A field case of rock-bolt deformations in pullout tests

The performance of any reinforcement support depends on the efficiency of the stress transfer mechanism. Extensive research was conducted over several decades to understand the complex interaction mechanism of load transfer along the reinforcement in soil as well as rock media. This paper presents a lucid comparative study of rock bolt deformations in pullout tests with a simplified theoretical prediction for geotechnical evaluations. Brief literature reviews on the topic are also summarised. Some selected field experiment results of typical rock bolt pullout tests of the Lam Ta Khong Pumped Storage project, Thailand are illustrated. The underground geology of the project site consists of soft quaternary deposit of clay/mudstone as well as sedimentary formation of sand/siltstones. The general patterns of deformation responses in rock-bolt pullout tests were observed to be linear.