CLASSIFICATION AND IDENTIFICATION OF FAILURE MODES OF ANCIENT CITY WALLS

This paper aims at a variety of failure phenomena of ancient city walls in different regions of China. It is based on the analysis of the failure mechanism. It uses the method of classification and induction to study the failure modes of ancient city wall. It puts forward a variety of ancient city wall failure modes. It uses the control factors that lead to the failure of the wall to classify the failure modes. It summarizes 11 typical failure modes including uneven settlement of foundation, surface bulging, wind erosion and heavy rainfall erosion. The corresponding occurring conditions and failure mechanisms are recommended for each failure modes. The protective measures are also proposed. Combined with the numerical simulation method, the failure mode of an ancient city wall in China is identified. The results show that the main failure mode of this ancient city wall is rainstorm erosion. The rainfall degree, the duration of rainfall, and the drainage channel in the wall all have a significant impact on the deformation of the wall. The rainfall leads to the bulging phenomenon in the lower part of the surface of the wall. The results can provide a scientific basis for the protection of the ancient city wall, effectively avoid the occurrence of local instability problems and provide a reference for the protection and restoration of the ancient city wall under various failure modes.