日照温差致残余应力场对高速铁路无砟轨道板动响应影响机制研究

Residual stress caused by sunshine thermal difference will affect the dynamic response of high-speed railway ballastless track slab a lot. Study this complex influence mechanism is the aim of this project. .Firstly, a rigorous experiment on big scale model of ballastless track slab will be undertaken by simulating the alternation of day and night, to obtain the complex 3-D distribution of residual stress field which is caused by sunshine thermal difference. Then the relation between the critical speed and the residual stress field in slab will be studied based on the theory of TLTSDB. With an extra semi-analytical solution of the dynamic response of initial stress concentrated region, an analyzing method for calculating the dynamic response of high-speed railway by considering the influence of initial stress field will be developed. Finally, based on the theory and MPM method, a program for analyzing the 3-D dynamic stability of track bed by considering the parameters of initial stress field will be compiled. This program aims to quantitatively assess the dynamic characteristics and fulfill the dynamic stability assessing frame of track bed system. .The work of this project will reveal the causes of residual stress in railway ballastless track slab. This project provides theory supports and technological reserve for the safe construction and operation of high speed railway in China.

日照温差引起的残余应力对高速铁路无砟轨道板的车致动力响应影响效应非常复杂，本项目旨在研究这一残余应力场对轨道板动力响应的影响机制。.首先，通过对无砟轨道板的大比例模型试验，严格模拟昼夜交替温差条件，获取日照温差引起的三维复杂应力场分布规律。其次，基于TLTSDB理论，对高速列车的临界速度与轨道板残余应力之间的关系进行理论分析，计算无砟轨道板的初始应力集中区域的动响应半解析解，建立考虑初始应力状态的高速铁路动响应的计算方法。最后，基于考虑初始应力状态的无砟轨道板动力响应理论模型以及MPM法，编制以初始应力场为主要特征参数的高速铁路道床三维动力稳定性分析程序，对高速列车运行引起的动应力分布特征进行定量评价，完善高速铁路基床稳定性评价方法。.本项目成果将揭示无砟轨道板中的残余应力病害成因，为我国的高速铁路的大范围推广建设、安全运营等方面提供重要的理论支撑和技术储备。

日照温差引起的残余应力对高速铁路无砟轨道板的车致动力响应影响效应非常复杂，本项目旨在研究这一残余应力场对轨道板动力响应的影响机制。首先，通过对无砟轨道板的现场原位观测试验，严格测量昼夜交替温差条件，获取日照温差引起的三维复杂温度场和应力场分布规律。其次，基于TLTSDB理论，对高速列车的临界速度与轨道板残余应力之间的关系进行理论分析，建立考虑初始应力集中效应的高速铁路动响应的计算方法。通过后期对高速列车运行引起的动应力分布特征进行实测，完善高速铁路基床稳定性评价方法，厘清残余应力与车致动响应的关系。本项目成果将揭示无砟轨道板中的残余应力病害成因，为我国的高速铁路的大范围推广建设、安全运营等方面提供重要的理论支撑和技术储备。