Vibration Serviceability Research On Top Head Estates Of Subway

With the increasing shortage of urban land resources, multi-level development with housing, official and commercial buildings and other infrastructures on top of the platform of car depot, which usually cover a large area, becomes the major approaches of planners for improving land utilization ratio and subway investment return rate. They can use its exploitation value and investment return to make up for the financial gap in metro construction and operation and lead it into a positive circulation of construction, operation and reconstruction.However, the frequently moving trains in stopping train checkup shed cause vibrations inevitably. Most of the vibration energy is carried by surface waves and transferred into adjacent surrounding soil, which may induce vibrations to the buildings via structural components such as columns and platform facilities. This effect may lead to an increasing exposure and higher vulnerability of buildings to traffic-induced vibrations, as well as a tougher living environment for the occupants in the buildings while the requirement of public on environments is becoming more and stricter with the social development.Since the history of the appearance and development of top head estates of subway is rather short, actual projects are rare and few academic are made. Therefore, focused on the top head estates of subway, the vibration serviceability of such project is researched systematically in this paper. 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 vibration serviceability are summarized in a systematic way. The standards to evaluate the vibration serviceability of the top head estates of subway in this papar are finally decided. The relationship between the standard to evaluate vibration serviceability and the standard of environmental vibration in evaluation indexes and limits is discussed.2. According to the vibration test plan, the field measurement is carried out at the site of BaWangFen car depot of Beijing subway. The dynamic effects of train-induced vibrations of buildings on top of subway are collected and then utilized to examine the structural serviceability based on the selected standards.3. Several typical sections of TianTongZhuang car depot of Ningbo subway are chosed, and their finite element model are built using ANSYS soft, which is a large general soft on FEM(Finite Element Method). Inputting the measured accelerations of train-induced ground vibration at the site of BaWangFen car depot of Beijing subway, the dynamic effects of the buildings on top of subway are calculated and the vibration serviceability is evaluated based on the selected standards. In addition, two kinds of vibration-decreasing measures are applied, and the effects of decreasing vibration are also analyzed.Finally, based on the summaries and conclusions of all research works, some suggestions and prospect for further researches are put forward.