Implications of rising groundwater level on structural integrity of underground structures – investigations and retrofit of a large building complex

Groundwater levels (GWL) are rising in many cities in the world. The purpose of this study is to present the multi‐faceted approach adopted for examining the impact of a 3 m rise in GWL on the durability, stability and strength of the structural components of a building complex with 40,000 m² basement. It also reports on the retrofit measures adopted to remedy the situation.

The overall stability of the building complex was examined for the revised loading conditions as well as the need to strengthen the structurally deficient components to satisfy owner's requirement of a dry and operational basement without the dewatering operation. Structural conditions of the basement walls and a slab of the building complex were assessed based on code guidelines, visual observations, site investigations, analytical finite element model (FEM) studies and sound engineering judgement.

About 25 percent of the existing basement slab was found to be structrally deficient to resist the applied hydrostatic load. A number of articulation and construction details were also found to be inadequate. Various options for retrofit for the deficient structural components and articulation details were examined and design details were presented for a cost‐effective solution.

The presented methodology is general and can be adopted for similar situations. However, the presented solutions and conclusions are specific to the problem presented herein and modifications will be required for adoption to other situations.

Practising engineers are made aware of the problem of rising GWL for underground structures. Practical information is presented for practising engineers to solve the problem of water leakage in a large basement.

This paper presents an integrated approach for addressing the structural implications of rising groundwater level in an operational basement of a large building complex.