[中英文PPT]砌體結構內力分析

1、Chapter 4Structural type and static analysis method of masonry buildings1preface4.1 structural type and constitution of masonry buildings (砌體房屋結構的形式和組成)4.2 arrangement of masonry structures (砌體結構的布置)4.3 transmission of vertical load (豎向荷載的傳遞)4.4 static calculation schemes of masonry structures and t

2、ransfer of horizontal load (砌體結構的計算簡圖與水平荷載的傳遞)4.5 calculating method of rigid scheme structures(剛性方案結構的計算)4.6 calculating method of Elastic scheme structures （彈性方案結構的計算)4.7 calculating method of rigid-elastic scheme structures （剛彈性方案結構的計算）4.8 calculating method of a building with structure flexible

3、at the upper storey and rigid at the lower storey (上柔下剛、上剛下柔多層房屋的內力計算)4.9 calculation of internal force of basement wall (地下室墻的內力計算)4.10 worst combination of load effect (最不利荷載效應組合)2prefaceCharacteristics of unreinforced masonry structures(無筋砌體的特性)Compressive performance is higher and tensile perfor

4、mance is lower.(墻體抗壓性能較好，抗拉性能較差)。Fig.4-1 cantilever member subjected to vertical and horizontal forcethe ratio of height and width of a wall is restricted (單片砌體墻高寬比受限)Constant that has relation to the distribution and transmission characteristics of lateral force and fortified intensity 為與側向力分布和地震烈度

5、、傳遞特性有關的常數(shù)The conditions of no tensile stress produced in the rectangular section is (矩形截面不產(chǎn)生拉應力的條件)3prefaceForce acting at the outer of the plan (平面外受力) Force acting in the plan (平面內受力) Fig. 4-2 平面外和平面內受力的墻體41definition of mixed structure(“混合結構”房屋定義)： The building is made up of masonry walls or col

6、umns and floors or roof made of other materials.由砌體墻、柱和其他材料樓屋蓋組成的房屋常稱為“混合結構”房屋。（磚混結構房屋、磚木結構房屋）4.1 Structural type and constitution of masonry buildings5674.1 Structural type and constitution of masonry buildingsNo deformation in x direction (x向不可變形) No deformation in y direction (y向受力不對稱扭轉存在 ) No de

7、formation in x and y directions (x、y向均不可變形)Fig.4-4 the structure consists of plates(由板塊構成的結構)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 (橫墻承重方案)4.2.2 Building that load is supported by longitudinal walls (縱墻承重方案)4.2.3 Building that load is supported by transverse and longitudinal walls (縱橫墻承重方案)4.2.4 Building with framework-supporting inside(內框架承重方案)4.2.5 Supporting system is the mixture of internal frame system and

9、other systems.(混合承重體系)4.2.6 Building with framework-supporting at the bottom storey(底層框架承重體系)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(荷載的主要傳遞路線為： 屋（樓）面荷載橫墻基礎地基)characteristics：1. 橫墻為承重墻，間

10、距較?。?4.5m），結構整體性好，空間 剛 度大，有利于抵抗水平作用和調整地基的不均勻沉降。2. 縱墻作為圍護、隔斷墻，其設置門窗洞口的限制較少，縱墻 立面處理比較靈活，可保證橫墻的側向穩(wěn)定。3. 樓蓋的材料用量較少，但墻體的用料較多 ，施工方便。 適用于宿舍、住宅、旅館等居住建筑和由小房間組成的 辦公樓等。10Transmission path of the load:Load of floor and roof longitudinal wall foundation foundation soils荷載的主要傳遞路線為：屋（樓）面荷載縱墻基礎地基縱墻承重體系特點：1.縱墻為承重墻，橫墻

11、數(shù)量相對較少，承重墻間距一般較大，房屋的空間剛度比橫墻承重體系??；縱墻上門窗洞口的大小和位置受到限制。2.橫墻為自承重墻，可保證縱墻的側向穩(wěn)定和房屋的整體剛度，房屋的劃分比較靈活。3.樓蓋的材料用量較多，墻體的材料用量較少。適用于教學樓、圖書館、食堂、俱樂部、中小型工業(yè)廠房等單層和多層空曠房屋。 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 縱橫墻承重體系特點：兼有橫墻和縱橫墻承重體系的特點，房屋平面布置比較靈活，空間剛度較好。 適用于住宅、教學樓、辦公樓及醫(yī)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內框架承重體系特點：1.室內空間較大，梁的跨度并不 相應增大；2.由于橫墻少，房屋的空間剛度 和整體性較差；3.由于鋼筋混凝土柱和磚墻的壓 縮性能不同，結構易產(chǎn) 生不均 勻的豎向變形；4.框架和墻的變形性能相差較 大，在地震時易由于變形不協(xié) 調而破壞。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(內框架承重體系與其他體系相結合就成為混合承重體系)混合承重體系 144.2.6 building with framework-supporting at the bottom storey (底層框架承重體系)Transmission path of the vertical load: Load of floor and roof upper walls wall beamframe column foundation foundation soils屋（樓）面荷載 上層墻體 墻梁 框架柱 基礎 地基底層框架承重體系特點： 1.底層使用空間較大，梁的尺度并

15、不 相應增大 2.由于底層墻體較少，沿房屋高度方 向，結構空間剛度將發(fā)生變化； 3.經(jīng)過合理設計，可獲得使用和抗震 性能較好的底層框架結構體系，實 現(xiàn)強柱弱梁的目標。 適用于上部住宅底層商店或車庫類房屋。154.3 Transmission path of the vertical loads(豎向荷載的傳遞)164.3 transmission path of the vertical loads1 transmission of vertical load of floors樓面豎向荷載的傳遞 2 transmission of vertical load of beam end梁端豎向荷

16、載的傳遞Stress distribution of rigid beam較剛的梁下的反力分布Fig. 4-11 Stress distribution of flexible beam較柔的梁下的反力分布174.3 transmission path of the vertical loads2 transmission of vertical load of beam end梁端豎向荷載的傳遞圖Stress distribution of rigid bearing block placed underneath the beam梁下加墊塊時的反力分布184.3 transmission

17、path of the vertical loadsConcentrated force shall diffuse and the diffusive degree is 45.集中力向下傳遞時，會逐漸擴散。在設計中，一般假定擴散角為45度。集中荷載的擴散191、effective supporting length at the beam end (梁端有效支承長度)whre，hc height of the cross section of a beam f - design value of the compressive strength of masonry 各量的量綱均按N-mm

18、制計。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. 梁端集中荷載作用點到支座內邊緣的距離：取此距離為0.4a0。4.3 Transmission path of the vertical loads204.4 static calculation schemeof masonry buildings and transmission of horizontal load

19、(砌體結構的計算簡圖與水平荷載的傳遞)4.4.1 spatial action of the buildings subjected to horizontal load 建筑物在水平荷載作用下的空間工作情況4.4.2 coefficient of the influence of spatial action 空間性能影響系數(shù)4.4.3 static calculation scheme of masonry buildings 砌體結構靜力計算方案214.4.1 spatial action of the buildings subjected to horizontal load (a)

20、 wind force acting on the outer longitudinal wall 風力作用于外縱墻； (b) bending moment acting to the floor (roof) and horizontal reaction force is produced in the joints 樓(屋)蓋水平方向受彎并在橫墻連接處產(chǎn)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：當受到局部荷載作用時，不僅在直接受荷單元中產(chǎn)生內力，而且房屋的所有單元都將參加工作，并使直接受荷的單元中的內力和側移遠小于該單元單獨承受相同荷載時的內力和位移。234.4.2 Coefficient of the influence of spatial action ymaxhorizontal displacement at th

22、e top of the wall of the calculated element(計算單元墻體頂部的水平位移)， ffhorizontal displacement at the top of the wall of the calculated element without the spring(該單元在無彈簧時的水平位移) coefficient of the influence of spatial action(空間性能影響系數(shù))：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，表示整體房屋的位移與平面排架的位移愈接近，即建筑物的空間性能較弱。反之，值愈小，建筑物的空間性能愈強。 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(我國現(xiàn)行的砌體結構設計規(guī)范GB50003，根據(jù)建筑物空間剛度的大小，靜力計算時可劃分為下列三種方案。)26Comparison of the internal force of three schemes 三種靜力計算方案內力比較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砌體房屋靜力計算方案的確定屋蓋或樓蓋類別剛性方案剛彈性方案彈性方案1整體式、裝配整體和裝配式無檁體系鋼筋混凝土屋蓋或鋼筋混凝土樓蓋s722裝配式有檁體系鋼筋混凝土屋蓋、輕鋼屋蓋和有密鋪望板的木

28、屋蓋或木樓蓋s483冷攤瓦木屋蓋和石棉水泥瓦輕鋼屋蓋s36備注S為房屋橫墻間距，其長度單位為m；對無山墻或伸縮縫處無橫墻的房屋，應按彈性方案考慮。表4-2 房屋靜力計算方案的確定4.4.3 Static calculation scheme of masonry buildings29剛性和剛彈性方案房屋的橫墻，為保證具有足夠的抗側剛度，應同時符合下列要求： 橫墻的厚度不宜小于180mm； 橫墻中開有洞口時，洞口的水平截面面積不應超過橫墻截面面積 的50； 單層房屋的橫墻長度不宜小于其高度，多層房屋的橫墻長度 不宜小于H/2 (H為橫墻總高度)。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.當橫墻不能同時符合上述要求時，應對橫墻的剛度進行驗算。 如其墻頂最大水平位移值umaxH / 4000時，仍可視作剛性或剛彈性方案房屋的橫墻。 314.4.3 Static calculation scheme of masonry buildings324.5 Calculation for buildings of rigid scheme (剛性方案結構的計算)4.5.1 determination of the calculation element

33、(計算單元選取)4.5.2 calculation method of single storey buildings of rigid scheme (剛性方案單層房屋)4.5.3 calculation method of multi-storey buildings of rigid scheme (剛性方案多層房屋)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. 承受集中荷載的單元較薄弱的單元4

35、.5.1 Determination of the calculating element 墻體計算單元：1、無洞墻段（單位寬）2、有洞墻段（窗間墻之間墻段長度） （荷載較大而截面較小的墻段）3、當墻體單獨承受集中荷載作用時，取2/3H34 1. Calculating element 2. Static calculation sketch (內力分析計算簡圖)： (1) the upper end of the wall or column is immovable hinge (墻體上端具有水平不動鉸支承點)； (2) the upper end is imbedded into the

36、 foundation (墻體下端為固定端支承)。單層剛性房屋墻體計算簡圖屋架Nl的作用點4.5.2 the calculation of single storey buildings of rigid scheme 353Critical section of longitudinal walls of single storey buildings (單層房屋縱墻控制截面) top section of the foundation, top section and middle section of the wall 一般為基礎頂面、墻頂和墻中部彎矩最大處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 (考慮墻體自重、樓蓋和風荷載，考慮下列三種荷載效應組合)： permanent load + wind (恒載+風載)； permanent load+ live load (恒載+屋面活載)； permanent load+ 0.85 (live load +wind ) 恒載+0.85（屋面活載+

38、風載） （當有吊車時，應與混凝土結構單層廠房相同，將吊車荷載效應參與組合）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 多層民用建筑橫墻多而密，由屋蓋、樓蓋、縱墻等構件組成空間受力體系，房屋空間剛度較大，故大多屬于剛性方案房屋。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(在豎向荷載作用下，上述計算單元在每層房屋中均為兩端鉸支的簡支梁，在水平荷載作用下，如同一豎向連續(xù)梁

41、，屋蓋、各層樓蓋和基礎均作為連續(xù)梁的支點。)豎向荷載水平荷載39（1）vertical load of each longitudinal walls (各層縱墻所承受的豎向荷載) 本層樓(屋)蓋傳來的豎向荷載Nl對于梁支承在墻上的情況，Nl的作用點離縱墻內邊緣的尺寸為0.4a0 。其中，a0為梁的有效支承長度，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 縱墻的內力 豎向荷載作用下剛性多層房屋結構計算簡圖的簡化 縱墻的荷載和內力4.5.3 The calculation of multi-storey buildings of rigid scheme the a

43、ction of vertical load 每層墻體控制截面: 計算單元的墻頂（II）和墻底（IIII）兩個端截面，底層墻的IIII截面取為基礎頂面處截面。 41 縱墻的荷載和內力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 上面各層屋蓋、樓蓋傳來的荷載Nu The self-weight of the wall of the story 本層墻體自重G。42 縱墻的

44、荷載和內力The internal force of the bottom section of the wall墻底截面內力：The internal force of the top section of the wall 墻頂截面內力：4.5.3 The calculation of multi-storey buildings of rigid scheme the action of vertical load 43Calculating element計算單元： 寬度為1.0m的墻段。Critical section： bottom of the wallEach transver

45、se wall shall be assumed as vertical members of which both ends are hinged. 每層橫墻視為兩端鉸支的豎向構件每層構件的高度H的取值與縱墻相同；坡頂層高取為層高加山墻尖高的1/2（3） bearing transverse wall 承重橫墻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. 洞口水平截面面積不超過全截面面積的2/3 the storey height and the total height do not exceed t

47、he stipulations stated in table 5.2; 層高和總高不超過表5-2的規(guī)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計算簡圖： 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: 縱墻內最大彎矩值可近似取為：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 彈性方案結構的計算4.6.1 calculating sketc

49、h 計算簡圖4.6.2 analysis of internal force 內力分析4.6.3 the static calculation of the elastic scheme buildings 彈性方案多層房屋的計算47Analysis of the wall according to the following assumptions 墻體內力分析時，按下列假定進行： (1) the upper end of the wall or column is immovable hinge and the bottom end is imbedded into the foundat

50、ion 將屋架或屋面 梁與墻體頂端的連接視為鉸接，墻下端則嵌固于基礎頂面； (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剛度視為無窮大，在荷載作用下，與其相連接 的兩側墻體頂端的水平側移相等。4.6.1 The calculation of buildings of elastic scheme under

51、 the action of vertical load (single-storey buildings)48在各種荷載作用下，內力分析的步驟為： (1)先在排架頂端加上一個不動鉸支座，算出不動鉸支座的約束反力R及相 應的內力圖。其內力計算方法同單層剛性方案房屋縱墻。(2)去除約束并把R反方向作用在排架頂端，按建筑力學的方法分析排架 內力，作內力圖。(3)將上述兩種內力圖疊加，得到最后結果。 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 墻體所承受的荷載與剛性方案房屋相同。49 多層彈性方案（hinged connection 鉸接）多層房屋彈性方案在受力上不夠合理。對于層高和跨度較大而又比較空曠的多層房屋，應盡量避免設計成彈性方案。 多層彈性方案（rigid connection 剛接）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 剛彈性方案結構的計算4.7.1 The calculation of buildings of rigid- elastic scheme under the action of vertical load (single-storey buildings) 剛彈性方案單層房屋的計算4.7.2 The calculation of buildings of rigid-elastic scheme under the action of vertical load (multi-storey buildings)剛彈

54、性方案多層房屋的計算4.7.3 gable 山墻514.7.1 The calculation of buildings of rigid-elastic scheme under the action of vertical load (single-storey buildings)剛彈性方案單層房屋承重縱墻 在排架柱頂加以一個彈性支座，內力分析過程如下： (1)先在排架頂端加上一個不動鉸支座，算出不動鉸支座的約束反力 R及相應的內力圖。 (2)去除約束并把R乘以，以R反方向作用在排架頂端，求出該 情況下的內力圖。 (3)將上述兩種內力圖疊加，即得到剛彈性方案的計算結果。52為簡化計算并偏

55、于安全，規(guī)范規(guī)定，多層房屋的空間性能影響系數(shù)可按單層房屋采用（見表4-1）。剛彈性方案多層房屋的計算簡圖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. 山墻的內力分析按剛性方案進行。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. 單層建筑物的山墻承受內側屋蓋傳來的偏心壓力以及水平風荷載。其內力計算方法與剛性方案房屋的承重縱墻相同。the outer transverse wall of the multi-storey buildings need not to be analyzed. 多層建筑物的山墻一般不必進行內力分析。 the thickness of

57、 the gable should be decided as per the following requirements:其厚度按下述兩個因素決定： the same thickness as the internal transverse wall 與相應內橫墻相同； meet the requirements of insulation hot heat preservation and insulation對外墻的保暖、隔熱要求。4.7.3 gable (山墻)544.8 Calculation method for buildings of flexible at the uppe

58、r storey and rigid at the lower storey scheme 上柔下剛方案結構的計算4.8.1 上柔下剛多層房屋的內力計算4.8.2 上剛下柔多層房屋的內力計算554.8.1 calculation of buildings of flexible at the upper storey and rigid at the lower storey scheme structure(上柔下剛多層房屋的內力計算)適用條件： 房屋頂層橫墻間距較大，只能滿足剛彈性方案的要求； 房屋下面各層的橫墻間距可滿足剛性方案的要求。計算方法： the top storey can b

59、e calculated as single-storey rigid-elastic scheme building 頂層可近似按單層剛彈性方案房屋進行分析； the lower storey can be calculated as rigid scheme building 下面各層仍按剛性方案進行計算564.8.2 the calculation method of rigid at the upper storey and flexible at the lower storey scheme structure(上剛下柔多層房屋的內力計算)上剛下柔多層房屋的計算適用條件： 房屋上面

60、各層的橫墻間距可滿足剛性方案的要求； 房屋底層橫墻間距較大，只能滿足剛彈性方案的要求。計算方法： the top storey can be calculated as rigid scheme building 上面各層仍按剛性方案進行計算； the bottom storey can be calculated as wall beam framework bearing 考慮水平作用造成的傾覆力矩，底層可按框支墻梁結構進行分析設計；574.9 calculation of internal force of basement walls 地下室墻的內力計算4.9.1 calculatin