跨水库布置的精密仪器厂房微变形与微振动控制研究

Study on micro-deformation and micro-vibration control of precision instrument workshops across reservoir

高桩框架结构通常用于跨水库建筑物设计,具有桩基悬空高、侧向刚度小等特点,在外界环境变化下易产生变形和振动,影响工程正常运行。针对高桩框架结构的微变形和微振动问题,提出在桩基外部加土体保护的方法进行控制,并以某高桩框架结构为例,采用有限单元法,分析了高桩框架、高桩框架+土体保护两种设计方案下整体结构的自振特性、温度荷载作用下的微变形、高铁经过时的微振动及波浪荷载作用下的位移响应。数值分析表明,高桩框架+土体保护方案可以降低桩基体系的高阶自振频率,避免与场地的共振风险,有效控制温度变化导致的微变形和高铁经过导致的微振动在允许范围内,大幅降低桩基体系在波浪荷载作用下的水平向变形。因此,在桩基外部设置土体保护的措施可以有效控制高桩框架结构的微变形和微振动,是一种经济、高效的振动控制方案。

The high pile frame structure with characteristics of high hanging pile foundation and low lateral stiffness is usually applied in the design of cross-reservoir buildings. It is easily deformed and vibrated under the change of external environment, which affects the normal operation of the project. In view of the micro-deformation and micro-vibration of high pile frame structure, a method of adding soil protection outside pile foundation was proposed for control. Taking the high pile frame structure of a scientific apparatus project as an example, the finite element method was used to analyze the vibration characteristics of the overall structure, micro-deformation under temperature load,micro-vibration during the passage of high speed rail, and displacement response subjected to wave load under two design schemes respectively: the high-pile frame scheme and the high-pile frame + soil protection scheme. The numerical analysis shows that the high-pile frame + soil protection scheme can reduce the high-order natural vibration frequencies of the pile foundation system, and avoid the resonance risk. Additionally, it can effectively control the micro-deformation caused by temperature change and the micro-vibration caused by the high speed rail within the allowable range of the project, and greatly reduce the horizontal deformation of the pile foundation system under wave load. Therefore, setting soil protection outside pile foundation can effectively control the micro-deformation and microvibration of the high pile frame structure, which is an economical and efficient vibration control scheme.