Abstract: Generation of an artificial earthquake ground motion for specific purpose mainly to develop a ground motion time-history at the ground surface as a basis to design and assess the structure at a site due to the earthquake load, so the thing should be carried out. To see the effect of the soil response to the earthquake ground motions frequency characteristics change, then two time-histories with different frequency characteristics have been generated. The time-histories is generated in based on the one time-history in base rock result of measurement. The time history then is developed to be two time-histories with the spectral matching method in two mathematical domains namely time and frequency domain. The results of spectral matching are two time-histories with differ frequency characteristic namely time history with narrow and blunt frequency characteristic. The both time history then were utilized as the earthquake ground motion waves in base rock. The waves have been propagated from base rock to the ground surface used a soil response analyses theory. The results of the analyses were acceleration and spectral amplification factor at ground surface caused by the soil response tend to decrease from the time history with narrow to blunt frequency characteristics. Relative velocity and displacement caused by the response of the soil layers tend to increase from the narrow to the blunt frequency characteristics.Abstract: Generation of an artificial earthquake ground motion for specific purpose mainly to develop a ground motion time-history at the ground surface as a basis to design and assess the structure at a site due to the earthquake load, so the thing should be carried out. To see the effect of the soil response to the earthquake ground motions frequency chara...Show More
Abstract: When a strong earthquake occurs, buildings are often damaged in varying degrees. The safety assessment of earthquake-damaged buildings is an important part of post-earthquake emergency rescue work. The aim of safety assessment is to quickly and effectively assess the safety of damaged buildings and reduce the loss of life and property of people in disaster areas. In the past, the safety appraisal of earthquake site was carried out according to experts' experience, the appraisal results varied from person to person, and the appraisal efficiency was low. In this paper, the seismic safety and availability standards are established by summing up the rich experience of earthquakes in China, and the relationship between these standards and different damage states is proposed, the damage assessment of reinforced concrete and masonry structures is specified in detail. The damage states of different structural and non-structural components are quantified, and the previous seismic damage pictures are added. Then, according to the severity and quantity of earthquake damage, the safety evaluation rules of the whole building are established, and the earthquake damage of the whole building is evaluated. The results show that the safety evaluation results based on these rules are consistent with the actual situation. Therefore, the proposed method can be used for fast and effective security identification.Abstract: When a strong earthquake occurs, buildings are often damaged in varying degrees. The safety assessment of earthquake-damaged buildings is an important part of post-earthquake emergency rescue work. The aim of safety assessment is to quickly and effectively assess the safety of damaged buildings and reduce the loss of life and property of people in ...Show More
Abstract: The structural behavior of pavements can be affected by seasonal variation in environmental factors such as temperature and moisture content. In Ethiopia the design, construction and maintenance process of roads mostly give attention to structural thickness of pavement layers, on which the designers and authoring focus on expected future traffic. However, it is critical to admit in practical the variation of pavement material properties due to seasonal environmental changes, especially the temperature and moisture. This study focused on assessment of the impacts of environmental factors (temperature and moisture) on performance of flexible pavement in generally and particularly on Tarcha-Omo River highway, hence doing this study, the objectives were: to investigate the impact of temperature on the performance of selected highway, analyze the impact of moisture on the performance of pavement through laboratory based investigation and to examine the efficiency of the drainage system in removing excess water from the pavement structure of selected highway by collecting all primary data from the project site and secondary from, standard specification, Ethiopian roads authority, Omo River-Tarcha road upgrading project. An assessment was done by using both field observation and laboratory tests to characterize materials toward the factors. The field observation was made to investigate the condition of drainage system in removing water from pavement and surrounding. The sample of base course, sub base and sub grade were collected from three different sampling stations and laboratory tests were conducted and finally compared with standards to check the moisture sensitivity of materials. NMC, Compaction, Particle size distribution, CBR and Atterberg’s Limit were tests conducted.. The assessment showed that temperature and moisture has considerable impact on performance of flexible pavement and the pavement failed due to moisture variation on pavement base, sub base and subgrade, due to, inadequate drainage facility, lack of effective protection work and excessive water in the sub grade in first section and temperature in second section of study. Therefore Standard of construction and design should be improved. More research should be carried out on the engineering geo-techniques of study road.Abstract: The structural behavior of pavements can be affected by seasonal variation in environmental factors such as temperature and moisture content. In Ethiopia the design, construction and maintenance process of roads mostly give attention to structural thickness of pavement layers, on which the designers and authoring focus on expected future traffic. H...Show More