Reinforcement element for a diaphragm wall provided with a seal-carrier

A reinforcement device including:

• at least one seal;
• a reinforcement element for a diaphragm wall including a reinforcement cage which has a height defining a longitudinal direction, a width and a thickness, the reinforcement cage having a first end part and a second end part opposite to the first end part along the width of the reinforcement cage, the first and second end parts extending along the longitudinal direction of the reinforcement cage, the reinforcement element further including at least one seal-carrier provided with a mounting part for receiving the at least one seal which is elongated, the at least one seal-carrier being fixed to the first end part of the reinforcement cage and extending along the longitudinal direction of the reinforcement cage, the at least one seal-carrier having two flanges extending along the longitudinal direction and a bottom so as to define a housing for receiving the at least one seal, the mounting part including a longitudinal slot formed in the bottom of the seal-carrier to receive the at least one seal;
• and
• a sacrificial material arranged in the housing defined by the two flanges and the bottom of the at least one seal-carrier, the at least one seal being mounted on the at least one seal-carrier while being at least partly bordered by the sacrificial material.

A method for making a diaphragm wall in the ground, comprising:

• drilling a first vertical trench in the ground;
• placing in the first trench a reinforcement element for the diaphragm wall including a reinforcement cage having a height defining a longitudinal direction, a width and a thickness, the reinforcement cage having a first end part and a second end part opposite to the first end part, along the width of the reinforcement cage, the first and second end parts extending along the longitudinal direction of the reinforcement cage, the reinforcement element further including at least one seal-carrier provided with a mounting part for receiving at least one seal which is elongated, the at least one seal-carrier being fixed to the first end part of the reinforcement cage and extending along the longitudinal direction of the reinforcement cage, the at least one seal-carrier having two flanges extending along the longitudinal direction and a bottom so as to define a housing for receiving the at least one seal, at least a first part of the at least one seal being surrounded by a sacrificial material, the mounting part including a longitudinal slot formed in the bottom of the at least one seal-carrier to receive the at least one seal;
• pouring concrete into the first trench then, after hardening of the concrete, drilling a second vertical trench in the ground, juxtaposed with the first vertical trench on a side of the at least one seal-carrier;
• discharging the sacrificial material out of the housing using a scraping tool including two parallel teeth spaced apart from each other so as to define a passage for the at least one seal, the width of the scraping tool being substantially equal to a distance between the flanges of the at least one seal-carrier, so that the first part of the at least one seal extends into the second trench;
• and
• putting concrete in the second trench.