摘要
有限元等效应力法今后将逐步取代拱梁分载法成为拱坝设计的主要方法,在计算有限元等效应力时,应直接进行数值积分,而不宜用二次曲线逼近,坝体自重宜用分步增量法计算.在坝体下游面压应力最大处,双向受压使混凝土抗压强度提高8%左右,如考虑施工期温度拉应力,抗压强度可能反而降低17%左右.在坝体上游面拉应力最大处,侧向压应力使混凝土抗拉强度下降7%～8%左右,在上游面拱冠区,三向受压,使抗压强度提高9%左右.
From integration of the stresses given by finite element method, the internal forces of arch dam are obtained and then the stresses are computed on the basis of beam theory. Thus the stress concentration near the foundation is avoided and the internal forces are more accurate than those given by the trial load method. The action of weight of concrete must be computed by incremental method to consider the process of joint grouting. At the point of maximum compressive stress on the downstream face, the concrete is subjected to biaxial compression and the strength of concrete will be 8% greater than the uniaxial compressive strength. At the point of maximum tensile stress on the upstream face, the concrete is subjected to triaxial stresses, tension-compression-compression, the tensile strength will be reduced 8% due to the lateral compression. In the central part of upstream face, the concrete is subjected to triaxial compression and the compressive strength will be about 9% greater than the uniaxial compressive strength.
出处
《水利水电技术》
CSCD
北大核心
2005年第1期43-47,共5页
Water Resources and Hydropower Engineering
关键词
拱坝
有限元等效应力
强度储备
复杂应力
arch dam
equivalent finite element stress
strength of concrete
triaxial stress
