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Structural Assessment Considering Architectural Constraints with Seismic Retrofitting
Abstract
The Kingdom of Saudi Arabia is located in a low to medium earthquake zone. Therefore, the inclusion of seismic loads in building design was limited to specific building structures such as highrise and midrise in the past decades. Recently, the development and adoption of the Saudi Building Code (SBC) and the experienced seismic activity at many regions in the Kingdom necessitate detailed seismic design considerations for all buildings. Given this, the current work initially emphasizes assessing structural grids obtained from an architectural plan for an existing building in AL Madina. Then the structure has been analyzed critically in such a way to reduce columns and simplify the structural grid. Also, the orientation of columns has been modified to obtain structure symmetry keeping in view the architectural constraints. Two cases have been developed initially: flat slab and solid slab and designed to withstand gravity loads using Saudi Building Provisions. These cases are analyzed for the seismicity of the Medina Region. Since Medina is less prone to seismicity, the building withstands the lateral load calculated based on static analysis. To assess these buildings for stronger earthquakes, we increased the applied load to assess their capacity. Since both the proposed cases fail to withstand the increased seismic load, a bracing system has been introduced at the locations where it does not disturb the architecture of the building. It was observed that introducing bracing improves the performance of the structures. Therefore concluding that complex structural grids schemes can be simplified, regularized, and economized as well. In addition, bracings provide an easy technique to retrofit already existing RC buildings.
... It was also discovered that durability makes sure the building functions properly and improve the safety of the users. It, however, lasts a relatively long time when supported by intensive maintenance according to its operational time [21,22,33,46]. At Stage 6, (n=6), serviceability (No. ...
The Ampel Mosque in Surabaya is an important historical site for Muslims in Indonesia. The architecture of the Ampel mosque is strongly influenced by Javanese and Arabic culture. a very harmonious integration between Javanese architecture as a form of authenticity and local wisdom in buildings, while Arabic architecture as a complementary and additional component. This research was, therefore, conducted to optimize the maintenance factor in the mosque building to ensure it functions properly and sustainably towards serving as a historic worship place for future generations. Data were collected using questionnaires distributed to the congregants or users of the mosques and analyzed through optimization using a dynamic program based on the level of importance. The results showed seven maintenance factors including the complexity of construction and design, serviceability, building durability, security and safety, aesthetics of the building, user comfort, and maintenance capability. Moreover, the optimization process prioritized the ease in construction work, stability of the construction, durability against structural damage to the building, use of non-hazardous materials, aesthetics of the building, the comfort of indoor and outdoor spaces, and ease of maintenance. These are expected to be the focus of the mosque manager in maintaining the authenticity of the building components. This, therefore, means the Ampel Mosque building can be maintained as a religious tourism destination at the national and international levels in order to ensure its historical value is sustained while the local and national economy is improved.
Climate change and natural resource depletion are likely to affect the future economic development of a country. The generation of power from oil and gas is among the major causes of reserves depletion and global warming. However, renewable energy is also deemed a clean and green choice for power generation to promote sustainability in engineering. The coastal lines of the Kingdom of Saudi Arabia (KSA) are widely extended, and wind energy appears to be a viable alternative to traditional sources, which needs to be investigated as it is highly desirable to seek energy from renewable energy sources, for instance, wind. This paper is aimed at addressing the wind energy potential along the Red Sea coast of KSA. Afterward, a suitable wind turbine based upon careful structural analysis has been proposed, which would form a basis, especially during the machine selection and design phases. For this purpose, seven different sites located along the coastal line, namely: Al Wajh, Umluj, Yanbu, Rabigh, Jeddah, Haddad, and Gizan, were initially selected to assess the wind energy availability. After that, a suitable turbine is recommended for yielding maximum output. It has been found from the reconnaissance that Al Wajh has sufficient land availability that receives high perennial wind speed, alongside shallow offshore water depth for monopile installation. Hence, this site is recommended for the development of a wind farm. Furthermore, turbines need to be installed at the height of almost 100 m to produce maximum energy to appropriately utilize the available indigenous wind energy. It is pertinent to mention that the superstructure of the turbines is designed based on the local loading conditions (wind, currents, waves, etc.) of the Al Wajh region. Also, the monopile substructures are proposed in the selected area in accordance with the available bathymetry.
Infill walls increase the strength and stiffness of the reinforced concrete frames, but they usually are not considering in design. However, when the infills are considered in the design, the opening for doors/windows necessitates investigation as well. This research work aims to investigate the effect of perforations (openings) in the infill walls on the performance of infilled RC frames, in other words, this research investigates the number of infill walls in infilled RC frames. Based on the current construction practices in Pakistan, two full scales perforated infilled RC frames were constructed in the laboratory. One infilled RC frame has an eccentric door and window (specimen-1) while the other has only window at its centre (specimen-2). Both the specimens were tested against reverse cyclic loading (quasi-static test). From the experimental testing, it was found that infilled RC frame having less amount of opening in infill wall has more resistance to lateral loads, have more stiffness and dissipated higher energy as compared to infilled RC frame having a significant size of the opening in infill wall. Similarly, displacement ductility (µD) and Response modification factor (R) also depend on the quantity of opening in infill wall in infilled RC frame.
The building sector is one of the major contributors to global CO2 emission. The energy retrofit of existing buildings reduces CO2 emission in the operation phase but entails new emissions to produce, maintain and dispose the materials used for retrofitting (non-operation CO2 emission). This study analyses the life cycle carbon balance of a building retrofitted to passive house level, considering two alternative standards applicable in Sweden. The study considers the implications of using different building materials for thermal insulation, building façade and windows of the retrofitted building. It also considers different electricity production scenarios, assuming standalone production with fossil coal, fossil gas, and a mix of wind and biomass. Our results show that the operation CO2 emission decreases by between 50-82% in the retrofitted building depending on the passive house standard, with minor deviations between electricity scenarios. The non-operation CO2 emission accounts for between 4-25% of the operation CO2 savings depending on the passive house standard and material option. Deviations between material options are increasingly reduced when assuming fossil gas and wind/biomass for electricity production instead of fossil coal. A careful selection of materials can reduce the net CO2 savings by up to 68%, especially when using wood material.
Nowadays, evaluation of the seismic performance of existing buildings has received great attention. This paper was carried out to study the effect of strengthening the existing reinforced concrete (RC) school buildings in Medina, Saudi Arabia through assessing the seismic performance and retrofitting where seismic analysis and design were done using equivalent static analysis method according to Saudi Building Code (SBC 301) and SAP2000 software. A Typical five-story RC school building designed according to the SBC301 has been investigated in a comparative study to determine the suitable strengthening methods such as RC shear walls and steel X-bracing methods. The results revealed that the current design of RC school buildings located in Medina was unsafe, inadequate, and unsatisfied to mitigate seismic loads. Moreover, adding steel X-bracing and RC shear walls represent a suitable strategy to reduce their seismic vulnerability.
Background: The designing of the reinforced concrete building for the reduction of the seismic load has significantly gained popularity. Most of the buildings in Saudi Arabia are designed for the gravity load, based on its seismicity level. Objective: The study evaluates the effects of the earthquake load on the RC school building located in Saudi Arabia. Method: An equivalent static analysis technique used to apply the seismic analysis and design method according to Saudi Building Code SBC301 (2007). This design code is used to redesign the chosen school building. The SAP 2000 structural analysis software was used to analyses and study the structure behaviour due to the seismic load. Results: The results of the study provide that the RC school building design in Saudi Arabia is inadequate, and unsafe for the earth quakes. Conclusion: One of the important conclusions in this study is that the designer of the school building in Saudi Arabia should take into consideration the earthquake loads. It also emphasizes on the development of the adequate framework for the implementation of the safe designing of the buildings inclusive of earthquake safety measures.
This paper provides general overview on the design principles of steel structures in Seismic Zones. In particular,
seismic design of multi-storey steel structures using limit states (ultimate, serviceability and damageability) and performance
based design approach is firstly discussed and the importance of steel structures is consequently highlighted; then, general
concepts to be incorporated in the structural design are provided. The well-known adopted lateral load resisting systems (moment
resisting and braced frames) are also criticized to highlight the pros and cons of each system. The concept of dissipative and
non-dissipative Zones is given for each lateral load resisting system; and therefore aims to give useful information for the
engineers and technicians involved in the design of steel structures in the seismic zones.
In this research, analytical fragility curves for typical mid-rise plane reinforced concrete moment-resisting frames in Kingdom of Saudi Arabia, KSA, which is considered low-seismicity area, are presented. The fragility curves are developed for 12-story reinforced concrete structure designed according to Saudi Building Code under dead, live and seismic loads. Three cities with different seismic intensities; Abha, Jazan and Al-Sharaf were selected to cover various values of mapped spectral accelerations in KSA. The 0.2-second spectral accelerations range from 0.21 g to 0.66 g while the 1.0-second spectral accelerations range from 0.061 g to 0.23 g. Incremental Dynamic Analysis, IDA, was performed under twelve ground motions using SeismoStruct. Five performance levels; Operational, Immediate Occupancy, Damage Control, Life Safety and Collapse Prevention, which define different possible damage states of a building after an earthquake, were considered and monitored in the analysis. Based on the results of the IDA and statistical analysis, the probability of reaching or exceeding a specific damage state was calculated for each structural model in the three cities. The results were fitted and the fragility curves were developed and presented.
The use of steel structures in the developing countries is limited in spite of its
better performance in the case of seismic events due to its high ductility. Al�though steel structures behave well under seismic excitation, nevertheless the
use of structural steel is limiting these days. This paper aims to address vari�ous parameters related to the capacity design approach involved in the seismic
design of conventional steel structures. Few cases of the early steel structures
construction such as bridges in Pakistan are briefly described. Philosophies
based on the capacity design approach and the importance of conventional
steel lateral load resisting systems with their global mechanisms are pro�vided. The design procedures of Eurocode 8 for Steel Moment resisting
frames, Concentric cross braced frames and Eccentric braced frames are
given and illustrated. It is believed that the paper will contribute and will be
helpful for the designers, researchers and academicians involve in the study
of lateral load resisting systems for incorporating in the design process.
Since synopsis tables are provided, therefore this will allow a clear under�standing of the capacity design approach for different lateral load resisting
systems.
This article summarizes a recent study in the framework of the Global Earth model (GEM) and the Earthquake Model of the Middle East (EMME) project to establish the new catalog of seismicity for the Middle East, using all historical (pre-1900), early and modern instrumental events up to 2006. According to different seismicity, which depends on geophysical, geological, tectonic, and seismicity data, this region is subdivided to nine subregions, consisting of Alborz–Azerbaijan, Afghanistan–Pakistan, Saudi Arabia, Caucasus, Central Iran, Kopeh–Dagh, Makran, Zagros, and Turkey (Eastern Anatolia; after 30° E). After omitting the duplicate events, aftershocks, and foreshocks by using the Gruenthal method, and uniform all magnitude to Mw scale, 28,244 main events remain for the new catalog of Middle East from 1250 B.C. through 2006. The magnitude of completeness (Mc) was determined as 4.9 for five out of nine subregions, where the least values of Mc were found to be 4.2. The threshold of Mc is around 5.5, 5.0, 4.5, and 4.0, for the time after 1950, 1963, 1975, and 2000, respectively. The average of teleseismic depths in all regions is less than 15 km. Totally, majority of depth for Kopeh–Dagh and Central Iran, Zagros, and Alborz–Azerbaijan, approximately, is 15, 13, and 11 km and for Afghanistan–Pakistan, Caucasus, Makran, Turkey (after 30° E), and Saudi Arabia is about 9 km.
Seismic design of steel braced frames in the modern building codes follow the capacity design approach where some of the members are obliged to dissipate energy whereas others are taken care to be protected. In this paper the seismic design methodologies used by European and American approaches for Concentric Cross Braced Frames (CCBF) and Eccentric Braced Frames (EBF) are highlighted. Synoptic tables for the design of such frames of the most advance seismic codes i.e., Eurocode 8 and the seismic provisions of American Institute of Steel Construction (AISC) are provided. Emphasizes are made on the provisions of Eurocode 8 both for CCBF and EBF. Finally, a general conclusion is drawn when dealing with CCBF and EBF.
Pakistan has an extreme climate that requires a heating system during the winter
season and cooling in the summer season. The frequent electric power cut-off due to
energy shortage causes occupants discomfort, especially in summer. In this paper, an
assessment of shallow geothermal feasibility is proposed to provide heating during winter
and cooling during summer. To assess such feasibility, the capital city of Pakistan is,
Islamabad, is considered to assess shallow geothermal energy for different soil types
within the selected region. Isotherms have been developed based on 36 years of data.
Islamabad receives the highest precipitation throughout the year; therefore, wet and dry
soil conditions are considered. The module of heat transfer in solids, implemented in
COMSOL multiphysics, is used, and the simulation results are validated against
analytical solutions within a 2-D context. The results showed that different soil
conditions affect the ground temperature for the same region. A complete 3-dimensional
numerical model of a PVC buried pipe considering sandy and clayey soils is presented
and validated against experimental results using COMSOL simulations. The temperature
history at the pipe ends, the temperature difference, and heat loss/gain, have been
recorded to provide helpful information by justifying the feasibility of a shallow
geothermal system in the region under consideration.
Western Saudi Arabia is tectonically considered as a region of low seismic activity. However, historical and instrumental records reflect some potentiality of earthquake and volcanic activities for the global importance of Al-Madinah City and surrounding areas, it was important to investigate the current state of ground motion affecting this region in light of the historical eruption of AD 1256 and the seismic swarm of 1999 in Harrat Rahat and the seismic swarm of 2009 in Harrat Ash Shaqa (Lunayyir), which forced the evacuation of more than 40,000 of the inhabitants of Al-Ays Town and its surroundings, some 220 km to the northwest of Al-Madinah City. This study is an attempt to develop peak ground velocity (PGV) and acceleration (PGA) maps for western Arabia using four different empirical ground motion relations. We integrated a large dataset merging the current seismicity that has occurred in the western Arabia with those of historical earthquakes and volcanic activities. This study shows that the maximum PGA and PGV values are found in the Gulf of Aqaba with average values of 310 cm/s2 and 52 cm/s, respectively. The Red Sea rift zone comes next with average PGA values between 150 and 230 cm/s2 and PGV values of 24–41 cm/s. Al-Madinah City exhibits an average value of 22 cm/s2 and 6 cm/s, for PGA and PGV, respectively.
Rigid diaphragm is generally an acceptable option in most of the seismic design codes in which the in-plane deformability is not permitted because of the infinite in-plane stiffness properties. Several building configurations may exhibit significant flexibility in floor diaphragms and accordingly using the semirigid diaphragm is recommended as significant in-plane deformation does occur. In this study, a comparative study by using rigid and semirigid diaphragms is performed to identify the related effect on the reinforced concrete (RC) walls. In this study, a numerical study for a twelve-story building with dual system of RC columns and walls is performed. All geometrical and loading properties have been kept constant while using two types of diaphragm as rigid (RD) and semirigid (SRD). The seismic performance of the studied two structures was evaluated in terms of the fundamental period, maximum inter-story drift, maximum base shear and stresses on RC walls. Generally, RD produce results nearly identical to those of SRD for base shear, story displacements and inter-story drifts as the slab is sufficiently thick and membrane deformation due to lateral loading is negligible. Compared to SRD, using RD led to increase the internal moment and shear forces resulted from the seismic loads and acting on the RC walls while the resulting vertical loads are nearly identical.
This paper is initially associated with critical comparisons of Steel Moment Resisting Frames using European and American code methodologies, wherein capacity design philosophyis recommended for the design of steel frames and in which steel is used smartly and efficiently, thereby ensuring the assumed ductility of the system. Interested philosophical concepts have been laid down which are based on the observed issues during the design phase of moment resisting frames. After the application of capacity rules, the primary concern for most of the designers is the lateral stiffness of the frames. Therefore the vital influential parameters of these codes are the response modification factors/behaviour factors, overstrength factors and drift limitations. This research is aimed to disseminate the awareness about the discrepancy between damageability and ductility and thus to mitigate the complexities that exist as hidden inconsistencies during the design phase of MRFs. The here presented philosophical concepts and ideas could be handy and interesting for the Technicians involved in the design of Steel MRFs. Few suggested values are presented at the end of the paper in diminishing challenges while making deciding for ductility class and drift limit.
This paper aims at addressing the variation of fundamental period when the ductility and the damageability criteria varies. In order to investigate the influence of drift limitation on the fundamental period of vibration a huge parametric study using modal dynamic analysis, composed of 144 designed cases of steel moment resisting frames has been conducted. These are compared with the code prescribed fundamental period. It is observed that as the drift limitation varies from the more relax to the most stringent the fundamental period decreases and therefore the stiffness of the frame increases. The obtained period from the code are in the same range to the one obtained from the modal analysis when the strict drift limit is employed in the design.
Current paper deals with the seismic design of 9-Storey office building using Eurocode 8 and AISC (American Institute of Steel Construction) provisions, where the seismic load resisting system is composed of either spatial or perimeter moment resisting frames. According to EC8, Ductility Class High (DCH) and Ductility Class Medium (DCM) with behaviour factor of 6.5 and 4.0 respectively are used, whereas in the case of AISC code, only Special Moment resisting Frame (SMF) with response modification factor of 8 is employed. In order to shed light on the pros and cons of the design criteria and thus the influence on the capacity design rules of the two aforementioned codes, designed frames are analysed by non-linear static analysis. The frame performances are measured in terms of overstrength and redundancy factors, strength demand to capacity and drift demand to capacity ratios, allowing interesting conclusions to be drawn
Saudi Building Code"; 2020
SBC, "Saudi Building Code"; 2020.
Available:https://www.sbc.gov.sa/En/Page
s/default.aspx
(Accessed Dec. 29, 2020).
A note on the structural assessment of perforated panels used in façade
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DOI: 10.9734/jerr/2021/v20i617335
Pushover response of multi degree of freedom steel frames
- M T Naqash
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degree of freedom steel frames. Civ. Eng.
J; 2020.
DOI: 10.28991/cej-2020-sp(emce)-08