ABSTRACT
ABSTRACT: Foundation design and construction can be divided into three phases: site investigation, design, and construction. In each of the phases, engineers attempt to ensure the quality and reliability of the foundation. This paper outlines the important roles reliability theory and quality assurance play in each of these phases. In the site investigation phase, reliability theory is used to enhance the planning of investigation boreholes and in-situ tests so that any anomalies and key ground features can be revealed more effectively. In the design phase, evaluation of design analysis models and model parameters, as well as verification of new construction workmanship are of great concern. A recommended way to risk management is to use an integrated approach that combines site investigation, design, and construction. In this approach, an early test program, additional borehole boring, and a verification test program at the end of construction are implemented as means to manage various sources of uncertainty. The practices can be expressed in a Bayesian framework of updating information. In the construction phase, site supervision, monitoring, and quality assurance tests such as integrity tests, PDA tests, and static load tests are routinely conducted to ensure the quality and safety of foundations. It is possible to apply reliability theory to effectively utilize both quantitative (e.g. load tests, movements and ground water monitoring) and qualitative information (e.g. site supervision and integrity tests in the form of “pass’’ or “no anomaly’’ statements) for updating model errors and design parameters, and assisting in decision-making.
