问题 单项选择题

某四层简支承重墙梁,如图所示。托梁截面b×hb=300mm×600mm,托梁自重标准值gkL=5.2kN/m。墙体厚度240mm,采用MU10烧结普通砖,计算高度范围内为M10混合砂浆,其余为M5混合砂浆,墙体及抹灰白重标准值为4.5kN/m2,翼墙计算宽度为1400mm,翼墙厚240mm。假定作用于每层墙顶由楼(屋)盖传来的均布恒荷载标准值gk和均布活荷载标准值qk均相同,其值分别为:gk=12.0kN/m,qk=6.0kN/m。砌体施工质量等级为B级。设计使用年限为50年,结构安全等级为二级。

假定使用阶段托梁顶面的荷载设计值Q1=12kN/m,墙梁顶面的荷载设计值Q2=150kN/m。试问,托梁剪力设计值Vb(kN),应与下列何项数值最为接近().

A.275

B.300

C.435

D.480

答案

参考答案:A

解析:

解答如下:

根据《砌体结构设计规范》7.3.8条:

βv=0.6,由规范式(7.3.8):

Vb=V1vV2=32.4+0.6×405.0=275.4kN

阅读理解

阅读理解。

     Ms Liu taught physics in a middle school. Last month she explained to one of her classes about

sound, and she decided to test them. She said to them, "Now, I have a brother in London. If I was

calling him on the phone, and at the same time you were 75 feet way, listening to me from across the

street, which of you would hear what I said first, my brother or you? Why?"

     The cleverest student answered at once, "Your brother, Ms Liu, because electricity (电) travels

faster than sound waves (波)."

     "That's very good," Ms Liu answered. But then one of the girls, Gao Hui, raised her hand and said, 

     "I don't think so." "Your brother would hear you earlier because when it's eleven o'clock here, it's

only eight o'clock in London."

1. The class studied _______. 

A. reason  

B. sound 

C. waves

D. electricity

2. Ms Liu asked the students ________.

A. who would first hear what she said  

B. who was listening to her 

C. who was in London               

D. whose answer was right

3. Who would hear Ms Liu's words first? 

A. Gao  Hui.                   

B. The students 75 feet away. 

C. They would hear the words at the same time. 

D. Her brother.

4. The first student thought her brother heard the words first because ________. 

A. her brother lived near her home   

B. her brother lived far from her home 

C. he thought the electricity travels faster than the sound waves 

D. her brother's telephone was good

5. Whose answer was right, the first student's or Gao Hui's? 

A. Gao Hui's.        

B. The first student's. 

C. Neither of theirs.    

D. Both of theirs.

单项选择题 A1/A2型题