悬臂现浇连续刚构桥预应力张拉技术的研究

发布时间：2018-07-25 09:42

【摘要】：大跨径连续刚构桥在预应力张拉期间的质量对桥梁服役期间的耐久性、安全性起决定性作用。但我国现行规范对于预应力张拉的施工过程,尤其是采用多顶快速张拉过程没有明确的定量规定,因此由张拉次序不当所引起的预应力损失较设计值偏大的现象较为普遍。本文针对张拉过程中有效预应力的储备问题,拟结合在建的昭麻高速腰岩特大桥工程,通过数值仿真技术与室内试验及现场工程化试验相结合的研究方法,给出具有较高精度的预应力结构模型的构建方法。通过研究多顶预应力同步张拉顺序,提出预应力张拉标准化施工技术原则。通过分析不同张拉顺序下结构的预应力效应,最终给出连续刚构桥预应力砼标准化快速施工方案。本文主要研究内容及结论如下：首先,开展了预应力简支梁的室内张拉试验,运用降温法建立数值模型对试验梁的张拉过程进行模拟。通过对比试验数据来修正模型参数,给出具有较高精度的构建预应力模型的方法。其次,基于多阶段施工全过程分析的理论,采用验证后的模拟方法,建立连续刚构桥悬臂施工节段预应力张拉过程的数值模型。主要研究了纵向预应力束在对称张拉和非对称张拉时的预应力效应,提出在同一截面上无法满足对称张拉的条件下,至少保证“左右对称、先张拉顶板束后张拉腹板束”,且优先张拉靠近截面中心线的原则。最后,通过不同张拉次序开展批量数值计算,对比研究墩顶0号块、1号块的变形与应力,提出多顶同步张拉的最优施工次序。上述研究有助于准确模拟预应力张拉的施工过程,分析结构在不同张拉顺序下的有效预应力的建立过程；同时,为连续刚构桥预应力砼标准化快速施工提供参考。
[Abstract]:The quality of long span continuous rigid frame bridge during prestress tensioning plays a decisive role in the durability and safety of the bridge during service. However, the construction process of prestress tensioning, especially the use of multi-roof rapid tensioning process, is not clearly and quantitatively stipulated in the current code of our country, so the phenomenon that the prestress loss caused by improper tensioning sequence is larger than the design value is more common. In this paper, aiming at the problem of effective prestress reserve in tension process, the research method of combining numerical simulation technology with indoor test and field engineering test is proposed to combine the Zhaomai high-speed waist rock bridge under construction. The construction method of prestressed structure model with high precision is given. By studying the synchronous tensioning sequence of multi-top prestress, the technical principle of standardization construction of prestress tensioning is put forward. Based on the analysis of the prestressing effect of the structure under different tensioning sequence, the standardized and fast construction scheme of prestressed concrete for continuous rigid frame bridge is presented. The main contents and conclusions of this paper are as follows: first, the indoor tensile tests of prestressed simply supported beams are carried out, and the numerical model of the test beams is established by using the cooling method to simulate the tensile process of the test beams. By comparing the experimental data to modify the model parameters, the method of constructing prestress model with high accuracy is given. Secondly, based on the theory of multi-stage construction whole process analysis, the numerical model of prestressed tensioning process of cantilever construction section of continuous rigid frame bridge is established by using the verified simulation method. In this paper, the prestressing effect of longitudinal prestressing beam in symmetrical tension and asymmetric tension is studied. It is proposed that under the condition that symmetrical tension can not be satisfied on the same section, at least "left and right symmetry, first stretching roof beam and then stretching web bundle" are guaranteed. And the principle of drawing close to the center line of section is preferred. Finally, through the batch numerical calculation in different tensioning order, the deformation and stress of block 0 and block 1 at the top of the pier are comparatively studied, and the optimal construction sequence of multi-roof synchronous tensioning is put forward. The above research is helpful to accurately simulate the construction process of prestressed tensioning and to analyze the establishment process of effective prestress of structure under different tensioning sequence, and to provide a reference for the standardization and rapid construction of prestressed concrete of continuous rigid frame bridge.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.57

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