Application of Bottom-Feed Vibroflot Crane-Mounted Offshore Stone Column Construction

In January 2021, the crane-mounted bottom-discharge vibroflot equipment, developed and manufactured by Beijing Vibroflotation Engineering Machinery Co., Ltd., was successfully deployed for offshore operations at Caofeidian Port Area in Tangshan. The project was part of the breakwater head construction for the 20-ton-class channel expansion within the port basin.

This marked a significant milestone in the application of domestically developed advanced vibroflotation technology in complex marine engineering environments, showcasing its effectiveness in offshore ground improvement and foundation reinforcement tasks.

The construction waters were located near the entrance of the port basin. On one hand, the steel wire ropes and anchor chains of conventional flat barges severely obstructed the passage of vessels entering and leaving the port. On the other hand, the disturbance caused by large inbound and outbound vessels, combined with waves and ocean currents, made it impossible to carry out traditional offshore vibro-replacement piling methods in this area.

To meet the foundation treatment requirements, it became a major challenge to accurately position and properly place fill material under such conditions. The restricted working space and high operational risks inherent to offshore environments placed greater demands on the automation capabilities of the equipment.

This situation highlighted the necessity of a more advanced, precise, and automated construction solution—an area where the crane-mounted bottom-discharge vibroflot system proved especially advantageous.

The bottom-feed vibroflot offers a unique method of vibration and compaction, effectively improving soil conditions. Its specially configured internal discharge pipeline system ensures reliable and precise material placement during piling operations. Additionally, the equipment is equipped with a one-touch automated piling function, which is especially convenient for offshore applications and significantly enhances operational efficiency. Naturally, it became the preferred choice for foundation treatment in this marine project.

Beijing Vibroflotation Engineering Machinery Co., Ltd. has been dedicated to the vibroflotation industry for over 40 years. As the pioneer in developing China’s first bottom-discharge vibroflot and a complete systems provider, the company also leads in the automation of vibroflotation construction and full-process quality control technologies. For this project, the company provided the complete set of bottom-discharge vibroflot equipment and collaborated with CCCC First Harbor Engineering Investigation and Design Institute Co., Ltd. to support the project’s construction design and related operations.

The construction area was subject to harsh weather conditions, with temperatures dropping as low as -25°C, placing stringent demands on the reliability and cold resistance of the vibroflotation equipment. To meet these challenges, the core components of our bottom-discharge equipment were all sourced from leading European and Japanese manufacturers, ensuring high performance under extreme conditions.

After extensive research and evaluation, the decision was made to modify a steel-legged cutter suction dredger to serve as the platform for the vibroflotation operations. This innovative solution effectively addressed the issues of precise pile alignment and limited operational space within the construction zone.

Despite the severe cold and uniquely demanding working environment, the project was completed successfully, with over 3,000 stone columns installed, totaling an impressive 25,000 linear meters of foundation treatment.