Masonry Pagodas Modal Parameter Identification Based On Dynamic Test Environment Research

The masonry pagoda is a example of high-rise building in ancient China, its blend of Chinese and foreign culture as well as essence of traditional architecture, it is not only represent the technical level of China ancient buildings, but also have a profound impact in the history, art, science and technology development. Most of the masonry pagoda building are located in seismic area in China, because of its structural weaknesses within the Tower, the erosion of natural disasters and man-made destruction for many years, led to its poor seismic capacity. If the masonry pagoda suffered earthquakes, is bound to cause huge losses, so for seismic protection of ancient pagoda became of great urgency..This article combined historical and archaeological materials, analysed the composition of the existing masonry pagoda, classification and structure characteristics, and take the four typical masonry pagoda on Wenchuan earthquake as an example, take on the structure of non destructive environment technology of vibration and ANSYS finite element calculation method of combining software simulations, focus on the masonry Tower’s dynamic characteristics and the measures to improve testing efficiency., for further repairs. Earthquake resistance evaluation of damage identification and maintenance to provide a reference basis. Full-text content and conclusions are as follows:1. Combined with the original data to analysis the composition of the existing masonry pagoda, classification and structure characteristics.2. look up the original archive material provided by Sichuan Bureau of cultural relics, through the site survey and mapping, understand the structure of the four masonry Tower’s constructed composition, structure damage and reinforcement of status, to obtain the structure’s geometric dimensions and material properties.3. using pulse method to make Field measurement. On the acquisition of signal processing, get the four pagoda’s structure of natural vibration frequency, mode and some basic modal parameters such as damping ratio. And summarized the key technology of fluctuation method in test of masonry pagoda and influence factor of treatment methods.4. Application of ANSYS finite element software, to establish solid model by spatial structure system of pagoda, simulation of dynamic characteristics of structure, go on the modal analysis of pagoda structure, obtains the four ancient tower’s structures modal parameters (natural frequency and vibration mode), and comparison with measured data, indicates that the test results obtained by this test program is ideal.5. This article use the natural vibration period of masonry pagoda through the site measurement, and combined with previous scholars measured data for analysis of inductive. Correction of masonry pagoda natural vibration period of formula. Through the comparison with measurement cycles, the error is little, identified this formula has better suitability.