| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a highly watertight electric wire common trench, wherein concrete forming on-site and workers are unnecessary, electric wires can be laid just after a laying operation, working period and cost can be reduced, edges which damage the inserted wire are not formed in the joints, and highly watertight structure can be assured. SOLUTION: Suitable number of pipe bodies 2 are embedded in the rectangular section of a precast concrete block 1 having a specified length. Both ends of the pipe body 2 have inclined inner peripheral surfaces 11 which open outward and increase the diameters. A seal packing 7 is engaged with the end portion of the inclined inner peripheral surface 11, and partly embedded in the block 1. The seal packing 7 is provided with an annular end surface 7a protruding from the end surface of the block 1, in parallel with the end surface in the axial direction. When a plurality of the blocks 1 are continuously laid in the length direction, the annular end surfaces 7a, 7a of the seal packings 7, 7 are mutually pressingly brought into contact with each other.</p> |
