Characteristics and implications of seismic damage in Jishishan Ms6.2 earthquake,Gansu Province
On December 18,2023,a Ms6.2 earthquake occurred in Jishishan Bao'an Dongxiang and Salar Autonomous County,Linxia Hui Autonomous Prefecture,Gansu Province(35.70°N,102.79°E),with an epicenter intensity of VIII degree.After the earthquake,the authors carried out intensity assessment and scientific investigation of the disaster area,statistically analyzed the seismic damage characteristics of different buildings(structures)and lifeline projects in the VI～VIII degree area,and put forward the lessons learned from the earthquake in terms of seismic design of houses and construction management,site amplification effect and seismic secondary hazards,and so on.The results of the study show that:1)The severely damaged and destroyed building structures are mainly concentrated in the old earth-wood buildings,brick-wood buildings,and brick masonry buildings with no or unstandardized defenses.2)The main reason for the destruction of building structures is the non-standardized seismic design and construction of self-built houses,and at the same time,amplification effect of sites and the secondary disaster of earthquakes are also the important reasons for the intensity abnormality and aggravation of the destruction.3)Optimizing and improving the raw earth masonry materials,improving the tie measures between vertical and horizontal walls,and strengthening the structural integrity are effective ways to improve the seismic resistance of civil engineering structures.Popularizing basic seismic measures such as"upper and lower ring beams and structural columns",standardizing the strength of cement mortar,and upgrading the construction level of rural craftsmen can effectively improve the structural integrity of masonry structures and prevent the complete collapse of houses.The walls of indoor restrooms should be effectively connected with the roof and vertical and horizontal walls to improve the seismic performance of the structure.4)Slopes,high river terraces and banks are seismically unfavorable zones.When land for construction is extremely scarce and such a site has to be chosen,a comprehensive consideration should be given to the topographical and geomorphological features of the site,the physical and mechanical characteristics of the rock and soil,hydrogeological conditions,seismic defense objectives,building structure types and other influencing factors,so as to do a good job of assessing the risk of seismic hazards,and set up a scientific seismic fortification according to the results of the assessment.In the process of post-disaster reconstruction,the government should unify the planning of site selection and design,and standardize the construction.
万方数据
