问题 问答题

(四)背景资料:某海港集装箱码头,采用沉箱重力式结构,沉箱尺寸为15m×22m×19.5m(宽×长×高),设计高水位+3.0m,设计低水位+0.5m,码头前沿水深-17.0m。码头基槽设计开挖断面如下图所示,采用抓斗式挖泥船施工,计算超深值取0.3m。计算超宽值取1.0m。 工程施工中,抛石基床采用爆炸夯实法密实。爆炸夯实后。进行了夯沉率验收,经测量验收,平均夯沉率为15%,满足设计要求,随即进行基床整平。抛石基床整平范围为沉箱底面宽度15m,基床顶面-17.0m,细平后预留了规范要求的相应斜坡。沉箱在预制场预制,海上采用浮运拖带法运至施工现场,沉箱安装后,在填砂压载前出现前倾,施工单位采取在沉箱后排仓格内先抛填一半高度砂的措施,进行偏心压载,以调整沉箱就位。港池疏浚工程量为200万m3,用一艘1600m3/h绞吸船开挖,开挖土直接吹填至码头后方的吹填区。1600m3/h绞吸船挖掘生产率为576m3/h,泥泵管路吸输生产率为410m3/h,三班作业,时间利用率为65%。码头交工验收后,在缺陷责任期内发生了两起事件,一是码头前沿停靠渔船,将橡胶护舷撞坏,二是码头后轨道梁两侧的连锁块局部出现下沉。

浮运拖带沉箱前,应对沉箱进行何种验算?拖运沉箱时,牵引作用点的最佳位置在何处?

答案

参考答案:

本小题共4分。浮运拖带沉箱前,应对沉箱进行吃水、压载、浮游稳定验算(2分)。牵引作用点的最佳位置在定倾中心以下10cm左右(2分)。

单项选择题 A1/A2型题
单项选择题

Statuses are marvelous human inventions that enable us to get along with one another and to determine where we "fit" in society. As we go about our everyday lives, we mentally attempt to place people in terms of their statuses. For example, we must judge whether the person in the library is a reader or a librarian, whether the telephone caller is a friend or a salesman, whether the unfamiliar person on our property is a thief or a meter reader, and so on.

The statuses we assume often vary with the people we encounter and change throughout life. Most of us can, at very high speed, assume the statuses that various situations require. Much of social interaction consists of identifying and selecting among appropriate statuses and allowing other people to assume their statuses in relation to us. This means that we fit our actions to those of other people based on a constant mental process of appraisal and interpretation. Although some of us find the task more difficult than others, most of us perform it rather effortlessly.

A status has been compared to ready-made clothes. Within certain limits the buyer choose style and fabric. But an American is not free to choose the costume of a Chinese peasant or that of a Hindu prince. We must choose from among the clothing presented by fit, as well as by our pocketbook. Having made a choice from minor adjustments, we tend to be limited to what the stores choice among them is limited.

In the last sentence of the second paragraph, the pronoun "it" refers to ()".

A.fitting our actions to those of other people appropriately

B.identification of other people’s statuses

C.selecting one’s own statuses

D.constant mental process