问题 单项选择题

某单层工业厂房,设置有两台Q=25/10t的软钩桥式吊车,吊车每侧有两个车轮,轮距4m,最大轮压标准值Pmax=279.7kN,吊车横向小车重量标准值g=73.5kN,吊车轨道的高度hR=130mm。

厂房柱距12m,采用工字形截面的实腹式钢吊车梁,上翼缘板的厚度hy=18mm,腹板厚度tw=12mm。沿吊车梁腹板平面作用的最大剪力为V;在吊车梁顶面作用有吊车轮压产生的移动集中荷载P和吊车安全走道上的均布荷载q。

当吊车为中级工作制时,试问,在吊车最大轮压作用下,在腹板计算高度上边缘的局部压应力设计值(N/mm2),与下列何项数值最为接近().

A.85.7

B.81.5

C.90.6

D.64.1

答案

参考答案:A

解析:

解答如下:

根据《钢结构设计规范》4.1.3条:

中级工作制软钩吊车,取ψ=1.0;又根据《建筑结构荷载规范》6.3.1条,取动力系数为1.05;取吊车荷载分项系数为1.4。

lz=a+5hy+2hR=50+5×18+2×130=400mm

由规范式(4.1.3-1):

应注意ψ的取值;动力系数的取值。

阅读理解

Doctor Seuss was born in 1904. By the middle 1950s, he had become one of the best-loved and most successful children's book writers in the world. His books are very popular with young readers. They enjoy the invented words and the pictures of unusual funny animals and plants.

In 1954, life magazine published a report about school children who could not read well. The report said many children's books were not interesting. Doctor Seuss strongly hoped to help children and decided to write books that were interesting and easy to read. He used words with the same ending sound, like fish and wish. He did not receive training in art. Yet, he drew the pictures for most of his books.

In 1957, Dr. Seuss wrote The Cat in the Hat. He used less than 230 words to write the book and even a six-year-old should be able to read it. It was a fun story and easy to read. Children loved it. Their parents loved it, too. Today it is still one of the stories they like best. The success of The Cat in the Hat made him want to write more books for children. In 1960, he wrote a book using less than fifty words. The book is called Green Eggs and Ham.

In 1984, Doctor Seuss won a Pulitzer Prize. He was honored for the education and enjoyment his books provided American children and their parents.

He died at the age of 87, but his influence remains. Millions of his books have been sold worldwide. People say his books helped change the way American children learned to read. Yet, his books are loved by people of all ages. Doctor Seuss once said, "I do not write for children. I write for people.

小题1:Doctor Seuss learned from the magazine that _______.

A.some school children could not read well

B.many children's books were interesting

C.children wanted to learn to write

D.a writer for children was wanted小题2: People like his books because the books ______.

A.are cheap and easy to get

B.were written in different languages

C.are easy and interesting to read

D.were written with invented words小题3:He wrote the book The Cat in the Hat at the age of _____.

A.50

B.53

C.56

D.87小题4:Which of the following is TRUE according to the passage?

A.Doctor Seuss wrote Green Eggs and Ham with over 230 words.

B.Doctor Seuss wrote books only for children in the United States.

C.The Cat in the Hat was written only for six-year-old children.

D.His books provided education and enjoyment for Americans.小题5: From the text we know that Doctor Seuss __________.

A.won a Pulitzer Prize soon after his death

B.sold millions of his books himself worldwide

C.changed American children's way of reading

D.wrote the largest number of books in the world

单项选择题