地震作用下坝后式水电站厂坝连接形式对比研究

为应对近几年西南地区坝后式水电站建设遇到的复杂坝址条件和强震给厂房稳定性带来的影响,以厂坝连接形式优化比选为目标,采用有限元法建立了金沙江中段某坝后式水电站的三维有限元模型。在校核洪水位工况和地震工况下对比了平缝相靠、整体连接和平缝灌浆三种不同的厂坝连接方案给过缝钢管及厂房结构受力特性带来的影响。结果表明:厂坝整体连接和平缝灌浆方案下过缝钢管和厂房上下游墙的应力和变形要明显小于平缝相靠方案,其中校核洪水位工况下整体连接方案钢管的最大轴向和环向应力分别只有平缝相靠方案的19%和17%,地震工况下厂房的变位也在承受范围内,且其更利于厂房和坝体通过联合作用达到钢管的均匀受力,因此推荐为采用的厂坝连接形式。

A comparative study on powerhouse-dam joint mode for hydropower station after dam under seismic action

In order to deal with the complicated dam site condition and the impact from strong earthquake on the stability of powerhouse during the construction of the hydropower station after dam in the Southwest China in recent years， a 3-D finite element model for a hydropower station after dam at the mid-reach of Jinshajiang River is established with finite element method by taking the powerhouse-dam joint mode as the objective of the comparative selection for optimization. Under both the conditions of check flood level and earthquake， the impacts from three schemes for the powerhouse-dam joint modes， i.e. flat joint connection， wholly integrated connection and flat joint grouting， on the stress characteristics of the joint-through steel pipe and the powerhouse structure are compared. The result shows that under the conditions of the powerhouse-dam wholly integrated and the flat joint grouting schemes， the stresses and deformations of the joint-through steel pipe and both the upstream and the downstream walls of the powerhouse are obviously less than those from the scheme of flat joint connection， in which the maximum axial stress and circumferential stress of the steel pipe in the wholly integrated scheme are only 19% and 17% of those from the flat joint connection scheme， thus the displacement of the powerhouse under seismic condition is also within the allowance range， and then it is more favorable for both the powerhouse and the dam reaching the uniformly stressed status of the steel pipe through the joint effect from them， so it is recommended to be the adopted powerhouse-dam joint mode.