| PaperNO | Paper / Abstract |
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SE2-003
15:20
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15:40
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DEVELOPMENT OF A BRIEF CODE-BASED SEISMIC DIAGNOSTIC TOOL FOR EXISTING RC BUILDINGS CONSIDERING VERTICAL IRREGULARITIES
A brief seismic diagnostic tool (BSDT) that is localized and based on the National Structural Code of the Philippines (NSCP) is developed as a tool for rapid visual screening of existing reinforced concrete buildings in the Philippines. A BSDT that uses seismic code parameters from the NSCP would be easier to use for local evaluators since local civil engineers are familiar with the NSCP parameters. Vertical irregularities are also known to contribute to the vulnerability of buildings when subjected to ground motion. This study will also present push-over analysis simulations of buildings with vertical irregularities specifically (1) Vertical Geometric Irregularity, (2) Soft Story, and (3) Mass Irregularity. Vertical irregularity parameters are introduced in the simulations and these parameters are introduced to determine score modifiers for the assessment of vulnerability of buildings with vertical irregularities. The result of the study is a more refined qualitative/semi-quantitative brief seismic diagnosis tool for existing reinforced concrete buildings for the Philippines.
Andres Winston Oreta, Adrian Dy
National Structural Code of the Philippines, Rapid Visual Screening, Reinforced Concrete Building, Vertical Irregularity
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SE2-020
15:40
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15:55
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SHEAR BEHAVIOR PREDICTION OF NON-DUCTILE REINFORCED CONCRETE MEMBERS UNDER EARTHQUAK LOADING
Prior to the introduction of modern seismic codes in the late 1990s for Taiwan, many reinforced concrete buildings were designed without adequate detailing and reinforcement for seismic protection. Based on the Chi-Chi Earthquake reconnaissance, the plastic hinge zones in the D-regions of structural members are especially vulnerable under earthquake loading. These non-ductile reinforced concrete members are usually dominated by shear behavior due to inadequate reinforcement and low concrete strength. If seismic evaluation and retrofitting of such vulnerable buildings are to be carried out, it is necessary to fully understand the shear behavior of the non-ductile reinforced concrete members. The objective of this paper is to report the current advancement of technology to predict the lateral load-displacement curves of these shear-critical elements, such as columns, shear walls, infilled walls with openings. The main purpose of the proposed model is to provide engineers with a simplified estimation procedure. By comparing with experimental results, it is found that despite the simplification, the proposed model can give reasonable estimations and therefore, is suitable for use in engineering practice.
Shyh-Jiann Hwang
D-region, lateral load-displacement curve, non-ductile, shear critical member, shear deformation, shear strength
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SE2-019
15:55
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16:10
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CYCLIC BEHAVIOUR OF LARGE-SCALE LIGHTLY REINFORCED CONCRETE COLUMNS
Lightly reinforced concrete columns have been known to cause numerous detrimental incidents of structural collapse during seismic events. While existing studies have attempted to investigate their complicate seismic behavior, most of these studies relied on small-scale experimental tests. The objective of this study was to understand the influence of critical design factors, i.e., axial load ratio and reinforcement detailing, on the shear strength and ductility of lightly reinforced concrete column via a series of experimental tests on full-scale column specimens. The seismic behavior of the tested columns was evaluated in terms of the cracking patterns, hysteretic response, shear strength, and drift ratio at axial failure. In addition, the adequacy of the shear design equations specified by ACI 318-14 code for the tested columns was assessed in this study.
Pham Phu Anh Huy, Hung Chung Chan
ductility, RC column, shear reinforcement, shear strength
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SE2-035
16:10
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16:25
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Axial Compression Behavior Of Pre-Damaged Concrete Prisms Confined With BFRP
In order to study the axial compression behavior of pre-damaged concrete prisms confined by basalt fiber reinforced polymers (BFRPs), thirty-seven concrete prisms, with a side length of 150 mm and a height of 300 mm, were tested under axial compression, including thirty-four BFRP-confined specimens and three plain concrete specimens. The test variables were the number of BFRP layers (one, two, three, four, and six layers) and the initial damage (slight, moderate and severe damage). The test results show that: the compression strength and axial deformation capacities of BFRP-confined prisms increase with the increase of FRP layers, especially the improvement of the deformation capacity; the initial damage levels have obvious influence on the strength of the turning and ultimate points of BFRP-confined specimens, but have little effect on the ultimate strain; when the BFRP layers is two or less, the stress-strain curves of BFRP-confined prisms has a softening section; when the BFRP layers is four or more, the stress-strain curves start to have an obvious strengthening section.
Zhi-Hu Zeng, Gao Ma
BFRP, pre-damage, strain, strength, stress-strain curve
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SE2-036
16:25
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16:40
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MODELING METHOD OF EARTHQUAKE-DAMAGED RC COLUMNS RETROFITTED WITH FRP
In order to study the seismic performances of earthquake-damaged RC columns retrofitted with fiber reinforced polymers (FRPs), the OpenSees analysis platform was used to build the finite element model of FRP-retrofitted earthquake-damaged RC columns based on the damage states of damaged RC columns. The degradation of mechanical properties of damaged steel rebar, concrete, and FRP-confined concrete was considered in the finite element model. Fiber-section beam-column element combined with zerolength-section element was utilized to simulate the cyclic behavior of FRP-retrofitted RC columns. The modeling method proposed in the present study showed good accuracy in predicting the test results reported in the literature. This modeling method can provide theoretical guidelines for engineers to determine FRP retrofit schemes efficiently and calculate the mechanical properties (strength, stiffness, and ductility) of earthquake-damaged RC columns retrofitted with FRP based on the damage states.
Ya-Feng Zou, Gao Ma
earthquake-damaged RC columns, finite element model, FRP retrofit, OpenSees
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SE2-005
16:40
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17:00
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REPAIR AND RESIDUAL CAPACITY OF REINFORCED CONCRETE PLASTIC HINGES
A prominent challenge following the 2010-11 Canterbury earthquakes was the insurance decision making process for earthquake-damaged buildings and lack of robust engineering guidelines for future risk assessment. Similarly, in the aftermath of the 2016 Kaikoura earthquake, these issues were again highlighted leaving engineers and building owners with limited guidance on the reparability of moderately damaged reinforced concrete (RC) structures in Wellington. Research is ongoing at the University of Auckland with experimental investigations into the post-earthquake residual capacity and impact of epoxy injection on the behaviour of RC beam elements following earthquake damage. Dynamic and pseudo-static testing of cantilever beam elements and beam-column assemblies have shown the potential for recovery of strength and energy dissipation capacity of components repaired via epoxy injection. This paper outlines the results of the experimental work undertaken thus far, as well as how this research contributes to the development of a proposed framework for post-earthquake building assessment.
Kai Marder, Mehdi Sarrafzadeh, Kenneth J. Elwood
Beam, Epoxy, reinforced concrete, Repair
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