What is the disaster prevention performance of American houses?

The environment in which human beings live suffers from various dangers and potential crises all the time. Therefore, it is more important to invest in overseas real estate and prevent natural disasters. Let's talk about the disaster prevention performance of American houses from the immigration network.

Natural disasters such as earthquakes, volcanoes, mudslides, typhoons and tsunamis, especially earthquakes and tsunamis, are the most difficult to predict and the most harmful, just like the sword of Damocles hanging over people's heads, threatening people's lives. On April 25th, Nepal, the only holy and beautiful country on earth, was the birthplace of Buddhism. In this 8. 1 earthquake, thousands of people were killed and houses collapsed seriously. Among them, 12 world cultural heritages were damaged in this earthquake, and most of them completely collapsed, causing great losses to the world.

Behind this series of figures, there is a very important question. The lack of seismic capacity of buildings is one of the main causes of economic losses and casualties. When disaster strikes, human beings will instinctively think that if people live in an extremely hard fortress, they will not be affected.

But the reality is that the layout of buildings in the earthquake zone is compact; Narrow streets and lanes; Poor housing structure; Weak earthquake resistance; Houses are mainly masonry structures, which is the main reason for the large-scale collapse of houses. So how do Americans who are also in the earthquake zone use their houses to prevent earthquakes and disasters? What is worth learning?

First, the per capita housing area is large and the population is scattered.

The population of the United States is about 250 million, and the level of urbanization is as high as 80%. However, the population is relatively scattered, the per capita living area is nearly 60 square meters, and the self-owned housing rate is about 66%, ranking first in the world.

Although there are many international metropolises in the United States, such as new york, Boston and Chicago, the degree of urban-rural integration is extremely high. According to the latest data from the US Census Bureau, there are 1 10,000 to 200,000 cities in the urban structure of the United States 13 1; There are 878 from 30,000 to 65,438+10,000; There are more than 34,000 small cities (towns) ranging from thousands to 30,000. Among them, small cities (towns) with less than 65438+ 10,000 people account for about 99% of the total number of cities. In this way, the relatively scattered urban geographical distribution and personnel distribution can control the losses in a limited range when major natural disasters come.

Secondly, the building floor, wood and frame-shear wall structures at the bottom are common.

California, USA, located in the Pacific Rim seismic belt, is an earthquake-prone area, with a magnitude of 1906 San Francisco of 8.3; 1989 San Francisco earthquake with magnitude 6.9; 1994 los Angeles earthquake with magnitude 6.6. Therefore, local laws require buildings to resist earthquakes. In terms of architectural form, most houses in the United States are below the third floor, and even many state capitals have laws expressly stipulating that if houses with more than three floors are to be built, they must go through very strict and cumbersome approval procedures. This will inevitably increase the construction cost, delay the project time, and the loss outweighs the gain.

Houses with wood structure are generally welcomed by people because of their excellent seismic function. The advantages of this kind of house are low cost, high speed, good thermal insulation and good seismic performance. Facts have also proved that wooden houses can effectively protect people's lives in the face of earthquake disasters.

For a big city like new york, high-rise buildings begin to adopt the new structure of "frame-shear wall". It can not only provide enough space to meet the needs of various functions, but also provide greater lateral stiffness to prevent the building from tilting and improve the seismic performance of the building structure. Compared with masonry structure and frame structure, "frame-shear wall" structure has better seismic performance.

1994, a strong earthquake of magnitude 6.6 occurred in Los Angeles, USA, with the epicenter located 35 kilometers northwest of Los Angeles. Although it was a moderate earthquake, the intensity was not as good as that of Nepal earthquake, but it was located in the economically developed area of Los Angeles, and the losses were equally heavy. Thousands of buildings were destroyed, highways were broken, water, electricity and gas were cut off, and the losses were staggering. Surprisingly, only 62 people were directly caused by this earthquake.

In 20 14, an earthquake of magnitude 6.0 occurred again in northern San Francisco, California, USA, with a focal depth of 1 1 km. Although many people in San Francisco felt the earthquake, there were no casualties and property losses were relatively light.

One of the main reasons is that there are a large number of low-rise wooden houses in severely affected southern California. Because of their relatively loose structural layout, low floors and light weight, the damage to people can be greatly reduced when they are damaged by strong earthquakes. The chances of people living in wooden houses are much higher than those living in brick and reinforced concrete structures, because most of the deaths caused by earthquakes are caused by the weight of roofs and walls.

Three, the housing function is perfect, and the disaster prevention system is complete.

Americans generally want to buy their own houses, so they prefer to scrimp and save. Although with the evolution of the times, many people choose to rent a house, for most Americans, owning a house that really belongs to them is still the core of their "American dream".

Americans attach great importance to the quality of life, so the supporting facilities of a house will be very complete. An ordinary house will have: living room, bedroom, bathroom, storage room, laundry room, garage and so on. , including air conditioning, heating and hot water. Many Americans also store some medicines, food or other disaster prevention supplies in the storage room for emergencies. In addition, in places where hurricanes and tornadoes are severe, people usually dig a basement strong enough to hide when disasters come.

After an earthquake or other disaster, water, electricity and food are usually cut off, and diseases will spread. Although many people survived the earthquake, food and water shortages and diseases may also bring another disaster. The Haiti earthquake in June 20 10 is a very unfortunate example. People fought bloody battles in the streets, killing each other for water and food, and the situation was out of control for a time, and diseases such as cholera spread even more. It can be seen how important it is for people to cope with post-disaster life faster and prevent the emergence of post-disaster epidemics.

Four, the establishment of specialized departments, effective emergency and early warning mechanism.

Taking California as an example, the "California Residential Disaster Reduction Plan" has been specially set up to provide a certain amount of cash subsidies for houses in earthquake-prone areas to repair houses that may be damaged in the earthquake.

Generally speaking, the applicant must meet the specified conditions. The house is required to be built before 1979 within the earthquake danger range, such as Los Angeles, Santa Monica, Pasadena, San Francisco, Oakland, San Leandro and other northern California areas, with unstable foundation and cracks in the wall. Each homeowner can get a cash subsidy of $3,000, and it is estimated that at least 575 families will benefit from this project.

After the "9. 1 1" incident in the United States, the United States government formulated a federal emergency mechanism, and state capitals also improved local emergency plans, such as requiring all hospitals in California to set up intensive care units and emergency rooms in buildings with earthquake resistance.

The United States Geological Survey (USGS) uses surveying and mapping satellites and other known knowledge to establish earthquake prediction models, calculates the probability of earthquakes of various levels that may occur in a certain area every day, and then projects the probability values on the regional map with different colors according to real-time data to obtain a series of distribution maps. On its official website, you can query the probability of earthquakes in places you care about in real time, so as to decide whether to take measures to avoid or reduce the losses caused by potential earthquakes as much as possible.

Take precautions, and never take disasters lightly. Compared with the strict rules and regulations, disaster prevention and early warning mechanism, rapid response speed after disasters and universal knowledge popularization in the United States, we still have a lot to learn in earthquake prevention and disaster prevention.