Reliability-based design of lining structures for underground space against water seepage

The use of underground spaces is becoming increasingly important in this era of rapid urbanization and population growth. However, underground spaces are susceptible to water ingress, which may trigger the deterioration of their structural performance and reduce their serviceability. This highlights the importance of the proper design of lining structures with an emphasis on water penetration. This study develops a reliability-based approach to guide the design of lining structures used for underground spaces. The equivalent depth of water seepage is considered for a two-dimensional lining structure in the presence of the randomness and spatial correlation of the water seepage distribution. The probabilistic behavior of the equivalent seepage depth that is derived serves as the basis for reliability-based design of lining structures. A simple design criterion is developed. An example is presented to demonstrate the applicability of the proposed approach.