Couplings for coupling pre-cast construction segments together and pre-cast construction segments having such couplings

A ring of a tunnel, comprising:

• a plurality of pairs of anchors, each anchor comprising a central portion and a pair of legs, the central portion defining an elongated bore, the pair of legs extending from opposite sides of the central portion, each leg extending in a direction generally transverse to the elongated bore and having a proximal end attached to the central portion and a free distal portion disposed away from the central portion;
• a plurality of ring segments comprising radial end surfaces, each radial end surface carrying one of the pairs of anchors and defining corresponding recesses;
• and
• a plurality of pins, each pin adapted to be received in the elongated bores of corresponding ones of the anchors to connect the pair of anchors together,
• wherein the legs comprise a first side and a second side and wherein the central portion comprises a protrusion, the protrusion of the central portion extends beyond the second side of the legs.