水电站地面明钢管地震响应有限元分析

为探讨明钢管在地震作用下的响应规律,采用有限单元法对正常运行遭遇地震和管道放空遭遇地震两种工况下某水电站地面明钢管进行了时程分析。结果表明,正常运行遭遇地震时明钢管主要产生较大的横向加速度和位移,而在放空遭遇地震时,由于管内无水及垂向限位措施,除了产生较大的横向位移外,管道还将在垂直管轴的竖向产生较大的加速度和位移,导致管道脱离支座向上跳动。由此可见,地震引起的钢管横向滑移和竖向跳动将对其安全稳定运行产生不利影响,建议同时采取横向和竖向限位措施。

Finite Element Analysis of Seismic Response of Exposed Steel Penstock in Hydropower Station

In order to study the seismic response characteristics of exposed steel penstock, finite element method was used to analyze the seismic responses of an exposed steel penstock in hydropower station under the working cases of normal operation condition combined with earthquake and penstock venting encountering earthquake. The results show that large acceleration and displacement in transverse direction will be induced under normal operation condition combined with earthquake; if the penstock is empty, larger acceleration and displacement in the vertical direction perpendicular to the pipe axis will be caused simultaneously due to the decrease of weight of the water in the penstock and the unlimitedness of support displacement, so that large relative sliding between penstock and supports in transverse direction may occur, and even the penstock may jump away from the supports if the vertical displacement is large enough. It can be seen that the aforementioned excessive transverse sliding and vertical jumping are not benefit for the safety and stability of the penstock and should be restricted in an appropriate range by both transverse and vertical limit measures.