Effect of building shape on the response to wind and earthquake

With the increase in the application of modern technologies in Civil Engineering, construction of high rise buildings is increasing very hastily. Such buildings are prone to lateral loads from wind or earthquake. Numerous approaches have been adopted to minimize the severe effects of lateral loads on the high rise buildings. Shape of building is one of such approaches. This paper presents a numerical study of the effect of building shape on the response to wind and earthquake. Three different shapes of buildings have been considered in the present study and a comparison between different shaped of buildings against the effect of lateral loads due to wind and earthquake has been presented. Computer aided analysis has been carried out to perform the relative comparison and focus the effect of the shape of building. The Bangladesh National Building Code (BNBC), 2006 has been considered in the analysis. The result depicts that the shape of building has noticeable effect in minimizing the drift of building

Effects of Redundancy in Bracing Systems on the Fragility Curve Development of Steel Jacket Offshore Platform

Steel jacket offshore platforms are typically employed for shallow to moderate water depth. During the platform operation, there are some historical accidents of the complete damages for the diagonal members of the bracing systems owing to explosion, fire and dropped objects. The different locations of damages in bracing members demonstrate different levels of risk for safety and integrity of the structures. This present research studies the effects of redundancy in the bracing systems for steel jacket offshore platforms. The assessments have been carried out by nonlinear pushover analysis method and formation of nonlinear hinges of different members were noted. Redundancy in different positions has been considered to investigate the consequences. Reserve strength ration, RSR and damage strength ratio, DSR of the global structure were also evaluated to understand the importance of different local members. From the collapse data of local failures, fragility curve for the global structure was estimated. The results demonstrated that position of damage can be a great concern which affects the overall performance of the structures. &nbsp

Dynamic Response Mechanics of 45 Degree Angled Layered Cross-Laminated Timber

This research is directed on dynamic properties of cross-laminated timber (CLT) panels constructed with alternate angled layers. All panels were manufactured using a modified industrial CLT production line, and the timber lamellas were glued and pressed together in a single step procedure to form the CLT panels. The paper also presents that the CLT with 45° configuration can be industrially produced at the same material quantity in comparison with standard production. Tests showed that the 45°-configured panels had 30% higher compression stiffness and 15% higher compression strength when compared to the 90° configuration. The results showed that the achieved mechanical properties of the new configuration can be utilized as a suitable construction material

A novel hybridized metaheuristic technique in enhancing the diagnosis of cross-sectional dent damaged offshore platform members

Offshore jacket platforms are widely used for oil and gas extraction as well as transportation in shallow to moderate water depth. Tubular cross‐sectional elements are used to construct offshore platforms. Tubular cross sections impart higher resistance against hydrodynamic forces and have high torsional rigidity. During operation, the members can be partially or fully damaged due to lateral impacts. The lateral impacts can be due to ship collisions or through the impact of falling objects. The impact forces can weaken some members that influence the overall performance of the platform. This demonstrates an urgent need to develop a framework that can accurately forecast dent depth as well as dent angle of the affected members. This study investigates the use of an adaptive metaheuristics algorithm to provide automatic detection of denting damage in an offshore structure. The damage information includes dent depth and the dent angle. A model is developed in combination with the percentage of the dent depth of the damaged member and is used to assess the performance of the method. It demonstrates that small changes in stiffness of individual damaged bracing members are detectable from measurements of global structural motion