Safety Research On The Ancient Masonry Pagodas Induced By Metro

Our country is the ancient civilizations, with the architectural history of more than7000years and the abundance of masonry pagodas. As a syncretism of the elite of Chinese traditional architecture art and external culture, masonry pagodas is an excellent representative of Chinese ancient high building. Because of built in a long time ago and influenced by environmental factors such as wind and rain erosion, humidity and temperature changes, Masonry pagodas whose durability and earthquake resistance beome weakening have many tiny damages and are more sensitive to strata subsidence and vibration.In recent years, because of advantage of the large carrying capacity, rapid, convenience, comfort, environmental protection and so on, subway has a rapid development in our country. However the subway needs consideration of the subway route planning and human traffic, a lot subway lines are near even through the masonry pagodas historic buildings. Subsidence and long-term slight vibration caused by metro construction and operation will cause irreversible damage to masonry pagodas.In order to show masonry pagodas’s charm and the architecture of our country’s ancient civilization to more people, this paper systematically studied the safety distance to the analogous masonry pagodas taken HongShan pagoda as the research object. The following research works are carried out:1. On the basis of referential review of domestic and foreign bibliography, the recent national standards and guidelines on historic buildings are summarized in a systematic way. The standards to evaluate the vibration of HongShan pagoda in this papar are finally decided.2. According to the vibration test plan, the field measurement is carried out at HongShang pagodas. The horizontal acceleration of HongShan pagodas’s1,3,5,7floor are collected and then analyzed to obtaine the first and the second natural frequency of vibration.3. HongShang pagoda finite element model are built using ANSYS soft, which is a large general soft on FEM(Finite Element Method). Final calculation model is determined by comparing with the field measeurement and considering the elastic modulus, windows and doors hole and the size of units. The model can calculate the horizontal vibration speed of the toppest bearing structure of HongShang pagoda when entering the ground acceleration of different distance to the center of the Beijing subway line4. It can conclude the safety distance by using the chosen technical specifications to evaluate the speed.Finally, based on the summaries and conclusions of all research works, some suggestions and prospect for further researches are put forward.