超长桩低应变应力波传导检测技术研究

发布时间：2018-01-18 05:08

本文关键词：超长桩低应变应力波传导检测技术研究　出处：《河北工业大学》2013年硕士论文　论文类型：学位论文

【摘要】：目前普通桩的桩身质量检测中，国内外普遍采用低应变反射波法，通过实测桩顶加速度或速度响应时域曲线，来判定基桩的桩身完整性。本方法可适用于检测桩身的完整性，，推定缺陷类型及其在桩身中的大概位置，也可对桩长进行核对，对桩身混凝土的强度等级做出初步估计。该方法操作简便、使用快捷、成本较低且可对工程进行普查，具有相对完善的理论基础和比较先进的诊断技术。但是，对于超长桩而言，该方法很难测到桩底反射或来自深度较大处的缺陷反射，即便是用较大力棒敲击宽脉冲信号，也不一定能测到清晰的反射信号，造成精度较差，从而使得检测结果不能做到充分的完整和准确。所以，研究一种快速、高效、节约、精度高、适用范围广的检测方法很有必要，我的论文正是以此为切入点展开研究。首先，进行桩身质量测试技术对比，分析低应变应力波反射法与传统方法相比在工程中的应用优越性。其次，对摩擦桩的低应变反射波方法建立桩土作用模型，分析应力波能量衰减的关键因素，提出基于低应变法的应力波接力传导检测技术。再次，通过对模型桩进行了低应变的有限元模拟分析，验证该技术在超长桩检测应用的可行性和优越性。最后，本章通过室内浇筑模型桩，进行接力传导方法检测试验，总结检测前准备、及现场安装、后期信号采集等一些实际的经验，为以后该方法的进一步的成功、准确的应用到实际工程奠定基础。
[Abstract]:At present, the low strain reflection wave method is widely used in the pile quality testing of common pile, and the acceleration or velocity response time domain curve of pile top is measured. This method can be used to detect the integrity of pile body, to estimate the type of defect and its general position in pile body, and to check the pile length. The strength grade of pile concrete is estimated preliminarily. This method is easy to operate, quick to use, low cost and can carry out a general survey of the project, which has relatively perfect theoretical basis and advanced diagnostic technology. However. For super-long piles, it is very difficult to detect the reflection from the bottom of the pile or the defect reflection from the higher depth. Even if the broad pulse signal is struck with a stronger rod, the clear reflection signal may not be detected. Therefore, it is necessary to study a fast, efficient, economical, high precision, wide range of detection methods. My thesis is just this as a starting point to carry out research. Firstly, the comparison of pile mass measurement techniques is carried out, and the advantages of low strain stress wave reflection method compared with the traditional method in engineering are analyzed. Secondly, the pile-soil interaction model is established for the low strain reflected wave method of friction pile, and the key factors of stress wave energy attenuation are analyzed, and the stress wave relay conduction detection technique based on low strain method is proposed. Thirdly, the feasibility and superiority of this technique in the detection of super-long pile are verified by the finite element simulation analysis of the model pile with low strain. Finally, this chapter through the indoor pouring model pile, carries on the relay conduction method test test, summarizes before the inspection preparation, and the spot installation, the late stage signal collection and so on some practical experience. It lays a foundation for the further success of this method and its application to practical engineering.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU473.16

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