I. Wind Resistance Design Theory System

Wind load grading defense system

First-level defense: based on the 100-year return period wind speed (60m/s) to calculate the benchmark wind pressure, the equivalent static wind load on the bridge deck reaches 4.5kN/㎡.

Second-level defense: adopting mixed probability method, considering the coupling effect of typhoon and monsoon, the critical wind speed of vibration ≥ 88m/s (far exceeding the upper limit of 17th level typhoon).

Tertiary defense: set up openable wind guide plate system, active pneumatic control under extreme wind conditions, vortex vibration amplitude suppression rate ≥95%.

Revolutionary innovation of pneumatic shape

Main beam section:

Slotted double-box section (slot width ratio 1:5), aerodynamic conductivity C*L reduced to 0.08

Nozzle inclination optimized to 25°, separation and re-attachment point shifted back by 40% chord length

Bridge tower modeling:

Elliptical conical tower (long axis/short axis ratio 1.5), drag coefficient Cd≤0.7

The tower top is equipped with helix-shaped spoiler wing, which reduces the turbulence intensity in the wake area by 35%.

Precise control of power characteristics

Frequency tuning:

First-order vertical bending frequency ≥ 0.25Hz, torsion frequency and vertical bending frequency ratio> 2.5

Damping enhancement:

Installation of liquid viscous dampers (damping coefficient 2000kN-s/m), the equivalent damping ratio increased to 1.2%

Second, the core technology product matrix

1. Split-type steel box girder bridge

Technical features:

Double main girder spacing of 8-12m, central slot width of 3-5m, Storoha number St≤0.12

Honeycomb stiffening ribs are set inside the girder (spacing 600mm), local buckling safety coefficient ≥ 2.0

Empirical case:

A cross-sea bridge with a main span of 1650m, the vortex vibration amplitude is only 32mm (limit value 50mm) after being subjected to a 65m/s gust of wind

2. Space cable-stayed bridge

Innovative design:

Three-dimensional braided cable (tensile strength ≥2100MPa), space cable inclination error ≤0.1°

Intelligent cable equalization system, temperature gradient ± 20 ℃ working conditions under tension fluctuations ≤ 1.5%.

Wind resistance index:

The wind speed of vibration test is 92.3m/s, which is a world record for the same type of bridge.

3. Wind-transparent truss bridge

Technical breakthrough:

Dynamic adjustment of truss porosity (30%-70%), wind load reduction factor K=0.6-0.9

The key node adopts triple web structure, stress concentration factor ≤ 1.8

Extreme test:

Wind tunnel test simulates 150m/s hurricane, structural residual deformation<L/5000

Third, the whole process of wind protection system

1. Material Strengthening

The main material is Q420qFNH weathering steel, -40℃ impact power ≥ 100J, salt spray corrosion resistance life ≥ 120 years.

High-strength bolts:

10.9S grade friction type connection, pre-tension deviation ≤±5%, slip coefficient ≥ 0.45

2. Manufacturing-level precision

Digital pre-assembly:

Laser tracker calibration, section matching error ≤0.5mm/10m

Welding seam control:

Double-wire submerged arc welding process, UT flaw detection Ⅰ qualified rate ≥ 99.8%.

3. Construction-level wind resistance

Intelligent lifting system:

Beidou positioning + wind speed warning linkage, lifting accuracy under 8 wind conditions to maintain ±3mm

Temporary wind-resistant measures:

Detachable wind-resistant cable system, with wind-resistant capability up to grade 12 during the construction period.

4. Operation and maintenance level monitoring

Health monitoring network:

256-channel anemometer + 400 FBG sensors, wind vibration response sampling rate of 1000Hz

Digital twin platform:

Real-time calculation of aerodynamic stability margins, warning accuracy ≥ 98

Extreme Scenario Solutions

1. Sea-crossing bridge in typhoon-prone area

Technology package:

Pneumatic airfoil active control system + carbon fiber tension cable

The foundation adopts inclined pile group (inclination 1:5), and the anti-drawing force is improved by 3 times.

Engineering Data:

The maximum instantaneous wind speed of a strait bridge is 58m/s during the operation period, and the lateral displacement of the bridge deck is only 18mm.

2. Wind bridge in mountain canyon

Innovative solution:

Asymmetric wind shield design, wind speed gradient adaptability of ±15%.

Gravity anchor + prestressed rock anchor, wind overturning safety coefficient ≥ 2.5

Measured effect:

Bridge site area annual extreme wind speed 42m/s, structural acceleration response<0.05g

3. Urban high-altitude ramp bridge

Response strategy:

Skeletonized steel web combination beams, wind load reduction by 28%

Magnetorheological damper (output force 200kN), axle coupling vibration suppression rate ≥ 90%

Social benefits:

Wind-induced rollover risk reduced to 10^-6/year, far exceeding the industry standard

Contact

Mobile number: 13848510731

Landline number: 0471-6490861

Address: Inside the courtyard of the Outer Transport Company, diagonally opposite the government of Haoqinying Town, Xincheng District, Hohhot City, Inner Mongolia (National Highway 110)