Drains

Drainage specialists

Californian drains, also known as horizontal drains, are an effective solution to improve drainage in natural land or landfills.

They consist of small diameter and long perforations, where slotted or perforated tubes are installed, covered with geotextile to prevent clogging. These tubes are arranged with an inclination of approximately 5-10º with respect to the horizontal, thus facilitating the drainage of water accumulated on the ground. In certain cases, such as in galleries or other structures, they can be arranged with different inclinations, even in a vertical position.

At Cimentaterra, we understand the importance of effective drainage for the stability of structures. That is why we offer specialized services in the installation of Californian drains, using advanced techniques and high-quality materials to guarantee optimal results. Our team of highly trained experts takes care of every aspect of the process, from initial planning to execution and subsequent follow-up.

California drain target

The main objective is to drain the slope in order to reduce the pore pressures that act on the surface slip potentials; which leads to an increase in the resistance of the soil and a reduction in the weight of the slope.

It is one of the most effective measures to promote stability, since along with the slope, water is the main source of instability.

Californian drain perforations

The perforation must be wide enough to be able to install the horizontal drain loosely and must present, as mentioned before, a slight inclination towards the slope that allows water to drain.

In cases where the drilling ground is unstable, casing pipes should be used until the installation of the drain pipe.

Horizontal drain pipes

Perforated or slotted PVC or metal tubes are used, the former being preferable as they are more resistant to corrosion.

The openings must be arranged in the sections where it is planned to capture groundwater and frequently the first 2 or 3 closest to the slope must not have holes so as not to erode the surface of the slope.

When significant clogging is expected, geotextile must be installed or periodic maintenance must be carried out with water or pressurized air in the drainage pipe.

Advantage of Californian drains

  • Quick and little complex installation compared to other deep drainage systems.
  • It allows reaching the entire surface of the slope.
  • It can be executed once the instabilities have started.
  • Drainage is carried out by gravity, not requiring the use of pumps or auxiliary systems.

Californian drains are highly effective in lands that intersperse permeable and impermeable levels, such as limestone or sandstone stratified on clay/marl banks. They also work very well on highly weathered rocky slopes.