考虑荷载-环境-尺度耦合的开启桥钢桥面铺装结构层间剪切疲劳破坏机理研究

The steel deck pavement system on bascule bridge is composed of an asphalt concrete pavement layer, a waterproof adhesive layer and a steel deck layer. The anti-shear performance of steel deck pavement system has become the primary factor for the success of steel deck pavement. In addition, the failure mechanism of shear fatigue of steel deck pavement system considering the effect of traffic loading and environment is one of the key scientific problems in the pavement engineering. In this research, the failure mechanism of shear fatigue of steel deck pavement system considering the effect of traffic loading and environment is analyzed by laboratory experiments and simulation coupling finite element method (FEM) and discrete element method (DEM). The main research contents are as follows: (1) The shear fatigue test program of pavement on bascule bridge is designed according to similarity theory, and the shear fatigue performance of pavement under vehicle loading and opening is analyzed. (2) The numerical model of pavement on bascule bridge based on the multiscale method of time and space by coupling FEM and DEM is established, and the calculation program for numerical model is developed to analyze the mechanical response of pavement. Then, the calculation result is compared with the test result. (3) The influence of various factors on the shear fatigue performance of pavement is discussed, and the failure mechanism of shear fatigue of pavement is put forward. The research results will make contributions to the mechanism of fatigue failure of steel deck pavement system and provide beneficial references for the design and construction of steel deck pavement.

开启桥钢桥面铺装结构层间抗剪切性能是决定铺装成败与否的首要因素，在车载及环境耦合作用下的铺装结构层间剪切疲劳破坏机理是钢桥面铺装领域的关键科学问题之一。本项目结合剪切疲劳试验和有限元离散元耦合分析方法研究考虑荷载-环境-尺度耦合的开启桥钢桥面铺装结构层间剪切疲劳破坏机理。主要内容如下：（1）基于相似理论，设计室内开启桥钢桥面铺装结构层间剪切疲劳试验方案，分析通车和开启两种工况下的铺装结构层间剪切疲劳性能。（2）基于离散元与有限元耦合的时空多尺度计算方法，建立开启桥钢桥面铺装的有限元离散元耦合数值模型，开发程序，计算开启桥钢桥面铺装力学响应，并与室内试验结果进行对比分析。（3）分析多种因素对开启桥铺装结构层间剪切疲劳性能的影响，提出开启桥钢桥面铺装结构层间剪切疲劳破坏机理。研究成果将丰富钢桥面铺装复合结构疲劳破坏机理理论，为钢桥面铺装工程设计与施工提供有益借鉴。

开启桥钢桥面铺装结构层间抗剪切性能是决定铺装成败与否的首要因素，在车载及环境耦合作用下的铺装结构层间剪切疲劳破坏机理是钢桥面铺装领域的关键科学问题之一。本项目结合剪切疲劳试验和有限元离散元耦合分析方法研究考虑荷载-环境-尺度耦合的开启桥钢桥面铺装结构层间剪切疲劳破坏机理。主要内容及结果如下：（1）分析了开启桥钢桥面铺装在通车和开启等两种工况下的瞬态动力响应，提出开启安全系数。研究结果建议开启桥在高温条件下工作时，适当延长开启时间，降低开启角加速度；采用变速开启方式安全系数比匀速高，建议在设计阶段采用变速开启方式。（2）设计室内温湿环境耦合作用下的钢桥面铺装复合结构剪切试验，并分析不同温湿条件下的层间剪切性能，研究结果建议在钢桥面铺装实际施工过程中同时监测粘结层摊铺温度与湿度，当湿度达到95%时可考虑暂时停止施工。（3）建立离散-连续耦合的钢桥面铺装分析模型，并通过FLAC与PFC软件编程实现数值模拟，通过数值仿真分析多种因素对开启桥铺装结构层间剪切疲劳性能的影响。研究成果为钢桥面铺装工程设计与施工提供有益借鉴。