红外热成像技术在震后房屋损坏快速鉴定中的应用研究.

本文引入了目前地震现场房屋快速安全性鉴定工作的辅助手段——红外热像无损检测技术,借用图像处理手段、数学统计方法等,探讨了震后房屋破坏红外图像的表现效果,分析了红外图像与各影响因素的关系.文中以汶川地震现场建筑物的典型震害为代表,重点分析了框架结构、砖混结构、简单结构房屋的红外图像表现.本文所涉及的建筑材料主要有水泥砂浆、钢筋混凝土、红砖、黏土、楠木、石棉瓦、水泥板等:表面装饰层材质有红漆、白色抹灰、黄色涂料、白色壁纸、红色瓷砖、白色瓷砖等.材料的物理性质不同,其表现出的红外图像特征差别较大.统计相关分析结果显示:图像的表现效果在下午时段优于中午时段和上午时段;晴天拍摄图像的表现效果最佳,雨天次之,阴天最差.同时,要考虑红外热像无损检测技术检测漏水破坏的优势,充分利用雨天对建筑物破坏的影响;光照射情况与红外图像表现效果的关系为:直面照射条件优于倾斜照射和不能照射;破坏程度相关分析统计结果显示,构件的“基本完好、轻微破坏、中等破坏”这3个破坏等级,随着破坏程度的递进,图像的表现效果增强;而构件的“中等破坏、严重破坏、毁坏”这3个破坏等级,随着破坏程度的递进,图像的表现效果无显著变化;对结构类型数据统计结果显示,底框架结构图像的表现效果优于砖混结构、框架结构和简单结构;装饰层材质分类相关统计分析结果显示,图像表现效果与材质性质、颜色、表面粗糙状况等因素有关.

Application of Infrared Thermography in the Rapid Post-earthquake Damage Assessment of Buildings

On the basis of the rapid safety appraisal of buildings in seismic field carried out by the seismic department during the period of earthquake emergency response, this paper, introducing the infrared nondestructive test technology, one supplementary means of the rapid safety appraisal of buildings nowadays, employing image processing, mathematical statistics and so on, discusses the infrared images of the damaged buildings in the earthquake and analyzes their relationship with all kinds of influence factors. Based on the typical damages of buildings in seismic field in Wenchuan Earthquake, emphasis is laid on the infrared images of the buildings of frame structure, brick and concrete structure or simple structure. This paper introduces evaluation systems for earthquake damage and losses of buildings, the characteristics and duties of seismic field work at the present in our country, and highlights the typical damage of buildings of different structure together with the features of the infrared and visible images. Building materials referred to in this paper are cement mortar, reinforced concrete, red bricks, clay, phoebe bournei, asbestos shingles, cement board and so on. The surface decorations are red lacquer, white plasterer, yellow coating, and white wallpaper, red or white tiles and so on. Different materials have different physical natures, leading to different features in their infrared images. This research designs a table for each infrared image, recording the capture time, location, weather, angle, distance together with the structure types, materials, damage level of the buildings. What the correlation analysis reveals are as follows： The image gives a better presentation in the noon than in the morning, and even better in the afternoon. In practice, the afternoon should be made full use of; A good presentation can be given in the sunny days, worse in the rainy days and worst in the cloudy days;The presentation of the infrared images is good in the case of direct sunlight, worse in the case of the slanting sunlight, and worst in the case of no sunlight. The correlation analysis shows that among the destruction degrees of well preservation, slight damage and moderate damage, the effect of the images enhanced as the damage degree increases, and as for images of moderate damage, severe damage and destruction, the effect of the images is inconspicuous as the damage degree increases. According to the decoration layer shows that the effect of images is correlated to the properties, color, and surface roughness of the materials. Among all the factors, the heat absorption of the material is directly influenced by the surface color, so the influence of surface color should not be ignored. The diversity of color appearing on the same material will interfere the interpretation of the images, and INDT is also not suitable when there are many kinds of decoration layers and complex background colors.