Document Details

Document Type : Thesis 
Document Title :
Buildings Pounding Mitigation using Tying Device
تخفيف تصادم المباني باستخدام أدوات ربط
 
Subject : Faculty of Engineering 
Document Language : Arabic 
Abstract : Adjacent buildings or blocks separated by thermal expansion joints are vulnerable to pounding during earthquakes. Saudi building code specified minimum separation may be very large and do not necessary eliminate pounding forces. This research discusses the feasibility of tying the adjacent building blocks with simple device to mitigate the structural pounding and to study if the required minimum separation by SBC 301-2007§10.12.2 may be reduced to that of a thermal joint. The device will allow thermal expansion and contraction of the adjacent blocks and guide them to sway in phase in order to mitigate pounding. Six and Twelve story moment resistance frames of intermediate ductility were designed for seismic loads for moderate risk. The seismic response was studied for the frames with variable separation distances (10mm-thermal, 25mm-practical, 50mm, 100mm, 200mm, 225mm-code demand, and 300mm-no pounding force). To assess the seismic response, nonlinear response history analysis was conducted using SAP2000 with Four ground motion records. The records had been selected and scaled to match the risk-targeted response spectrum of NEOM city based on ASCE 7-16 provisions. Linear elastic model was used to model the assigned gap links between the adjacent building blocks. Equivalent spring constant value based on floor lateral stiffness was selected as a gap link stiffness. It was found that pounding force increase slightly then reduced with the increase of separation distance. Maximum pounding force reached 600 kN (67% of the design base shear) for the code specified 225 mm separation. Hysteretic damage was slightly affected by separation distance but generally remained within the acceptable response level. The tying device was introduced between building blocks with 10mm allowance to account for thermal expansion of concrete. It was added in the model using a tension only hook links in the model with estimated axial stiffness based on assumed dimensions for the tying devices. The tying devices had successfully reduced pounding forces varying between 40% to 60% for adjacent building blocks with 10mm separation comparing to adjacent building blocks without them. Maximum pounding force with tying devices reached 500 kN, less than that associated with code separated distance. However, it was found that frequency of relatively light pounding was increased when tying devices are used. The tying devices did not show detrimental effect on the hysteretic damage of the frames. Also, observed that hinges hysteretic behavior improved for adjacent building blocks with separation of 10mm comparing to 225mm. recommendations are proposed to enhance the performance of the tying device and further mitigate pounding. Simple design criteria for the tying device are proposed. 
Supervisor : Dr. Mohammed-Sohib A. Alama 
Thesis Type : Master Thesis 
Publishing Year : 1440 AH
2019 AD 
Added Date : Monday, April 29, 2019 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
محمد سالم المصمومMasmoum, Mohammed ResearcherMaster 

Files

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 44394.pdf pdf 

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