Curing Monolayer Freezing Shaft Lining

CHEN Xiao-xiang; YANG Wei-hao

Abstract：Analog simulation was used to determine the temperature field in a curing concrete mono-layer freezing-shaft lining.The affect of different lining thickness and sidewall temperature was studied.The temperature is seen to rise rapidly after the pour and thicker linings result in higher peak temperatures.Shrinkage-compensating concrete is used to partially compensate for temperature differences developed in the lining.The temperature difference between the inside of the lining and the outside wall may slightly exceed the maximum allowable temperature of 25℃ stipulated by the standard.However the lining is unlikely to crack.High heat of hydration provides at least eight days of curing time at a positive temperature throughout the section and during this time the curing lining is free from the danger of freezing.For different sidewall temperatures the peak internal temperature of the fining will be different.Thicker linings show less effect from variation in sidewall temperature,Analog simulations based on in-situ measurements of rock and soil in the Longgu mine confirmed results from numerical simulations based on cement hydration parameters deduced from data taken at the Longgu outer shaft fining.