Evaluation method for multi-story buildings influenced by under-crossing metro tunnel

With the development of urban metro construction, there are more and more under-crossing metro tunnels completed under buildings in Beijing. However, the evaluation method for the upper buildings influenced by under-crossing metro tunnels is not mature. Based on the analysis of the measured settlement of the upper buildings, following conclusions are drawn: (1) The settlement of the upper buildings influenced by double tunnels can be calculated by the superimposed modified Peck equation; (2) Only appearance measurement, crack record and non-destructive detection are necessary for the evaluation of the upper buildings; (3) The additional incline for any local part of strip foundation must be in the control range, and the area with large additional incline value should be highlighted in monitoring; (4) The evaluation of a upper multi-story building can be finished after three steps: a) The completion drawings of the building are used to confirm; b) The appearance measurement, structural detection and original documents are stored for preserving the evidence; c) By reducing the existing deformation of building foundation from the total allowable value, the additional deformation during construction period is given.