What is a Seepage Control Curtain in Construction?

A cutoff wall refers to a continuous barrier used to prevent or reduce the inflow of groundwater from the side walls and bottom of a foundation pit into the pit. For instance, continuous mixed piles (such as cement-soil mixed piles) and cutoff walls formed by single-tube, triple-tube jet grouting piles are known as cutoff walls.

A cutoff wall is a concept, a general term for the waterproofing series around the perimeter of the main structure of a project. In the retaining system of excavation pits, cement-soil cutoff walls are commonly used to intercept water. If the bottom of the pit is below the groundwater level and it is difficult to dewater, it is generally necessary to set up a cutoff wall to prevent groundwater leakage.

Some not-deep excavations are divided into three parts for their excavation protection.

A portion consists of retaining piles, primarily serving as a retaining wall. The form may be reinforced concrete灌注桩 or other types of piles, with some spacing between the piles, yet capable of retaining soil.

The second part consists of the water-stop screen, which serves to consolidate the soil behind the retaining wall and to block the exchange of water layers between the foundation pit and its surroundings. The form may be cement-soil mixing piles or compacted grouting.

Three parts are the supports.

The underground continuous wall is another form of foundation pit protection, commonly used for large and deep foundation pits.

Common types of waterstop curtains include high-pressure jet grouting piles, deep mixed piles for waterstop curtains, jet grouting piles for waterstop curtains, and recently, spiral drilling machine plain concrete or grout waterstop curtains have emerged. Underground retaining structures such as continuous underground walls and bored pile walls, due to their good self-waterproofing effects, do not require additional waterstop curtains in some cases.

The use of plain concrete underground continuous walls for waterstop curtain is common, often involving the process of washing to form a trench. The thickness of the plain concrete underground continuous walls is generally 200 to 300 mm.