Risk Assessment Based On Unascertained Measurement Theory Of Continuous Rigid Frame Bridge During Cantilever Casting Stage

With the rapid development of China’s highways and railways construction, along with the increasing standard of urbanization, passenger and freight traffic demonstrates constant growth, which are challenging demands for structural safety of bridges’operation state and also posing higher standards for newly planned bridges’ construction technique. Applying systematic risk analysis during bridges’ construction stages is essential for maintaining bridge construction safety, bearing even greater important theoretical and practical significance.Affected by climate change, terrain alternation, environmental factors etc., technical difficulty of building roads and bridges increases correspondingly. Due to present technology limits, certain influences and rendering impacts have not yet been fully revealed and evaluated. Bridge construction process undertakes all variety of unknown non-determined factors, which make bridge construction safety status hard to control, leading bridge construction risk assessment full of uncertainty.Based on extensive research and comprehensive analysis of various safety evaluation methods, this paper introduces Unascertained Measurement Theory to evaluate bridge construction stage risk assessment, establishes a scientifically reasonable construction stage risk assessment system which suits cantilever casting continuous rigid frame bridge;Combined with the actual situation occurred during construction, this paper applies qualitative analysis to various risk factors, determines assessing risk levels and their corresponding values, thus establishes risk factors assessing index system;In order to reflect scores’ dispersion impact on risk factors’ values, the paper uses Entropy-Weight Method to determine all single index unascertained measurements’ weight values;For risk level determination, this paper engages Assurance Criterion of Fuzzy Evaluation Method to identify and sort the measure vector.In this paper uses some grand bridge of Er-Guang highway Hunan division as an engineering background, combines with practical engineering situation, applies Cantilever Casting Continuous Rigid Frame Bridge Risk Assessment Model to evaluate the risk level of construction stage, calculated the integrated unascertained measure vector based on expert score grading. Using Assurance Criterion, the construction stage risk level is determined, which accordant with the bridge’s actual status, indicating that this theory is applicable to Cantilever Casting Continuous Rigid Frame Bridge Risk Assessment Model.