Horizontal Drain

In order to further stabilise the slopes, other than typical berm drains, horizontal drains are installed at the slopes. The purpose is to discharge out ground water if any thus ensuring the stability of the slopes.

At this project, it is decided that the upper and lower sides of the slopes to be installed horizontal drains. As per construction drawing, the horizontal drains are installed at 12m depth and 6m interval. The holes of 100mm diameter are done by using rotary drilling with air compressed method. Then the 80mm diameter of PVC pipes wrapped with geotextile are slotted into the holes.

PVC pipes wrapped with geotextile



setting up of drilling machine


operator ready to use controller to operate the drilling machine


ready to drill. seen here is the driller bit with standard extension rod of 1.5m length.


drilling process to make a 100mm diameter hole


upon completion of the hole, then the PVC pipes wrapped with geotextile slotted into the hole


final push and adjustment of the pvc pipes into the hole