建筑结构(第2版)》-第六章 受拉构件承载力计算

1、.第六章受拉构件承载力计算【学习重点】轴心受拉构件承载力计算；偏心受拉构件承载力计算。【学习目标】了解受拉构件的种类；熟悉轴心受拉构件计算的适用范围；掌握受拉构件承载力的计算方法；熟悉偏心受压构件的构造要求及计算适用范围；掌握偏心受拉构件承载力的计算方法。钢筋混凝土受拉构件按纵向拉力作用位置的不同分为轴心受拉和偏心受拉两种类型。当纵向拉力<math display='block'> <semantics> <mi>N</mi> <annotation encoding='MathType-MTEF'>M

2、athTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaaba

3、uaakeaacaWGobaaaa3FF0</annotation> </semantics></math>作用在截面形心时，称为轴心受拉构件，如钢筋混凝土屋架下弦杆、高压圆形水管及圆形水池等。当纵向拉力<math display='block'> <semantics> <mi>N</mi> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9g

4、zLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGobaaaa3FF0</annotation> </sema

5、ntics></math>作用在偏离截面形心时，或截面上既作用有纵向拉力<math display='block'> <semantics> <mi>N</mi> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4r

6、NCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGobaaaa3FF0</annotation> </semantics></math>，又作用有弯矩<math display='block'> <seman

7、tics> <mi>M</mi> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpep

8、m0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGnbaaaa3FEF</annotation> </semantics></math>的构件，称为偏心受拉构件，如钢筋混凝土矩形水池、工业厂房中双肢柱的肢杆等。第一节轴心受拉构件承载力计算一、轴心受拉构件的受力特点承受节点荷载的桁架或屋架的受拉弦杆和腹杆、刚架和拱的拉杆、受内压力作用的圆形储液池的环向池壁、承受内压力作用的环形截面管道的管壁等通常按轴心受拉构件计算。钢筋混

9、凝土轴心受拉构件，开裂以前混凝土与钢筋共同负担拉力；开裂以后，开裂截面混凝土退出工作，全部拉力由钢筋承受。当钢筋应力达到其抗拉强度，截面到达受拉承载力极限状态。二、轴心受拉构件承载力计算根据承载力极限状态设计法的基本原则及力的平衡条件，轴心受拉构件正截面承载力计算公式为： <math display='block'> <semantics> <mi>N</mi> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatC

10、vAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGobaaaa3FF0</annotat

11、ion> </semantics></math><math display='block'> <semantics> <mrow> <msub> <mi>N</mi> <mi>u</mi> </msub> <mo>=</mo><msub> <mi>f</mi> <mi>y</mi> </msub> <msub> <mi>A&

12、lt;/mi> <mi>s</mi> </msub> <mo>+</mo><msub> <mi>f</mi> <mrow> <mi>p</mi><mi>y</mi> </mrow> </msub> <msub> <mi>A</mi> <mi>p</mi> </msub> </mrow> <annotation encodi

13、ng='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9

14、adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGobWaaSbaaSqaaiaadwhaaeqaaOGaeyypa0JaamOzamaaBaaaleaacaWG5baabeaakiaadgeadaWgaaWcbaGaam4CaaqabaGccqGHRaWkcaWGMbWaaSbaaSqaaiaadchacaWG5baabeaakiaadgeadaWgaaWcbaGaamiCaaqabaaaaa4C16</annotation> </semantics></math> （6-1）式中<math display='

15、;block'> <semantics> <mi>N</mi> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rq

16、qrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGobaaaa3FF0</annotation> </semantics></math>轴向拉力设计值；<math display='block'> <semantics> <mrow> <msub> <mi>N</mi> <mi&

17、gt;u</mi> </msub> </mrow> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9L

18、q=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGobWaaSbaaSqaaiaadwhaaeqaaaaa4116</annotation> </semantics></math>轴心受拉构件正截面承载力设计值；<math display='block'> <semantics> <mrow> <msub> <mi>f&l

19、t;/mi> <mi>y</mi> </msub> </mrow> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8

20、F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGMbWaaSbaaSqaaiaadMhaaeqaaaaa4132</annotation> </semantics></math>钢筋抗拉强度设计值，<math display='block'> <semantics> <mrow> <msub> &l

21、t;mi>f</mi> <mi>y</mi> </msub> </mrow> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqq

22、rpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGMbWaaSbaaSqaaiaadMhaaeqaaaaa4132</annotation> </semantics></math>大于300Nmm2时，按300Nmm2取值；<math display='block'> <semantics> <m

23、row> <msub> <mi>f</mi> <mrow> <mi>p</mi><mi>y</mi> </mrow> </msub> </mrow> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDY

24、LwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGMbWaaSbaaSqaaiaadchacaWG5baabeaaaaa4227</annotation> </semantics></math>预应力

25、钢筋的抗拉强度设计值；<math display='block'> <semantics> <mrow> <msub> <mi>A</mi> <mi>s</mi> </msub> </mrow> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfM

26、BaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGbbWaaSbaaSqaaiaadohaaeqaaaaa4107</annotation> </semantics>&

27、lt;/math>截面上全部纵向受拉钢筋的截面面积；<math display='block'> <semantics> <mrow> <msub> <mi>A</mi> <mi>p</mi> </msub> </mrow> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2Caerbu

28、LwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGbbWaaSbaaSqaaiaadchaaeqaaaaa4104</annotation> &

29、lt;/semantics></math>截面上预应力钢筋的全部截面面积。由式（6-1）可知，轴心受拉构件正截面承载力只与纵向受拉钢筋有关，与构件的截面尺寸及混凝土的强度等级无关。三、轴心受拉构件构造要求（一）纵向受力钢筋轴心受拉构件的受力钢筋不得采用绑扎搭接；搭接而不加焊的受拉钢筋接头仅仅允许在圆形池壁或管中，其接头位置应错开，搭接长度应满足规范要求。为避免配筋过少引起的脆性破坏，按构件截面面积计算的全部受力钢筋的直径不宜小于12mm，构件一侧受拉钢筋的最小配筋百分率不应小于0.2%和（45<math display='block'> <s

30、emantics> <mrow> <msub> <mi>f</mi> <mi>t</mi> </msub> </mrow> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMB

31、bXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGMbWaaSbaaSqaaiaadshaaeqaaaaa412D</annotation> </semantics></math>/<math display='block'> <

32、;semantics> <mrow> <msub> <mi>f</mi> <mi>y</mi> </msub> </mrow> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexL

33、MBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGMbWaaSbaaSqaaiaadMhaaeqaaaaa4132</annotation> </semantics></math>）%的较大值，也不宜大于5%。受力钢筋沿截面周边均匀对称布置，净间距不应小于5

34、0mm，且不宜大于300mm。（二）箍筋在轴心受拉构件中，与纵向钢筋垂直放置的箍筋主要是与纵向钢筋形成骨架，固定纵向钢筋在截面中的位置，从受力角度而言并无要求。箍筋直径不应小于纵筋直径的1/4，且不应小于6mm，间距一般不应大于400mm及构件截面短边尺寸。【例6-1】已知某钢筋混凝土屋架下弦，截面尺寸<math display='block'> <semantics> <mi>b</mi> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=fea

35、aguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGIbaaaa4

36、004</annotation> </semantics></math>×<math display='block'> <semantics> <mi>h</mi> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbI

37、tLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGObaaaa400A</annotation> </semantics></math>200mm×150mm，其所受的轴向拉力设计值为300kN，钢筋为

38、HRB335级，混凝土强度等级为C30，求纵向受拉钢筋截面面积<math display='block'> <semantics> <mrow> <msub> <mi>A</mi> <mi>s</mi> </msub> </mrow> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2Caer

39、buLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGbbWaaSbaaSqaaiaadohaaeqaaaaa4107</annotation>

40、 </semantics></math>并选配钢筋。 【解】由题意知此屋架下弦为轴心受拉构件，钢筋HRB335，<math display='block'> <semantics> <mrow> <msub> <mi>f</mi> <mi>y</mi> </msub> </mrow> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1

41、ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGMbWaaSbaaSqaai

42、aadMhaaeqaaaaa4132</annotation> </semantics></math>300Nmm2，C30混凝土，<math display='block'> <semantics> <mrow> <msub> <mi>f</mi> <mi>t</mi> </msub> </mrow> <annotation encoding='MathType-MTEF'>MathTypeMT

43、EF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaaca

44、WGMbWaaSbaaSqaaiaadshaaeqaaaaa412D</annotation> </semantics></math>1.43Nmm2，令<math display='block'> <semantics> <mi>N</mi> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2D

45、Gi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGobaaaa3FF0</annotation> </semantics></math><

46、;math display='block'> <semantics> <mrow> <msub> <mi>N</mi> <mi>u</mi> </msub> </mrow> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBa

47、erbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGobWaaSbaaSqaaiaadwhaaeqaaaaa4116</annotation> </semantics></math>，代

48、入式（6-1），得<math display='block'> <semantics> <mrow> <msub> <mi>A</mi> <mi>s</mi> </msub> <mo>=</mo><mfrac> <mi>N</mi> <mrow> <msub> <mi>f</mi> <mi>y</mi> </msub> </

49、mrow> </mfrac> <mo>=</mo><mfrac> <mrow> <mn>300000</mn> </mrow> <mrow> <mn>300</mn> </mrow> </mfrac> <mo>=</mo><mn>1000</mn><mi>m</mi><msup> <mi>m</mi> <mn>2&l

50、t;/mn> </msup> </mrow> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9v

51、qaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGbbWaaSbaaSqaaiaadohaaeqaaOGaeyypa0ZaaSaaaeaacaWGobaabaGaamOzamaaBaaaleaacaWG5baabeaaaaGccqGH9aqpdaWcaaqaaiaaiodacaaIWaGaaGimaiaaicdacaaIWaGaaGimaaqaaiaaiodacaaIWaGaaGimaaaacqGH9aqpcaaIXaGaaGimaiaaicd

52、acaaIWaGaamyBaiaad2gadaahaaWcbeqaaiaaikdaaaaaaa537B</annotation> </semantics></math> 纵向受拉钢筋的配筋率为：<math display='block'> <semantics> <mrow> <mi>&#x03C1;</mi><mo>=</mo><mfrac> <mrow> <msub> <mi>A</mi>

53、 <mi>s</mi> </msub> </mrow> <mi>A</mi> </mfrac> <mo>=</mo><mfrac> <mrow> <mn>1000</mn> </mrow> <mrow> <mn>200</mn><mo>&#x00D7;</mo><mn>150</mn> </mrow> </mfrac&g

54、t; <mo>=</mo><mn>3.3</mn><mi>&#x0025;</mi> </mrow> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2C

55、aeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacqaHbpGCcqGH9aqpdaWcaaqaaiaadgeadaWgaaWcbaGaam4CaaqabaaakeaacaWGbbaaaiabg2da9maalaaabaGaaGymaiaaicdacaaIWaGaaGimaaqaaiaaikdacaaIWaGaaGimaiabgEna

56、0kaaigdacaaI1aGaaGimaaaacqGH9aqpcaaIZaGaaiOlaiaaiodacaGGLaaaaa5302</annotation> </semantics></math><math display='block'> <semantics> <mrow> <msub> <mi>&#x03C1;</mi> <mrow> <mi>min</mi> </mrow> </msub> &l

57、t;mo>=</mo><mn>0.9</mn><mo>&#x00D7;</mo><mfrac> <mrow> <msub> <mi>f</mi> <mi>t</mi> </msub> </mrow> <mrow> <msub> <mi>f</mi> <mi>y</mi> </msub> </mrow> </mfra

58、c> <mo>=</mo><mn>0.9</mn><mo>&#x00D7;</mo><mfrac> <mrow> <mn>1.43</mn> </mrow> <mrow> <mn>300</mn> </mrow> </mfrac> <mo>=</mo><mn>0.429</mn><mi>&#x0025;</mi>

59、 </mrow> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=

60、yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacqaHbpGCdaWgaaWcbaGaciyBaiaacMgacaGGUbaabeaakiabg2da9iaaicdacaGGUaGaaGyoaiabgEna0oaalaaabaGaamOzamaaBaaaleaacaWG0baabeaaaOqaaiaadAgadaWgaaWcbaGaamyEaaqabaaaaOGaeyypa0JaaGimaiaac6cacaaI5aGaey41aq7aaSaaaeaacaaIXaGaaiOlaiaaisdaca

61、aIZaaabaGaaG4maiaaicdacaaIWaaaaiabg2da9iaaicdacaGGUaGaaGinaiaaikdacaaI5aGaaiyjaaaa5D47</annotation> </semantics></math> 因为<math display='block'> <semantics> <mrow> <msub> <mi>&#x03C1;</mi> <mrow> <mi>min</mi> </mr

62、ow> </msub> </mrow> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaq

63、pepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacqaHbpGCdaWgaaWcbaGaciyBaiaacMgacaGGUbaabeaaaaa43DB</annotation> </semantics></math>0.4290.4，所以上式中最小配筋率取0.429。所以配筋率满足要求，纵向受拉钢筋选用418钢筋，<math display='block'> <semantics>

64、 <mrow> <msub> <mi>A</mi> <mi>s</mi> </msub> </mrow> <annotation encoding='MathType-MTEF'>MathTypeMTEF55+=feaaguart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbWexLMBbXgBd9gzLbvy

65、Nv2CaeHbl7mZLdGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabauaakeaacaWGbbWaaSbaaSqaaiaadohaaeqaaaaa4107</annotation> </semantics></math>1017mm2。第二节偏心受拉构件承载力计算矩形水池的池壁、工业厂房双肢柱的受拉肢杆、矩形剖面料仓的仓壁或煤斗的壁板、受地震作用的框架边柱、承受节间竖向荷载的悬臂式桁架拉杆及一般屋架承担节间荷载的下弦拉杆等均可按偏心受拉计算。一、偏心受拉构件构造要求偏心受拉构件常用矩形截面形式，且矩形截面的长边宜和弯矩作用平面平行，也可采用形或工字形截面。小偏心受拉构件破坏时拉力全部由钢筋承受，在满足构造要求的前提下，以采用较小的截面尺寸为宜，大偏心受拉构件的受力特点类似于受弯构件，宜采用较大的截面尺寸，有利于抗弯和抗剪。矩形截面偏心受拉构件的纵向钢筋应沿短边布置。小偏心受拉构件的受力钢筋不得采用绑扎搭接接头。矩形截面偏心受拉构件纵向钢筋配筋率应满足其最小