大吨位预应力混凝土边墩三维有限元静动力分析

为了得到某工程大吨位预应力边墩的应力变形规律,采用有限元软件ANSYS建立闸墩整体的三维有限元模型,选取3种典型工况进行静动力计算,分析闸墩整体各方向的位移情况及闸墩颈部区域、锚块尾部、预留平孔等部位的应力分布特点。由于传统的等效荷载法和降温法施加预应力不够准确,改进了等效荷载法,并对锚块底部和闸墩按分离模型进行模拟。结果表明,闸墩预应力效果明显,位移应力分布符合一般规律。局部区域拉压应力超出了混凝土的设计强度,但在深度方向上范围较浅,可通过配置非预应力钢筋限制裂缝的开展。

Static and Dynamic Analysis for High-tonnage Prestress Side Pier by Three-dimensional FEM

To obtain the stress and deformation distributions of high-tonnage prestress side pier, three-dimensional FEM model was established by finite element software ANSYS. Then the displacement of pier in each direction and the stress distribution including pier neck, the tail of anchor block and prepared holes were analyzed through three typical operating conditions. Because both conventional equivalent load and decreasing temperature methods were not accurate to apply prestress, equivalent load method was improved. The connection between the bottom of the anchor block and pier was simulated by separating model. The results show that adding pre-stress gets marked effect, and the displacement and stress distributions are accord with the general rules. The tensile and compressive stresses in local regions exceed the design strength, but whose range is very shallow in depth direction and the measures to control the crack of the concrete can be made by setting the non-prestressed reinforcement.