International Application of Comprehensive Technical Measures for Mitigation of Earthquake Disasters

The use of high technology to carry out the defense of earthquake disasters is a frontier field of science. Its scale of research and development has been considerable, and some actual progress and results have been achieved.

Natural disasters (earthquakes) have caused severe impacts and damages on the sustainable development of the environment and society and economy. The rapid development of high technology has provided good conditions for effective earthquake disaster prevention. This article will review the application of comprehensive techniques to mitigate earthquake damage.

1 Base isolation technology

The earthquake caused the city destroyed statistics show that in the 1970s caused by the earthquake city 90% of houses collapsed and the death toll more than 90%; in the 1980s to 80% of the houses collapsed and the death toll accounted for 80%; to the 1990s The proportion of houses collapsed and the death toll is between 70% and 60% , and may be lower. Although these statistics is rough, not even reflect the destruction 1990s, several major earthquakes, but it highlighted the huge increase reflects the seismic design of buildings and construction quality, did receive mitigate casualties and property losses of significant effect.

Base isolation technology is the early 1980s, US and Japanese scientists have developed a high-rise buildings seismic technology. This new method is to install clusters of stainless steel balls under each pillar and wall of the house, so that the entire house is supported on the balls. The criss-crossing steel beams (joysticks) tightly connect the house and the housing base. Steel beams are flexible and steel beams can stretch when a strong earthquake occurs. Therefore, the whole housing can have slight back and forth sliding on the ball, which greatly reduces the destructive power of horizontally transmitted seismic waves. Ground isolation techniques typically defined in 3 - 11 using building layer. The technology involves a variety of systems designed to reduce house vibration. The method used by these systems is to install vibration cushions such as rubber elastic pads or friction sliding seats on the bottom of the house.

The base isolation method has been promoted in some high-rise and high-rise buildings in Kyoto and Tokyo, which can increase public safety and save maintenance costs. In earthquake-resistance and reconstruction projects in Los Angeles City Hall in the United States, ground-based seismic isolation technology that can reduce the damage caused by strong earthquakes has been adopted. The 26 - storey tower of the city hall was destroyed in the Beiling earthquake. The transformation project uses a high-rise ground-based seismic isolation technology. 430 rubber septa are installed below the main column in the city hall, just above the foundation. Foundation and installed in the upper multilayer viscous damper 10, and then to attenuate vibrations in the surrounding ground area and width of housing 12 - 30m Moves within the sulcus. In addition, a large number of traditional shear walls will continue to be built on the towers to enhance their anti-seismic capabilities.

2 Structure active control design

The 1985 survey of the Great Earthquake in Mexico showed that the design concept of earthquake-resistant structures in developed countries is developing in the direction of Rocco's earthquake-resistant structure and seismic-free structure. However, these design structures still play a passive role from the perspective of earthquakes. In this case, the U.S. State University of New York and other university institutions proposed to Kashima Construction Co., Ltd. of Japan that the two sides jointly study the active control of structural design technology, which is a second-generation structural design technology that addresses earthquake prevention. As the city’s high degree of informationization is rapidly developing, building smart buildings in cities, renovating urban areas, and adding new landmarks to cities, this technology is moving toward practicality. Structural active control design techniques will make smart homes themselves resilient against earthquakes. This is because the host computer, the personal computer, and the responsive sensing device are installed in the house to give them the function of recognition and judgment. If a large earthquake occurs in a high-information city, besides building an intelligent building with an earthquake-resistant structure and a shock-absorbing structure, the ideal countermeasure is to build an active and intelligent building that is actively controlled by the structure and that is active against earthquakes. system. At present, the 21st- century intelligent building plan for the US-Japan joint design agency has been implemented in the Tokyo Bay, the Hanshin area, and the San Francisco Bay Area , and is included in the work schedule of the International Agency for Disaster Reduction Strategy. In order to successfully mitigate the earthquake disaster, it must be considered. More futuristic features of building technology.

3 smart building materials technology

Scientists and engineers in the construction industry talked about how high technology affects the development of the construction industry. They say that using new technology and building materials will make buildings smarter, and their quality of life will be higher and safer. Several new building materials that have been successfully tested in recent years have the function of diagnosing and self-adjusting the buildings themselves. Various cables and pipelines as well as the environment (wind resistance, earthquake resistance, pollution prevention, etc.) are built between some floors of high-rise buildings and high-rise buildings constructed in the United States, Japan, Mexico, India, Turkey, and Singapore. In the buildings of the monitoring system against harmful radiation, the performance of these new materials has been effectively tested.

The Department of Transportation of California, USA, has transformed new composite materials to replace the house columns and used reinforced concrete columns alone to protect the columns from fracture. This material can also be used for retrofitting of bridge pillars. New tests have confirmed that thin layers of fiber-reinforced composites can be used to wrap the columns to prevent them from breaking during ground motion and enhance their flexibility. Preliminary results indicate that composite materials are stronger than steel materials and are suitable for use in areas where earthquakes are less frequent and earthquakes are less intense. However, adding special fibers will improve the composite's ability to withstand strong earthquakes.

The alloy with shape memory function is a smart material. When the house is hit by a strong earthquake, it can adjust the direction of the house swing in real time and play a solid role.

A special fiber of glass and polypropylene has been developed. When the concrete of a house is subjected to stress, the fiber will be stretched and broken, and a binder will be released to block and repair the cracks in the concrete to keep the building strong. Improve resistance to collapse.

The two major construction companies in Japan (Kashima and Shimizu) tested three types of optical fiber materials that penetrated light and applied them to the relevant parts of the house. If there were cracks during the earthquake, damage was caused to the material and cracks occurred. It will hinder the transmission of light signals, thus alerting the computer monitoring system and providing time for defense against earthquakes.

Another type of optical fiber can also be used to measure stress. Even a slight pull on the fiber will change the length of the light wave and thus provide a signal against earthquakes.

The development of house-specific seismographs is also a promising early warning system. The optical signal or stress signal recorded by the instrument, or the infrasound signal, through the computer program, shows the orientation of vibration in a short time, and also gives people an alarm signal.

4 Space Technology

The use of space satellite technology for earthquake prevention and mitigation is one of the important management tasks of the International Strategy for Disaster Reduction. Space technology involves VIBI , satellite laser range finder, GPS , satellite remote sensing, mobile satellite communications, synthetic aperture radar SAR , space electromagnetic radiation measurement satellite SEMES and other systems. In addition to earthquakes, there are eight kinds of disasters, including water and volcanoes . At present, the International Disaster Advisory Committee has compiled a spatial technology monitoring and prediction system for earthquake disasters, involving seismic feature parameter observation and seismic data resource analysis techniques, pure seismic information display, and technical and social vulnerability computers with time and system concepts. Models, Social Action Models for Earthquake Relief, Communication and Transportation Models for Earthquake Response, Real-time Spread of Earthquake Information to Industrial Enterprises and the Public, Post-earthquake Investigation System Models, Assessment of Space Technology Roles, Impacts, and Lessons Learned in the Entire Disaster Process etc.

Space technology can continuously observe the surface displacement associated with the earthquake cycle of the fault zone, the uplift before the volcanic eruption and the precursor of the landslide. Electromagnetic signals associated with hydraulic movements of geological structural fractures are an indicator of regional tension stress changes associated with these hazards. It has been demonstrated that these signals can be observed from satellites orbiting the Earth. The most important is to use space communication technology to transmit real-time geophysical parameters that can only be measured in the field for disaster assessment and for issuing alarms to the data processing center to obtain disaster reduction measures. The government agencies take measures to mitigate the earthquake. The impact of disasters.

5 Satellite Image Applications

In May 2000 , the Sustainable Development Strategy Forum proposed that in order to defend against natural disasters, satellite imagery resources should be fully utilized (hundreds of reports, hundreds of thousands of reports, prices ranging from a few dollars to tens of thousands of dollars) ). The solid earth satellite includes rivers and mountains, canyon faults, and so on. For earthquake disasters, what is needed is the seismic zone and its strike, large faults and extensions, location of large cities on seismic hazard belts and their surrounding conditions, deployment of global geophysical monitoring stations (nets), and volcanic activity belts. The location, etc., also require satellite orbits to pass through these locations and photos of satellites, GPS , remote-sensing satellites, geodetic satellites, special mission satellites, and orbital surveys. The Thornton Earth Observation Satellite Space Imaging Company, based in Colorado, USA, supplies some of these satellite photographs. For example, some oil and gas companies (Shell) use space imaging of the ground to determine the petroleum pipelines and avoid faults to prevent tearing. The system, in cooperation with the Geological Survey Bureau, installed seismic monitoring stations on and near the fault to serve the company's seismic work. U.S. FEMA used Wei Zhao to assess the extent of the damage caused by the earthquake and proposed a reconstruction plan. Indian Digital Technology Corporation took advantage of the images of two seismic disasters photographed by commercial orbit remote sensing satellites and used a network computer system to provide the Indian government with a technical plan for the reconstruction of the disaster area and to obtain relief funds for the United Nations and related banks. Regions and countries that experienced major earthquakes in 1999 , such as Turkey, Greece and Taiwan Province of China, purchased related photos to plan the disaster area. Some earthquake-hit countries, such as several countries in South America, use Weizhao to establish a national emergency communications system. In case of disaster, computer communications will supplement the damaged ground communications network. Therefore, satellite photographs have become an important resource for the prevention and mitigation of natural disasters and should be given due attention by the relevant departments of the earthquake system.

In summary, the successful application of comprehensive technical means for mitigating earthquake disasters in recent years is mainly reflected in:

1 General awareness of disaster reduction;

2 Great progress has been made in theory and technology for disaster reduction;

3 Disaster prevention technology and its application are widely promoted;

4 To further promote international disaster reduction.

The strategy laid a good foundation. In the unknown disasters and catastrophes, defensive disasters are the priority scientific research projects. Use high