Large-scale Sluice Reconstruction Decision-making And The Simulation Study Of The Temperature Of The Chamber Concret

Sluice is a kind of low-head hydraulic structure with double functions of blocking water and draining water.It plays an important role in irrigation and water supply,flood control,drainage,tide protection,water resources regulation and control,improvement of water environment and so on.As of 2017,a total of 10,3878 sluices with a flow rate of 5m~3/s and above had been built in the country,of which more than 2,600 are large and medium-scale sluices.The reinforcement and renovation of these sluices is of great significance to the national economy and the people's livelihood.Therefore,based on the renovation project of a large sluice in Henan Province,the decision-making of revonation and the temperature field of mass concrete in large sluice are studied in this paper.The main research contents are as follows:(1)According to the current codes,a comprehensive recheck and test of a sluice in Henan Province was carried out,and it was found that the height of the sluice pier,the depth of the stilling basin,the length of the riprap,the stability of the sluice chamber and the retaining wall are not in line with the current codes.The metal structure and electrical equipment are seriously aged;the joints and the following areas of the 1st,2nd,5th,and 7th sluice floors and the foundation have void areas and are suspected of filling water.And there are serious defects in the structure of the top of the hoist bent,the end of the traffic bridge beams.(2)On the basis of the comprehensive recheck and test of the original sluice structure,combined with the similar examples of renovation at home and abroad,two alternatives for the renovation of the sluice in Henan Province were proposed,and the specific work content of each scheme was drawn up.The feasibility of the value engineering method applied to the decision-making of the sluice renovation was analyzed.The function coefficient and cost coefficient of the two alternatives are determined by calculation,and then the value coefficient was finally calculated.According to the value coefficient,the scheme of"Demolition of the original sluice and reconstruction at the original site"was selected as the implementation scheme.(3)The characteristics of sluice mass concrete were summarized from the aspects of space size,material characteristics,temperature diffusion law and the damage of cracks.The temperature field theory of mass concrete and the finite element theory of temperature field were introduced,and the heat transfer equation was derived.The finite element model was established by taking the third joint floor and the middle pier on it,which is on the left side of a sluice in Henan Province.The variation of temperature field with time was analyzed.Several different points inside and outside the structure were selected as representative nodes to predict the position of the maximum temperature difference.The effects of different curing conditions on the temperature distribution of concrete and the maximum temperature difference are analyzed in order to provide guidance for the maintenance of concrete.