问题 单项选择题

某毛石砌体挡土墙,其剖面尺寸如图所示。墙背直立,排水良好。墙后填土与墙齐高,其表面倾角为β,填土表面的均布荷载为q。

假定δ=0,q=0,Ea=70kN/m,挡土墙每延米自重为209.22kN/m,挡土墙重心与墙趾的水平距离x0=1.68m,试问,挡土墙基础底面边缘的最大压力值pmax(kPa),与下列何项数值最为接近()

A.117

B.126

C.134

D.154

答案

参考答案:A

解析:

解答如下:

如图所示,重心G在形心轴的右侧,δ=0,则:

=-47.62kN·m/m,左侧受压最大

故基底反力呈梯形分布。

单项选择题
单项选择题

There (1) not one type of reading but several according to your reasons for reading. To read carefully, you have to (2) your reading speed and technique (3) your aim (4) reading. Skimming is a technique necessary for quick and efficient reading.

When skimming, you (5) the reading (6) quickly in order to get the (7) of it, to know how it is organized, (8) an idea of the tone or the intention of the writer. Skimming is (9) an activity which (10) an overall view of the text and (11) a definite reading competence.

Skimming doesn’t need reading all the material, but it doesn’t mean that it is an (12) skill for the lazy, because it need a high degree of alertness and concentration.

When you read, you usually start with (13) understanding and move towards detailed understanding rather than working the other way round. But (14) is also used after you have already carefully studied and you need to (15) the major ideas and concepts.

In order to be able to skim quickly and (16) through a text, you should know where to look for what you want. In preview skimming you read the introductory information, the headings and subheadings, and the summary, if one is provided. (17) this skimming, decide whether to read the material more thoroughly, and select the appropriate speed (18) you read.

The same procedure (19) for preview skimming could also be used to get an overview. Another method would be to read only key words. This is done by omitting the unnecessary words, phrases, and sentences.

In order to skim efficiently and fulfill your purpose, (20) practice is necessary.

1().

A.is

B.are

C.was

D.were