Comparative Parametric Analysis of Opening Area Usage of Shear Wall in Different Percentages Relating to Wall Area Used for Multistorey Building

It is highly recommend that the structure should be efficient in terms of the cost in diverse manner. To reduce the overall cost of the project, the cost cutting should be done in every construction stages. The dual systems in building structure consist of structural walls and moment resisting frames. The structural wall members are made up of RCC, which is a costly structural member. The purpose of current study is to explore the reduction in shear wall area in multi-storey building for reduction of overall project cost. Total 5 buildings abbreviated as SOA, SOB, SOC, SOD and SOE framed in analytical software supposed to be situated at Seismic Zone III. After the comparative result analysis, it proves that, the reduction in shear wall area should be adapted to a certain limit due to load transfer criteria of the members 20 % wall deduction is sufficient. Building SOD with 80% coverage performs best of all. Keywords: Deduction Area, Earthquake Effects, Opening Area, Shear Wall, Response spectrum, Wall Area Reduction, Wall Deduction Ratio.

Earthquake Damage Reduction in Timber Frame Houses Using Small-Size Fluid Damper

Timber frame structures are common traditional methods of housing construction, which use squared-off timber beams, columns, and walls as lateral load-bearing members. The seismic performance of timber frame houses can be secured by the load-bearing capacity of erected braces and walls; however, past major earthquakes have caused severe damage to earthquake-resistant timber frame houses. This study investigates the effect of small-size fluid dampers on the earthquake damage reduction in a timber frame house through earthquake response analyses. A detailed analytical model was generated based on an actual two-story timber frame house, which was designed for the highest seismic grade using the latest Japanese standards. Time-history response analyses were carried out for the analytical model subjected to the 2016 Kumamoto earthquake with and without small-size fluid dampers. The small-size fluid damper is equipped with a relief mechanism for the damping force, and its damping property can be expressed using the Maxwell model. Four or seven fluid dampers were installed in the first story of the model to investigate their effect on the earthquake damage reduction. The results of the earthquake response analyses show that the four and seven fluid dampers can reduce the maximum first-story drift angle by approximately one-third and half, respectively. The dampers suppress the residual deformation, control the elongation of the fundamental period during the response, and restrain the amplitude growth. A small-size fluid damper has an equivalent quake resistance to a conventional structural wall with a wall ratio of 3 plus.

Prediction Method for Condensation Heat Transfer in the Presence of Non-condensable Gas for CFD Applications

The objective of this study was to present a prediction method for condensation heat transfer in the presence of non-condensable gas (air or nitrogen) for CFD (computational fluid dynamics) analyses, where physical quantities in the computational cells in contact with the structural wall are generally used. First by using existing temperature distributions T(y) in the turbulent boundary layer along a flat plate as functions of the distance y from the condensation surface, we evaluated the distribution of condensation heat flux qc,pre(y) from the gradient of steam concentration, we derived a modification factor η(y+) as a function of the dimensionless distance y+ to obtain a good agreement with qc,cal calculated by the qc correlation defined by using the bulk quantities; and we obtained qc,mod(y)/qc,cal = 0.90-1.10 for the region of y+ > 17. Second we modified the local Sherwood number Sh(x) for flat plates for the boundary layer thickness d and obtained the function Sh(d). An existing qc correlation for flat plates as a function of Sh(d) was applied to predict the distribution of the local value qc,pre(y), and qc,pre(y)/qc,cal = 0.95-1.15 in the best case was obtained for the region of y+ > 30. Finally a correlation of the local Sherwood number Sh(y) was derived from the temperature distributions T(y) as a function of the local Reynolds number Re(y).

Inverted pyramid Azores - an eternal hybrid structure

Engineering structures are designed with observation of rules for structural performance under specific design loads, defined in the so-called structural codes. While dead loads are directly dependent from the selection of structural materials to a given structural function, live and accidental loads are often linked to the region where the structure must perform. In a complete opposition to engineering principles in Ancient Egypt, the inverted pyramid was designed to become a statement of how to bend gravitational laws, and what can be achieved by modern engineering, sill with intelligence to fulfill its function in a region where engineering structures are subjected to extreme live and accidental load regimes, e.g. high risk of earthquakes and high wind seasonal loads. A hybrid structural concept was specified, comprising lightweight structural wall elements anchored to a relatively heavyweight structural core. The suggested design concept fulfills the global equilibrium equation defined by architecture, and should become a structural example from a structural design perspective. As any other project involving non-comprehensive geometry, design and construction of the inverted pyramid is highly sensible to management options, which shall assure high precision manufacturing, and accurate control of its production.

Seismic Performance of Grille-Type Steel Plate Concrete Composite Walls with Application in a Super-High-Rise Building

The grille-type steel plate concrete composite wall (GSPCW) is an innovative shear wall system that mainly consists of steel faceplates, steel tie plates and infilled concrete. Compared to traditional steel plate concrete composite shear walls, the advantages of GSPCW walls include: (1) relatively high lateral and buckling resistance; and (2) simple structural measures for convenient construction and implementation. This paper presents the results of extensive numerical investigations regarding GSPCW systems, examining both GSPCW wall components and their application in a super-high-rise building as a case study. First, typical GSPCW wall models are established using DIANA software, and the numerical models are validated on the basis of comparison with results from previously reported experimental tests. The verified models are further used to perform parametric analyses with the aim of further understanding the effects of various design parameters on the seismic performance of GSPCW systems, including steel ratio, axial load ratio, height-to-width ratio, aspect ratio of the grille steel plate, and concrete compressive strength. Second, a super-high-rise building was selected for application to perform a case study of a GSPCW system. The seismic performance of the tall building in the case study was comparatively evaluated on the basis of both nonlinear time history analysis and modal pushover analysis (MPA), and the results from both of these methods validated the use of GSPCW is an efficient structural wall system appropriate for use in super-high-rise buildings. Finally, a simple economic assessment of the GSPCW building was performed, and the results were compared with those obtained for conventional reinforced concrete wall buildings.

Sustainable Reinforced Concrete Design of Structural Walls

Sustainability calls for reduction in the use of natural resources and man-made materials. In light of this, the present study demonstrates the potentials of the reduction of transverse reinforcement in structural walls. A structural wall 1.7 m long was designed following the Greek Code for Reinforced Concrete (GCRC). This wall was then constructed and tested under cyclic loading. The theoretical value of the uncracked stiffness was four times greater than the value calculated after the experiment. The wall was also designed according to the Compressive Force Path method (CFP), which allowed for a significant reduction in the transverse reinforcement for the same target values.