Reliability-Based Design and Quality Control of Bored Piles

Bored piles are a type of deep foundations which have been and are being widely used in construction engineering such as high-rise buildings, bridges, jetties, and so on. Although bored piles have remarkable advantages over driven piles, the quality of bored piles is frequently affected by many causes of imperfection, which mainly come from the inadequate ground investigation and construction procedures. It can be said that design and quality control of bored piles are two closely related stages. A quality control procedure has to be clearly addressed in the design stage; and decision making in the design, for many cases, has to be based on the testing results of a quality control procedure. Therefore, two major objectives need to be solved in this thesis as: (1) Propose models to calibrate resistance factors for the Load and Resistance Factor Design (LRFD) approach and find a suitable model aiming to directly determine reliability of a bored pile considering some types of defect that may occur in the bored pile. (2) Select a quality control method and evaluate its reliability when applied to bored piles. The thesis consists of chapters, in each of which a new model is proposed, and then is applied for a specific case study. The logicality and succession of the theoretical issues between chapters are systematically presented. In Chapter 2, a history of the development of design approaches is presented, including the Allowable Stress Design (ASD), the Limit State Design (LSD), and the Reliability-Based Design (RBD). Advantages and limitations of each design approach are discussed in detail. This chapter focuses on analyzing the LSD with the use of partial safety factors following the ultimate limit state. In which, the calibration of resistance factors under the framework of the LRFD is one of the main objectives of this thesis. The level II and level III reliability methods are used to calibrate these resistance factors. In Chapter 3, the quality control approaches
Hydraulic Engineering
Civil Engineering and Geosciences