Abstract: A system transformation method is proposed in batches and staged loading and unloading to control the risk of structural deformation and cracking during the system transformation between the Vshaped and temporary columns in the Huangmugang transportation hub. To this end, the measurement robot and computer vision technology are used to automatically monitor the displacement of the temporary column top, Vshaped column top, and steelconcrete beam midspan for early warning. The monitoring results reveal the following: (1) The measurement robot′s monitoring results agree with those of computer vision. When the steel cushion block atop the temporary column is disengaged following staged loading, the displacement of the temporary column′s top is less than the designspecified control value of 3 mm. Furthermore, after the third unloading stage(45% of the total unloading value), the settlement at the top of the temporary column reaches 86% of its maximum settlement. (2) While the influence range of system transformation primarily comprises the current frame and two adjacent frames, totaling three frames, the maximum deflection of the steelconcrete beam is approximately 30.0 mm, which is less than the allowable value of 64.0 mm. (3) Although the north side of the frame moves upward before the south side during the loading stage, the Vshaped column on the south side of axis 22 still produces a maximum settlement of 3.5 mm, indicating an asymmetric structural response. Therefore, the entire structure is safe during the transformation.

Key words:  comprehensive transportation hub, underground space, Vshaped column, system transformation, measuring robot, computer vision