考虑初始积水的悬索桥主缆温湿度变化分析

Analysis of Temperature and Humidity Change inside Main Cables for a Suspension Bridge Considering Initial Water Accumulation

为研究大跨度悬索桥主缆内部在考虑施工初始积水状态下的温湿度变化规律,根据主缆内部多孔介质的特点,基于温度场辐射、对流与传导分析理论、非饱和多孔介质渗流理论、气态水非稳定扩散规律,提出了一种考虑初始积水条件的主缆内部温湿度变化分析方法。以某悬索桥主缆为对象,建立了主缆内部温湿度变化模拟的二维数值模型,并拟定了相应分析参数。通过日温度与湿度数值模拟研究,获得了温度与湿度日变化规律,进一步比较了全年不同气候条件下主缆内部温湿度变化。分析表明,主缆内部温度场变化与太阳运行轨迹密切相关,空气含湿量随外界温度的升高而上升,温度越高,含湿量越高且分布越不均匀,即在一定的初始含水条件下,主缆外界温度变化为内部湿度变化的驱动因素。

To figure out the temperature and humidity change inside main cables of suspension bridge considering the initial water accumulation,a simulation theory of temperature and humidity change is established considering the initial water accumulation based on the thermal radiation,convection,conduction theory of the main cable temperature field,unsaturated porous media seepage theory and the unsteady diffusion laws of gaseous water.A two-dimensional numerical model of the temperature and humidity change inside the main cable is established based on a suspension bridge.The corresponding analytical parameters are determined.By the daily temperature and humidity numerical simulation,the diurnal variation of temperature and humidity is obtained,and the variation of temperature and humidity of main cable under different climatic conditions are compared.The study shows that the main cable temperature field variations are closely related to the sun trajectory.The higher the temperature is,the higher the humidity will become,and more unevenly distributed.It is concluded that with a certain initial water condition,the outside temperature is a driving factor of the variation of internal humidity inside main cable.