Construction Schedule Risk Analysis Of Core Rockfill Dams Based On Coupling Optimized ICSRAM And BBNs Method

The technology applied in core rockfill dams is complicated,involving large scale,long duration and complex construction technology.The actual construction process also contains many uncertainties and risk factors related to natural conditions,efficiencies of machinery and road conditions,which can directly or indirectly affect the construction schedule.Core rockfill dam construction progress is influenced by many risk factors at the same time,rather than the superposition results.In the process,all kinds of risk factors are combinated each other and generate both positive effect and negative effect on construction duration.So some risk factors' effect can be cancelled out.However,most core rockfill dam construction schedule risk studies ignored that multiple risk factors with mutual relation will implement non-additive impact on engineering activities.In addition,risk factors' weighting calculation mostly focuses on the local and subjective weight,which affects the precision of construction schedule risk analysis.Therefore,scientificly analyzing and calculating the construction schedule risk is very significant to reasonablely control the construction schedule.In order to analyze the schedule risk more comprehensive and accurate,the paper proposes construction schedule risk analysis model of core rockfill dams based on coupling optimized improved correlated schedule risk analysis model(ICSRAM)and Bayesian belief networks(BBNs)method.The model not only takes into account the construction features of core rockfill dams,but also the stochastic variations of risk factors with the construction schedule.It mainly refers to the ICSRAM principle and makes certain improvement relative to it,which applies analytic hierarchy process and entropy weight(AHP-EW)method to calculate the risk weights.Using BBNs to consider the relationship among risk factors and quantify the non-additive effect which multiple risk factors implement on engineering activities.Finally using Monte Carlo method to solve the model realizes the completion risk analysis of construction schedule and obtains a scientific and reasonable construction schedule plan.This model ensures the comprehensiveness,accuracy and objectivity of the analytical results.The engineering application results show that compared with project evaluation and review technique(PERT),ICSRAM and the coupled improved PERT-BBNs,completion probability obtained by the coupled optimized ICSRAM-BBNs is higher and distribution of simulation period is more convergent.In addition,a construction schedule plan with a high confidence level is obtained,enabling effectively control the core rockfill dam construction schedule.