问题 问答题 简答题

怎样搭设多层支撑式挑脚手架?

答案

参考答案:

(1)将长4-5m的悬挑杆按1.5-2m的间距沿楼板面的周边均匀布置,用3排大横杆分别置于悬挑杆的两端和中间,将各悬挑杆扣结成片后推出,使大横杆距建筑物外皮1-1.4m,将位于楼层之上的两排大横杆与楼板固定或扣结,紧顶在两层楼板之间的立管上。

(2)搭设斜撑杆,其下端与在下层的边梁或其它可靠的支承物上,上端与悬挑杆扣结牢固

(3)在大横杆与楼板之间按0.75-1m间距铺放小横杆,放上脚手板后,将小横杆外端与大横杆扣牢。

(4)搭设立杆排架并设置拉杆,沿高度方向不大于6m一道,以确保立杆排架稳定。

(5)铺设作业层和脚手板。

单项选择题 A1/A2型题
单项选择题

A total of 4.6 million digital televisions have been sold, and the sales of HDTV sets have quadrupled since last year. Consumers have bought HDTVs to play their DVDs and to have clearer pictures and wide screens. Only a small percentage of the people who have purchased HDTVs, however, have actually hooked their TVs up to receive high-definition television digital signals. Perhaps television viewers are having trouble keeping up with the changes in technology. Even the manufacturers of HDTVs, like Mitsubishi, Thomson Multimedia, Sony, and Samsung seem to have a tough time learning how to make their sets work with the various digital TV formats because little standardization has been required or implemented in the industry.

Some of the HDTVs weigh over 200 lbs., and a variety of retailers offer a delivery service to the buyer’s home to help install the heavy sets. This is known as a white-glove service and usually comes with an extra fee. After HDTV purchasers get their sets home and hook them up, they will still need to work to get the digital signals to their systems. Most of the industry’s cable providers do not yet offer high~definition programing, and only about 15% of commercial television stations have switched over to even the lowest improved digital pictures. Worse yet, viewers may need to install antenna before they can even get the digital signals to their new HDTV sets. Another frustration for home-theater seekers is that the current HDTV sets allow owners only to watch high-definition programs, not to record them.

According to the passage, which of the following offers most of the HDTV programmes so far().

A. Retailer delivery services.

B. Cable providers.

C. Commercial television stations.

D. HDTV set manufacturers.