dc.contributor.author | Aseno, Joseph O | |
dc.date.accessioned | 2013-05-04T12:03:18Z | |
dc.date.available | 2013-05-04T12:03:18Z | |
dc.date.issued | 1992 | |
dc.identifier.uri | http://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/19039 | |
dc.description.abstract | The outstanding problems that pose a challenge to the successful monitoring
of the deformations of engineering structures are discussed. A new approach to the
design of observations leading to a detailed analysis of the data is developed to
monitor fine horizontal movements.
First, the troublesome aspects of deformation monitoring when fine
movements are sought, are pointed out. It is shown that disparities and limitations in
the relevant geometrical and physical concepts pertaining to deformation monitoring
work against the idea of integrated analysis. The message that comes out at this point
is that different sources of deformation data should be analyzed separately in order
to remove the statistical misgivings associated with the analysis of hybrid systems.
Second, the level of accuracy desired in structural deformation monitoring and
how that accuracy is exposed to damage by the presence of undetected systematic
errors are examined. Since such errors may easily attain magnitudes matching those
of the point displacements sought, the consequence of the give-and-take process of
least squares adjustment on the required point displacements is discussed. The
discussion reveals that there is reason to doubt the appropriateness of the use of the
concept of networks, coordinates and least squares adjustment in the extraction of
fine movements. Such a doubt provides justification for adopting a different
perspective of investigating structural deformation phenomena.
Third, the establishment of a different approach begins with the formulation of
deformation hypotheses. This is followed by the presentation of the principles of
design and analysis of observations. The design of observations takes into account the
fact that the displacements sought in structural deformation monitoring are at the
margin of measuring errors and undetected systematic errors. Separation of the
displacements from such errors requires a considerable amount of statistical control.
In an attempt to assert this statistical control. a randomization technique has been
incorporated. The technique, which basically involves carrying out the observations
in a random order, guarantees inferential validity in the presence of the fluctuations
in the atmospheric factors during the observation period and enhances the reliability
of the estimates of errors in the resultant point displacements.
The fine movements are revealed by verifying specific hypotheses regarding
the deformation of a structure. Towards this end, the magnitude of a structural
displacement at any point is determined from the field observations involving that
point only - thereby eliminating the influence of undetected systematic errors in other
observations relating to other points. Evidence is provided to the effect that the give and-take process of least squares adjustment may lead to incorrect estimates of small
structural displacements in the presence of measuring errors and undetected
systematic errors of about the same magnitude. The proposed approach localizes the
influence of such errors and, therefore, yields better estimates of point displacements
under such circumstances. | en |
dc.description.sponsorship | The University of Nairobi | en |
dc.language.iso | en | en |
dc.subject | The design of observations for monitoring horizontal deformation | en |
dc.subject | Engineering structures | en |
dc.title | The design of observations for monitoring Horizontal deformations of engineering structures and the analysis of subsequent data | en |
dc.type | Thesis | en |
local.publisher | Department of Civil Engineering, | en |