预应力锚索张拉伸长量计算方法研究

发布时间：2018-10-23 16:37

【摘要】：预应力锚索是一种安装在岩土体内部的受拉索体结构,通过主动施加预应力,以实现限制变形和加固岩土体,提高稳定性的目的。由于锚索具有经济、方便和加固效率较高的特点,现已被广泛应用于边坡工程、水利工程、结构抗浮工程和市政工程等领域。对于预应力技术而言,有效预应力是最为重要的一个参数,它直接影响了被加固结构是否安全稳定。目前工程上普遍采用双控法对预应力张拉进行监控,即以张拉荷载的控制为主,结合伸长量反推锚下有效预应力,两者相互比较以达到校核的目的。然而,伸长量的计算方法却一直少有人进行研究,各种规范中给出的计算公式也过于简单,与实际情况偏差较大。本文针对以预应力锚索张拉伸长量的计算方法开展研究,主要工作包括:①以明德林问题为模型,分析了拉力型锚索的受力特点,指出其两个界面上粘结应力分布的不均匀性,并推导了伸长量的计算公式和锚固段与自由段交界处脱粘段的长度。分析了压力型锚索的受力特点,指出承载体位移对伸长量测量的影响,并推导出了相应的计算公式。②分析了预应力锚索锚孔的钻凿轨迹分布规律与特征,介分析了各种钻孔表示方法和钻孔计算方法的优劣,选定了投影图表示法和校正平均角法作为相应的表示方法和计算方法,为探讨摩擦力的影响打下了基础。③在已有研究工作的基础上,针对预应力锚索在孔道中与孔道壁的接触应力及其对摩阻力的影响进行了探讨。④总结了现在广泛使用的张拉工艺,分析了其中可能造成伸长量测量误差的环节,指出了其中的有些不足之处,并提出采用智能张拉工艺取代传统张拉工艺,并提出了智能张拉工艺流程及智能张拉系统的技术框架。⑤结合云南蒙新高速第11合同段中的两个边坡锚固工程验收报告进行了试算,并对得到的数据进行了初步的分析。
[Abstract]:Prestressed Anchorage cable is a kind of cable body structure which is installed in rock and soil body. The purpose of limiting deformation and strengthening rock and soil mass and improving stability can be achieved by applying prestressing force actively. Because of its economic convenience and high efficiency Anchorage cable has been widely used in slope engineering hydraulic engineering structural anti-floating engineering and municipal engineering. Effective prestressing is the most important parameter for prestressing technology, which directly affects the safety and stability of reinforced structures. At present, the double control method is widely used to monitor the prestress tension, that is, the tension load is mainly controlled and the effective prestressing force under the anchor is combined with the extension. The two methods are compared to each other in order to achieve the purpose of checking. However, the calculation method of elongation has been seldom studied, and the formulas given in various specifications are too simple and deviate from the actual situation. In this paper, the method of calculating the tensioning elongation of prestressed anchor cable is studied. The main work is as follows: 1 taking the Minderlin problem as the model, the stress characteristics of the tension type anchor cable are analyzed, and the inhomogeneity of the bond stress distribution on the two interfaces is pointed out. The calculation formula of elongation and the length of debonding section at the junction of anchoring section and free section are deduced. This paper analyzes the stress characteristics of pressure-type anchor cables, points out the influence of load-bearing displacement on the measurement of elongation, and deduces the corresponding calculation formulas. 2. The distribution law and characteristics of drilling track of prestressed anchor holes are analyzed. In this paper, the advantages and disadvantages of various borehole representation methods and borehole calculation methods are analyzed, and the projection map representation method and the correction average angle method are selected as the corresponding representation and calculation methods. It lays a foundation for the discussion of the influence of friction. 3 on the basis of existing research work, In this paper, the contact stress of prestressed anchor cable in the channel and its influence on friction resistance are discussed. (4) the tensioning technology which is widely used now is summarized, and the links which may cause the measuring error of elongation are analyzed. Some shortcomings are pointed out, and the intelligent tensioning process is proposed to replace the traditional tensioning process. Finally, the technical framework of intelligent tensioning process and intelligent tensioning system is put forward. 5 combined with the acceptance report of two slope anchoring projects in the 11th contract section of Yunnan Mengxin Expressway, the preliminary analysis of the obtained data is made.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU476;U416.14

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