The sensitivity of bridge safety to spatial correlation of load and resistance

Abstract

Publication informationStructures, 5 : 23-34 Publisher ElsevierItem record/more information http://hdl.handle.net/10197/6997 Publisher's statement þÿ T h i s i s t h e a u t h o r s v e r s i o n o f a w o r k t h a t w a s a c c e p t e d f o r p u b l i c a t i o n i n S t r u c t u r e s .Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this AbstractRandom Field theory has emerged in recent years to model the statistical correlation of resistance in concrete structures and to determine its influence on the probability of structural failure. A major shortcoming in the work carried out to date is the spatial variability and corresponding correlation associated with applied traffic loads. In this paper the influence of spatial correlation of both traffic load and resistance is considered in the context of bridge safety assessment. The current study, explores, the nature of the problem by three theoretical examples. As a general trend, examples show that while traffic loads are weakly correlated, load effects are strongly correlated as the same heavy vehicle often causes extremes of load effect in different parts of the bridge which is due to the transverse sharing of load (measured here using a load sharing factor).It is found that the strength of correlation of load effect depends greatly on the load sharing factor which is treated in a simple way in many studies. In a more sophisticated beam-and-slab bridge example, load sharing factors are derived from a finite element analysis to assess transverse load sharing, and are shown to vary by girder number, girder segment and by load location. Despite the fact that load effect at points along the length of a bridge are strongly correlated, the combined influence of correlation in load and resistance on probability of failure is small

Regularization Methods Applied to Noisy Response from Beams under Static Loading

“…The varying stiffness profile has been chosen to simulate small variations of stiffness that can be expected in a reinforced concrete beam of constant cross-section, not only due to the inherent variability of concrete but also to corrosion. The correlation function (Hajializadeh et al 2016) is defined by Equation (11). As a result, the obtained stiffness profiles are smooth, with realistic variations between consecutive elements.…”

Finite Element Updating using Cross-Entropy combined with Random Field Theory

“…In this case, no correlation between random variables has been considered. However, if variables are assumed to be correlated, being 0.75 the value of the coefficient of Equation (2), the distribution of probability is modified as illustrated by Due to the effect of correlation, the contours are not symmetrical anymore and combinations of values along the diagonal are more probable than off-diagonal ones [16]. It can also be noticed that more probability is concentrated around the centre point (μ X , μ Y ).…”

“…In a homogeneous random field, the value of this function will only depend on the distance between elements [15]. In this paper, a correlation function, adopted for a 1-D field, of the following form [16] is considered:…”