Natural frequencies evaluation on existing reinforced concrete bridges using microtremor testing

Most bridges in Malaysia do not take earthquake loadings into their structural design consideration. Structure constructed without the consideration of seismic design is generally more vulnerable to ground shaking during seismic event. Even though Malaysia is located on the stable Sunda shelf wit...

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Main Author:	Idris, Nurul Shazwin
Format:	Thesis
Language:	English English English
Published:	2019
Subjects:	TA401-492 Materials of engineering and construction Mechanics of materials
Online Access:	http://eprints.uthm.edu.my/654/1/24p%20NURUL%20SHAZWIN%20IDRIS.pdf http://eprints.uthm.edu.my/654/2/NURUL%20SHAZWIN%20IDRIS%20COPYRIGHT%20DECLARATION.pdf http://eprints.uthm.edu.my/654/3/NURUL%20SHAZWIN%20IDRIS%20WATERMARK.pdf
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spelling	my-uthm-ep.6542021-08-19T03:16:42Z Natural frequencies evaluation on existing reinforced concrete bridges using microtremor testing 2019-08 Idris, Nurul Shazwin TA401-492 Materials of engineering and construction. Mechanics of materials Most bridges in Malaysia do not take earthquake loadings into their structural design consideration. Structure constructed without the consideration of seismic design is generally more vulnerable to ground shaking during seismic event. Even though Malaysia is located on the stable Sunda shelf with low to medium seismic activity level, effects of tremors due to Sumatran earthquakes have been reported several times. Identification of natural frequencies is important to avoid bridge resonance which could happen when frequency of excitation coincides with a bridge natural frequency. Resonance can cause failure to bridges. Therefore, it is important for newly constructed and old bridges to be tested using simple dynamic test such as microtremor test in order to determine the natural frequencies of the bridges. Microtremor is also known as ambient vibration test. The test is a non-destructive test and easy to be conducted with less labor, time and cost. From the testing, „ambient‟ vibration excitation experienced by a structure under normal operating conditions can be determined. The aim of this study was to determine the natural frequencies of two different lengths of reinforced concrete bridges crossing Sungai Sembrong and Sungai Simpang Kiri. By using GEOPSY software, Fourier Spectra Amplitude Ratio (FSA) analysis used for determining bridge natural frequencies and Horizontal-To-Vertical-Spectra-Ratio (HVSR) analysis for ground natural frequencies, fo. The natural frequency results for Sungai Sembrong Bridge (70 meter) was 2.2 Hz and for Sungai Simpang Kiri Bridge (75 meter) was 2.0 Hz, while the ground natural frequencies were 1.4 Hz to 2.1 Hz at Sungai Sembrong and 1.0 Hz to 1.5 Hz at Sungai Simpang Kiri. The frequency values for both bridges were almost the same. The bridge with longer span length had a lower frequency value compared to the one with shorter span. The frequency results were verified by calculating and developing empirical equation from previous researchers and code of practice. 2019-08 Thesis http://eprints.uthm.edu.my/654/ http://eprints.uthm.edu.my/654/1/24p%20NURUL%20SHAZWIN%20IDRIS.pdf text en public http://eprints.uthm.edu.my/654/2/NURUL%20SHAZWIN%20IDRIS%20COPYRIGHT%20DECLARATION.pdf text en staffonly http://eprints.uthm.edu.my/654/3/NURUL%20SHAZWIN%20IDRIS%20WATERMARK.pdf text en validuser mphil masters Universiti Tun Hussein Onn Malaysia Fakulti Kejuruteraan Awam dan Alam Bina
institution	Universiti Tun Hussein Onn Malaysia
collection	UTHM Institutional Repository
language	English English English
topic	TA401-492 Materials of engineering and construction Mechanics of materials
spellingShingle	TA401-492 Materials of engineering and construction Mechanics of materials Idris, Nurul Shazwin Natural frequencies evaluation on existing reinforced concrete bridges using microtremor testing
description	Most bridges in Malaysia do not take earthquake loadings into their structural design consideration. Structure constructed without the consideration of seismic design is generally more vulnerable to ground shaking during seismic event. Even though Malaysia is located on the stable Sunda shelf with low to medium seismic activity level, effects of tremors due to Sumatran earthquakes have been reported several times. Identification of natural frequencies is important to avoid bridge resonance which could happen when frequency of excitation coincides with a bridge natural frequency. Resonance can cause failure to bridges. Therefore, it is important for newly constructed and old bridges to be tested using simple dynamic test such as microtremor test in order to determine the natural frequencies of the bridges. Microtremor is also known as ambient vibration test. The test is a non-destructive test and easy to be conducted with less labor, time and cost. From the testing, „ambient‟ vibration excitation experienced by a structure under normal operating conditions can be determined. The aim of this study was to determine the natural frequencies of two different lengths of reinforced concrete bridges crossing Sungai Sembrong and Sungai Simpang Kiri. By using GEOPSY software, Fourier Spectra Amplitude Ratio (FSA) analysis used for determining bridge natural frequencies and Horizontal-To-Vertical-Spectra-Ratio (HVSR) analysis for ground natural frequencies, fo. The natural frequency results for Sungai Sembrong Bridge (70 meter) was 2.2 Hz and for Sungai Simpang Kiri Bridge (75 meter) was 2.0 Hz, while the ground natural frequencies were 1.4 Hz to 2.1 Hz at Sungai Sembrong and 1.0 Hz to 1.5 Hz at Sungai Simpang Kiri. The frequency values for both bridges were almost the same. The bridge with longer span length had a lower frequency value compared to the one with shorter span. The frequency results were verified by calculating and developing empirical equation from previous researchers and code of practice.
format	Thesis
qualification_name	Master of Philosophy (M.Phil.)
qualification_level	Master's degree
author	Idris, Nurul Shazwin
author_facet	Idris, Nurul Shazwin
author_sort	Idris, Nurul Shazwin
title	Natural frequencies evaluation on existing reinforced concrete bridges using microtremor testing
title_short	Natural frequencies evaluation on existing reinforced concrete bridges using microtremor testing
title_full	Natural frequencies evaluation on existing reinforced concrete bridges using microtremor testing
title_fullStr	Natural frequencies evaluation on existing reinforced concrete bridges using microtremor testing
title_full_unstemmed	Natural frequencies evaluation on existing reinforced concrete bridges using microtremor testing
title_sort	natural frequencies evaluation on existing reinforced concrete bridges using microtremor testing
granting_institution	Universiti Tun Hussein Onn Malaysia
granting_department	Fakulti Kejuruteraan Awam dan Alam Bina
publishDate	2019
url	http://eprints.uthm.edu.my/654/1/24p%20NURUL%20SHAZWIN%20IDRIS.pdf http://eprints.uthm.edu.my/654/2/NURUL%20SHAZWIN%20IDRIS%20COPYRIGHT%20DECLARATION.pdf http://eprints.uthm.edu.my/654/3/NURUL%20SHAZWIN%20IDRIS%20WATERMARK.pdf
_version_	1747830654398103552

Natural frequencies evaluation on existing reinforced concrete bridges using microtremor testing

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