Structural Topology Optimization And Temperature Control Of Extra High Head Ship-locks

In the central and western regions of China,the built navigable buildings are gradually unable to meet the current transport needs of goods,and it is necessary to expand the capacity by building extra high head ship-locks.The design of extra high head ship-lock often involves the massive concrete structure under the action of extra high head.In the pouring process,the temperature stress is one of the important factors that produce cracks,and even affects the safety of the structure.Based on the design of a single-stage extra high head ship-lock project,and according to the design experience of the lock chamber structure in the past,this paper puts forward a structure type different from the common separated lock chamber as a design scheme.In view of this design scheme,the structural optimization and temperature control measures of lock chamber of extra high head ship are studied,which provides reference for structural optimization and temperature control measures of similar extra high head ship-locks in the future.The main results and conclusions are as follows:1.Through the structural stress analysis of the design scheme,it is known that due to the excessive weight of the structure itself,the gate wall structure bears large tensile stress at the heel inflection point,which needs to reduce the structural stress of the gate wall and the hydration heat generated in the pouring process.The single-condition topology optimization was carried out on the design scheme,and the optimized structure at the intersection of strain energy curves(equal stiffness)of each condition was taken for Boolean operation.Because the surface of the structure after topology optimization is irregular and there are many curved surfaces,it is difficult for the current construction technology to be directly used in practical engineering.Therefore,the shape is further simplified by ’replacing the curve directly’,and the structural type of the optimization scheme is finally obtained.The results show that compared with the design scheme,the stress of the optimized structure is reduced obviously,the volume of the gate wall is reduced,the material utilization rate is improved,and the overall structural stiffness is improved obviously.The optimization scheme meets the structural stability and stress requirements.2.The numerical simulation analysis of hydration heat of the optimized gate wall structure is carried out,and the temperature field and stress field of the pouring layer in each construction stage are calculated.The temperature control measures for burying stones in the optimized regional structure are proposed.The temperature field and stress field of the gate wall under the optimized structure of 15%,25%,35%and 45%block stone rate are analyzed and compared.The results show that the proportion of temperature in the high temperature region decreases with the increase of block stone rate from 15%to 45%.Compared with conventional concrete,the surface tensile stress value decreases significantly,which greatly reduces the possibility of temperature cracks in concrete.Comprehensive consideration,this project adopts 45%stone rate of stone concrete temperature control effect is better.3.Through the analysis of the temperature field and stress field of 45%block stone concrete,the external tensile stress area of concrete is large,indicating that the ultra-high head ship lock still has a large possibility of cracking only by adopting the two temperature control measures of empty box and block stone concrete.Therefore,the temperature control measures of embedded cooling water pipe are further proposed.In this project,the calculation results show that compared with conventional concrete,the maximum decrease of tensile stress value reaches 1.13 MPa,and the temperature control effect is obvious.