At 23:59 on December 18, a game of 6Level 2** raided Jishishan County, Gansu Province, and as of 8 o'clock on the 22nd, a total of 117 local people were killed and 781 people were injured, nearly 150,000 houses collapsed. 6.Why did Level 2** cause a large number of houses to collapse?In recent years, has the security of rural housing been in place?What are the difficulties in improving the seismic performance of rural self-built houses?The relevant person in charge of the Gansu Provincial Department of Housing and Urban-Rural Development responded to the above questions.
Wang Yong, deputy director of the Gansu Provincial Department of Housing and Urban-Rural Development, said that this time it is a backlash type, and the energy released by itself is greater. At the same time, Jishishan County is located on sedimentary strata, at the junction of the Loess Plateau and the Qinghai-Tibet Plateau, on the western edge of the Loess Plateau. Relevant studies have shown that the occurrence of ** in the Loess Plateau will have a more significant site amplification effect, resulting in greater surface destructive power.
According to the Ministry of Emergency Management's "Gansu Jishi Mountain 6Level 2 ** Intensity Map", the maximum intensity of this ** reached 8 degrees, with an area of 331 square kilometers, mainly involving Dahejia Town, Liuji Township, Shiyuan Town, Liugou Township and other hard-hit areas in Jishishan County. Wang Yong said that this maximum intensity exceeds the 7-degree fortification intensity of Jishishan County determined in the relevant annex of the national standard "Code for Seismic Design of Buildings", and at the same time, rural housing is mainly self-raised, self-built and self-used, and the seismic performance is uneven, which is the main reason for the collapse of houses.
*After the incident, the Gansu Provincial Department of Housing and Urban-Rural Development organized various forces to carry out emergency housing assessment in the disaster area, and nearly 50,000 households have been assessed so far. Ma Xiaodong, director of the village and town construction department of the Gansu Provincial Department of Housing and Urban-Rural Development, said that most of the collapsed and seriously damaged houses were built earlier, and the newly built or rebuilt farmhouses in recent years have wall cracks and flashes, and there is basically no overall collapse.
In recent years, Jishishan County has promoted the transformation of dilapidated houses in rural areas, solved the safety problems of the people's main residential houses in daily use, and subsidized projects that have passed the acceptance. Ma Xiaodong said that the collapsed houses are mainly partial houses and auxiliary houses built by the villagers themselves, and most of these houses are adobe, civil or brick structures, and the load-bearing walls are earth walls or brick walls, and the parts connected by the wall and the wooden frame are not firm, the integrity is not strong, and the seismic performance is weak.
In addition, although some rural households have built new houses, they have kept some of the old houses, and prefer to live in the old houses in winter, because the old houses have traditional rural ondols. The assessment found that many** was caused by living in an old house.
Experts said that the disaster highlighted the urgency of improving the seismic performance of rural houses. Wang Yong and others pointed out that improving the seismic capacity of rural housing requires many efforts, and it is necessary to further popularize and enhance the awareness of rural households to build earthquake-resistant houses, strengthen the technical guidance and construction management of rural houses to resist earthquakes, promote the use of building materials with better seismic performance, and train qualified rural construction craftsmen.
Experts also suggested that in the project to improve the quality and safety of rural houses, we should increase support for the seismic renovation of rural houses in remote areas, and continue to improve the seismic capacity of rural houses.