【作者】 白光亮；

【导师】 蒲黔辉；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2009， 博士

【摘要】 近年来,超大跨径斜拉桥在我国各地大量兴起。索塔锚固区是斜拉桥中的关键部位,受力比较复杂。随着跨度的增加,斜拉索的设计吨位已达到了“千吨”级的水平,使得索塔锚固区的受力越来越大。因此,斜拉桥索塔锚固区节段受力性能分析的探讨一直以来受到桥梁界的瞩目。本文在收集国内外相关资料和深入分析已有研究成果的基础上,以金塘大桥索塔锚固区为背景,结合模型试验,对斜拉桥索塔锚固区钢混组合结构剪力键选型、拉索锚固结构传力机理、实用计算方法展开研究,主要研究内容如下：1、首次提出在索塔锚固区钢混组合结构使用新型PBL剪力键(带孔钢板剪力连接件),采用试件中部设计加载梁传力装置的方法代替传统的推出试验方法,对两类共计6组钢混组合结构剪力键模型(栓钉和PBL)进行破坏试验。研究了两者的抗剪承载力、破坏形态及其内力分布规律,通过本文定义的方法获得了两类剪力连接件的抗剪刚度,并与日本钢结构协会(JSSC)定义的方法进行了对比,考察了试件在荷载作用下的位移响应。试验结果表明,PBL剪力键比栓钉在钢混组合结构之间具有更高的抗剪承载力。2、在弹塑性变形理论基础上,对钢混组合结构结合面粘结应力分布函数进行了推导,建立了索塔锚固区钢混组合结构剪力键的荷载-滑移本构方程。基于最小二乘法的基本原理编制了相应的MATLAB程序,对实测数据曲线拟合得到剪力连接件非线性剪切刚度,同时给出了相应的计算公式。提出了如何模拟剪力键滑移效应的详细方法,在此基础上,对不同混凝土强度、栓钉间距、PBL孔洞直径、贯通钢筋直径和钢肋条厚度下的剪力键试件进行单因素的拓展参数分析,研究各影响因素对索塔锚固区钢混组合结构剪力键受力性能的影响。3、以金塘大桥索塔锚固区首次采用的拉索锚固结构为背景,对其进行足尺模型试验研究。在加载系统上,设计拉索锚固台座加载系统,克服了以往反力架对加载空间要求大的困难。对索塔锚固区钢锚梁-钢牛腿组合传力结构在设计荷载、断索和超载等多种状态下进行了模拟,揭示了不同工况下塔壁混凝土和拉索锚固结构的应力变化规律。试验结果表明钢锚梁-钢牛腿组合结构有很大的安全贮备,同时验证了在索塔锚固区钢混组合结构应用新型PBL剪力键的可行性。4、基于钢混组合结构剪力键荷载-滑移本构方程,对索塔锚固区拉索锚固结构受力行为进行了数值模拟,研究了塔壁混凝土、钢锚梁、钢锚箱及钢牛腿各部位应力分布规律,数值结果与试验结果吻合良好,理论计算模式能够反映结构实际受力状态,并根据数值结果和试验结果对钢锚梁-钢牛腿组合结构的传力机理进行了分析。5、为了便于工程应用和设计方便,及时修改调整索塔及锚固结构方案,提出了索塔锚固区拉索锚固结构简化分析方法。通过与塔壁混凝土、钢锚梁和钢牛腿控制测点的实测应力对比,验证了简化实体模型方法的正确性。最后结合索塔锚固区模型试验以及实桥钢锚梁的安装工艺流程,编制了具体的施工工法,为推广钢锚梁结构在斜拉桥方面的应用以及今后其它类似结构的施工方案选择、施工过程控制提供参考或借鉴。更多还原

【Abstract】 At present, large span cable-stayed bridges have sprang up over the country. The anchorage zone on pylon is the key parts for cable-stayed bridge and the forces acting on the zone are complicated. With the increase of span, the anchorage zone on pylon bear more heavy load because of the increase cable force. Study on the structural behavior of anchorage zone of cable-stayed bridge has attracted much attention in bridge circles. Based on the domestic and international research results, the Jintang bridge as a case, it has made the study on experimental research of different shear connectors for steel-concrete joint section of bridge pylon, transfer mechanism and utility computed methods of the anchorage structure. The main research work covers the following aspects:1、It is suggested that the Perfobond Leiste(PBL) shear connector could be applied for steel-concrete joint section of bridge pylon for the first time. In order to improve the reality of the experimental data, the loading device is fixed in the middle of the specimen instead of the push-out test. A new type of connector and traditional stud connector models for the joint section with different structural forms are put forward, and 3D FEM analysis and contrastable model experiments are carried out for models. The principal results of the simulation calculation, comparison of the results to the measurement values in the tests are provided, and some important conclusions in relation to the calculation and tests are generalized. Base on tests of these specimens, relation between load and slip, shear rigidity, ultimate bearing capacity, failure pattern etc. of shear connectors are discussed. The analysis results show that the calculating results coincide with the experimental results, and the PBL shear connector has much higher bearing capacity than stud connector for steel-concrete joint section of bridge pylon.2、The distribution function of bond stress on joint surface of the composite structures is derived based on elasticity and deformation plasticity theories.According to constitutive model of shear connectors, a constitutive equation of load-slip is established from statistical analysis of test data at different loads. The nonlinear shear rigidity is developed based on MATLAB program language and a calculation equation is provided. The methods to simulate the slip of connectors is suggested. Then a configuration algorithm based on the model is presented. A series of extending parametric analysis are carried out on models with different concrete strengthes, spacing interval of stud connector, size of the holes, diameter of the perforated rebar for PBL shear connector and thickness of the steel ribs by means of numerical simulation combining with full-scale experimental verification. Some useful conclusions are obtained by the parametric study.3、Taking the composite structure of steel anchor beam and steel corbel as project background,which is firstly used in the anchorage zone of Jintang bridge, a full scale segmental model test is performed. The pedestal loading system is designed to overcome the disadvantage of the reaction frame for loading in this paper. The stress redistribution of concrete and the anchor structure is obtained under many different situations. The structural performance satisfies the design requirement. The results show that the composite structure of steel anchor beam and steel corbel has enough safety tolerance and the PBL shear connector is feasible for steel-concrete joint section of bridge pylon.4、Based on the load-slip constitutive equation of the steel-concrete composite structure, stress analysis of the pylon cable anchor zone is simulated numerically. Through a series of analysis including stress distribution of tower wall concrete, steel anchor beam, steel anchor box and steel corbel, the numerical result shows good agreement with the experimental result, and the theoretical calculation model can reflect the real stress states. The composite structure transfer mechanism about steel anchor beam and steel corbel is analyzed according to these results.5、For the engineering convenience and convenient design, a new simplified analytical method of the anchor-hold structure is put forward. By means of that, the structural concept can be adjusted timely. Compared to the measured stress of the tower wall concrete, steel anchor beam and steel corbel, the conclusion is that the simplification of the physical model is visible. In combination with the model test and installation technological process of the steel anchor beam, the construction methods in detail are established. This article can provide information about the popularization and application of the steel anchor beam structure, construction scheme selection and construction process control.更多还原