TITLE:
Monitoring Bridge Deformation Using Auto-Correlation Adjustment Technique for Total Station Observations
AUTHORS:
Ashraf Abd El-Wanis Beshr, Mosbeh R. Kaloop
KEYWORDS:
Monitoring; Total Station; Auto-Correlation; Bridges; Deformation
JOURNAL NAME:
Positioning,
Vol.4 No.1,
February
27,
2013
ABSTRACT: Bridges are omnipresent in every society and they affect
its human, social, ecological, economical and cultural aspects. This is why a
durable and safe usage of bridges is an imperative goal of structural
management. Measurement and monitoring have an essential role in structural
management. The benefits of the information obtained by monitoring are apparent
in several domains. In deformation analysis, the functional relationship
between the acting forces and the resulting deformations should be established. If
time depending observations are given, a regression could be used as a
functional model. In case of stochastic model uncorrelated observations with
identical variance are assumed. Due to the high sampling rate, a small time
difference arises between two observations. Thus the assumed stochastic model
is not suitable. The calculation has to be effected by means of auto-correlated
observations. This paper investigates an integrated monitoring
system for the estimation of the deformation (i.e., static, quasi-static) behavior of bridges from total station
observations and studies the effect of autocorrelation technique on the
accuracy of the estimated parameters and variances. The results have shown that
autocorrelation technique is reduced the standard deviation of X&Y-direction about 6.7% to 29.4% and 6.5% to 15.5% of the original
value, respectively, but the situation was differ in Z direction; the standard deviation in vertical component Z was increased.