Damage distribution and mechanical properties analysis of CRTS III slab track under uneven subgrade settlement
Damage distribution and mechanical properties analysis of CRTS III slab track under uneven subgrade settlement
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DOI：
10.1016/j.istruc.2023.105350
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发表时间：
2023-12
期刊：
影响因子：
4.1
通讯作者：
S. Sun;Qingyuan Xu
中科院分区：
文献类型：
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作者：
S. Sun;Qingyuan Xu
高速铁路沿线地质条件复杂，路基不均匀沉降在所难免，对铁路的安全稳定造成重大影响。本文建立了CRTS III型平板轨道的三维实体模型。基于混凝土损伤塑性（CDP）模型，分析了USS对结构损伤、变形、应力和间隙的影响。同时，作为钢筋混凝土结构，结构加固是增强其抗拉能力的重要组成部分。因此，详细考虑了内部配筋的分布，并进一步探讨了配筋对轨道结构力学性能的影响。结果表明：底板是履带下最脆弱的构件，其主要损伤部位为履带中段和边缘以及履带中段边缘；下一个容易损坏的部件是自密实混凝土，其主要损坏位置是限位凸台的纵向外侧和USS中部。各构件的损伤随沉降幅值的增加呈单调增加趋势，随波长的增加先增加后降低，特别是l = 15 ~ 20 m时，在大多数幅值的最不利波长范围内。随着损伤程度的增加，CDP模型与线弹性模型的结果差异越来越大。钢筋对结构混凝土的损伤值、范围和位置有显著影响。在严重损伤位置，承重应力的分量从混凝土转移到钢筋。
Due to the complex geological conditions along the high-speed railway, the subgrade uneven settlement (USS) is inevitable, and the safety and stability of the railway are significantly affected. In this paper, a three-dimensional solid model of the CRTS III slab track is established. Based on the concrete damaged plasticity (CDP) model, the influence of USS on structural damage, deformation, stress, and gap is analyzed. Simultaneously, as a reinforced concrete structure, the structure reinforcement is an essential part of strengthening its tensile capacity. Consequently, the distribution of internal reinforcement is considered in detail, and the influence of reinforcement on the mechanical properties of the track structure is further explored. The results show that the base plate is the most vulnerable component under the USS, and its primary damage locations are the middle and edge of the USS and the middle track slab edge. The next component that is susceptible to damage is the self-compacting concrete, whose primary damage locations are the longitudinal outer side of the limit lug boss and the USS middle. The damage of each component increases monotonically with increasing settlement amplitude, first increasing and then decreasing with increasing wavelength, especially noting the cases ofL= 15–20 m, which is the most unfavorable wavelength range for most amplitudes. The difference between the results under the CDP and linear elastic models increases with the increase in damage. The reinforcement significantly influences the value, range, and location of the structural concrete damage. The component of load-bearing stress shifts from concrete to reinforcement at severe damage locations.