Advanced

Methodology for analysis of traffic-induced building vibrations

Torndahl, Rickard LU and Svensson, Tobias LU (2017) In TVSM-5000 VSM820 20171
Structural Mechanics
Department of Construction Sciences
Abstract
Urban population growth leads to denser cities where buildings are being constructed closer to sources of vibration like motorways, railways and tramways. The risk of disturbing vibrations is thereby increasing which could affect residents and sensitive equipment, for instance equipment used in hospitals. In the Master’s thesis, the effect of structural design on traffic-induced building vibrations has been studied.

A methodology was developed and numerical simulations were carried out using the finite element (FE) method. The methodology holds two parts, one part where a large FE model of the ground is reduced and one part where a parameter study is conducted. In the reduction part, the FE ground model is established and a dynamic... (More)
Urban population growth leads to denser cities where buildings are being constructed closer to sources of vibration like motorways, railways and tramways. The risk of disturbing vibrations is thereby increasing which could affect residents and sensitive equipment, for instance equipment used in hospitals. In the Master’s thesis, the effect of structural design on traffic-induced building vibrations has been studied.

A methodology was developed and numerical simulations were carried out using the finite element (FE) method. The methodology holds two parts, one part where a large FE model of the ground is reduced and one part where a parameter study is conducted. In the reduction part, the FE ground model is established and a dynamic condensation is performed which results in a reduced ground model. In the parameter study part of the developed methodology, a FE building model is created and a dynamic stiffness matrix for each studied frequency is determined. The dynamic stiffness matrix of the building model is assembled with the dynamic stiffness matrix of the reduced FE ground model and analyses are conducted. This allows for changes to be made in the building model and new analyses to be performed without the need to implement the large non-reduced ground model. The computational time to perform the parameter study was thereby decreased by 99.7% compared to using the non-reduced FE ground model.

The parameter study was performed by steady-state analyses in the frequencies interval of 5–50 Hz with 1 Hz steps. A unit load was applied at a distance of 20 m from a reference building. The results from the parameter study showed that structural design can influence the response of the building significantly. The eigenfrequencies of the building are of importance and a coinciding frequency between the load and the eigenfrequency of the building resulted in a peak response of the vibration level inside the building.

The work made in the thesis contributes in the ambition towards enabling predictions of vibrations by use of numerical models. As the developed methodology in the thesis can make numerical simulations more efficient in a way that less computational time and less computational resources are needed. (Less)
Popular Abstract (Swedish)
Kan en byggnad utformas så att störande vibrationer från trafik minimeras? För att undersöka detta utfördes numeriska experiment där förändringen hos de störande vibrationerna undersöktes då en byggnadsstommes material och utformning ändrades. Dessa experiment kräver ofta stor datorkapacitet. Därför utvecklades en metodik som minskade datormodellerna och på så sätt kunde experimenten utföras med mindre datorkapacitet.
Please use this url to cite or link to this publication:
author
Torndahl, Rickard LU and Svensson, Tobias LU
supervisor
organization
course
VSM820 20171
year
type
H3 - Professional qualifications (4 Years - )
subject
keywords
infinite elements, soil dynamics, structural dynamics, wave propagation, dynamic reduction, traffic-induced vibration, finite element method, building vibration, structural design
publication/series
TVSM-5000
report number
TVSM-5224
ISSN
0281-6679
language
English
id
8919855
alternative location
http://www.byggmek.lth.se/english/publications/tvsm-5000-masters-dissertations/
date added to LUP
2017-08-17 14:40:30
date last changed
2017-08-17 14:40:30
@misc{8919855,
  abstract     = {Urban population growth leads to denser cities where buildings are being constructed closer to sources of vibration like motorways, railways and tramways. The risk of disturbing vibrations is thereby increasing which could affect residents and sensitive equipment, for instance equipment used in hospitals. In the Master’s thesis, the effect of structural design on traffic-induced building vibrations has been studied.

A methodology was developed and numerical simulations were carried out using the finite element (FE) method. The methodology holds two parts, one part where a large FE model of the ground is reduced and one part where a parameter study is conducted. In the reduction part, the FE ground model is established and a dynamic condensation is performed which results in a reduced ground model. In the parameter study part of the developed methodology, a FE building model is created and a dynamic stiffness matrix for each studied frequency is determined. The dynamic stiffness matrix of the building model is assembled with the dynamic stiffness matrix of the reduced FE ground model and analyses are conducted. This allows for changes to be made in the building model and new analyses to be performed without the need to implement the large non-reduced ground model. The computational time to perform the parameter study was thereby decreased by 99.7% compared to using the non-reduced FE ground model.

The parameter study was performed by steady-state analyses in the frequencies interval of 5–50 Hz with 1 Hz steps. A unit load was applied at a distance of 20 m from a reference building. The results from the parameter study showed that structural design can influence the response of the building significantly. The eigenfrequencies of the building are of importance and a coinciding frequency between the load and the eigenfrequency of the building resulted in a peak response of the vibration level inside the building.

The work made in the thesis contributes in the ambition towards enabling predictions of vibrations by use of numerical models. As the developed methodology in the thesis can make numerical simulations more efficient in a way that less computational time and less computational resources are needed.},
  author       = {Torndahl, Rickard and Svensson, Tobias},
  issn         = {0281-6679},
  keyword      = {infinite elements,soil dynamics,structural dynamics,wave propagation,dynamic reduction,traffic-induced vibration,finite element method,building vibration,structural design},
  language     = {eng},
  note         = {Student Paper},
  series       = {TVSM-5000},
  title        = {Methodology for analysis of traffic-induced building vibrations},
  year         = {2017},
}