Numerical Modelling, Monitoring, and Field Observations for Comparative Evaluation of Subsidence-induced Building Damage Caused by Shaft Construction

The magnitude and distribution of the ground movements to be caused by the construction procedures and building distortions sustained as a result is one of the most important issue encountered in urban underground projects. The influence of excavating a vertical shaft on the ground subsidence distribution and its effects on the adjacent residential buildings are discussed in this paper. A three-dimensional finite element model along with monitoring results and also the visual comprehension of the field covering Shahani access shaft from Amirkabir underpath and tunnel project are used to illustrate the study objectives. The three-dimensional numerical modelling is performed under Plaxis 3D Foundation and the subsidence around the shaft is predicted during construction. Finally, the predicted subsidence is compared with the measured ones by instrumentation and field observation of the dominant cracks in the adjacent building. The output results of numerical modelling reasonably accord with the measured ones and appropriately prove the asymmetrical distribution of subsidence pattern. According to the measurements and numerical modelling, the maximum amount of about 0.0014 angular distortion has occurred in the building that is less than the accepted lower limit of 0.002 in most of cases. Therefore, the origin of the initiated tensile cracks in the lateral walls of building during the shaft construction is not expected to be direct influences of shaft excavation, where the weakness in bracing elements of the building intensified the subsidence-induced building damages caused by shaft construction.

کلیدواژه ها:

Ground Subsidence ، Shaft Construction ، Monitoring ، Field Observations ، Numerical Modelling ، Building Crack