列车振动荷载对古建筑的动力影响

在建的北京地下直径线周边有3处需保护的古建筑文物（Ⅰ-明城墙、Ⅱ-老车站、Ⅲ-正阳门和箭楼）,对其进行列车振动荷载下的动力影响研究十分必要.应用列车-轨道耦合动力学理论,计算得到作用在隧道结构上的列车动荷载,并作为激励作用于动力有限元模型上,通过数值模拟计算,预测评估直径线与既有线列车荷载对周边古建筑文物的振动响应.结果表明,列车振动引起古建筑结构的动力响应随水平距离和竖向距离改变呈规律变化,地下结构以竖直方向动力响应为主,建筑物超过一定高度后,地上结构以水平方向动力响应为主,且地上结构的动力响应高于地下结构;直径线与既有线的列车运营对古建筑产生的振动影响,未超过但接近控制标准,不需特殊减振,应采取适当减振以对古建筑文物的保护留有余量.

Dynamic Effect of Train-Induced Vibration on Historic Buildings

There are three historic buildings： Ⅰ-the Ming Dynasty Wall,Ⅱ-the Old Railway Station,Ⅲ-the Zhengyangmen and Jianlou,which are in close proximity to the existing metro lines and the new Diameter line in Beijing.The vibration prediction and assessment of the three historic buildings induced by trains are presented in this paper,since it is very necessary for the preservation of these ancient architectures.Numerical methods are used to simulate the dynamic response in the structures.The excitation of trains onto the tunnel structure is obtained by using the vehicle-track interaction model,which is applied on the dynamic finite element models.The results include： the dynamic response of velocity in historic structures vary regularly along with the horizontal and vertical distance;The vertical dynamic response is a major factor in underground structures,while the horizontal is a major one in structure on the ground;Train-induced vibration in historic buildings is within but close to the criteria,so vibration mitigation measures should be taken to reduce the impacts in order to make allowance to the preservation of cultural heritages.