(1) System Setup and Debugging After the piling ship arrives at the piling dock, it first prepares for debugging that the ship-borne GPS offshore positioning system receives the data link sent by the reference station. After the receiver, mobile station and mobile phone phone book are set up as required, the control points provided by the measurement and control center are used for detection, and the plane positioning accuracy is estimated according to the following formula: m = √ m station 2+a2+(b×D)2m. Error in GPS plane control point of M station reference station, maximum fixed error of nominal accuracy level of B-class network measuring instrument 10mmaRTK, horizontal proportional error of nominal accuracy level of Trimble5700GPS measuring instrument, distance from Trimble5700GPS reference station to rover station 1 ppm MD, This project takes 10km to substitute the above data into the above formula to get a numerical value, that is, the plane point error precision of RTK measurement, and takes twice the median error as the tolerance requirement of RTK measurement, so that the difference between the result measured by RTK method and the three-dimensional coordinate of the point provided by the measurement and control center should be within the tolerance requirement of 34 mm. If it does not meet the requirements, the reason should be checked and re-tested before it can be used for piling control.
(2) Calculation of positioning data Before preparing for piling, the positioning data such as plane coordinates of all piles at the top elevation of each bent pile are calculated according to the design drawings, and the anchor position coordinates of each anchor of the pile boat are calculated according to the predetermined anchor position of the pile boat, so as to be used for anchor position positioning of the pile boat. All positioning data must be checked by special personnel after calculation, and can be used only after it is confirmed.
(3) Maintenance of control points Permanent control points are retested once a month and temporary control points are retested once a half a month. The observation points for settlement and displacement of bank slopes, wharves and approach bridges are ready (permanently) and will be observed once a month. After pile sinking or after heavy wind and rain, all observation points should be re-measured. The above measurements shall be recorded and put into a book, and the construction baseline shall be adjusted.
(4) Settlement and displacement observation points shall be set during the construction period, and shall be set along the boundary line, and shall be observed regularly according to regulations. Settlement and displacement observation points shall be buried on the completed representative structures, and shall be measured and observed regularly according to the requirements of observation accuracy, and the original observation records shall be made. Permanent settlement and displacement observation points shall be set up, and the position and frequency of observation points shall be confirmed by the supervision engineer, and observation records shall be made.
(5) When the piling boat is in place, the anchor cables on the piling boat will not interfere with each other, and the distribution is reasonable, while ensuring the stability of the hull. When the piling ship arrives at the piling position, according to the anchor position coordinates of each anchor, the anchor is positioned and anchored on the anchored ship by RTK measurement.
(6) Positioning pile sinking of piles Input the pre-calculated pile number, X coordinate value, Y coordinate value, ship position angle, pile inclination angle and Z coordinate value of each pile into MicrosoftAccess database, and call the positioning data of piling from the database when piling. After the inspection is confirmed, start the monitoring program and start monitoring the ship position. Display the offset map, moving direction and moving amplitude of the pile on the screen. According to the graphics and data displayed by monitoring, move the pile boat close to the scheduled ship position until the longitudinal and transverse difference between the current ship position and the scheduled ship position is less than 5cm and the torsion angle is less than 0.5 degrees, and then lower the pile and press the hammer. Before hammer opening, record and print the data before hammer opening, and then start piling.
(7) Pile sinking control GPS pile sinking positioning system can control the positioning of pile foundation and the pile sinking elevation itself, and double control the whole pile sinking process.
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