Comprehensive Evaluation Of Safety Risk-Cost Risk During Construction Period Of Earth-Rock Dam

The construction period of earth-rock dam is the high incidence period of dam failure.Once a dam failure occurs,it will pose a huge threat to the project itself and the lives and property of the downstream people.This will present a major challenge to the management of safety risks during construction.Moreover,it is difficult to control the investment cost reasonably because of the large investment amount and the long period of the earth-rock dam construction.It is very easy for investment costs to exceed the investment budget.Or there may be an increase in engineering risk due to low investment costs.This will seriously affect the smooth progress of the construction of the project.Therefore,it is of great significance to carry out research on the cooperative control of safety risks and cost risks during the construction of earth-rock dams.At present,the research on cooperative control of safety risk and cost risk is relatively few,and the consideration of cost risk is not comprehensive.This leads to the research results can not guide the construction of the project very well.Based on the National Natural Science Foundation of China(51379192)and Henan Province Water Conservancy Science and Technology Research Project(GG201813),this paper analyzes the safety risk and cost risk.And the TOPSIS method is introduced to construct the comprehensive evaluation model of safety risk-cost risk during the construction period of earth-rock dam.This realizes the cooperative management of safety risk and cost risk in the process of engineering construction.The main research work and results are as follows:(1)Safety risk analysis of earth-rock dam during construction period.This paper analyzes and selects the flood control mode in flood season during the construction period,and uses flood regulation calculus to analyze the flood control mode in detail,and obtains the elevation of the top of the retaining building corresponding to the different flood standard.The safety risk of water retaining structures designed and built with different flood standards is analyzed by the method of recurrence period.(2)Cost risk analysis of earth-rock dam during construction period.The concrete composition of cost risk is analyzed,and the cost risk is divided into deterministic cost and uncertain cost,and the cost risk under different level of safety risk is obtained.The fuzzy uncertainty analysis of cost risk is carried out by using the triangular fuzzy number theory and optimistic pessimistic indicator of the fuzzy measure Me method,and the fuzzy cost risk is obtained.(3)Comprehensive evaluation of safety risk-cost risk during construction period of earth-rock dam.Based on the analysis results of safety risk and cost risk,a hierarchy of attribute indicators is established.The weight of each attribute indicator is calculated by the combination weighting method.The TOPSIS method is used to fully consider the connection and contradiction between safety risk and cost risk,and a comprehensive safety risk-cost risk evaluation model is constructed to achieve the decision-making optimization goal of the construction period.(4)Example application.The safety risk-cost risk comprehensive evaluation model constructed in this paper is applied to the comparison of the second flood season scheme in the construction period of Qianping Reservoir.It is concluded that the scheme of increasing the cofferdam in the 100-year design flood is the best solution,which provides a powerful theoretical support for the flood management of the project,and further verifies the practical value of the comprehensive evaluation model constructed in this paper.