Energy-based evaluation method for soil densification effects induced by vibro-compaction of stone columns

In view of the fact that the conventional ground inspection methods are not suitable for the real-time monitoring and quality check of ground improvements due to the limitations in timely and full-scale inspection, an energy-based evaluation method for soil densification effects induced by vibro-compaction of stone columns is proposed, which can timely estimate the average densification effects of soils between stone columns. Based on the propagation theory of elastic waves in foundation, a calculation procedure of energy absorbed by soils is established, and the corresponding undrained cyclic triaxial tests on a prototype silty sand are conducted to establish the empirical model for generation of the excess pore water pressure. Then a case study of a reservoir dam project is conducted. It is found that, compared with that of the field monitored excess pore water pressure and the final void ratio obtained via post-construction inspection, the prediction accuracy of the proposed method is about 90%, which preliminarily validate the feasibility of the proposed method.