When a retaining wall is designed, the lateral thrust of the soil behind it is calculated. But if the drainage behind the wall is not working, water accumulating after rainfall adds hydrostatic pressure to that thrust. This additional load often exceeds the design load.
The remedy is not complicated: a drainage layer (filter material) is placed behind the wall, geotextile prevents fine material from migrating into it, weep holes are left at regular intervals and a drainage pipe is installed at the toe.
These items are a small part of the cost; omitting them puts the entire wall at risk. At ACARTEK we do not build a retaining wall without drainage.
