混凝土结构中册混凝土结构与砌体结构设计知识题目解析

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6 弯矩图： ○

MA底?MB底11q1H2?VAH??2.16?10.52?0.55?10.5?124.85kNm22 1??1.35?10.5?7?10.5?147.8kNm2 MA=124.85kN

12．3 解：从前题知 nA=0.148, nB=0.369, ○

1 计算剪力分配系数： C30A??2.1?0.3183??1

?0.148?1?53?? C0B?3?2.841?0.3183??1??0.369?1??MB=147.8kNm

??3.511?0.318 ?uEcA? H3?114.38?2.53?1

36.38?uE11

cB?H3?19.5?2.84?55.38 .

1?u?1?(36.38?55.38)EcE3?91.76c3 （相对值） A?uBHH

?36.38A?91.76?0.4， ?55.38B?91.76?0.6 ○

2 计算约束反力RA、RB： C3A?1.5?1?0.3182?1.5?0.899M1 1?0.3183??1

?0.148?1??1.185?1.138?1?0.31820

C3B?1.5?1?0.3183??1?1.5?.899??1.055?1.278A

?0.3691??RM1A?H?C153.2

3A?11?1.138?15.85kN???RM?131

B?2H?C3B?11?1.278??15.22kN????R?15.85?15.22?0.63kN???

○3 柱顶剪力：

VA?RA??A?R?15.85?0.4?0.63?15.6kN???VB?RB??B?R??15.22?0.6?0.63??15.6kN???

○4 弯矩图： 98.6kNm

76.4kNm

54.6kNm

54.6kNm

18.4kNm 40.6kNm

12．4 解：fy=300 N/mm2, FV=324 kN, Fh=78 kN, a=250 mm

A324?103?25078?1032s?0.85?300??800?40??1.2?300?418?312?730mm

小于最小配筋量612的面积，故按构造配筋

M2 B

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12．5 由于解答不唯一，故从略。

第15章

15．1 解：查得砌体抗压强度设计值f=1.5 N/mm2,

H06800M8.1?106e???32.4mm; ????10.97; 3N250?10h620e32.4??0.052; h620

1?0.8461???21?0.0015?1121???0.73 2?1?1????1?12?0.052??1???12?0.846??????0?1?

?fA?0.73?1.5?490?620?332.66kN?N?250kN

6800?13.88 4901?0??0.776?? ?承载力应会满足。 21?0.0015?13.88按轴压计算时

??15．2 解：抗压强度设计值 f=1.19 N/mm2, 翼墙间距s=6.8 m,层高H=3.5 m,

2H>s>H,?计算高度 H0?0.4s?02H?0.4?6.8?0.2?3.5?3.42m

3.42?1.1?19.8, ??0.0015

0.191?0??0.63

1?0.0015?19.82??底层轴力N=118+3.36*3.5=129.76Kn

?0fA?0.63?1.19?1000?190?142.47?129.76

215．3 解：Nl?180kN, N0?50kN, A0??250?2?240??240?0.1752m

f?1.3N/mm2, a0?10600?215mm?240mm 1.3 .

Al?a0bb?215?250?53750mm2;

A0175200??3.26?3 Al53750

???0 ??1?0.353.26?1?1.526?2

??fAl?0.7?1.526?1.3?53750?74.64kN?Nl

局部受压不满足要求。

15．4 解：首先计算中和轴位置y

3600

490

y=2022

538

240

114 500

490?7402?0.5??3600?490??2402?0.5y??202mm

490?500?3600?240惯性矩 I:

22?490?7403740?3600?490??2403240???I??490?740?538???3600?490?240?202????122122?????1.655?1010?1.0234?1010?0.3583?1010?0.5019?1010?3.5386?1010mm2A?490?500?3600?240?1.109?106mm2

回转半径 i?I3.5386?1010??179mm 6A1.109?10