道路致灾空洞热效应与快速探测可行性研究

Thermal Effects and Rapid Detection Feasibility of a Disaster-causing Cavity in Road Structure

为了快速有效地探测出城市道路结构中的致灾空洞,预防路面突然塌陷而导致财产和生命的损失。采用理论和数值模拟手段,分析了城市典型的沥青混凝土道路存在致灾空洞时的热效应和温度场变化规律。研究表明:致灾空洞的存在改变了沥青混凝土道路结构传热特性,提高了其热流通量,致使路面结构层传热增多、热量留存减少、引起道路路面温度发生下降。在夏季晴好天气的2:00—22:00时段,致灾空洞提高了道路结构热流通量约4倍多,使道路路面在致灾空洞约2.2倍尺度范围内温度下降1.061~1.368℃,目前红外热像仪的探测精度能够探测出其温度变化。因此,采用红外热像技术探测城市道路致灾空洞具有可行性。

In order to quickly and efficiently detect disaster-causing cavities in urban road structures,to prevent the road suddenly collapsing and leading to loss of property and lives.The thermal effect and the variation of temperature field of typical asphalt concrete road with disaster-causing cavity were analyzed by theoretical and numerical simulation methods.The research shows that the existence of disaster-causing cavity changes the heat transfer characteristics of asphalt concrete road structure,improves the heat flux,increases the heat transfer of pavement structure layer,reduces the heat retention,and finally causes the decrease of pavement temperature.During the period from 2:00 to 22:00 in summer,the disaster-causing cavity increases the heat flux of the road structure by more than 4 times,and makes the temperature of the road surface decrease by 1.061~1.368℃in the scale range of 2.2 times the disaster-causing cavity.This temperature change can be detected with the accuracy of the infrared thermal imager.Therefore,it is feasible to detect urban road disaster-causing cavities by the use of infrared thermal imaging technology.