Settlement behavior of treated hemic peat at Parit Nipah, Johor

Abstract

Peat is classified as soft material which consists of decaying wood and plant remains. Peat has been considered as a challenging material for engineers due to its high natural moisture content, large void ratio, and high compressibility. Its rapid initial settlement followed by large long-term settlement always caused problems for any form of construction on peat. Numerous ground stabilization method for peat have been developed in recent years. Polyurethane grouting is one of the ground stabilization method that is gaining recognition as a fast and effective way to stabilize ground. Polyurethane is a lightweight material with high compressive strength. This study investigated the settlement of polyurethane treated peat under static embankment through full scale testing at Research on Peat Station (REPEATS), Parit Nipah, Johor. The peat in Parit Nipah is categorized as hemic peat with thickness of 4.0m. Four static embankments were constructed representing different depth of peat stabilization by polyurethane grouting. The settlement of the embankments was monitored on daily basis. Results indicated that the injection of polyurethane grout into the peat able to reduce the settlement of peat under static embankment loading. This study also shows the potential of polyurethane grouting to mitigate long term settlement of peat.