Soundproofing (GWV) — Segments

Soundproofing facilities (GWV).

A GWV file is delivered/created annually, which describes the situation on 31-12 of that year.
The GWV file contains, among other things, the following sound-resistant objects: 1. Soundwalls 2. Sound screens 3. Tunnel entrances 4. Deepened reclining road sections.
The data in the GWV file consists of: 1. Geometry of the object 2. Descriptive features of the object that are important for the sound-resistant function 3. Photos of the object.
The reason for the changes to the GWV file can be divided into 3 categories: 1. New location facilities. 2. Changes due to the placement of smaller facilities or extension of existing facilities. 3. Changes due to the demolition of facilities.

Segment
For sound calculation purposes, a soundproof device is divided into segments and values of characteristics are recorded per segment.
A soundproofing device always consists of at least 1 segment.
A segment always belongs to a soundproofing device.
The division into segments shall be subject to the following requirements:
A. A segment belongs to no more than one soundproof device. When a new soundproofing device starts, a new segment always starts.
B. A new segment begins
1. in the case of a height jump, where an altitude jump is defined as an (abrupt) change of the height of the upper edge of 1.0 metres or more over a length of at least 5.0 metres (see Figure 2);
2. when the value of at least one of the following characteristics changes over a length of at least 5.0 metres:
Road number
Job position
Hectometer letter
Height_Combination_Tov_Screen
Type
Inclined
Gradient angle
Nod
Bending
Top shape
Top corner
Primary material
Secondary material
Structural material
3. in the event of an interruption of the upper edge of the screen, except for an interruption of less than 5.0 metres, where the “hole” is closed by a shielding obstacle behind the hole, e.g.
on the spot of a portal.

隔音设施（GWV）。
GWV文件每年生成或报送，用于描述对应年份12月31日的设施现状。
GWV文件包含以下几类隔音设施对象（涵盖范围不限于上述）：1. 声屏障（Soundwalls）2. 隔声屏（Sound screens）3. 隧道入口 4. 深挖式下坡路段。
GWV文件内的数据包含以下三类：1. 设施的几何形态参数 2. 对隔音功能至关重要的设施描述性特征 3. 设施的实拍照片。
GWV文件的更新原因可分为三类：1. 新增落地设施 2. 增设小型附属设施或对既有设施进行扩建引发的变更 3. 设施拆除引发的变更。

分段（Segment）
为开展声学计算，需将隔音设施划分为若干分段，并为每个分段记录对应的特征参数值。
单个隔音设施至少包含1个分段。
每个分段均隶属于某一隔音设施。
分段划分需遵循以下规则：
A. 单个分段仅可隶属于一个隔音设施。当新增隔音设施时，需同步开启新的分段。
B. 出现以下任一情况时，需开启新的分段：
1. 发生高度突变：高度突变定义为在至少5.0米的长度范围内，设施上沿高度发生1.0米及以上的突发变化（详见图2）；
2. 以下至少一项特征参数在至少5.0米的长度范围内发生变化：
道路编号（Road number）、作业位置（Job position）、百米桩字母标识（Hectometer letter）、屏体高度组合参数（Height_Combination_Tov_Screen）、设施类型（Type）、倾斜状态（Inclined）、坡度角（Gradient angle）、节点状态（Nod）、弯曲状态（Bending）、顶部造型（Top shape）、顶部转角（Top corner）、主体材料（Primary material）、辅助材料（Secondary material）、结构材料（Structural material）；
3. 屏体上沿出现中断时：若中断长度不小于5.0米，则需划分新分段；若中断长度小于5.0米且中断处由后方遮蔽障碍物（如门架位置）填补，则无需划分新分段。