通过外观调查，可以确定酒店方面提出的噪音现象是确实存在的，经过调用该项目原幕墙施工图纸，对于该噪音产生的可能原因，我司分析如下：

1．   梁柱连接处未采取足够措施以吸收幕墙龙骨伸缩变形

噪音主要出现在酒店的圆弧幕墙部分，其幕墙横梁对立柱的连接收力情况相对于直线横梁收力要求更高，由幕墙施工图纸可以看出，幕墙龙骨梁柱连接处通过角铝连接（见附图1、2），但连接角铝与幕墙柱及横梁之间接触面图纸显示未有放置有弹性垫片，是以密封胶密封，根据《玻璃幕墙工程技术规范》（JGJ 102-2003）第4.3.7的规定，“幕墙的连接部位，应采取措施防止产生摩擦噪声。构件式幕墙的立柱与横梁连接处应避免刚性接触，可设置柔性垫片或预留1-2mm的间隙，间隙内填胶；…”（见附图3）；而经酒店方面证实，噪音出现最多的位置就是在幕墙龙骨梁柱连接处，因此有理由相信，此处设计虽未违反规范要求，但由于施工和加工偏差较大，因此仅以密封胶密封是不够的。幕墙龙骨梁柱接触处未设置吸收变形的弹性垫片及未预留足够间隙是该幕墙系统产生噪音的主要原因之一。

2．   上下立柱连接间的空隙过小

另根据酒店方面工程部拍摄照片显示，在部分位置幕墙上下立柱连接间的空隙过小，小于15mm，根据《玻璃幕墙工程技术规范》（JGJ 102-2003）第6.3.3的规定，“上、下立柱之间应保留有不小于15mm的缝隙”（见附图4），此项指标该项目未能符合规范要求。

Through visual investigation, we can confirm that the noise phenomenon raised by the hotel really exists, after calling the original curtain wall construction drawings of the project, we do an analysis on possible causes of the noise as follows:

1. No adequate measures are taken at the beam-column joint to absorb the expanding and contracting deformations of curtain keels

Noise mainly exists at the circular-arc curtain wall part of the hotel, compared with the load carrying of straight-line beams, its curtain wall beam has higher requirements in the connection and load-carrying of stand columns, it is shown from the curtain wall construction drawing that the beam and column are connected by angle aluminium at the beam-column joint of the curtain keel (see attached figure 1 and 2), but it is shown in the drawing of the contact surfaces between the connecting angle aluminium and curtain wall column and beam that no elastic washer is placed and they are sealed with sealant, in accordance with provisions of Article 4.3.7 of Technical Code for Glass Curtain Wall Engineering (JGJ 102-2003), “adequate measures shall be taken at the joints of curtain walls to prevent the generation of frictional noise. Rigid contact shall be avoided at the joints of stand columns and beams of stick built curtain walls, a flexible gasket can be provided or a 1-2mm clearance may be reserved and it is filled with glue:…” (see attached figure 3); moreover, it is verified by the hotel that the position where such noise exists the most frequently is the beam-column joint of curtain keels, so we have reasons to believe that, though the design does not violate the requirements of the code, due to large construction and processing deviations, it is not enough to seal it with sealant. One of the major causes which make the curtain wall system generate noises is that no flexible gasket absorbing deformation is placed and no adequate clearance is reserved at the beam-column joint of curtain keels.

2. The gap between the connecting parts of the upper and lower columns is too narrow

What’s more, it is shown in the photos taken by Engineering Department of the hotel that the gap between the connecting parts of the upper and lower columns is too narrow and less than 15mm at some positions, in accordance with provisions of Article 6.3.3 of Technical Code for Glass Curtain Wall Engineering (JGJ 102-2003), “a gap not less than 15mm shall be kept between the upper and lower columns” (see attached figure 4), the index shows that the project does not conform to requirements of the code.