Highway water crossing bridge flood control sign water level instrument

Technical requirements for the establishment of infrastructure support facilities

(Flood prevention signs for highway water crossing bridges)

1、 Classification standards and value methods for water level lines

The flood control sign water level can generally be divided into historical maximum flood level, safe operation benchmark water level, and fortification warning water level.

1. The fortified warning water level indicates that water crossing bridges may begin to encounter danger, and as the water level continues to rise, the danger will increase. When there are no special circumstances, the warning water level should be set according to the General Design Specification for Highway Bridges and Culverts (JTG) The corresponding flood frequency obtained by multiplying the flood frequency values specified in Table 3.2.9 (D60-2015) by 2 is calculated. For water crossing bridges in mountainous areas, the warning water level should be calculated based on the corresponding flood frequency obtained by multiplying the design flood frequency of bridges and culverts specified in Table 3.2.9 of the General Code for Design of Highway Bridges and Culverts (JTG D60-2015) by 4.Highway water crossing bridge flood control sign water level instrument

2. The safe operation benchmark water level is the highest water level that ensures the safe operation of water crossing bridges. The benchmark water level for safe operation should be in accordance with the "Hydrological Survey and Design Specification for Highway Engineering" (JTG C30)-2Determination of the design water level calculation method specified in Section 6.5. Among them, the design flow rate should be determined according to the design flow value given in the bridge design documents, and the parameters of the riverbed section should be determined based on the results of the riverbed section survey conducted before setting flood control signs.

3. The historical maximum flood level refers to the maximum flood level that has occurred in the history of the location of the bridge site. In areas with hydrological data, the historical maximum flood level should be determined based on the data provided by the gate. In areas without hydrological data, the historical maximum flood level can be determined based on flood marks left on bridge structures, local chronicles, or memories of nearby elders.

2、 Font, text scale size, and color requirements for flood control signs

1. The font for flood control signs should be B-type traffic sign font. The font of the text within the same flood control sign should be consistent.

The height of the water level scale text in flood control signs should not be less than 5cm, and the height of the graded water level line marking text should not be less than 7cm.

The width of the water level scale in flood control signs should not be less than 2cm, and the width of the graded water level line should not be less than 10cm. When flood control signs are set on bridge piers, the graded water level line should surround the pier once.

In the grading water level marking text, the warning water level marking text should be dark blue, and the marking can be abbreviated as "warning"; The text indicating the safe operation benchmark water level should be in red, and the annotation can be abbreviated as "benchmark"; The maximum historical flood level annotation text should be black, and the annotation can be abbreviated as "history". The background color of flood control signs should be white.

5. The top of the flood control sign should indicate the name and contact phone number of the highway maintenance department.

3、 Specifications and installation requirements for flood control signs

1. Flood control signs should be made by applying reflective and anti fouling coatings on the surface of stainless steel plates to create sign boards.

2. The minimum scale of the flood control sign water level should not be greater than 50cm.

3. The reading range of flood control signs should be at least 0.5m higher than the higher of the historical maximum flood level and the safe operating reference water level, and below 0.5m below the fortification warning water level.

4. Flood control signs should be installed on water crossing components such as bridge piers, bridge piers, and cone slope protection at bridge piers

A prominent location for easy observation by highway patrol personnel.

5. Flood control signs should be fixed on bridge components by bolts, welding, etc., and should not be fixed by pasting.

4、 Example diagram of flood control signs for highway water crossing bridges

Example diagram of flood control signs for highway water crossing bridges as shown in the figureAs shown in Figure 1.

imageExample diagram of flood control signs for highway water crossing bridges

5、 Emergency control measures during flood season

When the water level under the bridge exceeds the warning water level line, timely warning information should be issued and a dedicated person should be arranged to be on duty 24 hours a day. The water level changes should be recorded every hour, and the inspection of water crossing bridges along the line should be strengthened. Implement traffic control, restrict or prohibit vehicle passage when necessary.

When the water level under the bridge exceeds the safe operating reference water level line, the emergency plan should be activated in a timely manner and a dedicated person should be on duty. The water level change should be recorded every 30 minutes, and the bridge should be closed and traffic diverted. When the water level drops below the safe operating reference water level line and continues to decline, traffic can be opened according to the on-site situation.Highway water crossing bridge flood control sign water level instrument