Installation method for closure joint of immersed tunnel

An installation method for a closure joint of an immersed tunnel, comprising following steps:

• establishing a first coordinate system:
• establishing the first coordinate system at a tail end of an installed N+3 tube coupling;
• distributing feature points:
• distributing breakthrough points NHS and N+1W at a head end and a tail end of a N+1 tube coupling respectively, distributing breakthrough points DS and DW at a push-out segment, and distributing breakthrough points N+2S and N+2W at a head end and a tail end of a N+2 tube coupling respectively;
• and calculating coordinates of the breakthrough points DS, DW, NHS, N+1W, N+2S, N+2W in the first coordinate system respectively;
• installing the N+2 tube coupling:
• calculating a deviation between the N+2 tube coupling and the N+3 tube coupling by using the coordinates of the breakthrough points N+2S and N+2W in the first coordinate system, and adjusting an installing position of the N+2 tube coupling to make the head end of the N+2 tube coupling butt with the tail end of the N+3 tube coupling;
• installing an N+1 tube coupling:
• butting the head end of the N+1 tube coupling with a tail end of an installed N tube coupling:
• calculating a deviation between the N+1 tube coupling and the N+2 tube coupling by using the coordinates of the breakthrough points N+1S and N+1W in the first coordinate system, and adjusting an installing position of the N+1 tube coupling to make the tail end of the N+1 tube coupling close to the tail end of the N+2 tube coupling;
• pushing out a push-out segment:
• calculating a deviation between the push-out segment and the N+1 tube coupling and a deviation between the push-out segment and the N+2 tube coupling respectively by using the coordinates of the breakthrough point DS and/or DW in the first coordinate system, and adjusting a pushing-out direction of the push-out segment disposed inside the N+1 tube coupling towards the N+2 tube coupling, so as to allow the push-out segment to be precisely butted with the tail end of the N+2 tube coupling;
• in the step of distributing the feature points, distributing a control point N+3D at the tail end of the N+3 tube coupling, by taking the control point N+3D as a reference point, measuring relative positions of the breakthrough points DS, DW, N+1S, N+1W, N+2S, N+2W with respect to the control point N+3D respectively, and converting the relative positions into coordinates in the first coordinate system, where coordinates of the breakthrough point N+3D in the first coordinate system are (x0, y0, z0), coordinates of the breakthrough point DW in the first coordinate system are (x1, y1, z1), coordinates of the breakthrough point DS in the first coordinate system are (x2, y2, z2), coordinates of the breakthrough point N+1S in the first coordinate system are (x3, y3, z3), coordinates of the breakthrough point N+1W in the first coordinate system are (x4, y4, z4), coordinates of the breakthrough point N+2S in the first coordinate system are (x5, y5, z5) and coordinates of the breakthrough point N+2W in the first coordinate system are (x6, y6, z6);
• in the step of pushing out the push-out segment, a method for calculating the deviation between the push-out segment and the N+2 tube coupling is as follows:
• Δ
• ⁢
• x
• 3
• =
• x
• ⁢
• 1
• -
• x
• ⁢
• 5
• +
• x
• ⁢
• 6
• 2
• ;
• Δ
• ⁢
• y
• 3
• =
• y
• ⁢
• 1
• -
• y
• ⁢
• 5
• +
• y
• ⁢
• 6
• 2
• ;
• Δ
• ⁢
• z
• 3
• =
• z
• ⁢
• 1
• -
• z
• ⁢
• 5
• +
• z
• ⁢
• 6
• 2
• ;
• where, Δx3 is a deviation between the push-out segment and the N+2 tube coupling in the x-axis direction:
• Δy3 is a deviation between the push-out segment and the N+2 tube coupling in the y-axis direction;
• and Δz3 is a deviation between the push-out segment and the N+2 tube coupling in the z-axis direction;
• a method for calculating the deviation between the push-out segment and the N+1 tube coupling is as follows:
• Δ
• ⁢
• x
• 4
• -
• x
• ⁢
• 2
• -
• x
• ⁢
• 3
• +
• x
• ⁢
• 4
• 2
• ;
• Δ
• ⁢
• y
• 4
• =
• y
• ⁢
• 2
• -
• y
• ⁢
• 3
• +
• y
• ⁢
• 4
• 2
• ;
• Δ
• ⁢
• z
• 4
• =
• z
• ⁢
• 2
• -
• z
• ⁢
• 3
• +
• z
• ⁢
• 4
• z
• ;
• where, Δx4 is a deviation between the push-out segment and the N+1 tube coupling in the x-axis direction:
• Δy4 is a deviation between the push-out segment and the N+1 tube coupling in the y-axis direction;
• and Δz4 is a deviation between the push-out segment and the N+1 tube coupling in the z-axis direction.