Abstract:

Based on the influence of Xi’an Metro Line 2 underneath crossing City Wall and Bell Tower in construction period and operation period, a new series of measures for protecting City Wall and Bell Tower have been studied. Many construction plans about protecting City Wall and Bell Tower are compared and analyzed. Finally, the construction plan that is bilateral around ancient buildings, foundation reinforcement about segregation of pile, and strengthening the ancient buildings structure is adopted. Finite element software have been used to analyze the effect of the protective measures; and it is shown that the influence on City Wall and Bell Tower is lower than the before reinforcement about 2/3. The monitoring data during construction is found that the, ancient buildings settlement displacement is lower than earlier forecast data; and it keep within the limits of design value. The data demonstrate that the protective measures are valid and reasonable. At the same time, metro vibration influence on City Wall in the operation period is analyzed; and vibration damping measures are put forward. Through scheme selection, numerical analysis, specific implementation procedures and real-time monitoring, a new series of protective measures for protecting ancient buildings due to tunnel underneath crossing have been put forward and demonstrated. And the series of protective measures is very practical.

Key words: Xi’an Metro, Bell Tower, city wall, protecting measures, design and construction schemes