[中英文PPT]砌体结构内力分析

1、Chapter 4Structural type and static analysis method of masonry buildings1preface4.1 structural type and constitution of masonry buildings (砌体房屋结构的形式和组成)4.2 arrangement of masonry structures (砌体结构的布置)4.3 transmission of vertical load (竖向荷载的传递)4.4 static calculation schemes of masonry structures and t

2、ransfer of horizontal load (砌体结构的计算简图与水平荷载的传递)4.5 calculating method of rigid scheme structures(刚性方案结构的计算)4.6 calculating method of Elastic scheme structures （弹性方案结构的计算)4.7 calculating method of rigid-elastic scheme structures （刚弹性方案结构的计算）4.8 calculating method of a building with structure flexible

3、at the upper storey and rigid at the lower storey (上柔下刚、上刚下柔多层房屋的内力计算)4.9 calculation of internal force of basement wall (地下室墙的内力计算)4.10 worst combination of load effect (最不利荷载效应组合)2prefaceCharacteristics of unreinforced masonry structures(无筋砌体的特性)Compressive performance is higher and tensile perfor

4、mance is lower.(墙体抗压性能较好，抗拉性能较差)。Fig.4-1 cantilever member subjected to vertical and horizontal forcethe ratio of height and width of a wall is restricted (单片砌体墙高宽比受限)Constant that has relation to the distribution and transmission characteristics of lateral force and fortified intensity 为与侧向力分布和地震烈度

5、、传递特性有关的常数The conditions of no tensile stress produced in the rectangular section is (矩形截面不产生拉应力的条件)3prefaceForce acting at the outer of the plan (平面外受力) Force acting in the plan (平面内受力) Fig. 4-2 平面外和平面内受力的墙体41definition of mixed structure(“混合结构”房屋定义)： The building is made up of masonry walls or col

6、umns and floors or roof made of other materials.由砌体墙、柱和其他材料楼屋盖组成的房屋常称为“混合结构”房屋。（砖混结构房屋、砖木结构房屋）4.1 Structural type and constitution of masonry buildings5674.1 Structural type and constitution of masonry buildingsNo deformation in x direction (x向不可变形) No deformation in y direction (y向受力不对称扭转存在 ) No de

7、formation in x and y directions (x、y向均不可变形)Fig.4-4 the structure consists of plates(由板块构成的结构)2Members of the building Wall-masonry unit Column-masonry unit , reinforced concrete Floor and roof-reinforced concrete, timber84.2 Arrangement of masonry structures4.2.1 Building that load is supported by t

8、ransverse walls (横墙承重方案)4.2.2 Building that load is supported by longitudinal walls (纵墙承重方案)4.2.3 Building that load is supported by transverse and longitudinal walls (纵横墙承重方案)4.2.4 Building with framework-supporting inside(内框架承重方案)4.2.5 Supporting system is the mixture of internal frame system and

9、other systems.(混合承重体系)4.2.6 Building with framework-supporting at the bottom storey(底层框架承重体系)94.2.1 Building that load is supported by transverse wallTransmission path of the load:Load of floor and roof transverse wall foundation foundation soils(荷载的主要传递路线为： 屋（楼）面荷载横墙基础地基)characteristics：1. 横墙为承重墙，间

10、距较小（34.5m），结构整体性好，空间 刚 度大，有利于抵抗水平作用和调整地基的不均匀沉降。2. 纵墙作为围护、隔断墙，其设置门窗洞口的限制较少，纵墙 立面处理比较灵活，可保证横墙的侧向稳定。3. 楼盖的材料用量较少，但墙体的用料较多 ，施工方便。 适用于宿舍、住宅、旅馆等居住建筑和由小房间组成的 办公楼等。10Transmission path of the load:Load of floor and roof longitudinal wall foundation foundation soils荷载的主要传递路线为：屋（楼）面荷载纵墙基础地基纵墙承重体系特点：1.纵墙为承重墙，横墙

11、数量相对较少，承重墙间距一般较大，房屋的空间刚度比横墙承重体系小；纵墙上门窗洞口的大小和位置受到限制。2.横墙为自承重墙，可保证纵墙的侧向稳定和房屋的整体刚度，房屋的划分比较灵活。3.楼盖的材料用量较多，墙体的材料用量较少。适用于教学楼、图书馆、食堂、俱乐部、中小型工业厂房等单层和多层空旷房屋。 4.2.2 Building that load is supported by longitudinal wall11Transmission path of the load: longitudinal wall Load of floor and roof foundation foundati

12、on soils transverse wall 纵横墙承重体系特点：兼有横墙和纵横墙承重体系的特点，房屋平面布置比较灵活，空间刚度较好。 适用于住宅、教学楼、办公楼及医院等建筑。4.2.3 Building that load is supported by transverse and longitudinal wall12Transfer path of the load: （beam）outer wall Load of floor and roof foundationfoundation soils beam frame column4.2.4 Building with fram

13、ework-supporting inside内框架承重体系特点：1.室内空间较大，梁的跨度并不 相应增大；2.由于横墙少，房屋的空间刚度 和整体性较差；3.由于钢筋混凝土柱和砖墙的压 缩性能不同，结构易产 生不均 匀的竖向变形；4.框架和墙的变形性能相差较 大，在地震时易由于变形不协 调而破坏。134.2.5 Supporting system is the mixture of internal frame system and other systems (混合承重方案)Supporting system is the mixture of internal frame system a

14、nd other systems(内框架承重体系与其他体系相结合就成为混合承重体系)混合承重体系 144.2.6 building with framework-supporting at the bottom storey (底层框架承重体系)Transmission path of the vertical load: Load of floor and roof upper walls wall beamframe column foundation foundation soils屋（楼）面荷载 上层墙体 墙梁 框架柱 基础 地基底层框架承重体系特点： 1.底层使用空间较大，梁的尺度并

15、不 相应增大 2.由于底层墙体较少，沿房屋高度方 向，结构空间刚度将发生变化； 3.经过合理设计，可获得使用和抗震 性能较好的底层框架结构体系，实 现强柱弱梁的目标。 适用于上部住宅底层商店或车库类房屋。154.3 Transmission path of the vertical loads(竖向荷载的传递)164.3 transmission path of the vertical loads1 transmission of vertical load of floors楼面竖向荷载的传递 2 transmission of vertical load of beam end梁端竖向荷

16、载的传递Stress distribution of rigid beam较刚的梁下的反力分布Fig. 4-11 Stress distribution of flexible beam较柔的梁下的反力分布174.3 transmission path of the vertical loads2 transmission of vertical load of beam end梁端竖向荷载的传递图Stress distribution of rigid bearing block placed underneath the beam梁下加垫块时的反力分布184.3 transmission

17、path of the vertical loadsConcentrated force shall diffuse and the diffusive degree is 45.集中力向下传递时，会逐渐扩散。在设计中，一般假定扩散角为45度。集中荷载的扩散191、effective supporting length at the beam end (梁端有效支承长度)whre，hc height of the cross section of a beam f - design value of the compressive strength of masonry 各量的量纲均按N-mm

18、制计。The distance from the concentrated force at the beam end to the internal side of a wall is 0.4 time of the effective supporting length. 梁端集中荷载作用点到支座内边缘的距离：取此距离为0.4a0。4.3 Transmission path of the vertical loads204.4 static calculation schemeof masonry buildings and transmission of horizontal load

19、(砌体结构的计算简图与水平荷载的传递)4.4.1 spatial action of the buildings subjected to horizontal load 建筑物在水平荷载作用下的空间工作情况4.4.2 coefficient of the influence of spatial action 空间性能影响系数4.4.3 static calculation scheme of masonry buildings 砌体结构静力计算方案214.4.1 spatial action of the buildings subjected to horizontal load (a)

20、 wind force acting on the outer longitudinal wall 风力作用于外纵墙； (b) bending moment acting to the floor (roof) and horizontal reaction force is produced in the joints 楼(屋)盖水平方向受弯并在横墙连接处产生水平反力； (c) bending moment acting to the transverse wall due to the horizontal reaction forcehorizontal load longitudina

21、l wall floor (roof) transverse wall foundation foundation soil224.4.2 Coefficient of the influence of spatial action Spatial effect：当受到局部荷载作用时，不仅在直接受荷单元中产生内力，而且房屋的所有单元都将参加工作，并使直接受荷的单元中的内力和侧移远小于该单元单独承受相同荷载时的内力和位移。234.4.2 Coefficient of the influence of spatial action ymaxhorizontal displacement at th

22、e top of the wall of the calculated element(计算单元墙体顶部的水平位移)， ffhorizontal displacement at the top of the wall of the calculated element without the spring(该单元在无弹簧时的水平位移) coefficient of the influence of spatial action(空间性能影响系数)：Spatial effect：24When coefficient is bigger, the displacement of the build

23、ing is close to the planar rowed trusses. Spatial action of the building is weak. 值愈大，表示整体房屋的位移与平面排架的位移愈接近，即建筑物的空间性能较弱。反之，值愈小，建筑物的空间性能愈强。 4.4.2 Coefficient of the influence of spatial action 25Static calculation schemes of masonry buildings can be categorized into rigid schemes, rigid-elastic scheme

24、s and elastic schemes on the basis of their spatial behavior.rigid schemes elastic schemes rigid-elastic schemes4.4.3 Static calculation scheme of masonry buildings(我国现行的砌体结构设计规范GB50003，根据建筑物空间刚度的大小，静力计算时可划分为下列三种方案。)26Comparison of the internal force of three schemes 三种静力计算方案内力比较4.4.3 Static calcula

25、tion scheme of masonry buildings27Types of roof or floor structureRigid schemeRigid-elastic schemeElastic scheme1Reinforced concrete roof or floor of monolithic, assembled integral system and assembled purline free systems722Reinforced concrete roof of assembled purline system, light steel roof, and

26、 wood roof or floor with closely covered roof boardings483Tiled wood roof and light steel roofs36Note:The s indicated in this table denotes the spacing of transverse walls of building, its unit of length is in meter.For gable free building or building with no transverse wall at expansion joints, the

27、 static calculation scheme shall be considered as elastic scheme。Table 4-2 Coefficient of the influence of spatial action of each storey of a building4.4.3 Static calculation scheme of masonry buildings28砌体房屋静力计算方案的确定屋盖或楼盖类别刚性方案刚弹性方案弹性方案1整体式、装配整体和装配式无檩体系钢筋混凝土屋盖或钢筋混凝土楼盖s722装配式有檩体系钢筋混凝土屋盖、轻钢屋盖和有密铺望板的木

28、屋盖或木楼盖s483冷摊瓦木屋盖和石棉水泥瓦轻钢屋盖s36备注S为房屋横墙间距，其长度单位为m；对无山墙或伸缩缝处无横墙的房屋，应按弹性方案考虑。表4-2 房屋静力计算方案的确定4.4.3 Static calculation scheme of masonry buildings29刚性和刚弹性方案房屋的横墙，为保证具有足够的抗侧刚度，应同时符合下列要求： 横墙的厚度不宜小于180mm； 横墙中开有洞口时，洞口的水平截面面积不应超过横墙截面面积 的50； 单层房屋的横墙长度不宜小于其高度，多层房屋的横墙长度 不宜小于H/2 (H为横墙总高度)。Transverse wall of build

29、ing of rigid scheme and rigid-elastic scheme shall be in accordance with the following requirements: the thickness of the transverse wall should not be less than 180mm； when openings are reserved in a transverse wall, the horizontal sectional area of the opening shall not be exceed 50% of the sectio

30、nal area of the transverse wall. the length of the transverse wall of a single-storey building should not be less than its height, while for a multi-storey building, should not be less than H/2. (H denotes the total height of the transverse wall )4.4.3 Static calculation scheme of masonry buildings3

31、04.4.3 Static calculation scheme of masonry buildingsWhen the transverse wall can not meet the above-mentioned requirements simultaneously, the stiffness of the transverse wall shall be conducted for computation checking. If its maximum displacement value umaxH / 4000. the transverse wall can still

32、be assumed that of building of rigid scheme or rigid-elastic scheme.当横墙不能同时符合上述要求时，应对横墙的刚度进行验算。 如其墙顶最大水平位移值umaxH / 4000时，仍可视作刚性或刚弹性方案房屋的横墙。 314.4.3 Static calculation scheme of masonry buildings324.5 Calculation for buildings of rigid scheme (刚性方案结构的计算)4.5.1 determination of the calculation element

33、(计算单元选取)4.5.2 calculation method of single storey buildings of rigid scheme (刚性方案单层房屋)4.5.3 calculation method of multi-storey buildings of rigid scheme (刚性方案多层房屋)33calculating element: 1.walls with no openings （one meter width） 2. walls with openings（the length of the piers) （walls that bearing lar

34、ger load and with smaller cross-section). 3.when the corner section of a corner wall is subjected to vertical concentrated load, the calculation of the length of the cross-section may be conducted from the corner point and 1/3 height of the storey is taken for each side of the wall. 承受集中荷载的单元较薄弱的单元4

35、.5.1 Determination of the calculating element 墙体计算单元：1、无洞墙段（单位宽）2、有洞墙段（窗间墙之间墙段长度） （荷载较大而截面较小的墙段）3、当墙体单独承受集中荷载作用时，取2/3H34 1. Calculating element 2. Static calculation sketch (内力分析计算简图)： (1) the upper end of the wall or column is immovable hinge (墙体上端具有水平不动铰支承点)； (2) the upper end is imbedded into the

36、 foundation (墙体下端为固定端支承)。单层刚性房屋墙体计算简图屋架Nl的作用点4.5.2 the calculation of single storey buildings of rigid scheme 353Critical section of longitudinal walls of single storey buildings (单层房屋纵墙控制截面) top section of the foundation, top section and middle section of the wall 一般为基础顶面、墙顶和墙中部弯矩最大处4.5.2 the calcu

37、lation of single storey buildings of rigid scheme 364Three load effect combination should be considered including permanent load, live load and wind (考虑墙体自重、楼盖和风荷载，考虑下列三种荷载效应组合)： permanent load + wind (恒载+风载)； permanent load+ live load (恒载+屋面活载)； permanent load+ 0.85 (live load +wind ) 恒载+0.85（屋面活载+

38、风载） （当有吊车时，应与混凝土结构单层厂房相同，将吊车荷载效应参与组合）4.5.2 the calculation of single storey buildings of rigid scheme 37There are many transverse walls and the distance of them are short. Meanwhile the spatial bearing system are made up of roof , floor and longitudinal walls. The rigid of buildings are strong. The

39、static calculation scheme shall be considered as rigid scheme.4.5.3 The calculation of multi-storey buildings of rigid scheme 多层民用建筑横墙多而密，由屋盖、楼盖、纵墙等构件组成空间受力体系，房屋空间刚度较大，故大多属于刚性方案房屋。38Walls and columns under the action of vertical load, within the height of each story, can be approximately assumed as

40、vertical members, of which both ends are hinged. While under the action of horizontal load, walls and columns can be assumed as vertical continuous beam.4.5.3 The calculation of multi-storey buildings of rigid scheme under the action of vertical load(在竖向荷载作用下，上述计算单元在每层房屋中均为两端铰支的简支梁，在水平荷载作用下，如同一竖向连续梁

41、，屋盖、各层楼盖和基础均作为连续梁的支点。)竖向荷载水平荷载39（1）vertical load of each longitudinal walls (各层纵墙所承受的竖向荷载) 本层楼(屋)盖传来的竖向荷载Nl对于梁支承在墙上的情况，Nl的作用点离纵墙内边缘的尺寸为0.4a0 。其中，a0为梁的有效支承长度，取4.5.3 The calculation of multi-storey buildings of rigid scheme under the action of vertical loadBeams are supported on walls, the distance fr

42、om the bearing compression at the beam end to the internal side of a wall should be taken as 0.4 time of the effective length a0 at the beam end.40（2）the internal force of the longitudinal wall 纵墙的内力 竖向荷载作用下刚性多层房屋结构计算简图的简化 纵墙的荷载和内力4.5.3 The calculation of multi-storey buildings of rigid scheme the a

43、ction of vertical load 每层墙体控制截面: 计算单元的墙顶（II）和墙底（IIII）两个端截面，底层墙的IIII截面取为基础顶面处截面。 41 纵墙的荷载和内力4.5.3 The calculation of multi-storey buildings of rigid scheme the action of vertical load the load Nu transmitted from the upper floor 上面各层屋盖、楼盖传来的荷载Nu The self-weight of the wall of the story 本层墙体自重G。42 纵墙的

44、荷载和内力The internal force of the bottom section of the wall墙底截面内力：The internal force of the top section of the wall 墙顶截面内力：4.5.3 The calculation of multi-storey buildings of rigid scheme the action of vertical load 43Calculating element计算单元： 宽度为1.0m的墙段。Critical section： bottom of the wallEach transver

45、se wall shall be assumed as vertical members of which both ends are hinged. 每层横墙视为两端铰支的竖向构件每层构件的高度H的取值与纵墙相同；坡顶层高取为层高加山墙尖高的1/2（3） bearing transverse wall 承重横墙4.5.3 The calculation of multi-storey buildings of rigid scheme under the action of vertical load44Where the outer walls of multi-story buildin

46、g of rigid scheme meet the following requirements of wind load may not be considered in conducting static calculation: the horizontal cross sectional area of the opening does not exceed 2/3 of the whole cross sectional area. 洞口水平截面面积不超过全截面面积的2/3 the storey height and the total height do not exceed t

47、he stipulations stated in table 5.2; 层高和总高不超过表5-2的规定； the self-weight of the roof in not less than 0.8kN/m2. 屋面自重不小于0.8kN/m2。 4.5.3 The calculation of multi-storey buildings of rigid scheme under the action of horizontal load45Calculating sketch计算简图： vertical continuous beam。When the wind load has t

48、o be considered, the bent moment caused by the wind load may be calculated as per the following formula: 纵墙内最大弯矩值可近似取为：4.5.3 The calculation of multi-storey buildings of rigid scheme under the action of horizontal load464.6 Calculation for buildings of elastic scheme 弹性方案结构的计算4.6.1 calculating sketc

49、h 计算简图4.6.2 analysis of internal force 内力分析4.6.3 the static calculation of the elastic scheme buildings 弹性方案多层房屋的计算47Analysis of the wall according to the following assumptions 墙体内力分析时，按下列假定进行： (1) the upper end of the wall or column is immovable hinge and the bottom end is imbedded into the foundat

50、ion 将屋架或屋面 梁与墙体顶端的连接视为铰接，墙下端则嵌固于基础顶面； (2) the horizontal rigid of roof truss and roof beam are infinite. Under the action of the horizontal load, the lateral displacement of the top walls is same. 屋架或屋面梁的水平刚度视为无穷大，在荷载作用下，与其相连接 的两侧墙体顶端的水平侧移相等。4.6.1 The calculation of buildings of elastic scheme under

51、 the action of vertical load (single-storey buildings)48在各种荷载作用下，内力分析的步骤为： (1)先在排架顶端加上一个不动铰支座，算出不动铰支座的约束反力R及相 应的内力图。其内力计算方法同单层刚性方案房屋纵墙。(2)去除约束并把R反方向作用在排架顶端，按建筑力学的方法分析排架 内力，作内力图。(3)将上述两种内力图叠加，得到最后结果。 4.6.1 The calculation of single-storey buildings of elastic scheme under the action of vertical loadT

52、he load of the wall is the same as that of rigid scheme 墙体所承受的荷载与刚性方案房屋相同。49 多层弹性方案（hinged connection 铰接）多层房屋弹性方案在受力上不够合理。对于层高和跨度较大而又比较空旷的多层房屋，应尽量避免设计成弹性方案。 多层弹性方案（rigid connection 刚接）4.6.1 The calculation of multi-storey buildings of elastic scheme under the action of vertical load504.7 Calculation

53、 for buildings of rigid-elastic scheme 刚弹性方案结构的计算4.7.1 The calculation of buildings of rigid- elastic scheme under the action of vertical load (single-storey buildings) 刚弹性方案单层房屋的计算4.7.2 The calculation of buildings of rigid-elastic scheme under the action of vertical load (multi-storey buildings)刚弹

54、性方案多层房屋的计算4.7.3 gable 山墙514.7.1 The calculation of buildings of rigid-elastic scheme under the action of vertical load (single-storey buildings)刚弹性方案单层房屋承重纵墙 在排架柱顶加以一个弹性支座，内力分析过程如下： (1)先在排架顶端加上一个不动铰支座，算出不动铰支座的约束反力 R及相应的内力图。 (2)去除约束并把R乘以，以R反方向作用在排架顶端，求出该 情况下的内力图。 (3)将上述两种内力图叠加，即得到刚弹性方案的计算结果。52为简化计算并偏

55、于安全，规范规定，多层房屋的空间性能影响系数可按单层房屋采用（见表4-1）。刚弹性方案多层房屋的计算简图4.7.2 The calculation of buildings of rigid-elastic scheme under the action of vertical load (multi-storey buildings)53The static calculation scheme shall be assumed as rigid scheme. 山墙的内力分析按刚性方案进行。The loads acting on the gable of the single-storey

56、 buildings are compression load and wind load. The calculation method is the same as bearing longitudinal wall of the rigid scheme. 单层建筑物的山墙承受内侧屋盖传来的偏心压力以及水平风荷载。其内力计算方法与刚性方案房屋的承重纵墙相同。the outer transverse wall of the multi-storey buildings need not to be analyzed. 多层建筑物的山墙一般不必进行内力分析。 the thickness of

57、 the gable should be decided as per the following requirements:其厚度按下述两个因素决定： the same thickness as the internal transverse wall 与相应内横墙相同； meet the requirements of insulation hot heat preservation and insulation对外墙的保暖、隔热要求。4.7.3 gable (山墙)544.8 Calculation method for buildings of flexible at the uppe

58、r storey and rigid at the lower storey scheme 上柔下刚方案结构的计算4.8.1 上柔下刚多层房屋的内力计算4.8.2 上刚下柔多层房屋的内力计算554.8.1 calculation of buildings of flexible at the upper storey and rigid at the lower storey scheme structure(上柔下刚多层房屋的内力计算)适用条件： 房屋顶层横墙间距较大，只能满足刚弹性方案的要求； 房屋下面各层的横墙间距可满足刚性方案的要求。计算方法： the top storey can b

59、e calculated as single-storey rigid-elastic scheme building 顶层可近似按单层刚弹性方案房屋进行分析； the lower storey can be calculated as rigid scheme building 下面各层仍按刚性方案进行计算564.8.2 the calculation method of rigid at the upper storey and flexible at the lower storey scheme structure(上刚下柔多层房屋的内力计算)上刚下柔多层房屋的计算适用条件： 房屋上面

60、各层的横墙间距可满足刚性方案的要求； 房屋底层横墙间距较大，只能满足刚弹性方案的要求。计算方法： the top storey can be calculated as rigid scheme building 上面各层仍按刚性方案进行计算； the bottom storey can be calculated as wall beam framework bearing 考虑水平作用造成的倾覆力矩，底层可按框支墙梁结构进行分析设计；574.9 calculation of internal force of basement walls 地下室墙的内力计算4.9.1 calculatin