桥梁结构温度场测点布置方法

目的分析既有桥梁温度场测点布置存在的问题和缺点,提出桥梁结构温度场测点布置方法,为提高桥梁结构温度场的测量精度和效率提供参考.方法为合理优化桥梁结构的温度场测点布置,提出了太阳辐射影响深度的概念.基于切比雪夫数值拟合方法分析太阳辐射影响深度范围内的温度测点布置间距.从温度传感器测点布置深度、间距、温度测量时机角度对既有桥梁结构温度场测点布置方法及测试结果进行对比分析.结果混凝土桥梁的太阳辐射影响深度可取0.5 m;采用非等间距的温度场测点布置方法能够得到较为合理的竖向温度曲线;合理选择测量时机能够有效提高测量效率.结论总结并绘制了T型截面梁、单箱单室箱梁、单箱多室箱梁、钢管混凝土结构和箱型墩的温度场测点布置图,该布置方法可为后续温度场测量工作的测点布置和测量时机的选择提供参考.

日照作用下混凝土板温度场分析

环境热作用下混凝土板温度场分布对结构设计及分析至关重要。在先前研究基础上,考虑自然环境热荷载对混凝土板温度场的影响,通过分析混凝土板热交换过程,建立了混凝土板热流边界条件的余弦函数模型,采用一维混凝土温度场模型计算了混凝土板温度场分布,其温度计算值与实测值的最大误差为5.6%。基于混凝土温度场模型研究了日照和气温作用下混凝土板内温度响应规律,并结合混凝土板模型试验定量地分析了混凝土板增温幅度和太阳辐射深度,得到以下结论:1)太阳辐射是混凝土板产生温度梯度的主要因素;2)太阳辐射对混凝土板内0~0.3m范围内温度影响最明显;3)混凝土板内太阳辐射深度的理论值为0.5m左右,可为混凝土结构温度场的监测及分析方法提供相应的参考。

Fine Measurements and Analysis of Temperature Gradients in the Wells of the Jinsha River Groundwater Observational Network

Fine measurements have been conducted to temperatures and their gradients of six wells of the Jinsha River Groundwater Observational Network.The results show that the influence depths of sun radiation heat are 50m to 125m,average temperature gradients in the wells range from 0.11 to 2.81℃/hm and most are 1～2℃/hm,and the temperature gradients on varied depth sections of one well are highly changeable.Lithology of strata and their integrity,particularly high-angle crashed fault zones,have imposed major effects on the influence depths of sun radiation heat and temperature gradients of the wells.The micro dynamic characteristics of water temperature,such as coseismic effects,tidal effects and anomalies of the wells prior to earthquakes,probably depend,to a large degree,on the temperature gradients of the depths at which the water temperature sensors are settled.