Seismic Performance Of Reinforced Concrete School Buildings In Sabah

One of the methods to evaluate the seismic performance is the nonlinear time history analysis where the structural models are imposed to the real or artificial earthquake ground motion records. Current practice only considers single earthquake in the analysis. However, in reality the earthquake tremors are always occur multiply. Ranau earthquake which occurred on 5th June 2015 was also not a single earthquake, but followed by several number of aftershock. This project investigated the performance of reinforced concrete school buildings in Sabah when subjected to multiple earthquakes. A total number of 3 models of school building which have 2, 3 and 4 storeys has been used for the project. . All models have been designed based on BS8110 to represent the existing reinforced concrete school buildings. A total of 7 ground motions for both single and multiple earthquake has been considered in nonlinear time history analysis conducted on all models. All models are assumed to be located in moderate seismic region in Sabah, Malaysia. Based on a series of nonlinear time history analyses, this study concludes that the action of multiple earthquake has contributed around 55% to 107% higher interstorey drift ratio compared to the single earthquake. Thus, multiple earthquake should be considered in order to design new buildings as well as the evaluation for maintenance and rehabilitation for existing buildings

Cost Estimation of Structural Work for Residential Building with Seismic Design Consideration

The Sumatra-Andaman earthquakes had triggered local earthquakes in Malaysia by reactivation of ancient inactive faults. Previously on 5th June 2015, Ranau, a region located in Sabah, Malaysia, had experienced a moderate earthquake of Mw6.1. The structural failures occurred because all existing buildings only designed for gravity load without any seismic provision. Recent research work exhibits the seismic designs’ impact on the cost of material and its parameters that impact the cost. There are two types reinforced concrete residential buildings called Type 1 and Type 2 for two storey and four storey which had been used as models. This research applied four seismicity levels to the reference peak ground acceleration value, αgR = 0.07g, 0.10g, 0.13g & 0.16g, and two soil types: Soil Types B and D. The result shows that for two storey reinforced concrete residential buildings on soil types B and D, seismic design increases structural work costs, which is around 0.62% to 1.31% and 0.61% to 2.16%, respectively, for Type 1 model compared to non-seismic design. Besides, model Type 2, the increment is around 0.24% to 1.22% and 0.20% to 1.71%, respectively. Otherwise, for reinforced concrete residential building with four storey on soil types B and D, the result shows that seismic design tends to have a higher structural work’s cost around 0.41% to 2.48% and 0.98% to 11.23%, respectively, for Type 1 model. Besides, for model Type 2 the increment is around 1.80% to 2.05% and 2.34% to 8.53%, respectively, compared to nonseismic design

Cost Estimation of Structural Work for Residential Building with Seismic Design Consideration

The Sumatra-Andaman earthquakes had triggered local earthquakes in Malaysia by reactivation of ancient inactive faults. Previously on 5th June 2015, Ranau, a region located in Sabah, Malaysia, had experienced a moderate earthquake of Mw6.1. The structural failures occurred because all existing buildings only designed for gravity load without any seismic provision. Recent research work exhibits the seismic designs’ impact on the cost of material and its parameters that impact the cost. There are two types reinforced concrete residential buildings called Type 1 and Type 2 for two storey and four storey which had been used as models. This research applied four seismicity levels to the reference peak ground acceleration value, αgR = 0.07g, 0.10g, 0.13g & 0.16g, and two soil types: Soil Types B and D. The result shows that for two storey reinforced concrete residential buildings on soil types B and D, seismic design increases structural work costs, which is around 0.62% to 1.31% and 0.61% to 2.16%, respectively, for Type 1 model compared to non-seismic design. Besides, model Type 2, the increment is around 0.24% to 1.22% and 0.20% to 1.71%, respectively. Otherwise, for reinforced concrete residential building with four storey on soil types B and D, the result shows that seismic design tends to have a higher structural work’s cost around 0.41% to 2.48% and 0.98% to 11.23%, respectively, for Type 1 model. Besides, for model Type 2 the increment is around 1.80% to 2.05% and 2.34% to 8.53%, respectively, compared to nonseismic design

Ground Motion Observation of Sabah Earthquakes on the Use of Next Generation Attenuation (NGA) Ground-Motion Models

Ground motion prediction equations (GMPEs) are being used for the estimation of the ground motion parameters which are needed for the design and evaluation of important structures. The seismic hazard may contribute greatly to the total risk; therefore the selection of appropriate GMPEs may have a substantial influence on the design and safety evaluation. For low-seismicity areas, however, the available database of strong ground motion measurements is limited, with determination of an appropriate GMPE been a rather difficult task. The objective of this study is to evaluate the next generation attenuation (NGA) ground-motion models to be applied in Sabah region. In this study, six next generation attenuation (NGA) models have been selected to be evaluated. The representation of all NGA models, are compared with the Sabah ground motion database comprises 209 two horizontal-component acceleration time series recorded within 10 to 1000 km of source to site distances for 173 earthquakes with moment magnitudes (MW) ranging between 3.0–6.0. The comparisons are made using analyses of root of the mean square (RMS) and residuals. Two GMPEs present better residual fits than other models with smaller RMS value and indicates better estimation of the peak ground acceleration (PGA). Based on these findings, it is recommended on using the NGA relations for seismic hazard assessment of Sabah

Effect of long-distance earthquake from Philippines and Sulawesi to Sabah region

Sabah is known for its active earthquake activities, especially in Ranau, Kudat and Lahad Datu areas. The effects of local earthquake can reach M W 6.0. Furthermore, Sabah was also hit by earthquakes from neighbouring countries such as Sulawesi and Philippines. These countries produce highly active earthquakes that can reach as high as M W 8.6. The increase in the frequency of earthquakes is one of the concerns of the Sabah government for the safety of its people because most people live in concentrated areas near the coast. This study shows the effects of major earthquakes from the Philippines and Sulawesi which have been recorded between 1900 to 2020 and analyzed in terms of peak ground acceleration (PGA). The eastern region of Sabah is adopted in the analysis for the effect of long-distance earthquakes, as these areas are close to both countries. The analysis uses standard seismic hazard assessment procedure with compilation magnitudes greater than M W 5.0. In the final analysis, it is shown that the effects of large earthquakes from both countries are relatively small compared to the effects of local earthquakes

Effect of Long-distance Earthquake from Philippines and Sulawesi to Sabah Region

Sabah is known for its active earthquake activities, especially in Ranau, Kudat and Lahad Datu areas. The effects of local earthquake can reach MW 6.0. Furthermore, Sabah was also hit by earthquakes from neighbouring countries such as Sulawesi and Philippines. These countries produce highly active earthquakes that can reach as high as MW 8.6. The increase in the frequency of earthquakes is one of the concerns of the Sabah government for the safety of its people because most people live in concentrated areas near the coast. This study shows the effects of major earthquakes from the Philippines and Sulawesi which have been recorded between 1900 to 2020 and analyzed in terms of peak ground acceleration (PGA). The eastern region of Sabah is adopted in the analysis for the effect of long-distance earthquakes, as these areas are close to both countries. The analysis uses standard seismic hazard assessment procedure with compilation magnitudes greater than MW 5.0. In the final analysis, it is shown that the effects of large earthquakes from both countries are relatively small compared to the effects of local earthquakes

Assessing the vulnerability of Kota Kinabalu buildings

A gradual increase in moderate and low seismic activity has occurred in Sabah over the course of several years due to the presence of certain moderately active fault lines in the region. Around 300 moderate earthquakes with magnitudes ranging from MW 4.0 to 7.0 have occurred in the last 120 years. The majority of existing buildings in Sabah are wind and gravity loaded. This study proposes a preliminary seismic vulnerability assessment methodology based on empirical and analytical vulnerability method for 250 existing buildings in Kota Kinabalu city. The empirical vulnerability assessment focuses on building evaluation utilizing a standard Rapid Visual Screening (RVS) method and the FEMA 154 guidebook's moderate seismicity assessment form. A field survey was conducted on the buildings ranging in height from low-rise to high-rise. As a result, when subjected to moderate-intensity earthquakes, 60% of the buildings are classed as susceptible and vulnerable to seismic hazard. The current study included the use of nonlinear static analysis to seven different building cases for further investigation. The findings of the analysis demonstrate that the majority of the buildings respond linearly elastical when subjected to peak ground acceleration (PGA) at 0.17g, which indicate that, buildings without seismic design accumulate damage early when subjected to moderate earthquake loadings

Increment of material usage in construction of four storey reinforced concrete building due to seismic design

Malaysia is fortunate because it is located outside the Pacific Ring-Fire region which is seismically active. However, it still exposes to earthquake hazard from Far-Field earthquake from neighbouring countries. In Peninsular, it is exposes to Sumatra-Andaman earthquake from Indonesia. In East Malaysia, to states namely as Sabah and Sarawak are expose to Philippines earthquake. Besides, Malaysia also experienced earthquakes from local faults such as Bukit Tinggi in 2007. On 5th June 2015, a moderate earthquake with Mw6.1 occurred in Ranau, Sabah which caused 18 fatalities. The same event also caused damage to 61 buildings around Ranau and Kundasang. For the sake of safety, construction of new buildings in Malaysia has to consider seismic design. This paper presents a study to evaluate the increment of construction materials used due to consideration of seismic design. A typical four-storey generic reinforced concrete school building had been used as model. This study adjusted the value of reference peak ground acceleration, αgR in modelling, analysis, and design process. The concrete grade was fixed as C30. Four soil types had been considered for all models with seismic design consideration. Findings from this study demonstrate that the consideration of seismic design caused the increment of steel reinforcement around 16% to 32% for beam and 1% to 14% for column. In term of cost of structural work, consideration of seismic design increases the cost in range of 2% to 5% compared to the nonseismic design. Therefore, it is worth for Malaysia to fully implement the seismic design in new development

Seismic Performance of Single Bay Two Storey RC Frame under In-Plane Lateral Cyclic Loading

A half-scale single-bay two-storey RC frame was designed in accordance to Eurocode 8 and constructed using ready mix-concrete by considering seismic load with Ductility Class Medium (DCM). The two-storey moment resistant RC frame was constructed by preparing reinforcement bars caging, preparation of formwork, concreting and curing process. Then, the specimen was tested under in-plane lateral cyclic loading usinga double actuator starting from ±0.01% until ±2.25% with incremental of 0.25% drift. The total number of twenty-four cycles of drift was imposed to RC frame under control displacement method. The visual observations showed that a lot of cracks were concentrated at the corner and exterior beam-column joints where these were the points of transferred the load from top to the bottom of the structure. The ultimate lateral load of 158.48 kN in pushing direction and -126.09 kN in pulling direction was recorded at 2.25% drift. Based on the experimental result, elastic stiffness is 4.04kN/mm, secant stiffness is 1.14kN/mm, effective stiffness is 2.06kN/mm and ductility is 3.51. It can be concluded that the RC moment resistance frame able to withstand minor to moderate earthquake because the value of ductility is ranging between 3 to 6

Nonstructural Damages of Reinforced Concrete Buildings Due to 2015 Ranau Earthquake

On 15th June 2016 a moderate earthquake with magnitude Mw5.9 was occurred in Sabah, Malaysia. Specifically, the epicentre was located at 16 km northwest of Ranau. Less than two days after the first event, a reconnaissance mission took action to investigate the damages on buildings. Since the reinforced concrete buildings in Ranau were designed based on gravity and wind load only, a lot of minor to severe damages was occurred. This paper presents the damages on the nonstructural elements of reinforced concrete buildings due to Ranau earthquake. The assessment was conducted via in-situ field investigation covering the visual observation, taking photo, and interview with local resident. Based on in-situ field investigation, there was a lot of damages occurred on the nonstructural elements like the brick walls. Such damages cannot be neglected since it can cause injury and fatality to the victims. Therefore, it can be concluded that the installation of nonstructural elements should be reviewed for the sake of safety