In case of traffic jam or centralized transportation, the bridge deck is full of cars in a short time, which can be resisted by redundancy. The parking lot has been built for a long time, which is obviously beyond the previous planning.
Period. The good news is that the load of these trains is often calculated by trucks, which are much heavier than cars, and even if they are halved, they will be fully loaded.
Cars are not a big problem.
However, some curved bridges, sea-crossing bridges and rapids-crossing bridges are vulnerable to other unfavorable factors brought by typhoons (wind, water
Force, the impact of floating objects), and additional inspections may be needed after the car is paved. There are also short and wide bridges, the design standards are not high, and they are folded.
The reduction factor can be 0.5, which is a bit risky. Some bridges on rural roads have not considered trucks from the design stage, and may not be full yet.
Shops should not be used as parking lots.
Generally speaking, if they are all urban trunk bridges, they should be safe if they are all stopped. But if the truck driver comes,
If you want to use the bridge deck to avoid water, no matter what bridge, the traffic police should intervene immediately, which is really possible.
Secondly, this shows that the ignorance of the bridge structure by the traffic management department may lead to very serious consequences. In the process of bridge design, the maximum wind load will not be combined with the vehicle load, because according to common sense, when the wind speed is extremely high.
Bridges usually block traffic. Generally speaking, the wind-resistant design only combines the vehicle load with the 50-year wind load, or
Wind load with return period of 100 years is applied separately, and both of them take the most unfavorable value. In other words, bridges that meet the requirements of the code will only consider small winds.
+vehicle or strong wind+no vehicle, it is entirely possible to be damaged under the superposition of strong wind+vehicle.
Especially for those people shown in the video.
As far as cable-stayed bridge is concerned, its stiffness is relatively low and its wind resistance is very poor. In the wind tunnel test, the situation of full-scale vehicles is absolutely not considered.
Aerodynamic characteristics of shape under different conditions. At the same time, the stiffness of cable-stayed bridge is highly related to the load. If a bridge is used,
Its purpose is to tune the mass damper, which may reduce the effectiveness of the damper due to the change of stiffness and frequency. Anyway, this is a comparison.
Danger, I hope the traffic control departments in other parts of the country will never follow suit.
Third, the load that will not appear in typhoon days: temperature gradient temperature. These two will be small in typhoon days, but
Temperature difference has great influence on stay cables, and gradient temperature has great influence on main girder and main tower. These two loads are considered as a normal load combination.
In the room, there is no need to consider this time, leaving some allowance.
Crowd load, this load is unlikely to appear in typhoon days, how big is it? It's usually more loaded than the driveway … leaving a lot of room.
Be measured. The impact coefficient of vehicles need not be considered, but should be considered as 1.05 times (maybe more
More) vehicle load (at least 0.05 times higher), now the car is not moving, so naturally it is not necessary to consider it.
First of all, protecting people's lives and property is the first priority. Is there any objection? Second, Ningbo politics.
The government is accumulating anti-Taiwan experience every year. Will the government take such a risk as the subject said? I prefer to believe that this is a decision made by the government after weighing the pros and cons.
Settings; Finally, if you don't mean geographical discrimination, I'm happy to communicate with you, but if you smuggle contraband and fuck foreign media.
Business activities, then I have to say hello with a big mouth.
The typhoon is heading north, and the wind should slow down before landing. I hope that Zhejiang, Anhui, Shanghai and Jiangsu will be affected by fireworks.
Friends from other places travel safely, friends from Zhengzhou hang in there, and everything will be fine!
Fourth, intuitively feel that the bearing capacity of the bridge is not a big problem. Because when there is a big traffic jam, the bridge is often full of cars, and the vehicle density is the same as this parking.
Almost. At that time, there was no need to worry about bridge load, and now there is no need to worry. Because of the real traffic jam scene, the car will still
There are buses, buses, buses and trucks, which may be full of goods. The total weight of cars arranged in traffic jams is smaller than these empty cars.
The car will be heavier.
When the bearing capacity is satisfied, it will be beneficial to put these cars on the bridge, because each car is equivalent to a damper, which is conducive to lowering the bridge.
Vibration will help a little. ?
When the storm comes, long-span bridges are prone to vibration. For example, the Humen Bridge experienced vortex vibration due to crosswind. suspension bridge
It's a good idea to install a shock absorber before the storm comes, even though the car itself
The damping of the bridge is not big enough, but it is better than nothing.
When the bridge really vibrates due to the storm, it will drive the cars on the upper part of the bridge to vibrate together. As we know, all four wheels of a car are related to cars.
The car body is connected by a shock absorber. When the car vibrates up and down, the shock absorber will consume energy and convert the vibration energy of the storm into
Some heat energy is dissipated, thus reducing the vibration amplitude of the bridge and protecting the bridge to some extent.
Subjectively, these car owners didn't water their cars, but objectively, they also helped the bridge to reduce vibration, which can be regarded as an unintentional good thing.
Fifth, the suspension of the bridge is entirely voluntary. Nobody took care of it at first, because everyone didn't want their baby car to be flooded, and the third one was exclusive.
Row, the innermost owner wants to use the car and finds that he can't get out at all. There are many faults in the car, and the storm and strong wind have not brought disaster, and the road is artificial.
Disaster, the traffic police came, so Yuyao started a humorous joke in various group chats: the parking fee is the most expensive 150 yuan, but it is worse than.
It is cost-effective to raise the premium in the second year after being flooded.
Finally, due to special circumstances, the traffic control department is still very humanized.
By the way, many standard cars used in bridge dynamic load test have a load of 30 tons /35 tons to accelerate, jump and suddenly brake on the bridge.
According to the rules and regulations, if only four trucks are needed to get on the grade bridge, it is estimated that 99%.
The owner didn't do this test, but they are all small bridges, and we can draw a conclusion according to the appearance inspection. I don't know where the bridge collapsed this time because of parking, but because of reasonable disposal, the possibility of blisters is greatly reduced.
Yes, it saved huge economic losses. Flexible praise for Ningbo traffic police.
The trees on the ground were blown down a lot, and some places were flooded, but the tunnel was not flooded and there were no dead people, which was very good.