| Large amount of high dam concrete pouring,high strength, thousands of concrete blocks,construction conditions complicated , it is necessary to consider the influence of construction diversion, flood,natural environment, structure, but also consider the influence of temperature cnntrol,structure stress and other factor, so the consruction of concrete dam is a very important and complicated process.At the same time, in order to pursue the benefits of water storage in advance, in the construction of water hydropower projects,How to construct the concrete dam project is a problem that people pay attention to for a long time.Easy to crack and affect the safety of the project in the construction of the concrete,it is necessary to analyze the influence factors of concrete construction in thickness and intermittent period. Find the rule of rapid castting of concrete. It can be used as reference for temperature control design of similar projects in the future.This text established 3D finite element model of spillway dam,lt has studied the temperature and stress of concrete dam under different intermittent time and diffeient pouring temperature.The results show that:(1)The thicker the pouring layer is,The higher the maximum temperature inside the dam. The temperuture of the dam in different regions is not only related with the casting thickness, but also closely related with the pouring season.Pouring concrete in the same season,The thicker the concrete layer is, The greater the highest temperature .The tensile stress of X,Y and Z in the cushion region of concrete increases with the increase of pouring thickness ;Thetensile stress of X, Y and Z in the three graded RCC area increases with the increase of the thickness of the concrete; The tensile stress of X?Y and Z in the region of two graded normal concrete decrcsees with the incresse of pouring thickness; The tensile stress of X?Y and Z in the region of two graded normal concrete increases with the increase of the thickness of concrete.(2)Whfen the thickness of the concrete layer is invariant,as ihe imermittent period is longer, the more the heat dissipation, the lower the maximum temperature inside the concrete,the smaller the concrete temperature difference between the inside and outside of the dam.The longer the intermittent time of the concreate foundation, the greater the tensile stress of X?Y?Z,the heel of the dam is in the state of stress concrntration; The tensile stress of X?Y?Z in the region of three graded RCC decreases with the increase of the intermittent time;The temsilesiress of X?Y?Z in the tegion of two graded RCC upstream impervious layer increases with theincrease of intermittent time ; The X?Y?Z direction tensile stress of two normal gradedoverflow surface concrete with increase of the intermittent time decreases.(3)Finatlly, taking a project as an example, The 7 calculation construction scheme research of temperature control for rapid construction is formulated, The results show that: scheme 2?scheme 3, schemce 6 and scheme 7 can meet the control requirements of temperature field and temperature stress field.But in the sanme condition of taking the temperature control measure,the construction period of scheme 6 is shortest , greatly speeding up the progress of the construction , so that the project investment can also save the project ahead of schedule to achieve efficiency.therefore, the adoption of die program 6 is more reasonable for the rapid construction temperature control scheme. |
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