砌体结构教学楼抗震加固设计计算方法研究

发布时间：2018-04-17 12:27

本文选题：中小教学楼 + 抗震　；参考：《长沙理工大学》2015年硕士论文

【摘要】：我国存在大量的砖混结构中小教学楼,历经数次地震表明,若教学楼这种建筑没有合理的抗震设计,极容易倒塌和造成人员伤亡。因此,提高对中小学教学楼的重视程度,加强中小学教学楼抗震是当今社会的重中之重。砖混结构中小教学楼在地震中倒塌率很高,对于其倒塌原因的分析我们往往忽略了窗间墙的影响,只考虑了平面内的地震作用力。窗间墙在地震作用下是易倒塌墙,砖混结构中小教学楼大多采取纵横混合承重体系,它实际上是由无筋砌体纵向窗间墙与钢筋混凝土进深梁形成的“框架”以及横向砌体“剪力墙”组成的“框架-剪力墙”结构。设计中,这种侧向刚度很小的“框架”受到忽视,然而大震时,砌体剪力墙开裂,楼盖水平位移大大增加,砌体纵向窗间墙平面外水平位移大大增加窗间墙倒塌。通过钢筋网水泥砂浆对砖砌横墙和窗间墙进行加固,加固后的横墙、窗间墙就会形成组合砌体墙、组合砌体柱。对比混凝土框架-剪力墙结构,本文提出了采用“组合砌体框架-剪力墙”计算方法对砖混结构中小教学进行加固计算。“组合砌体框架-剪力墙”计算方法主要包括三大块:内力计算、承载力验算、位移验算。一、内力计算。结构的内力分析和混凝土框架-剪力墙计算方法类似,但区别主要是体现在用钢筋网水泥砂浆加固的组合砌体墙、组合砌体柱与混凝土剪力墙、混凝土柱上,包括刚度参数的计算、内力的调整、内力的组合等。二、承载力验算。承载力验算包括组合墙抗剪承载力验算和组合柱受压承载力验算。文中提出的组合墙的抗剪承载力计算公式充分考了虑砖墙高宽比、轴压比、面层砂浆强度、厚度、钢筋强度、配筋率等的共同影响,弥补了现有组合墙抗剪承载力计算公式得不足。文中的组合柱承载力计算方法是采用砌体结构设计规范组合砖砌体偏心受压构件承载力的计算公式。三、位移验算。“组合砌体框架-剪力墙”计算方法对于位移的验算包括多遇地震下和罕遇地震下两部分。多遇地震的位移计算与混凝土框架-剪力墙计算方法类似,其变形限值取抗震规范中的1/1000。罕遇地震的变形验算同样是采用混凝土框架-剪力墙的计算方法,但其变形限值是通过对纯砌体结构下窗间墙的最大容许位移计算得到,采用南加州结构工程师协会提出的砌体的层间容许变形公式得到,其变形限值为1/150。对于提出的“组合砌体框架-剪力墙”计算方法,本文还进行了工程实例分析。通过“加固前无筋砌体计算方法”、“加固后传统方法计算方法”、“组合砌体框架-剪力墙计算方法”三种计算方法在实例中得到的计算结果,得到组合砌体框架-剪力墙计算方法能够能完整的验算结构在加固后地震作用的每个阶段的受力和变形的优点。总的来说,本文提出的“组合砌体框架-剪力墙”计算方法为砖混结构中小教学楼抗震加固计算提供了一种新的途径。
[Abstract]:China has a large number of small and medium-sized brick concrete structure teaching building, after several earthquakes show that, if the teaching building construction without reasonable seismic design, very easy to collapse and casualties. Therefore, to improve the degree of attention to elementary and middle school building, teaching building seismic strengthening of primary and secondary school is the priority among priorities in today's society and teaching. Floor brick structure collapsed at a high rate in the earthquake, for its analysis of the causes of the collapse of the US often ignored the effect of wall between windows, only consider the seismic force in the plane. The wall between windows under earthquake is easy to collapse of the wall, brick and concrete structure of small and medium-sized buildings mostly adopts the combined load bearing system, it is actually the masonry longitudinal wall between windows and reinforced concrete deep beams formed "framework" and "horizontal masonry shear wall" composed of "frame shear wall structure. In the design, the lateral stiffness is very small "Framework" has been neglected, however large earthquakes, the cracking of the masonry shear wall, floor horizontal displacement increases greatly, masonry longitudinal wall between windows out of plane displacement greatly increase the wall between windows collapsed. Through the brick wall and cross wall between windows of cement mortar reinforced with steel mesh reinforcement, transverse wall reinforcement, the wall between windows it will form a composite masonry wall, composite masonry columns. Concrete frame shear wall structure, this paper proposes a reinforcement calculation method of combined masonry frame shear wall of brick concrete structure teaching. "Small and medium-sized composite masonry frame shear wall calculation method mainly includes three parts: internal force calculation, bearing capacity checking. Displacement calculation. A calculation of internal force. The internal force analysis and concrete frame - shear wall structure calculation method is similar, but the difference is mainly reflected in the strengthening with reinforced mortar composite masonry wall, masonry column combined with coagulation Shear wall, concrete column, including the calculation of stiffness, internal force adjustment, internal force combination. Two, bearing capacity. Capacity checking including checking the bearing capacity of composite columns and checking the bearing capacity of composite shear wall composite wall is proposed in this paper. The calculation formula of the shear strength of the full test consider the wall height width ratio, axial compression ratio, mortar strength, surface layer thickness, steel strength, influence of reinforcement ratio, make up the existing composite wall shear strength calculation formula of the shortage. The bearing capacity of composite columns is calculated by the bearing capacity of composite brick masonry subjected to eccentric component calculation the formula of masonry structure design. Three, displacement calculation. "Composite masonry frame shear wall calculation method for displacement calculation including under frequent earthquake and rare earthquake of two. Calculate the displacement calculation and concrete frame - shear wall earthquake A similar method, the deformation deformation limit value of seismic code in 1/1000. is also a rare earthquake by using the calculation method of concrete frame shear wall, the deformation limit is obtained by the maximum allowable displacement of wall between windows pure masonry structure calculation, the masonry proposedsouth California Structural Engineers Association of the layer between the allowable deformation formula, the deformation limit of 1/150. for the "composite masonry frame shear wall" method, this paper through the analysis of engineering examples. "Before the reinforcement of masonry calculation method, calculation method of reinforcement after the traditional method, the composite masonry frame shear wall calculation method" three kinds of calculation methods in the case of the calculation results, a calculation method of composite masonry frame shear wall structure can check to complete each stage in strengthening earthquake force and change The shape of the advantages. In general, the proposed "composite masonry frame shear wall calculation method provides a new way for the calculation of small brick concrete structure teaching building seismic strengthening.

【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU364;TU352.11

【参考文献】