Analysis On Temperature Stress Of Roller Compacted Concrete Gravity Dam

Roller compacted concrete gravity dam is an important hydraulic structure with mass concrete,temperature stress must be considered in the procession of construction and storage.The crack which is caused by temperature stress will affect the safe operation of the dam,and the variation of temperature field and temperature stress field is different in the practical engineering.therefore,the study of temperature stress is of great practical value.In this paper,a three-dimensional finite element model of RCC gravity dam is established,according to the actual construction situation and operational data of RCC dam,finite element analysis of the temperature-structure coupling is conducted in the whole process of construction and water storage,The following studies were carried out:Firstly,the finite element method of temperature field is used,and the influences of temperature and water temperature,initial soil temperature,hydration heat of cement and initial pouring temperature were taken into account,respectively get regularities of distribution about the end of construction and storage with the three condition of natural construction temperature,control pouring temperature,natural pouring temperature with water-cooling.The regularities of distribution about temperature field and the temperature duration curve of the dam characteristic points are compared between the three cases,The influence of various measures on the change of temperature field is analyzed.And let the base temperature of calculation with the three condition compare with the range of temperature which is allowed by standard.It can be seen that the control of pouring temperature and natural pouring temperature with water-cooling can meet the requirements of temperature control.According to enveloping line of maximum temperature,which explain whether the three schemes can meet the requirements of temperature control.Then,according to the envelope line of temperature stress and the nephogram of maximal tensile stress which is the parts of the three scheme about feature,the effect of various schemes on reducing temperature stress is analyzed.And the temperature stress with three different directions of the dam and the distribution law of the first principal stress are obtained by the basis of the temperature field with the condition of controlling temperature,which take into account creep about the end of construction and storage.In order to dynamically study the temperature stress in three different directions which leads to the development of crack,the duration curve of temperature stress is analyzed about the surface point and the center point.For the same node,the curve of temperature stress which is compared about whether is considered with creep,the influence of creep on temperature stress is analyzed.The temperature stress values of the characteristic parts are compared about whether is considered with weight in the procession of construction,the advantages of selfweight which eliminate thermal stress during construction are explained.Finally,the stress distribution law of the dam body under the combined action of gravity,water pressure and temperature action is analyzed.