【作者】 孙广臣；

【导师】 傅鹤林；

【作者基本信息】 中南大学 ， 土木工程， 2013， 博士

【摘要】 摘要：桥隧相连工程,是桥梁、隧道、洞口围岩及其防护工程的复杂组合体,在国内、外均有十分广泛的应用。我国西部、南部很多山区的高速公路中,桥隧相连的现象十分普遍,其显著的特点是桥梁、隧道及洞口岩土体之间存在相互影响,因此受到的扰动或损伤来源广泛,在各种作用下的力学行为也异常复杂。尤其是软弱围岩条件下的桥隧相连工程,由于各结构或部位间的相互影响更加显著,其桥、隧结构各关键部位、洞口围岩及附近岩土体的多源损伤、力学行为以及各类工程病害的产生和发展,必然是多种复杂影响因素的耦合作用的结果。然而,目前国内外对软弱围岩(如Ⅳ、Ⅴ级围岩)中桥隧搭接(或邻接)工程的研究,存在着对施工过程及后期运营中的桥梁与隧道结构各部位、洞口围岩及附近岩土体等的多源损伤或多部位损伤与力学行为响应或病害规律及机理鲜有深入研究的情况,以及极少考虑桥、隧、岩三者间的相互影响或长期的车辆荷载(尤其是重载、超载车辆)及其冲击作用对桥隧相连段中桥、隧结构及相关岩土体等产生的各种不利影响的现状。随着桥隧相连在国内外的日益广泛应用和发展,越来越多的多源损伤或工程病害现象以及各种复杂多变的影响因素与相关问题的不断出现,在对相关工程的设计、施工提出新要求的同时,还必须慎重考虑其对大量已建成的桥隧相连工程在后期运营、管理或维护中产生的各种具体影响等问题。针对上述问题,本文结合贵州省重大专项研究项目(200904)和湖南省交通科技项目(200928)“桥隧相连工程多源损伤力学行为与控制技术研究”,在试验和理论研究的基础上,主要开展了以下几项工作：(1)在阐述和分析桥隧相连工程应用及主要特点的基础上,分析了桥隧相连工程的多源损伤特点,探讨了导致桥隧相连工程多源损伤及复杂力学行为机理,并分析了诱发桥隧相连多源损伤与复杂力学行为的主要影响因素。(2)通过多工况下的桥隧相连工程室内模型试验研究,初步探讨了桥隧相连工程的多源损伤特点和各部位间的相互作用机理,在桥隧相连的施工过程及后期运营中桥梁、隧道各部位及周围岩土体等的力学行为特征,易出现的各种损伤或病害的诱发机理及发展规律,并根据相关模型试验结果提出了控制或减少多种损伤或病害产生或发展的合理化建议。(3)分析了桥隧相连中各种工程材料的损伤特性,给出了材料普适弹塑性本构关系的详细表述,并以此为基础探讨了材料的弹塑性损伤本构的一般形式,给出了相应的损伤本构关系、损伤演化方程的具体形式；之后,基于损伤理论探讨并分析了一些常用且适于描述桥隧相连工程中混凝土和岩土体材料各种损伤的本构模型及其具体形式,以及各自的特点和适用性。(4)依据工程结构和材料的弹塑性损伤及疲劳损伤累积等理论和分析方法,提出了桥隧相连多源损伤力学行为数值模拟简化分析方法和考虑损伤效应的桥隧相连处桩基桥台的简化计算方法；进行了适用于软弱围岩条件下桥隧相连中桥隧结构及岩土体损伤数值分析程序和本构模型的二次开发,给出了相应的实现方法、程序分析步骤与相关计算公式的具体表达式,方便工程实际应用或简化分析时采用。(5)根据相应的数值模拟简化分析方法,建立了一系列模拟桥隧相连多源损伤力学行为的有限元分析模型。通过系统的数值模拟计算和结果分析,研究了考虑不同部位的损伤对桥隧相连工程中桥梁、桥台及桩基础、洞口附近隧道衬砌及围岩等在车辆荷载及冲击作用下的多源损伤与力学行为(或响应)的具体影响及变化规律。(6)基于有限元模拟,系统分析了各种车辆荷载(重载、超载车辆及冲击)作用下的软弱围岩桥隧相连段各结构或部位的多源损伤力学行为中的关键影响因素,提出了桥隧相连工程多源损伤不利力学行为与病害控制的技术措施。图80幅,表20个,参考文献216篇更多还原

【Abstract】 Abstract:Section between bridge and tunnel is a complex combination of bridge, tunnel with its surrounding rocks, the side or front slopes and the protection works nearby the entrance etc., which has a wide application both at home and abroad. It is very common on highways in mountain areas either west China or south China, which has a remarkable characteristic that all parts nearby have effects on each other causing many kinds of multiple-source damages and complex mechanical behaviors. Especially on bridge and tunnel connected project in weak surrounding rocks (such as grade IV or V surrounding rock), some key parts have much more significant effects on each other, with a characteristic that kinds of multiple-source damages, diseases and mechanical behaviors are certainly caused by coupling influences of each other. But according to the current comparatively little investigation situation at home and abroad, it is easily seen that little research has been done on multiple-source damages, mechanical behaviors or responses or diseases laws on some key parts of bridge, tunnel, surrounding rocks or soils nearby, but most of related researches or studies have little consideration of the influences among each other (bridge, tunnel and surrounding rocks) or influences caused by vehicle loads especially heavy load or overload at long time and so on.With wide application and rapid development of the bridge and tunnel connected project, more and more problems or influence factors will come across, which will not only bring new demands to its design or construction method but also bring things into consideration that some particular influences affect the operation, management or maintenance works of those existed projects.Aiming at problems mentioned above, supported by the major research project of Guizhou province (No.200904) and the transportation scientific research project of Hunan province (No.200928)-"Study on Mechanical Behavior and Control Technology of Multiple-Source Damage on Section between Bridge and Tunnel", main research work of this dissertation based on model tests and theoretical researches can be summarized as follows:(1)The characteristics, mechanism and main influence factors of multiple-source damage and mechanical behavior on bridge and tunnel connected project are discussed based on the discussion and analysis on its application and main features which cause kinds of multiple-source damages and mechanical behaviors.(2) A preliminary study has been performed on the characteristics of multiple-source damages and acting mechanism among some key parts of bridge and tunnel connected project, the characteristics of mechanical behaviors and the inducements along with its mechanism and developing law of some damages or diseases that easily seen on some parts of the bridge, tunnel or surrounding rocks during the construction or operation period on the basis of indoor model tests under multiple load cases. And some suggestions on how to control or reduce several kinds of damage or diseases have been provided according to the test results.(3) The elastoplastic damage model has been discussed together with the constitutive relation equations and the damage evolution equations, based on the summary and analysis on the damage characteristics of various materials and the detailed description of the constitutive relation of the elastoplastic model. Then several constitutive models and their detail forms of kinds of concretes, rock and soil masses which are suitable and in common use for researches on section between bridge and tunnel have been discussed along with some analysis on their characteristics and applicability, according to certain damage theories, massive research results and reference materials.(4) Some simplified numerical simulation and analysis method on multiple-source damage and mechanical behavior of bridge and tunnel connected project and a simplified calculation method on the bridge abutment with piles with the consideration of damage effects have been put forward based on theories or analysis methods such as the elastoplastic damage model, the fatigue damage accumulation model, etc. Secondary development of the numerical simulation software and the elastoplastic damage model are carried out which suitable for the damage analysis or calculation for concrete or rock and soil mass of bridge and tunnel connected project in weak surrounding rocks along, along with the implementation methods or the detailed analysis steps of each program, for the purpose of practical engineering application or uses for simplified analysis.(5) Series of models for finite element analysis on characteristics or law of multiple-source damage and its mechanical behavior of bridge and tunnel connected project have been created according to certain simplified numerical simulation and analysis method. Some specific influences along with variations of some multiple-source damages and mechanical behaviors under different vehicle load considering impact on beam, abutment with pile foundation, tunnel lining and surrounding rocks near the entrance in the bridge and tunnel connected project under circumstances of different part in different damage grade, which are summarized through systematical calculations of different finite element models and analyses of the results.(6) Systematical analyses and studies on some key influence factors of kinds of multiple-source damages and mechanical behaviors of some certain parts of in bridge and tunnel connected section in weak surrounding rocks under different kinds of vehicle loads (especially heavy load or overload ones considering impact) have been performed through systematical analyses and calculations of finite element models under different cases. And then some control technologies or reasonable treatments on how to reduce or control some certain damages, unfavorable mechanical behaviors or engineering diseases in bridge and tunnel connected projects have been investigated and and put forward according to some related theories and FEA results.更多还原