基于分布式光纤测温技术检测灌注桩完整性试验研究
发布时间：2018-12-28 18:03
【摘要】：灌注桩直径大、承载力高、施工成桩时无振动扰土、施工现场噪音小、经济合理等优点,在城市地区、建筑物密集的场地被广泛应用。但桩基施工工艺要求较高,稍有不慎,就会出现各种质量问题,所以采取有效的方法检测灌注桩的质量至关重要。然而现今的检测方法存在设备笨重、费用高、误差大、无法快速、在线、长期监测等问题。分布式光纤测温技术应用于灌注桩基检测具有很大的优势,比如其体积小、质量轻,灵敏度高,抗电磁干扰,能长期在线、实时快速分布式检测桩基的质量。本文介绍了光纤测温技术检测桩基完整性方法的原理和基本理论,并在已有的研究基础上,对检测系统的布线方式的设计进行了探讨和研究,制作了灌注桩模型,进行了光纤影响范围的试验研究,开展了灌注桩完整性现场试验及模型试验对比研究,主要研究结果下:(1)简单介绍现在常用的桩基检测方法及其存在的问题,对桩基检测技术的基本研究现状进行总结;介绍分布式光纤测温技术的研究现状以及该技术用于检测桩基完整性的优势;介绍了基本的原理和方法。(2)检测光纤布置方案优化设计研究。分析课题组前期的模型试验和现场试验存在的不足之处;由一维径向热传导理论,得出热传导临界半径主要影响因素及热传导的温度分布特征;针对检测系统的布线方式的设计进行探讨和研究,得出光纤采用“U”型回路布设,加热光纤热传导的临界半径等于桩身半径的一半。当布设多条光纤检测时,要分开间隔加热检测。(3)检测光纤影响范围的模型试验研究。根据一维内热源的径向传导理论,推导出光纤热传导临界半径的理论公式;试验证实了临界半径理论公式中加热功率对临界半径起决定作用的结论,但光纤热传导临界半径的理论公式计算得到的结果与试验得出的临界半径结果相差较大,表明理论公式还有待进一步的修正和完善,将在后续的研究中做进一步的深化研究。(4)灌注桩完整性现场试验及模型试验对比研究。取某工程的钻孔灌注桩,以加热光纤方式来对灌注桩完整性进行研究。试验表明无论何种加热功率,现场试验的平均稳定温升值大于模型试验的平均稳定温升值;提出了关于定量分析夹泥缺陷灌注桩含泥量的思路。
[Abstract]:The cast-in-place pile has the advantages of large diameter, high bearing capacity, no vibration disturbance, low noise, reasonable economy and so on. It is widely used in urban areas where buildings are concentrated. However, the construction technology of pile foundation requires high quality problems, so it is very important to adopt effective method to detect the quality of cast-in-place pile. However, the current detection methods have some problems, such as heavy equipment, high cost, large error, can not be quickly, online, long-term monitoring and so on. The application of distributed fiber temperature measurement technology in pile foundation detection has great advantages, such as small volume, light weight, high sensitivity, anti-electromagnetic interference, long-term on-line, real-time and fast distributed detection of pile foundation quality. This paper introduces the principle and basic theory of the fiber optic temperature measurement technique for detecting the integrity of pile foundation, and on the basis of the existing research, discusses and studies the design of the wiring mode of the inspection system, and makes the model of the cast-in-place pile. The field test and model test of the integrity of cast-in-place pile are carried out. The main results are as follows: (1) the commonly used testing methods of pile foundation and the existing problems are briefly introduced. The basic research status of pile foundation detection technology is summarized. This paper introduces the research status of distributed optical fiber temperature measurement technology and its advantages in detecting pile foundation integrity, and introduces the basic principles and methods. (2) Research on optimal design of optical fiber layout detection scheme. Based on the one-dimensional radial heat conduction theory, the main factors affecting the critical radius of heat conduction and the temperature distribution characteristics of heat conduction are obtained. This paper discusses and studies the design of the wiring mode of the inspection system, and concludes that the critical radius of the heating fiber heat conduction is equal to half of the radius of the pile body when the optical fiber is arranged in "U" type loop and the critical radius of the heating fiber is equal to that of the pile body. When a number of optical fibers are deployed, the detection should be heated separately. (3) the model test of the influence range of the optical fiber is studied. According to the radial conduction theory of one dimensional internal heat source, the theoretical formula of critical radius of optical fiber heat conduction is derived. The conclusion that heating power plays a decisive role in the theoretical formula of critical radius is confirmed by experiments. However, the calculation results of critical radius of optical fiber heat conduction are quite different from the results of critical radius obtained by experiment. It shows that the theoretical formula still needs to be further revised and perfected, and further research will be done in the follow-up study. (4) the field test of the integrity of the cast-in-place pile and the comparative study of the model test. The integrity of cast-in-place pile is studied by heating optical fiber. The experimental results show that the average stable temperature rise of field test is higher than that of model test regardless of heating power, and the idea of quantitative analysis of mud content of mud-filled pile with defect is put forward.
【学位授予单位】：湖北工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU473.1
本文编号：2394254
[Abstract]:The cast-in-place pile has the advantages of large diameter, high bearing capacity, no vibration disturbance, low noise, reasonable economy and so on. It is widely used in urban areas where buildings are concentrated. However, the construction technology of pile foundation requires high quality problems, so it is very important to adopt effective method to detect the quality of cast-in-place pile. However, the current detection methods have some problems, such as heavy equipment, high cost, large error, can not be quickly, online, long-term monitoring and so on. The application of distributed fiber temperature measurement technology in pile foundation detection has great advantages, such as small volume, light weight, high sensitivity, anti-electromagnetic interference, long-term on-line, real-time and fast distributed detection of pile foundation quality. This paper introduces the principle and basic theory of the fiber optic temperature measurement technique for detecting the integrity of pile foundation, and on the basis of the existing research, discusses and studies the design of the wiring mode of the inspection system, and makes the model of the cast-in-place pile. The field test and model test of the integrity of cast-in-place pile are carried out. The main results are as follows: (1) the commonly used testing methods of pile foundation and the existing problems are briefly introduced. The basic research status of pile foundation detection technology is summarized. This paper introduces the research status of distributed optical fiber temperature measurement technology and its advantages in detecting pile foundation integrity, and introduces the basic principles and methods. (2) Research on optimal design of optical fiber layout detection scheme. Based on the one-dimensional radial heat conduction theory, the main factors affecting the critical radius of heat conduction and the temperature distribution characteristics of heat conduction are obtained. This paper discusses and studies the design of the wiring mode of the inspection system, and concludes that the critical radius of the heating fiber heat conduction is equal to half of the radius of the pile body when the optical fiber is arranged in "U" type loop and the critical radius of the heating fiber is equal to that of the pile body. When a number of optical fibers are deployed, the detection should be heated separately. (3) the model test of the influence range of the optical fiber is studied. According to the radial conduction theory of one dimensional internal heat source, the theoretical formula of critical radius of optical fiber heat conduction is derived. The conclusion that heating power plays a decisive role in the theoretical formula of critical radius is confirmed by experiments. However, the calculation results of critical radius of optical fiber heat conduction are quite different from the results of critical radius obtained by experiment. It shows that the theoretical formula still needs to be further revised and perfected, and further research will be done in the follow-up study. (4) the field test of the integrity of the cast-in-place pile and the comparative study of the model test. The integrity of cast-in-place pile is studied by heating optical fiber. The experimental results show that the average stable temperature rise of field test is higher than that of model test regardless of heating power, and the idea of quantitative analysis of mud content of mud-filled pile with defect is put forward.
【学位授予单位】：湖北工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU473.1
【相似文献】
相关硕士学位论文 前1条
1 饶兰;基于分布式光纤测温技术检测灌注桩完整性试验研究[D];湖北工业大学;2017年
，本文编号：2394254
本文链接：https://www.wllwen.com/jianzhugongchenglunwen/2394254.html
