Finite Element Analysis-Based Damage Metric for Airtightness Performance Evaluation of Concrete Tube Structures

摘要

The super speed tube transport (SSTT) system is considered as a strong candidate for next-generation long-distance transport systems because of its anticipated highly efficient performance. Several studies have been conducted on infrastructure systems using concrete to improve the construction and economic feasibility of SSTTs. However, most of these only focused on the applicability of concrete in maintaining its airtightness; the effects of concrete cracks on the airtightness performance have not been investigated. Accordingly, this paper proposes a method using the finite element analysis (FEA) for evaluating the structural damage associated with the airtightness performance of concrete tube structures. An experimental work was conducted to measure this performance by subjecting a concrete tube structure to four stages of displacements at the midspan. Thereafter, to analytically measure the structural damage, the FEA was conducted and the results were compared with the experimental values. It is found that the structural damage expressed in terms of the eroded volume fraction (VF) calculated at each stage is closely correlated with the corresponding airtightness performance obtained from the experiment. These results show that FEA can be efficiently used for conducting experiments in the SSTT design phase to verify the concrete tube's airtightness performance under many load cases.