【作者】 司秀勇；

【导师】 白象忠；

【作者基本信息】 燕山大学 ， 工程力学， 2013， 博士

【摘要】 随着科技技术的不断发展，钢混组合结构由于能够同时发挥钢材和混凝土两者的优点，以其优异的力学性能，已经被越来越多的桥梁结构所釆用。钢混组合结构组合结构能否充分发挥其自身的力学性能，很大程度上取决于钢材与混凝土是否能良好连接，因此需要对桥梁结构中的钢混结合段进行充分研究和探讨。本文采用结构试验、数值分析、解析推导三种途径，系统研究了钢混结合段的受力性能，并对其中的PBL剪力键进行了重点分析。本文的主要研究内容有以下几个方面：在回顾了钢混结合段发展历史和研究背景的基础上，依据相似原则，对某公铁两用斜拉桥公路桥面钢混结合段进行了结构试验，测试了荷载作用下试验模型的控制断面和主要构件的应变、位移情况，结合有限元分析，对钢混结合段的传力机理和力学性能进行了研究。在综合考虑某桥主塔钢混结合段的受力及构造特点的基础上，采用几何、物理以及边界条件相似原则对结合段进行了结构试验，分别考虑正常使用极限状态与承载能力极限状态对试验模型进行加载，测试了试验模型的控制断面和控制构件的应力、变形随加载历程的变化形态，得到了结合段的应力状态、钢与混凝土的相对滑移等性能参数，将模型试验与有限元分析相结合，分析了结合段的传力机理及传力性能。在该桥桥塔钢混结合段大比例模型试验的基础上，对某桥主塔钢混结合段进行了精细化的非线性有限元分析。详细模拟了钢混结合段的细部构造，分析了1.7倍设计极限荷载（包含最大弯矩、最大轴力）作用下结合段的应力状态和应力分布规律。依据钢混结合段中的PBL剪力键的受力特点，对其进行了合理简化，将钢混结合段中单个PBL剪力键的弹性受力问题，简化为混凝土圆环的平面应变问题和贯穿钢筋的Winkler弹性地基梁问题，并得到了相应的解析解答。混凝土圆环问题是一个在圆环内外同时承受非轴对称载荷的厚壁圆柱壳体的平面应变问题，在假设接触应力分布函数之后，借助于Airy应力函数得到了应力解答，并通过区分弹性体位移和刚体位移，由应力得到了其位移解答，通过与有限元解的对比，证明了解析解的可靠性。将贯穿钢筋模拟为无限长的Winkler弹性地基梁，得到了其位移解答和应力解答。本文进行了板桁组合结构钢混结合段的模型试验，丰富了板桁组合结构钢混结合段的试验数据，揭示了板桁组合结构钢混结合段的传力机理。在国内首次进行了上塔肢采用钢结构、下塔肢采用混凝土结构、结合段内设置钢锚箱的斜拉桥桥塔钢混结合段的结构试验，研究了该种钢混结合段的受力特点。将钢混结合段中单个PBL剪力键的弹性受力问题，简化为混凝土圆环的平面应变问题和贯穿钢筋的Winkler弹性地基梁问题，给出了圆环内外同时承受非轴对称载荷的厚壁圆柱壳体平面应变问题的应力解析解答和位移解析解答，为解决类似力学问题提供了基础。更多还原

【Abstract】 As technology continues to develop, steel-concrete composite structures have beenmore and more used in bridge structures because of excellent mechanical properties.Mechanical properties of steel-concrete composite structures depend largely on whetherthe well connection is achieved, so steel-concrete composite sections need to bethoroughly studied and discussed. With three ways of structural testing, numerical analysis,analytic derivation, steel-concrete composite sections are systematically studied, and theemphasis is put on the PBL shear connectors.The following aspects are included in this paper:After reviewing the history of the development of steel-concrete composite sections,based on the similarity principle, push-out tests are carried ouf for the steel-concretecomposite sections of a cable-stayed bridge railway-road bridge. The strain anddisplacement of control section and the main components are tested. The force transfermechanism and mechanical properties of steel-concrete composite sections are studiedwith combination of the finite element analysis.After considering a combination of the force transfer mechanism and structuralfeatures of a steel-concrete composite section, a push-out test is carried out based onsimilar principles of geometry, physics and boundary conditions. The test model areloaded separately based on the serviceability limit state and the bearing capacity limit state,and the stress and deformation history with load changes are measured for the controlsections and the control members. Based on the stress state and the relative slip of steeland concrete of steel-concrete composite sections, the force transfer mechanism andmechanical performance are analyzed.A refined non-linear finite element analysis of steel-concrete composite sections isperformed based on large scale model tests. The stress state and stress distribution areanalyzed by a detailed simulation considering1.7times the design limit loads (includingmaximum bending moment, the maximum axial force).Based on the mechanical characteristics of the PBL shear connector, it is reasonably simplified as a concrete ring’s plain strain problem and a perforating rebar’s Winklerelastic foundation beam problem, and the corresponding analytical solutions are found out.The concrete ring problem is a plane strain of thick-walled cylindrical shell withstandingnon-axisymmetric loads at the inner and the outer board-line. On the assumption that thecontact stress distribution function, stress solutions are obtained by means of Airy stressfunction. The displacement solutions are found out from the stress solutions bydistinguishing between elastic displacement and rigid displacement. The analyticalsolutions are proved by contrast with the finite element solution. The perforating rebar ismodeled as an infinitely long Winkler elastic foundation beam, and their displacement andstress solutions are obtained.The model test of the plate-truss composite structure’s steel-concrete compositesections is conducted. Its test data enrich the research findings and reveal the force transfermechanism. The domestic first model test for the steel-concrete composite section of acable-stayed bridge tower with steel upper leg, concrete bottom leg, and steel anchor boxis carried out. The PBL shear connector is reasonably simplified as a concrete ring’s plainstrain problem and a perforating rebar’s Winkler elastic foundation beam problem, and thestress solutions and displacement solutions are found out for the plane strain problem ofthick-walled cylindrical shell withstanding non-axisymmetric loads at the inner and theouter board-line.更多还原