李明慧的答辩信息:

Document Sample
李明慧的答辩信息: Powered By Docstoc
					                    李其林的答辩信息:


答 辩 人:李其林

中文题目: 八一大桥病害分析及其加固研究

英文题目 The Damage Analysis and Strengthening Research

          of Bayi Bridge

指导老师:李之达

答辩组成员名单:

   主席:张开银

   委员:

           教   授 杨平

           教   授 张少雄

           副教授 周增国

           副教授 向木生

   秘书:张嵘峰

      讲    师

答辩时间:2010.5.16,星期日 下午 2:00

答辩地点:结构系二楼会议室
                  摘   要

  早在 50、60 年代,我国就建造了许多 T 型梁桥,由于结构简单,安装方便
等特点,这种桥型对改善我国公路交通起到了重要作用。但是,随着交通运输的
发展,交通量越来越大,车辆荷载不断增加,以及随着运营年限的增加,T 型梁
也暴露出了一些问题,由于翼板厚度远小于梁高,当按铰接考虑梁的横向连接时,
由于翼板相接处的结构高度与梁高相差太大,其铰接作用很难实现,且未设置足
够的横向连系,从而在翼板连接处造成损坏;按刚接考虑梁的横向连接时,如果
横梁数量设置不够,也形不成横向刚性连接,实际受力状态与理论不符,会形成
单梁受力过大而损坏,当横梁本身抗力较弱时,也极易由于承受较大的横向弯曲
力的作用而损坏,桥梁承载能力逐年降低。特别是以前修建的桥梁,设计标准低,
承载力已不能适应交通发展的需要;而且钢筋混凝土 T 型梁桥随着使用年限的增
长,加之养护的不及时,自然就会出现混凝土的表面碳化、裂缝加大、表面破损、
雨水侵入、钢筋锈蚀等一系列问题,最终都会导致桥梁的承载力下降,出现病害,
成为病桥、危桥,严重者甚至造成桥梁垮塌,一定程度上制约了国民经济的发展。
  笔者查阅了大量文献,对所研究领域的国内外研究状况及其进展有较全面的
了解。在此基础上,以孝感市八一大桥为工程背景,对八一大桥存在的病害进行
分析及其加固进行研究。主要进行了如下工作:
  (1)首先按传统计算方法验算主梁承担的设计荷载,分析该桥梁裂缝产生
的主要原因, 并提出三种增强装配式 T 梁桥横向联系的加固方案;
  方案一:横隔板方案,对损坏严重的横隔板进行更换,对焊接质量有问题的
钢筋钢板补焊;
  方案二:叠合梁方案,凿除原有桥面铺装,重新布置钢筋网,现浇 15cm 厚
混凝土,做成整体式桥面板,在T梁梁顶隔一定间距植入钢筋,与桥面板的钢筋
焊接起来,使得桥面板与主梁共同受力、协调变形。
  方案三:T 转箱方案,在 T 型梁下方粘贴一层 6mm 厚的钢板,使 T 梁腹板底
部封闭,形成钢板-混凝土组合箱形截面。
  (2)利用有限元软件针对三种方案分别建模,对大桥主要结构部位进行力
学分析;计算分析表明,钢筋混凝土简支 T 梁桥在主梁承载能力满足要求的情况
下,桥面纵向裂缝的产生主要由于中横隔板的破坏后桥梁在超载车辆作用下导致
T梁翼缘板横向拉应力过大和各T梁在车载作用下变形不协调。
  (3)对三者计算结果进行对比,然后以此为基础进行桥梁加固设计;结果
表明,采用植筋技术,更换桥面铺装层同时加固横隔板的加固方案与单纯加固横
隔板的方案相比,前者不仅在力学指标上更优秀,同时更方便施工,也更经济合
理。
  论文工作对旧桥改造设计有一定指导意义。


关键词:旧桥加固;T 梁桥;加固设计;横隔板;横向联系;桥面铺装受力;T
转箱
                                    Abstract


      Back in the 1950s and 1960s, China built many T-beam bridge, as simple
structure, ease of installation, and other characteristics, the type of the bridge to
improve road traffic in China has played an important role. However, as the
development of transport, traffic volume increasing, the increasing load of vehicles, as
well as the increase in life as carriers, T-beam also exposed some problems, because
WING PLATES high beam thickness is much smaller than that if Articulated consider
horizontal beam connection, as WING PLATES connecting the structure of the beam
height and high much difference, the role hinged be very difficult to achieve and does
not provide adequate lateral links, resulting in damage to the connecting WING
PLATES; by has just consider the horizontal beam connected, and if the number of
beams not installed, do not form a horizontal rigid connection, the actual state of the
theory inconsistent with the will of a single beam by too much damage, when their
resistance is weak beam, but also bear more vulnerable because of the lateral bending
of the role of damage to a bridge carrying capacity reduced with each passing year.
Especially before the construction of the bridge, lower design standards, the
development of transport capacity has been unable to meet the needs and reinforced
concrete T-beam bridge with the use of the growth period, and the conservation of not
timely, there will be natural carbonation of concrete surface, Cracks up, the surface
broken, rainwater intrusion, a series of issues such as steel corrosion, the bridge will
eventually lead to decreased capacity, a disease, a disease Bridge, Bridge, or even
serious bridge collapsed, to a certain extent, this has hampered the national economy
development.
   In this paper, The author has looked up large amount of information, has been
aware of what be studied the field home and abroad studies situation. Here takes the
Bayi bridge of Xiao Gan City as project background on the basis, carry out analysis
and their strengthening on the disease that exists in the bridge studies.the auther has
been in progress mainly working as follows:
      1. The primo pushes down the design load that reckoning checking calculation
main beam bears , analyses the main cause owing a bridge rift creation, and brings
forward two kinds possible strengthening schemes by traditional method ; Scheme
one: Transverse diaphragm scheme , the replacement being in progress to damaging
transverse diaphragm, correct problematic reinforced bar of welding quality steel
plate repairing welding Scheme two: The scheme chisels the bridge face ply except
that original bridge floor shop installing , arranging the reinforced bar net again ,
deposit thickness of 15 cms concrete now , make up into the dyadic overall bridge
face ply, plant certan steel by certain spacing extremely on the top of the T-shape
beams, the reinforced bar with bridge face ply welds feasible bridge face ply and main
beam accept a force , harmonize deformation commonly.
      2. Making use of the finite element software of Ansys specifically for three kinds
schemes building a model respectively , location carrying out mechanics on main
structure of bridge; The analysis secretly scheming against indicates vehicle , the
bridge is in under simple armoured concrete branch T-shape beamsbridge condition
satisfying call for in main beam load support capability, in overloading a vehicle
leading to T beam wing predestined relationship board under the effect have pulled
strain preparing every T beam greatly transversely after bridge floor direction rift
creation is main since being hit by transverse diaphragm destroying be loaded with
effect lower deformation out of tune.
      3. Calculation bear fruit carries out contrast on the both , consolidates and then
design take this as the basis carry out a bridge; Finally indicate a technology , adopt to
establish a tendon, the scheme changing the bridge floor laying the baffle plate
holding tier of strengthening schemes with and consolidating a horizontal stroke
exclusively is compared with each other, not only, the former more excellent , goes to
the lavatory at the same time more on Mechanics index to be under construction, also
more economical reasonableness.
      This paper has some guide with the reforming design to old bridge and
construction.

Keywords: old bridge strengthening; T-shape beam bridge; strengthening design;
diapharagm; transverse distribution coefficient; bridge deck pavement; section
coversion

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:1
posted:7/1/2012
language:
pages:5