The potential earthquake disaster in Liaocheng cannot be ignored. There are many places in China.

The potential earthquake disaster in Liaocheng cannot be ignored.

"Since 1996, Liaocheng has been identified as a national key earthquake monitoring and defense area by the State Council, with a tectonic background of earthquakes of magnitude 5 or above." According to Liu Fali, chief of the Earthquake Prevention and Disaster Reduction Section of the Municipal Seismological Bureau, Liaocheng belongs to the Hebei Plain seismic belt in the North China seismic belt. There are many seismic structural faults in Liaocheng, such as Liaokao fault, chiping fault and Dong 'a fault, which have suffered serious earthquake damage in history. Since the beginning of this year, there have been many felt earthquakes at the junction of Shenxian County in our city and Fanxian County in Henan Province. The potential earthquake disaster that our city is facing at present cannot be ignored.

Among the seismic structural faults distributed in Liaocheng, Liaocheng-Lankao fault is the most important one, starting from Lankao in Henan in the south and reaching Gaotang in the north, with a length of about 270 kilometers. On both sides of this fault, there have been many earthquakes in history, and the largest earthquake recorded in history is17.0 earthquake in Heze in August, 937, with heavy casualties.

"Clear the underground" can "build the ground firmly"

Wang, a researcher at the Seismological Bureau of Shandong Province, said in an interview: "Only by understanding the underground geological environment can we strengthen earthquake prevention and minimize earthquake losses."

Wang said that earthquake zoning will fully consider the influence of earthquake environment, fault structure and site conditions on engineering construction. Through engineering drilling, fault detection, soil wave velocity test, soil dynamics experiment, soil model establishment and seismic response analysis and calculation, the favorable and unfavorable sections of seismic fortification are determined, the failure of faults and their engineering effects are evaluated, and different seismic fortification areas are divided to provide scientific, reasonable, safe and reliable seismic fortification parameters.

The seismic zoning map is a refinement and improvement of the national seismic zoning map, which is more targeted, scientific, reasonable and applicable. The results of seismic zoning will provide an important basis for the revision of urban master plan, functional zoning, planning and construction, seismic fortification of projects and seismic reinforcement of existing projects. At present, zoning first, then planning, then reconstruction; Understanding the underground is a basic work of building firmly on the ground, and it is a concrete practice of earthquake prevention and disaster reduction experience at home and abroad.

It is necessary to find out the fault activity, determine the potential source area, carry out earthquake zoning and determine scientific and reasonable seismic fortification parameters. There are buildings of different importance and heights in Liaocheng, which need to adopt different seismic design parameters. There may be differences between Tuhai River in Liaocheng and Quaternary soil machine structures, which have different seismic geological units, so it is impossible to achieve reasonable seismic purpose by using a set of parameters for fortification. Moreover, the Haihe River and its tributaries pass through, which has the conditions of sand liquefaction and engineering geological zoning, so the evaluation of seismic geological disasters is of great significance.

Avoiding active faults can reduce the earthquake risk.

Wang frankly said that the historical events of earthquake disasters have been proved by facts. As long as engineering buildings avoid active faults and take seismic fortification measures, the harm of earthquakes can be greatly reduced.

From 65438 to 0976, the heavy earthquake zone in the epicenter of Tangshan earthquake was distributed along the Tangshan earthquake fault. During the period of 1995, the hardest hit areas of the Hanshin earthquake in Japan were concentrated along the Nojima-Huishan-Nishimiya fault, and more than 90% of the earthquake deaths were concentrated in the width range of 2-3 kilometers along the fault. During the period of 1999, the hardest hit areas of Izmit earthquake in Turkey were concentrated in the northern branch of the western section of the North Anatolia fault, and all the buildings built on this fault basically collapsed, while the main structure of the buildings only tens of meters away from the fault on both sides was much less damaged; During 1999, the Chi-Chi earthquake in Taiwan Province Province also razed almost all the buildings on the Chelongpu fault and within a dozen meters on both sides, including a solid underground arsenal, while the buildings more than ten meters away were basically intact.

Wang said that practice has proved that earthquake disasters can be greatly reduced by carrying out earthquake zoning and seismic safety evaluation, dividing different seismic fortification zones, determining the distribution of active faults and seismic risks, and taking effective defensive measures, which is of great significance to promoting the economic and social development of Liaocheng City.