PURPOSE: To promote work efficiency by pivoting an expansion device on a ring device to bear it so that it is capable of pivoting in a horizontal direction and, at the same time, providing a segment holding device to a front end expansion section thereof.

CONSTITUTION: In the case a segment 68 conveyed to the front end of a lining 22 is assembled to the lining 22, a ring device 70 is rotated until an expansible direction of an expansion device 88 is changed into a vertical direction. Then, a second driving device 102 and a driving mechanism 98 are extended, the device 88 is pivoted to incline backward and, at the same time, a holding device 100 is displaced to a specific position against the segment 68. After that, after the segment 68 is held by a chuck 108 of the device 100, the driving mechanism 98 and driving device 102 are contracted to suspend the segment 68 to a segment erector 66. The devices 70, 88, 100 and 102 are driven to move the segment 68 to a specific position. In addition, after the segment 68 is assembled to the lining 22, the erector 66 is returned in a wait and see state. According to the constitution, the segment of the front end of the lining is held and can be accurately and easily assembled.