Based on the working principle of the wideband tiltmeter,this article categorizes typical faults into control functional faults,signal conditioning faults,and network faults.It analyzes and summarizes the faults and maintenance situations of the wide-band tiltmeter at Linfen Station from June 3 to December 4,2022,deriving a practical set of troubleshooting and maintenance experi-ences.This holds certain reference significance for ensuring the stability of instrument operation and improving the quality of data observation.
Accurate population distribution information is crucial for rapid post-disaster assessment and emergency rescue decision-making.The precision of population distribution data based on administrative divisions no longer meets practical needs.In this stud-y,we integrate remote sensing building data,residential data,natural environmental factors,and statistical population data.Focu-sing on Shanxi Province as the target research area,we establish a mathematical model for kilometer grid population distribution.The generated population grid data from the model are compared and analyzed against real-world situations to verify the model's accu-racy.Improvement suggestions are proposed to gradually develop a simple,efficient,and application-oriented method for gridding population data that meets practical requirements.
The author,a practitioner and witness of earthquake group monitoring and group defense,reviews the history,develop-ment process,and the main work and achievements of earthquake group monitoring and group defense based on personal experiences.It is emphasized that earthquake group monitoring and group defense played a significant role in specific historical periods,leaving a vivid mark in the history of disaster prevention and reduction in our country.The article reminds everyone not to forget this history.
"Regional-Time-Length Algorithm"is a research method that describes the deviation of seismic activity level in a certain re-gion from its background seismic activity level.In this study,this method is applied to analyze the seismic activity variations before 8 significant earthquakes of magnitude 6.0 and above in the North China region since 1970.The results show that an enhancement of seismic activity is observed in all cases,with abnormal periods ranging from 5 to 24 months and significant deviations from the back-ground level.Additionally,the Fourier Transform is used to convert the obtained time-domain values into frequency-domain values,which further enhances the operability of this method.However,determining the extent to which the amplitude rise can be consid-ered abnormal during the change process requires comprehensive analysis in conjunction with other conditions.
To improve the efficiency of instrument calibration management for seismic monitoring station networks,a calibration man-agement software has been developed.The software is designed and developed using the C++ programming language,and it mainly includes five modules:user management,information query,calibration result entry,table output,and backend database.After ap-plying this software to the seismic monitoring station network in Shanxi,it optimizes the original calibration process,reduces calibra-tion time,enhances the efficiency of instrument calibration for the seismic monitoring station network,and achieves unified manage-ment of calibration information.
From September 2021 to February 2022,abnormal changes were observed in the geoelectric field observation data in Heze.To identify the cause of the anomalies,station personnel conducted anomaly recognition and interference elimination work.Through inspections,tests,and comparisons between the main and backup systems of the observation system,external device system,elec-trodes,and electrical circuits in the observation room,interference sources were identified.After eliminating abnormal changes in the geophysical field,it was determined that the abnormal data variation was caused by electrode aging and poor contact between the e-lectrode lead and external circuits.
Analysis of variations and influencing factors of electromagnetic disturbance data at Long County Seismic Station from 2019 to 2021.It is believed that the annual and diurnal variations of electromagnetic disturbance values were found to exhibit a significant negative correlation with temperature.The study explores the influencing factors of electromagnetic disturbance abnormal changes and finds that the electromagnetic disturbance at Long County station exhibits significant coseismic effects for moderate to strong earthquakes occurring within a certain distance from the station.Additionally,the observation data can be easily affected by factors such as lightning,heavy rainfall,and high-power electrical appliances.By summarizing the influence patterns of different interfer-ence factors,it provides a basis for rapid interference elimination and accurate identification of precursor anomalies.
A case study of seismic safety evaluation project in a specific district in Changzhi City,Shanxi province is taken to conduct comprehensive research on the accurate observation of multiple concealed faults such as Anjiazhuang and Ancheng through artificial shallow two-dimensional seismic observation.The research focuses on three aspects:data acquisition,processing,and interpreta-tion.Based on obtaining high-precision imaging seismic profiles,key parameters such as the thickness of the Quaternary cover layer,the location,nature,and attitude of the faults,and the burial depth of the upper fault plane are inferred and interpreted.The results indicate that shallow seismic surveys can accurately detect concealed faults in the target area and provide reliable basic data for their activity identification.It can serve as an important method for the exploration of major concealed faults in the target area during re-gional seismic safety evaluation work.
In order to assess the seismic performance of houses in Ruicheng County,a sampled detailed inspection of building con-struction was conducted.The investigation covered aspects such as building types,proportional distribution,and spatial arrange-ment.The seismic performance of reinforced brick structure houses was evaluated,focusing on the relationship between the width of walls between windows and the height of the lintel above windows,the ratio of lintel height to wall height,the ratio of wall height to wall width,and the stiffness ratio between walls between windows and lintels.Additionally,based on the principle that damage of-ten initiates from lintels during earthquakes,and to maximize the protection of seismic columns or load-bearing walls to maintain the rule that buildings do not collapse during significant earthquakes,an evaluation of the seismic performance of 30 reinforced brick hou-ses in Ruicheng County was conducted.The results indicate that the seismic performance of reinforced brick houses in urban areas of Ruicheng County ranges from moderate to poor,while in rural areas,it ranges from poor to very poor.
Utilizing deep learning methods,we conducted microseismic detection on continuous waveforms from eight stations of the Datong non-natural seismic experimental network and 32 fixed stations from seismic networks in Shanxi and surrounding provinces,covering the period from June 1 to August 31,2022.The automated catalog of non-natural seismic events was generated.A compari-son between the automated and manual catalogs revealed that the automated catalog identified 7.9 times more non-natural seismic e-vents than the manual catalog,with a detection matching rate of 86.9%.Events with a time deviation within 1 second accounted for 91.5%of the total matching events,while those with an epicenter deviation within 5 km constituted 83.0%.Additionally,events with a magnitude deviation within±0.3 ML comprised 81.1%,and those with a depth deviation within 2 km constituted 60.1%.The analysis suggests that the real-time intelligent processing system significantly supplements the completeness of the non-natural seismic catalog in the Datong mining area,demonstrating high localization accuracy.This system can be applied to non-natural seis-mic detection,activity analysis,and localization in the Datong mining area.
Summarizing the advantages and disadvantages of previous seismic monitoring instrument monitoring and management soft-ware,and leveraging the use of big data and smart application technologies,a seismic monitoring management platform tailored to lo-cal needs has been developed.Taking the Suqian Seismic Network as an example,this platform enables the maintenance and manage-ment of seismic monitoring devices,facilitates the quick identification and timely resolution of faults in the seismic monitoring sys-tem,reduces the workload of monitoring personnel,improves instrument uptime and data continuity,and provides timely dissemina-tion of seismic information and display of relevant earthquake prevention and disaster reduction dynamics.Since its implementation,the system allows staff to receive alert messages in real-time regarding network faults,abnormal instrument operating status,and missing data in seismic observation instruments.It also provides timely access to domestic and international earthquake bulletins.As a result,the seismic monitoring level and management efficiency of the network have significantly improved.
地震危险性计算是山西省地震灾害风险普查工程的基础工作内容之一,文章基于概率地震危险性分析方法对山西省地震危险性进行计算.简述地震危险性计算的原理、数据处理与图件制作流程,将计算结果与第五代地震区划图潜源模型的计算结果进行对比分析,结果表明基于风险普查潜源模型的晋西北、晋东南山区计算结果稍有增大;汾渭断陷带内的计算结果略有降低,但差距很小,可认为结果基本一致.同时对产生差异的原因进行初步分析.
房屋建筑抽样详查是山西省地震灾害风险普查工程的关键内容之一,旨在摸清房屋建筑的抗震设防情况、为评估其抗震能力提供支撑.文章以2020-2022年临汾市浮山县房屋建筑抽样详查工作为基础,重点对房屋建筑的结构特征、年代特征及设防情况进行分析.结果表明,临汾市浮山县城区房屋以2000年新建的多层钢筋混凝土结构、砖混结构和高层建筑为主,均采用基本设防烈度8度(0.20 g)进行抗震设防;乡镇及农村房屋以20世纪80年代修建的土木结构为主,基本未进行抗震设防.建议通过采取抗震加固措施进行加固,加强防震减灾科普宣传,提高民众的意识等方式,降低房屋的地震灾害风险.
基于山西省中部、南部4169栋典型农村房屋建筑的抗震性能调查,得到抗震性能属性基本信息,从房屋的地基与基础处理、材料性能与施工质量、结构承载力与整体性能等方面,分析农村房屋在建筑结构抗震方面存在的缺陷.依据调查得到的房屋抗震共性问题,针对性地提出现有房屋与新建建筑抗震性能提升的可行性方案.
为摸清山西省芮城县地震灾害风险状况,基于山西省地震灾害风险普查工程,按照抽样相关规范规定,对芮城县房屋建筑开展抽样详查.对本次调查的79栋建筑物进行分析表明,城区中心、乡镇中心的建筑绝大多数结构使用功能正常;郊区、农村地区个别老旧建筑出现墙体腐蚀剥落、地基不均匀沉降,多数土木结构墙体开裂,地基不均匀沉降.根据详查结果,对该地区典型结构房屋建筑的抗震性能进行分析,并提出相应的地震灾害风险防治建议.
地震灾害风险普查工程是全省自然灾害综合风险普查工作的重要内容之一.按照"三年见成效"的要求,2023年是第一次全国自然灾害综合风险普查全面收官之年.文章全面总结分析地震灾害风险普查工作部署、机制建设、支撑保障能力建设、试点和全面铺开、成果及其应用等重要环节和不同工作阶段的主要经验做法和取得的成效,为下一步震防领域相关重大项目的组织实施提供借鉴.
土层剪切波速是地震小区划和工程场地地震安全性评价中的重要参数.选取临汾市汾河冲积平原一二级阶地和三级阶地共60个典型工程的土层剪切波速资料,分别采用三种经验模型进行统计回归分析,随机选取4个实测钻孔检验拟合程度.结果表明,该地区剪切波速与埋深存在明显的相关关系,将实测结果与拟合结果进行检验,经验关系式与实测的剪切波速值基本吻合,表明可用于该地区剪切波速的推测.
建筑物抽样详查是地震灾害风险评估中的基础工作之一,其结果可为建立科学、可靠的建筑物易损性模型提供基础数据.按照相关的技术规范,对临汾市古县房屋建筑开展抽样详查工作,结合搜集到的城乡住房建筑资料,对古县的砖混结构、多层钢筋混凝土结构、高层结构、砖木结构、土木结构不同类型的房屋从建筑结构特点、存在的抗震设防问题等进行分析,并提出相应的提高房屋抗震性能的建议.
山西断陷带是华北地区新近纪以来构造活动强烈的典型代表,其控盆边界断裂的活动是造成山西省地震灾害风险的重要因素之一.在山西断陷带14条断层填图研究的基础上,利用晚更新世以来滑动速率的比对来表征断层的晚第四纪运动学特征,得出交城断裂、霍山山前断裂和六棱山山前断裂晚更新世以来的滑动速率分别为＞1.4 mm/a、0.76～1.49 mm/a和1.6 mm/a,其余断裂均小于1 mm/a.同时,结合山西省地震灾害风险普查工程中的方案划分山西断陷带活动断层避让区划,探讨不断加强完善山西省活动断层探测工作.
工程场地地震安全性评价活动断层探测成果数据库建设是山西省地震灾害风险普查工程中的一项重要工作.文章介绍数据库建设使用的数据库模板、入库软件等,简述资料收集整理、数据转换入库、检测汇交的过程,并以运城市地震小区划项目为例进行成果展示,讨论数据库建设中数据格式转换、坐标转换等关键点的技术处理.该数据库的建设方法可为其他数据库建设提供参考.
