单向板肋梁楼盖设计例题.doc

单向板肋梁楼盖设计例题【例题1.1】设计图1．23所示的单向板肋梁楼盖，板和次梁按调幅法设计，主梁按弹性理论设计楼面活荷载标准值为4．5kN／m2，混凝土强度等级为C20解】一、板的设计(一)板的计算跨度及荷载(图1．24)　　拟定板厚80mm，次梁高h=(1／12--1／18)l=(1／12-1／18)×5500=460～305，取h=450mm，次梁宽b=(1／2～1／3)h=(1／2～1／3)×450=225～150，取b=200mm图2.23　单向板肋梁楼盖例题的施工图因板两端与梁固接，按调幅法计算故板的计算跨度取净跨　　边跨　　中间跨　　活荷载设计　　恒荷载标准值：20mm厚砂浆抹面 ，80mm厚现浇板　　天棚粉刷，　　恒荷载设计值：，(二)计算截面的弯矩设计值及配筋　　取板的计算宽度为1lm，按端支座是固定的五跨等跨连续板计算中间区格板带中的中间区格板和的四个周边都是与梁连接的，考虑拱作用，将弯矩设计值降低20％，边区格板以及中间区格板带中的边区格板 的弯矩则不降低采用HPB235级钢筋，采用分离式配筋，弯矩及配筋计算见表1.8，配筋见图1.22为减少板面负钢筋(包括构造的)在施工中被踩下，故都采用。

表1．8　连续单向板按调幅法设计的截面弯矩及配筋计算表　边区格板带B1、B2、B3中间区格板带B4、B5、B6截 面端支座边跨跨中第一内支座中间跨中中间支座端支座边跨跨中第一内支座中间跨中中间支座计算跨度(m)1.851.852.02.02.01.851.852.02.02.0弯矩系数amb-1／161／14-1／111／16-1／l4-1／241/141／111／16-1／14弯矩(kN·m)-1.912.19-3.252.24-2.56-1.282.19-2.61.79-2.05As(mm2)156179270195210103179214157167配筋φ8@250φ6@150φ8@180φ8@140φ8@220φ8@250φ6@150φ8@220φ6@180φ8@250钢筋有效面积(mm2)201189279202229201189229157201注：为了减少施工中板面负钢筋被踩下，故采用08．且配筋量适当放宽二、次梁的设计(L3.1)(一)次梁的计算跨度及荷载(图1．25)图1.25　计算简图1.计算跨度　　主梁高h一(1／8～1／14)z一(1／8～1／14)×6600—830～470mm，取主梁截面650mm×250mm。

　　因次梁两端与主梁或柱连接，按调幅法计算，故次梁的计算跨度取净跨度：　　边跨　　中间跨2.荷载　　恒荷载　　活荷载　　(二)次梁正截面受弯承载力计算　　因跨度相差小于10％，故次梁按端支座是固定的五跨等截面等跨连续梁计算(表1．9)承受正弯矩的跨中截面按的T形截面计算表1．9　次梁正截面受弯承载力计算及配筋计算(三)次梁斜截面受剪承载力及箍筋计算　　由表l．4可查得值　　端支座剪力设计值：　　第一内支座左侧截面剪力设计值：　　第一内支座右侧截面及中间支座的两侧截面的剪力设计值：　　核算截面尺寸：(符合要求)　　设只配双肢箍筋，不配弯起钢筋　　设箍筋间距s=200mm，则箍筋单肢所需截面面积：拟采用三、主梁的设计(KL3.1)(一)主梁的计算跨度及荷载(图1．26)图1.26　计算简图　　按弹性理论计算，故计算跨度取柱轴线间的距离，即边跨，中间跨　　活荷载　　恒荷载(二)主梁的内力计算　　按端支座是固定的三跨等截面连续梁计算，故采用实用弯矩分配法计算　　(1)固端弯矩　　恒　　总　　(2)支座A、B的最大负弯矩及相应的支座的负弯矩计算(注：计算是为了求支座最大剪力)，见图1．27所示　　以上求得的是B支座的支座中心处的弯矩值，由式(1．10)知B支座边缘截面弯矩设计值为图1.27　主梁支座最大负弯矩MA、MB及相应值的计算　　(3)支座最大剪力　　支座A右截面最大剪力　　支座B左截面最大剪力　　支座B右截面最大剪力　　(4)主梁跨中最大正弯矩　　先用实用弯矩分配法算出与边跨跨中最大正弯矩相对应的支座负弯矩值，如图l．23所示。

图1.28　与边距跨中最大正弯矩相对应的支座负弯矩的计算　　1)边跨跨中最大正弯矩　　边跨跨中最大正弯矩发生在B支座左侧第一个集中荷载处，其值为　　2)中间跨跨中最大正弯矩　　先用实用弯矩分配法算出与中间跨跨中截面最大正弯矩相对应的8支座负弯矩值，见图1．29故中间跨跨中最大正弯矩：(三)主梁的正截面受弯承载力计算及配筋(见表1．10)图1.29　与中间跨跨中最大正弯矩相对应的B支座负弯矩值的计算表1．10主梁正截面受弯承载力计算及配筋计算(四)主梁斜截面受剪承载力计算及配置箍筋　　(1)截面验算　　(2)不设弯起钢筋，只配箍筋，并用，现验算如下：(五)主梁附加箍筋的计算　　在支承次梁处只设附加箍筋，不再设置吊筋在传递的集中力设计值中不应包括主梁自重，即　　用双肢箍，以n=2，由式(1．22)得　　采用在次梁每一侧边各加密3道箍筋．间距50mm四、施工图　　如图1．23所示，为了节省篇幅，图上既表达了结构平面布置和板的配筋，也用平面表示法表达了主梁和次梁的配筋，以及附加箍筋其中主、次梁相交处A表示在主梁上于次梁截面两侧各配置加密箍筋3道  （英文版 ） Two regulations promulgated for implementation is in the party in power for a long time and the rule of law conditions, the implementation of comprehensive strictly strategic plan, implementation in accordance with the rules and discipline to manage the party, strengthen inner-party supervision of major initiatives. The two regulations supporting each other, the < code > adhere to a positive advocate, focusing on morality is of Party members and Party leading cadres can see, enough to get a high standard; < rule > around the party discipline, disciplinary ruler requirements, listed as "negative list, focusing on vertical gauge, draw the party organizations and Party members do not touch the" bottom line ". Here, the main from four square face two party rules of interpretation: the first part introduces two party Revised regulations the necessity and the revision process; the second part is the interpretation of the two fundamental principles of the revision of laws and regulations in the party; the third part introduces two party regulations modified the main changes and needs to grasp several key problems; the fourth part on how to grasp the implementation of the two regulations of the party. < code > and < Regulations > revised the necessity and revised history of the CPC Central Committee the amendment to the Chinese Communist Party members and leading cadres honest politics several guidelines > and < Chinese Communist Party discipline and Punishment Regulations > column 1 by 2015 to strengthen party laws and regulations focus. Two party regulations revision work lasted a Years, pooling the wisdom of the whole party, ideological consensus, draw historical experience, respect for the wisdom of our predecessors, which reflects the unity of inheritance and innovation; follow the correct direction, grasp the limited goals, adhere to the party's leadership, to solve the masses of the people reflect a focus on the problem. The new revision of the < code > and < rule >, reflects the party's 18 and the eighth session of the third, the spirit of the fourth plenary session, reflecting the experience of studying and implementing the General Secretary Xi Jinping series of important speech, reflects the party's eighteen years comprehensive strictly practice. (a) revised two regulations of the party need of < the ICAC guidelines > in < in 1997 Leaders as members o。