure are proposed from the aspects of prevention at the source, control in the process and treatment at the end.