Abstract: The assessment of the strength insufficiency defects in slope protection piles for the deep excavation projects is a topic that receives few attentions in the geotechnical society. This paper presents a case history of testing and evaluation of the concrete strength from the slope protection piles. The compressive strength values, the representative cored samples from the pile, principles of strength determination and calculation of the compressive strength are thoroughly discussed in the paper. The method of assessment of the low strength in the slope protection piles are established and the mitigation of these defected piles are proposed. This approach can be applied in the continuation of the deep excavation and reuse the existing support structures.

Key words: Deep Excavations, Slope Protection Piles, Strength Insufficiency, Defect Evaluation, Reinforcement Design