Design and Analysis of Forced Drop Hammer Hydraulic Compactor for Soft Foundation Reinforcement of Large Dike Breach

Abstract

This study addresses the engineering challenges of high water content, low bearing capacity, poor equipment accessibility and unsatisfactory reinforcement performance in soft foundations following large-scale dike breaches. A forced-drop-hammer hydraulic compactor is designed for emergency foundation reinforcement at dike-breach sites. Based on the geotechnical characteristics of post-breach soft soil, the overall system configuration and hydraulic-circuit scheme are determined, and a constant-pressure, low-shock hydraulic circuit for forced-drop-hammer operation is optimised. Dynamic governing equations describing the complete hammer-lifting and compaction cycle are established. The AMESim platform is used to investigate system-pressure fluctuations, dynamic response and hammer-motion stability under multiple working conditions. Comparative laboratory-scale model tests are conducted to identify an appropriate compaction-parameter range for dike-breach soft ground, and a targeted emergency construction procedure is proposed for on-site rescue applications. The simulation and laboratory-test results show that the optimised hydraulic power supply maintains stable constant-pressure output with reduced hydraulic shock and reliable cyclic compaction performance. Within the recommended parameter range, the compactness of the simulated soft foundation increases by more than 12 %, improving compaction uniformity and reinforcement quality. The findings provide support for structural design and hydraulic-parameter matching of similar compaction equipment and offer a technical reference for rapid emergency reconstruction of breached dikes.