重载铁路隧底结构动力响应及疲劳寿命研究

发布时间：2018-05-20 19:04

本文选题：重载铁路 + 隧道　；参考：《中南大学》2014年硕士论文

【摘要】：摘要：重载铁路以其轴重大、运能高、运输成本低等特点,已经成为铁路运输发展的一个重要方向。列车轴重的增加必然会使轨下基础承受更大的振动荷载,对重载铁路隧底结构安全性造成影响。为了保证其运营的安全稳定,就要求结构设计更合理并具有更长的使用寿命。本文依托国家自然科学基金资助项目煤炭联合基金(U1361204)和国家自然科学基金资助项目(51278494),采用理论分析和数值计算相结合的方法,对不同结构型式、不同基底状况下重载铁路隧道底部结构动力响应特性及疲劳寿命进行了系统研究,主要研究内容和成果如下： (1)建立重载铁路隧道-围岩耦合三维有限元模型,探讨了不同仰拱矢跨比、仰拱厚度、填充层厚度等条件下重载铁路隧底结构动力响应变化特征,量化分析了各结构设计参数对动力响应的影响规律。 (2)根据隧底结构受力状态,选择合适的疲劳寿命预测方法,结合动力有限元计算结果,利用疲劳计算软件分析了不同结构型式下隧底结构疲劳寿命变化规律,提出了满足隧道底部结构耐久性与使用寿命的设计参数合理取值。 (3)通过动力计算与疲劳寿命计算的对比分析,确定了隧底结构是重载铁路隧道设计的关键部位,结构的受力状态则是重载铁路隧道设计中应考虑的首要因素。 (4)采用动力计算和疲劳计算相结合的方法,量化分析了隧道底部基岩软化、基底脱空等基底状况对隧底结构动力响应及疲劳寿命的影响规律与影响程度,并探讨了结构疲劳寿命随基底状况变化的发展趋势。
[Abstract]:Abstract: heavy haul railway, with its major axis, high transportation energy and low transportation cost, has become an important direction for the development of railway transportation. The increase of train axle load will inevitably make the base of the rail bear greater vibration load and influence the safety of the heavy load railway tunnel structure. In order to ensure the safety and stability of its operation, the structure requires structure. The design is more reasonable and has longer service life. In this paper, based on the National Natural Science Foundation of China, the project coal joint fund (U1361204) and the National Natural Science Fund support project (51278494), the combined method of theoretical analysis and numerical calculation is used to analyze the bottom structure of the heavy railway tunnel under different structural type and different base condition. The dynamic response characteristics and fatigue life are systematically studied. The main research contents and achievements are as follows:
(1) the three-dimensional finite element model of heavy load railway tunnel coupled with surrounding rock is established, and the dynamic response characteristics of the heavy load railway tunnel under the conditions of different invert arch span ratio, the thickness of the inverted arch and the thickness of the filling layer are discussed, and the influence of the design parameters on the dynamic response is quantified.
(2) according to the stress state of the tunnel structure, the suitable fatigue life prediction method is chosen, and the fatigue life change law of the tunnel bottom structure under different structural types is analyzed by the fatigue calculation software, and the reasonable value of the design parameters to meet the durability and service life of the tunnel bottom structure is put forward.
(3) through the comparison and analysis of the dynamic calculation and fatigue life calculation, it is determined that the tunnel structure is the key part of the heavy haul railway tunnel design, and the stress state of the structure is the most important factor to be considered in the design of heavy haul railway tunnel.
(4) using the method of dynamic calculation and fatigue calculation, the influence regularity and influence degree of the base rock softening at the bottom of the tunnel and the basement void on the dynamic response and fatigue life of the tunnel bottom structure are quantified, and the trend of the structural fatigue life changing with the base condition is also discussed.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U451;U239.4

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