【作者】 高建军；

【导师】 宋一凡；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2007， 硕士

【摘要】 预应力混凝土因其良好的受力性能等诸多优点,已经成为我国公路桥梁最常用的结构型式。预应力钢束在施工条件、自然环境、使用过程和材料内部因素的作用下,会出现各种损伤,从而导致预应力有效值的降低。因此,基于有效预应力实测值评价预应力混凝土桥梁的研究,具有重要的工程意义。本文作为西部交通建设科技项目《大、中跨径混凝土桥梁预应力检测技术》的一个重要组成部分,首次次提出了基于有效预应力实测值评价预应力混凝土桥梁的方法。首先,本文对有效预应力的计算方法进行了系统研究,并以有效预应力理论值为基础,提出了评价预应力混凝土桥梁的两个基本参数,即截面应力和截面预应力度。其次,本文介绍了基于预应力实测值评价预应力混凝土桥梁的等效参数法。以现行规范中损失σ11和损失σ12的计算公式为基础,参照《混凝土设计规范》(GB 50010--2002)并结合桥梁专用软件的计算方法,改进了损失σ11和损失σ12的计算公式,给出了通过改变μ、k和△l出来模拟钢束实际有效预应力沿纵向变化趋势的方法,最终利用桥梁专用软件对桥梁结构进行评价。再次,本文介绍了基于测试截面普通钢筋的初始应力,求得截面的实际合力效应,并以此评价预应力混凝土桥梁预应力度法。通过对比实际预应力度和设计预应力度确定了评价准则,并以此对桥梁结构进行定性评价。最后,本文利用Visμal Basic编制了等效参数求解程序和截面平衡程序,介绍了其编制原理及程序功能,为上述评价方法提供了技术支持。通过本文研究提出了一种对在役预应力混凝土桥梁综合评价的方法,为预应力混凝土桥梁加固维修提供基本依据,避免盲目判断,并节省时间和人力资源,充分延长其使用寿命,避免发生不必要的破坏,并填补了国内外基于预应力实测值评价预应力混凝土桥梁的空白。更多还原

【Abstract】 Because concrete of prestressing force has a lot of advantages such as good behaviors, it has already become the most frequently structural pattern of highway bridge of our country.Under the function of condition of construction、matieral envirtion、precess of using and matieral,Steel bunch of prestressing force will appear various damage,and then cause the reducing of effective prestessed. So the research of appraising the concrete bridge of prestressing force based on the real value of effective prestessed, have important project meanings.As an important part of the Western Project about Communication Science and Technology entitled《research on the prestressing force detection technology about large and medium prestressed concrete bridges》,This paper has bringed forward the method of appraising of prestressing concrete bridge based on the real value of effective prestessed for the first time.First of all, this paper has carried on systematic research to the calcaulating method of prestressing force,and has bringed forward two basic parameters for appraising prestressing concrete bridge which based on theory value of effective prestressing force, i.e. stress and degree of prestessing.Secondly, this paper has bringed forward method of equivalent parameter of appraising the concrete bridge based on the real value of effective prestessed. Basing on the current criterion, this paper has improved the calculating formula of lossσl1 and lossσl2,consulting "the concrete design specification"(GB 50010-2002) and combining the calculating technology of the special-purpose software of the bridge,and has provided the method of imitating variation tendency along the longitudinal of a bunch of real effective prestressing force by changingμ、k andΔl, and has appraised to the structure of the bridge utilizing special-purpose software of the bridge.Moreover, this paper has introducd the method of degree of prestressing appraising of prestressing concrete bridge which getting sectional reality effect of joining forces, based on testing the initial stress of the ordinary reinforcing bar of section. It has made sure of the appraising the criterion through comparing with the real degree of prestressing and designing degree of prestressing, so as to determine the nature on appraisal to the structure of the bridge. Finally, this paper has compiled the procedure of calculating equivalent parameter and the procedure of section balance utilizing Visal basic, and has introduced its principle of establishment and procedure function, and has offered technical support for appraisal method described above.The comprehensive method of appraisal for prestressing concrete bridge has been offered by research of this paper, and the basic thereunder has been offered for the maintainrance of the concrete bridge,which will avoid judging blindly, save time and human resources, increase its service life,avoid unnecessary destruction, and fill in the blank of the appraising concrete bridge of prestressing force on the basis of the surveying value of prestressing force both at home and abroad.更多还原