The Sravasti ruins : a scientific approach to a proposed conservation plan for a nationally important archaeological site at the Beijing Old Summer Palace

Abstract

The Sravasti Ruins in the Old Summer Palace in Beijing has significant historical value. This former walled city complex was an important place for the emperors and nobles to pay homage to the Buddha in Qing Dynasty and was the only royal Buddhist city in Beijing built after the layout of a Buddhist city in India. Today, the only remains are three sides of the rammed earth walls formerly enclosing the city. The city wall ruins show visible marks of Qing Dynasty construction techniques adding to the scientific value of the site. the Sravasti Ruins is neglected and in urgent need of a conservation plan to protect its physical evidence. In this dissertation, it was determined that the erosion from liquid water (accumulated, non-draining water) and plant growth, as well as uncontrolled access (vandalism), are the most severe damage affecting the stability and preservation of the walls. The stability and strength of the walls are closely related to the moisture content. Through 3D scanning and safety index calculation, it was found that the moisture content of the city walls shows reduced stability at 10% moisture content and a critical point of instability at 20% moisture content. The higher the moisture content of the walls, the worse the stability and strength of the walls. Currently, the site has poor drainage. During heavy rain, especially in the rainy period in summer, water accumulates on the site and the walls and the water content of the walls rises critically putting the structure into high risk of collapse. Combining the on-site analysis at the Sravasti, published research on earthen architecture conservation and reviewing existing guidelines and regulation for earthen sites conservation in China and abroad, this paper proposes a protection plan for the Sravasti with two key aspects: 1) intervention to conserve the fabric and 2) improvement of management and interpretation. For the intervention, the control of water content through the installation of a drainage system and the elimination of surface indentations at the wall tops are proposed. Further, plants are to be removed and any larger cracks should be repaired using local soil. The organization of the entire site and provision of appropriate site interpretation informing the public about the significance of this site will play an important role in its preservation.