scholarly journals Correlation Analysis of Factors Affecting Shoring Construction Techniques in Central Business District of Addis Ababa, Ethiopia

2020 ◽  
Vol 14 (10) ◽  
2020 ◽  
Author(s):  
Hailemariam Kassu ◽  
Eyob Mekonnen ◽  
Dumesa Gudissa ◽  
Emer Quezon

Recent urbanization of central parts of Addis Ababa has necessitated the use of deep excavations for the foundation of high-rise buildings and related infrastructure projects. The conditions of the subsoil, the safety of neighboring structures, groundwater conditions, experience by contractors, working space, the effect of vibration, and noise must be considered for the choice of deep excavation support system. Besides, economic factors, local availability of equipment, and technical staff are also governing factors for choosing an appropriate shoring technique. The study focused on the major construction methods and techniques of shoring works in Addis Ababa, Ethiopia. Only four projects utilized shoring construction techniques from the total number of high-rise buildings available in the City. The target population included a minimum of twenty respondents from the four construction sites constructed around Beherawi, Lideta sub-city in Addis Ababa. Two of the projects were supervised by Specialists from Varnero Foundation and Meseret Foundation PLC. Primary and secondary data are gathered to support the objective of the study. All the frequency distribution, Reliability, and Pearson correlation were analyzed using SPSS. All groups of factors that affect shoring construction were ranked using the Relative Importance Index (RII). Results indicated that geotechnical investigation, building type, and excavation depth were the major factors with an RII value of 0.89 and 0.86, respectively. Besides, the analyses showed that were strong correlations between the different factors within each group of factors in undertaking the shoring construction. Hence, it is suggested to take a deep and detailed sub-soil investigation to determine the suitability of shoring materials, appropriate construction methods, and techniques.


2022 ◽  
Author(s):  
Jiaoe Wang ◽  
Yanan Li ◽  
Jingjuan Jiao ◽  
Haitao Jin ◽  
Fangye Du

AbstractUnderstanding the temporal and spatial dynamics and determinants of public transport ridership play an important role in urban planning. Previous studies have focused on exploring the determinants at the station level using global models, or a local model, geographically weighted regression (GWR), which cannot reveal spatial autocorrelation at the global level. This study explores the factors affecting bus ridership considering spatial autocorrelation using the spatial Durbin model (SDM). Taking the community in Beijing as the basic study unit, this study aims to explore the temporal and spatial dynamics of bus ridership and identify its key determinants considering neighboring effects. The results show the following: (1) The temporal dynamics are quite distinct on weekdays and weekends as well as at different time slots of the day. (2) The spatial patterns of bus ridership varied across different time slots, and the hot areas are mainly located near the central business district (CBD), transport hubs, and residential areas. (3) Key determinants of bus ridership varied across weekends and weekdays and varied at different time slots per day. (4) The spatial neighboring effects had been verified. This study provides a common analytical framework for analyzing the spatiotemporal dynamics and determinants of bus ridership at the community level.


2016 ◽  
Vol 55 (3) ◽  
pp. 723-741 ◽  
Author(s):  
Xiao-Ming Hu ◽  
Ming Xue ◽  
Petra M. Klein ◽  
Bradley G. Illston ◽  
Sheng Chen

AbstractMany studies have investigated urban heat island (UHI) intensity for cities around the world, which is normally quantified as the temperature difference between urban location(s) and rural location(s). A few open questions still remain regarding the UHI, such as the spatial distribution of UHI intensity, temporal (including diurnal and seasonal) variation of UHI intensity, and the UHI formation mechanism. A dense network of atmospheric monitoring sites, known as the Oklahoma City (OKC) Micronet (OKCNET), was deployed in 2008 across the OKC metropolitan area. This study analyzes data from OKCNET in 2009 and 2010 to investigate OKC UHI at a subcity spatial scale for the first time. The UHI intensity exhibited large spatial variations over OKC. During both daytime and nighttime, the strongest UHI intensity is mostly confined around the central business district where land surface roughness is the highest in the OKC metropolitan area. These results do not support the roughness warming theory to explain the air temperature UHI in OKC. The UHI intensity of OKC increased prominently around the early evening transition (EET) and stayed at a fairly constant level throughout the night. The physical processes during the EET play a critical role in determining the nocturnal UHI intensity. The near-surface rural temperature inversion strength was a good indicator for nocturnal UHI intensity. As a consequence of the relatively weak near-surface rural inversion, the strongest nocturnal UHI in OKC was less likely to occur in summer. Other meteorological factors (e.g., wind speed and cloud) can affect the stability/depth of the nighttime boundary layer and can thus modulate nocturnal UHI intensity.


2017 ◽  
Vol 117 (3) ◽  
pp. 284-289 ◽  
Author(s):  
Melissa Pike ◽  
Dirk H. R. Spennemann ◽  
Maggie J. Watson

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