桥架是由托盘、梯架的直线段、弯通、附件以及支、吊架等构成，用以支承电缆的具有连续的刚性结构系统的总称。是应用在水平布线和垂直布线系统的安装通道。

A cable tray is a collective term for a continuous rigid structural system composed of straight sections, bends, accessories, supports, hangers, etc. of trays and ladders, used to support cables. It is an installation channel used in both horizontal and vertical cabling systems.

电缆桥架是使电线、电缆、管缆铺设达到标准化、系列化、通用化的电缆铺设装置。

Cable tray is a cable laying device that standardizes, serializes, and generalizes the laying of wires, cables, and conduit cables.

一、 电缆桥架的分类

1、 Classification of cable trays

二、 电缆桥架的安装规定

2、 Installation regulations for cable trays

三、 桥架内电缆敷设的规定

3、 Regulations for laying cables inside cable trays

四、 电缆桥架的计算

4、 Calculation of cable tray

五、BIM软件技巧---桥架材质的添加

5、 BIM Software Tips - Adding Bridge Materials

一、电缆桥架的分类

1、 Classification of cable trays

1、槽式电缆桥架

1. Trough type cable tray

槽式电缆桥架是一种全封闭型电缆桥架。它适用于敷设计算机电缆、通信电缆、热电偶电缆及其他高灵敏系统的控制电缆等。

Trough type cable tray is a fully enclosed cable tray. It is suitable for laying computer cables, communication cables, thermocouple cables, and control cables for other highly sensitive systems.

它对控制电缆的屏蔽干扰和重腐蚀中环境电缆的防护都有较好的效果。

It has good effects on the shielding interference of control cables and the protection of cables in heavily corroded environments.

2、托盘式电缆桥架

2. Tray type cable tray

托盘式电缆桥架是石油、化工、轻工、电讯等方面应用广泛的一种。它具有重量轻、载荷大、造型美 、结构简单、安装方便等优点。

Tray type cable tray is a widely used type in petroleum, chemical, light industry, telecommunications, and other fields. It has the advantages of light weight, large load capacity, beautiful design, simple structure, and convenient installation.

它既适用于动力电缆的安装，也适合于控制电缆的敷设。

It is suitable for both the installation of power cables and the laying of control cables.

它的外观和槽式简直没什么不同，不过它的底部带有打孔，所以散热功能会比槽式的好许多。

Its appearance is not much different from the slot type, but its bottom has perforations, so its heat dissipation function is much better than the slot type.

3、梯级式电缆桥架

3. Cascade cable tray

桥架与线槽的主要区别

The main difference between cable trays and cable trays

● 桥架主要用于敷设电力电缆和控制电缆，线槽用于敷设导线和通讯线缆；

Cable trays are mainly used for laying power cables and control cables, while cable trays are used for laying wires and communication cables;

● 桥架相对大（200×100到600×200)，线槽相对较小；

The cable tray is relatively large (200 × 100 to 600 × 200), and the cable tray is relatively small;

● 桥架拐弯半径比较大，线槽大部分拐直角弯；桥架跨距比较大，线槽比较小；固定、安装方式不同；

The bending radius of the cable tray is relatively large, and most of the cable trays are bent at right angles; The bridge span is relatively large, and the cable tray is relatively small; Different fixing and installation methods;

● 在某些场所，桥架没盖，线槽通常全是带盖封闭的线槽来走线，桥架则是用来走电缆的。

In some places, cable trays are not covered, and cable trays are usually enclosed with covers for cable routing. Cable trays are used for cable routing.

二、电缆桥架的安装规定

2、 Installation regulations for cable trays

1、直线段钢制电缆桥架长度超过30m、铝合金或玻璃钢制电缆桥架长度超过15m设有伸缩节；电缆桥架跨越建筑物变形缝处设置补偿装置；

1. Steel cable trays with a length exceeding 30m in straight sections and aluminum alloy or fiberglass cable trays with a length exceeding 15m are equipped with expansion joints; Install compensation devices at the deformation joints of cable trays crossing buildings;

2、电缆桥架转弯处的弯曲半径，不小于桥架内电缆小允许弯曲半径；

2. The bending radius at the turning point of the cable tray shall not be less than the small allowable bending radius of the cables inside the tray;

3、当设计无要求时，电缆桥架水平安装的支架间距为1.5～3m；垂直安装的支架间距不大于2m；

3. When there are no design requirements, the support spacing for horizontal installation of cable trays is 1.5-3m; The spacing between vertically installed brackets shall not exceed 2m;

4、桥架与支架间螺栓、桥架连接板螺栓固定紧固无漏掉，螺母位于桥架外侧；当铝合金桥架与钢支架固定时，有相互间绝缘的防电化侵蚀措施；

4. The bolts between the bridge and the bracket, as well as the bolts of the bridge connection plate, are fixed tightly without any leakage, and the nuts are located on the outer side of the bridge; When the aluminum alloy bridge is fixed to the steel bracket, there are insulation measures to prevent electrochemical corrosion between them;

5、敷设在竖井内和穿越不同防火区的桥架，按设计要求位置有防火隔堵措施；

5. Cable trays laid in vertical shafts and passing through different fire zones shall have fire blocking measures in accordance with the design requirements;

6、支架与预埋件焊接固定时，焊缝丰满；膨胀螺栓固定时，选用螺栓适配，螺栓紧固，防松零件齐全。

6. When welding and fixing the bracket and embedded parts, the weld seam should be full; When fixing expansion bolts, bolts should be used for adaptation, bolts should be tightened, and anti loosening parts should be complete.

三、桥架内电缆敷设的规定

3、 Regulations for laying cables inside cable trays

1、大于45°倾斜敷设的电缆每隔2m处设固定点；

1. Cable laid at an angle greater than 45 ° shall have fixed points every 2 meters;

2、电缆出入电缆沟、竖井、建筑物、柜（盘）、台处以及管子管口处等做密封处理；

2. Seal the entry and exit of cables in cable trenches, shafts, buildings, cabinets (panels), platforms, and pipe openings;

3、电缆敷设排列整洁，水平敷设的电缆，首尾两端、转弯两侧及每隔5～10m处设固定点；敷设于垂直桥架内的电缆固定点间距符合要求。

3. Cable laying should be arranged neatly, and fixed points should be set at both ends of the cable, on both sides of the bend, and every 5-10m for cables laid horizontally; The spacing between cable fixing points laid in vertical cable trays meets the requirements.

四、电缆桥架的计算

4、 Calculation of cable tray

1、电缆桥架的实际荷载量计算

1. Calculation of actual load capacity of cable tray

G总 = n1*q1+ n2*q2 + n3*q3……nn*qn

G total=n1 * q1+n2 * q2+n3 * q3... nn * qn

公式中：G总为总荷载，q1、q2、q3……qn为每根电缆单位重量（kg/m），n1、n2、n3……nn为相同电缆的根数。

In the formula, G is the total load, q1, q2, q3... qn is the unit weight of each cable (kg/m), and n1, n2, n3... nn is the number of identical cables.

（G总<G允，G允电缆桥架的允许荷载，因为当电缆桥架带护罩在室外安装时，还应计人电缆桥架承受的大冰雪等载荷的影响。）

(G total<G allowed, G allowed the allowable load of cable tray, because when the cable tray is installed outdoors with a cover, the influence of large loads such as ice and snow borne by the cable tray should also be taken into account.)

2、电缆桥架宽度的计算

2. Calculation of cable tray width

电缆桥架宽度的确定随着电力电缆和控制电缆工作制的不同而有所区别。

The determination of cable tray width varies with the different working systems of power cables and control cables.

GB50054-95第5.6.14条中规定，电缆在桥架内敷设时，电缆总截面面积与桥架横断面之比，电力电缆不应大于40%，控制电缆不应大于50%。

According to Article 5.6.14 of GB50054-95, when laying cables in cable trays, the ratio of the total cross-sectional area of the cable to the cross-sectional area of the tray should not exceed 40% for power cables and 50% for control cables.

（1）由于电力电缆在桥架内一般是单层水平排放，所以其安装桥架宽度b为：

(1) Due to the fact that power cables are generally laid horizontally in a single layer within the cable tray, the installation width b of the cable tray is:

b=n1*(d1+k1)+n2*(d2+k2)+n3*(d3+k3)+……nn*（dn+kn）

B=n1 * (d1+k1)+n2 * (d2+k2)+n3 * (d3+k3)+... nn * (dn+kn)

公式中：d1、d2、d3……dn为桥架内各种电缆的外径，单位为mm；n1、n2、n3……nn为上述同种型号规格电缆的根数；K1、k2、k3……为上述电缆放置时的间距，其值小应大于电缆直径的1／4。

In the formula: d1, d2, d3... dn is the outer diameter of various cables inside the cable tray, in mm; N1, n2, n3... nn is the number of cables of the same model and specification mentioned above; K1, k2, k3... are the distances between the cables when they are placed, and their values should be greater than 1/4 of the cable diameter.

（2）控制电缆桥架的宽度b的计算：（一般电缆桥架的填充率取40%左右）

(2) Calculation of controlling the width b of cable tray: (Generally, the filling rate of cable tray is around 40%)

电缆的总截面积：S=S0/40%d=S/H=S0/40%h

Total cross-sectional area of cable: S=S0/40% d=S/H=S0/40% h

公式中：S0=n1*S1+n2*S2+n3*S3+……；n1、n2、n3...为相应电缆的根数；S1、S2、S3...为各电缆横截面积（按电缆外径计算）；

In the formula: S0=n1 * S1+n2 * S2+n3 * S3+; N1, n2, n3... are the number of corresponding cables; S1, S2, S3... are the cross-sectional areas of each cable (calculated based on the outer diameter of the cable);

需要的托架横载面积：So=n1，式中：h为电缆桥架净高。

The required cross-sectional area of the cable tray is So=n1, where h is the net height of the cable tray.

针对上述复杂的计算公式，我们非人士还是很难计算，现在告诉大家一个经验表格，辅助大家在电缆桥架支架受力演算时查找对应数值。

For the complex calculation formulas mentioned above, it is still difficult for us non professionals to calculate. Now, let me share with you an experience table to assist you in finding the corresponding values when calculating the stress on cable tray supports.