KUALA LUMPUR: The site where a landslide occurred on Jalan Wawasan is an embankment area with a sloping base that lacks retaining structures, aside from having water channels and drainage structures at the bottom.
The Mineral and Geoscience Department (JMG) said field observations reveal pre-existing cracks in building structures such as floors and retaining walls.
"This indicates that soil movement had occurred earlier before the landslide incident.
"JMG, in line with recommendations, proposes to cover the landslide embankment with a tarpaulin sheet and install sheet pile structures as an initial mitigation measure," it said in a report shared with the New Straits Times when contacted.
The estimated dimensions of the landslide are 3,000 square metres of area (Width 60m x Length 50m) with a depth of 3 metres and an estimated volume of 5,000 cubic metres.
JMG said it will establish Control and Danger Zones at the incident site.
"The Selangor and Federal Territories JMG will continue to monitor soil movements together with the Subang Jaya City Council, the Petaling District and Land Office, and the police.
"From observations, it is evident that the soil collapse occurred due to continuous rainfall, saturating the soil layers with water and causing slippage.
"On Dec 18, no significant signs of movement were detected, and the site was deemed stable compared to the initial incident observations," it said.
The vibrations from the sheet piling might have contributed to the collapse of loose soil yesterday at 3.30pm.
Earlier today, Serdang District police chief Assistant Commissioner A Anbalagan raised concerns about another soil movement if heavy rain occurs.