Seismic Behavior of an Innovative System for Preventing Gas Leakage through Reinforced Concrete Shear Walls of Nuclear Facilities

Abstract

ABSTRACT During extreme events such as earthquakes or explosions, cracks in reinforced concrete (RC) shear walls of facilities housing hazardous gases or radioactive substances may escape to outdoor environment through cracked concrete. For this reason, it is crucial to produce safe and reliable design and reinforcement details of such walls. This paper presents results of a comprehensive study that focuses on developing cost-effective and reliable gas barrier for RC walls used in underground hazardous facilities, such as nuclear plants, utilizing surrounding soil. The gas leakage experiments were performed in two phases. In the first phase, simulated leakage through cracks of reduced-scale RC shear wall specimens was examined and was used as a baseline for comparison with the proposed leak-tightening protection system. The second phase of the experimental program involved evaluation of the performance and leak-tightening efficiency of the proposed hybrid shear walls/soil system. During the second phase, several types of soils with different characteristics such as soil layer thickness, soil ingredients, moisture content, etc., were assessed experimentally. Results of this study indicated that in general, the presence of soil in the downstream side reduced the gas leakage remarkably. Results also showed that the use of sandy soil with smaller grain sizes has lower permeability as compared to those with larger grain sizes. Similarly, the gas leakage decreases, to some extent, when soil protective layer thickness increases. In addition, it was concluded that gas leakage is inversely proportion to soil’s moisture content.