Anti-Seismic Performance Evaluation of Waterproofing Materials for Underground Pile Wall Structures

This study introduces and demonstrates the application of an experimental regime for anti-seismic performance evaluation of waterproofing materials used for concrete pile walls. Concrete pile walls are subject to high degrees of seismic load, and the resultant stress can affect the waterproofing integrity of the structure, but there is currently no existing methodology or standard for evaluating this property of waterproofing materials. To propose and conduct this evaluation, a new testing apparatus was designed and manufactured to test an installed waterproofing material's seismic resistance performance. Under three different inclined angle conditions (0°, 10°, 20°), each with three different rotation speed conditions (10, 20 and 30 rotations per minute), three types of waterproofing materials were subjected to 30 s of increasing seismic stress and tested for their waterproofing performance. Waterproofing performance was determined by whether the specimen installed with the respective type of material was able to prevent leakage path formation during the seismic stress, and the performance was summarized and compared based on the average results for four specimens of each material type and the duration before leakage occurrence. Results of the demonstration testing yielded significantly different results for the tested material types, prompting the need to further investigate different types of waterproofing materials, products, and techniques for a comprehensive understanding of waterproofing material response properties against seismic stress. The demonstration process shown in this research was intended to serve as a proposal for the development of these performance evaluation criteria, methodologies, and equipment for possible future application.