Development Background

With the rapid development of wind power technology, offshore wind power has become the focus of attention in the development of renewable energy worldwide. In recent years, China's offshore wind power industry has developed rapidly, and the newly installed offshore wind power capacity has continued to increase. Offshore wind power piles have shown new characteristics:

(1) Ultra-long: The bearing stratum of pile foundations often exceeds 50m in depth, and can even reach 100m;

(2) Ultra-large: Pile diameters exceed 2m, and can even reach more than 5m or 8m;

(3) Ultra-heavy: Because the wall thickness of such ultra-large and ultra-deep piles reaches 40–80mm, the weight of a whole pile often exceeds several hundred tons, and can even exceed 1,500 tons;

(4) High-precision construction characteristics: The construction verticality is required to be within 3/1000. Therefore, the demand for pile-driving equipment with greater energy has emerged. 

"Old Equipment" Cannot Meet "New Requirements"

At present, the main equipment for offshore wind power pile construction is impact hammers and vibratory pile hammers. Impact hammers are traditional offshore wind power pile-driving equipment, and their main problems include low driving efficiency, heat generation and dissipation, construction safety, and quality control. The pile-sinking principle of vibratory pile hammers is soil "liquefaction," which reduces resistance. Piles can be driven as long as the necessary amplitude, necessary exciting force, necessary weight and impulse, and necessary power are met. At present, the main problems faced include difficult startup, resonance hazards, manufacturing difficulties, and transportation difficulties. The development of single-machine "super-large-scale" equipment is greatly limited.

Multi-hammer Synchronization "Teaming Up" to Solve Construction Challenges

In this context, Shanghai Zhenzhong's vibratory pile hammer "large-scale and resonance-free technology" and "synchronization technology" have become important solutions for future offshore wind power pile construction. Multi-hammer synchronization uses synchronization technology to make multiple vibratory pile hammers of the same specification and model into an ultra-large vibration system. Compared with existing equipment, it has many advantages and practicality:

1. Simple manufacturing: Single-machine manufacturing is no longer limited by manufacturing processes such as factory buildings, motors, and bearings, and mass production can be achieved under existing conditions.

2. Simple transportation: It is not limited by overweight or oversized dimensions and can meet transportation needs by road, water, and other methods.

3. Easy startup: The multi-unit combination does not require ultra-high-power motors, and the equipment can be easily started under existing conditions.

4. Resonance-free: The resonance-free vibratory pile hammer achieves zero-eccentric-moment startup and zero-eccentric-moment shutdown through stepless adjustment technology for the eccentric moment, avoiding the environmental protection problems of intense vibration and noise caused by "resonance" as well as the safety hazards caused by damage to equipment. At the same time, zero-eccentric-moment startup, i.e., no-load startup, solves the problem that ordinary electric vibratory pile hammers require a large-capacity power supply for startup with eccentric moment, i.e., startup under load, with obvious energy-saving effects. The amplitude can be steplessly adjusted from "0 to maximum" or "maximum to 0," adapting to soil changes, with good pile-driving efficiency and results.      

5. Multiple combinations and systematic operation. Multiple vibratory hammers can be reasonably combined for systematic operation to meet the construction needs of different working conditions.

6. High construction precision: Because the hook center, crossbeam center, vibration center, and pile center are aligned on four points in one line, together with a verticality monitor, pile-driving precision is ensured, making it especially suitable for pile foundation construction of large projects such as offshore wind power generation.