中文摘要：

西藏的遗产大楼有高历史、文化的价值。没有重要损坏，他们在几百年忍受了不利环境装载。然而，在动态装载下面他们在正常环境装载和他们的行为下面的结构的特征上有很少报告。在这研究，一座典型西藏的木墙框架大楼被选择学习它的动态特征。结构的领域大小在环境刺激下面被进行收集加速回答。随机的 subspace 鉴定(SSI ) 方法被采用计算结构的形式的参数并且获得平板和框架的 out-of-plane 颤动特征。结果显示墙框架结构由于石头墙的存在有更低的 out-of-plane 僵硬和更大的在里面飞机僵硬。由于从 SSI 方法的差的识别抑制比率估计，基于变化，上面的界限被建议补充存在变化的一个方法为估计形式的抑制比率到重要抑制可变性从不同的点和大小获得了的地址降低界限方法。建议方法的可行性从结构的地板平板与测量数据被说明。更低、上面的变化绑了两个从传统的 SSI 方法与那些相比提供了一致结果的方法。

英文摘要：

Tibetan heritage buildings have a high historical and cultural value. They have endured adverse environmental loadings over hundreds of years without significant damage. However, there are few reports on their structural characteristics under normal environmental loadings and their behavior under dynamic loadings. In this research, a typical Tibetan wooden wall-frame building is selected to study its dynamic characteristics. Field measurements of the structure were conducted under environmental excitation to collect acceleration responses. The stochastic subspace identification （SSI） method was adopted to calculate the structural modal parameters and obtain the out-of-plane vibration characteristics of the slab and frames. The results indicated that the wall-frame structure had a lower out-of-plane stiffness and greater in-plane stiffness due to the presence of stone walls. Due to poor identified damping ratio estimates from the SSI method, a method based on the variance upper bound was proposed to complement the existing variance lower bound method for estimating the modal damping ratio to address the significant damping variability obtained from different points and measurements. The feasibility of the proposed method was illustrated with the measured data from the floor slab of the structure. The variance lower and upper bound methods both provided consistent results compared to those from the traditional SSI method.