地震作用下进水塔弹塑性损伤分析

Analysis on Elastoplastic Damage of Intake Tower under Strong Earthquake

进水塔荷载作用复杂,特别是塔体在地震荷载作用下,塔体混凝土的强度、刚度会在往复作用进程中逐渐降低,所以把这些复杂、真实的因素考虑进去,对进水塔进行弹塑性损伤动态分析,并寻求其损伤破坏模式具有实际意义。根据能量等价原理并结合混凝土设计规范,建立进水塔混凝土弹塑性本构关系与损伤模型,结合实际进水塔工程,建立塔体-地基三维有限元模型。根据计算结果,分析塔体损伤破坏的进程模式。结果表明,塔体拉压损伤比压损伤严重,拉压损伤主要集中在塔体腰部且损伤程度较高,在地震作用进程中塔体损伤由无到有,破坏程度加重,破坏区域向四周扩张。分析结果对类似工程具有实际意义。

Load action of intake towerare complex, and the intake tower concrete strength and stiffness will decrease gradually in the process of reciprocating compression and tension under seismic cyclic loading. So dynamic analysis of the elastic plastic damage to the intake tower and the optimum design and safety analysis of the intake tower according to the analysis results appears to be particularly important and meaningful as taking into account these complex and real factors.In this paper, according to energy equivalence principlehe and concrete design criterion, the elastoplastic constitutive relation and damage model of the concrete in the intake tower are established, combined with a practical intake tower project, a 3D finite element model of the tower foundation is established.According to the calculation results,The process mode of damage of tower body is analysised.The result shows that in stress concentration area the stress of the tower is not increased, and the stress field is expanded, the location of the pressure and damage of the tower body is mainly concentrated in the geometry of the tower, the damage area between the tower and the backfill concrete （the waist of the tower body） is more serious, the degree of damage is aggravated, and the damage area expands to the surrounding with the earthquake action time increasing. Research findings is of great significance to the seismic and safety of intake tower structure and a reference for similar projects.