采空区输电线路恒阻大变形锚杆基础稳定性研究

发布时间：2018-04-08 12:02

本文选题：采空区　切入点：输电线路　出处：《中国矿业大学》2014年硕士论文

【摘要】：近年来，针对煤矿采空区的输电线路勘测设计技术取得了一定的发展，在输电线路勘测设计、施工、运行等方面均积累了一定的经验。但是目前我国尚无具体规范对采空区输电线路设计提供指导，尽管已有多种针对输电塔基和铁塔的防护纠偏措施得到了实施，但是它们的适用条件和取得的效果参差不齐，并不能完全达到理想的要求。本文从煤矿采空区输电线路塔基的破坏机理分析出发，通过研究恒阻大变形锚杆的性能和恒阻大变形锚杆基础的结构组成，提出了煤矿采空区输电线路岩石地基大变形锚杆基础的形式，并通过理论分析、物理试验和数值模拟等方法，进一步验证恒阻大变形锚杆基础的工作机理。首先，研究了恒阻大变形锚杆基础的结构和组成，提出了一种能适应煤矿采空区典型高压输电直线塔的锚杆基础结构形式——恒阻大变形锚杆支撑复合大板基础，并验证了锚杆受到的压力与随后拉开力的关系。在不同地基下沉状态下按照是否设置锚杆的情况，采用基础底面边缘的压应力分布为三角形的形式，根据力和弯矩平衡方程，对一边下沉和一角下沉状态下的锚杆基础进行受力分析，得出了锚杆设计恒阻值、地基塌陷面积比、锚杆支撑力等参数的理论计算公式。其次，针对支撑复合大板的恒阻大变形锚杆基础进行了物理模型试验，通过模拟“不同的地基塌陷面积”，对模型基础施加不同工况下的作用力，得到了模型基础在正常运行、一边下沉和一角下沉状态下的下沉端位移和锚杆支撑力曲线，并分析了地基塌陷面积比、基础上部施加荷载、锚杆杆体伸出长度等因素对大板基础下沉端位移和下沉侧锚杆支撑力的影响。通过物理试验研究，，分析了锚杆对于维持基础稳定性所起到的作用。在正常运行、一边下沉和一角下沉状态下，对基础和锚杆的受力与变形进行了数值模拟，研究了不同地表变形情况对基础位移和地基反力的影响，分析了锚杆直径、锚杆长度以及基础刚度等因素对维持锚杆基础稳定性的影响。将数值模拟结果与理论分析结论和物理试验数据进行对比，分析各种方法研究的准确性，验证了锚杆基础稳定性研究的有效性。最后，针对恒阻大变形锚杆基础进行安全性评估，提出了采空区高压输电直线塔的恒阻大变形锚杆基础的适用条件、应用方式和设计方法，并对恒阻大变形锚杆基础的进一步研究提出了展望。
[Abstract]:In recent years, the transmission line survey and design technology of coal mine goaf has made a certain development, and has accumulated certain experience in transmission line survey design, construction, operation and so on.However, there are no specific specifications in China to provide guidance for the design of transmission lines in goaf. Although a variety of protection and correction measures for transmission towers and iron towers have been implemented, their applicable conditions and effects are not uniform.It does not fully meet the desired requirements.Based on the analysis of the failure mechanism of transmission tower foundation in goaf of coal mine, this paper studies the performance of constant resistance large deformation anchor and the structure composition of constant resistance large deformation anchor foundation.This paper puts forward the form of large deformation anchor foundation of transmission line in coal mine goaf, and further verifies the working mechanism of constant resistance and large deformation anchor foundation by means of theoretical analysis, physical test and numerical simulation.Firstly, the structure and composition of large deformation anchor foundation with constant resistance and large deformation are studied, and a structure form of anchor rod foundation which can adapt to the typical high voltage transmission line tower in goaf of coal mine is put forward, that is, the composite large plate foundation with constant resistance and large deformation anchor rod support, which is suitable for the typical high voltage transmission line tower in the goaf of coal mine.The relationship between the pressure of the bolt and the subsequent pull force is verified.According to the condition of whether or not the anchor rod is installed in different subgrade subsidence condition, the compressive stress distribution on the bottom edge of the foundation is triangular, according to the equilibrium equation of force and bending moment,The stress analysis of anchor foundation under the condition of one side sinking and one corner sinking is carried out, and the theoretical calculation formulas of the design constant resistance of anchor, the ratio of ground collapse area to ground collapse area, anchor support force and so on are obtained.Secondly, the physical model test is carried out for the anchor foundation with constant resistance and large deformation. By simulating "different ground collapse area" and applying the force under different working conditions to the model foundation, the normal operation of the model foundation is obtained.The displacement curve of the sinking end and the anchor support force curve under the condition of one side sinking and one corner sinking are analyzed, and the area ratio of foundation collapse and the load on the upper part of the foundation are analyzed.The influence of the length of the anchor body on the displacement of the sinking end of the large plate foundation and the supporting force of the anchor rod on the sinking side.The effect of anchor rod on the stability of foundation is analyzed by physical experiment.Under the condition of normal operation, one side sinking and one corner sinking, the force and deformation of foundation and anchor rod are numerically simulated, the influence of different ground deformation on foundation displacement and foundation reaction force is studied, and the diameter of anchor rod is analyzed.The influence of anchor length and foundation stiffness on the stability of anchor foundation.The numerical simulation results are compared with the theoretical analysis results and the physical test data, and the accuracy of various methods is analyzed to verify the validity of the stability research of anchor foundation.Finally, according to the safety evaluation of large deformation anchor foundation with constant resistance, the suitable condition, application mode and design method of constant resistance and large deformation anchor foundation for straight line tower of high voltage transmission in goaf are put forward.Furthermore, the prospect of further research on the large deformation anchor foundation with constant resistance is put forward.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU476

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