Offshore steel pipe pile construction process and precautions:
Preliminary preparation:
The construction of offshore steel pipe pile needs sufficient preparation. First of all, conduct investigation and study, select a suitable construction site, conduct environmental risk assessment, and determine operating procedures and safety measures. Secondly, prepare the necessary equipment and tools, such as cranes, pile drivers, hanging baskets, ships, etc. Materials should also be prepared, such as steel pipe piles, steel wire ropes, sandbags, paint, etc.
The construction process of offshore steel pipe pile mainly includes the following steps:
1、 the production of steel pipe pile and steel casing: the steel pipe used in the steel pipe pile and the steel casing used in the underwater part of the drilling are rolled on the site. The steel plate of 10~14mm thick is rolled into small sections and the small sections are welded into large sections. Each section of steel pipe is welded with inner and outer edges, and the weld width is not less than 2cm.

2、assembly of the float: the float is the foundation of the floating crane, composed of a number of small steel boxes. The small steel box is rectangular block, with rounded corners around the bottom and a rectangle at the top. Small steel boxes are connected with bolts and bayonet pins, and anchor holes are reserved at the top for connecting the anchor machine or other devices that need to be fixed.                3、 floating crane assembly: Floating crane is a lifting equipment for water operation, composed of a buoy and CWQ20 detachable mast crane. The main body of the floating crane is a tripod, and the structure of the crane is composed of arm, column, diagonal support, turntable base and cab.

4、 Build an underwater platform: First use a floating crane to fix the anchor at 60~100m away from the design pile, marked by a buoy. Then using the four winches on the guide ship (commonly known as anchor machines), under the command of the measurement, the telescopic anchor machine is used to locate the guide ship, and the steel pipe piles are accurately released to the guide ship according to the layout position.
5、steel trestle design: steel trestle and main bridge center line parallel. The design of the center line of the steel trestle takes into account the navigation needs in the construction process to ensure the smooth channel during construction.
‌6、Construction technology ‌ : including the assembly of floats, I-beams, trusses, winches, rotating pedestal and boom to form a floating crane, using the floating crane to use the guide ship composed of floats and I-beams as the guide frame, using the floating crane to drive steel pipe piles with the help of the guide ship to set up an underwater working platform. With the support of the underwater working platform, the steel casing is set up, the drilling hole is drilled, the steel cage is lowered and the concrete is poured. Basic composition of piling ship:
The basic composition of piling ship generally includes the following parts: hull, crane, steel pipe pile, pile driver and so on. The steel pipe pile is an important part of the pile driving ship, which is hoisted into the sea by the crane, and then driven into the sea by the pile driver.
The working principle of steel pipe piling:
The working principle of steel pipe piling is to drive the steel pipe pile into the sea bottom and fix it on the sea bottom through the impact of the pile driver. The specific working principle is as follows:
1、 lifting steel pipe pile: First by the crane to lift the steel pipe pile into the sea, and positioned in the need of construction position. 

2、 pile driver positioning: Then, the pile driver is positioned on the top of the steel pipe pile by the equipment on board, so that it exerts an impact force on the steel pipe pile.

3、 into the steel pipe pile: when the pile driver began to work, constantly impact the top of the steel pipe pile, and gradually the steel pipe pile into the sea. 

4、Concrete pouring: When the steel pipe pile is driven to the required depth, concrete can be injected into the steel pipe through the corresponding equipment to fill it and firmly connect the steel pipe to the seabed.

Advantages and Applications:
Piling ship has the advantages of fast construction speed, reliable quality and long service life, and is widely used in the field of ocean engineering. For example, offshore Bridges, wharfs, offshore platforms, etc., need to be built by piling boats to ensure the stability and safety of the project.
Through the above steps, the piling construction of steel pipe piles can be carried out safely and effectively at sea to ensure the stable foundation of cross-sea Bridges or other water buildings.