MUHAMAD SHAHRIL ROSLI/The Star
PETALING JAYA: While Kuala Lumpur is a safe place to live in, construction in limestone areas should be designed through proper engineering to prevent sinkholes, says Malaysian Geotechnical Society (MGS) immediate past president Lee Peir Tien.
“Construction in limestone areas can lead to sinkholes if not properly designed and treated,” he said.
Lee explained that natural sinkholes typically occur in areas with limestone formations.
“Limestone is a naturally soluble rock, which means it can dissolve over time, leading to the formation of cavities or empty spaces underground.
“These cavities are an inherent issue in limestone regions. When the roof of a cavity collapses, it can cause a sinkhole to form at the ground surface.”
For construction in limestone areas, Lee said detecting and treating cavities is a common practice before starting any construction work.
“This helps prevent sinkholes from forming during or after the construction process,” he said when contacted.
Lee said that man-made sinkholes can be prevented through proper engineering measures.
“Sinkholes can happen in two ways: man-made or naturally.
“The first occurs when underground soil is gradually washed away due to a leaking water pipe or sewer pipe.
“Over time, this process weakens the ground beneath buildings or pavements, eventually causing a sinkhole to form at the surface.”His comments came in light of the Aug 23 tragedy when a 48-year-old Indian national disappeared into a sinkhole on Jalan Masjid India in Kuala Lumpur.
Lee said that the sinkhole was “likely caused by leakage from utilities”.
“This subsequently induced ground erosion, washing away the supporting soil and causing it to collapse.
“However, the actual cause will be confirmed based on the investigation outcome of the task force, of which MGS is a member.”
Geotechnical engineers, he said, would carry out engineering analyses to provide solutions to geological hazards such as sinkhole occurrences.
Academy of Professors Malaysia environment and sustainability cluster chairman Prof Emeritus Datuk Dr Ibrahim Komoo said good engineering practices could have prevented the Jalan Masjid India incident.
“To me, this is land subsidence (the sudden sinking of the earth’s surface) – not a sinkhole – as the causes of this incident seem to be more towards human factors.”
Explaining about land subsidence, Ibrahim said the phenomenon can be caused by soil piping (groundwater erosion) that flows into a sewer, which is about 8m below the surface.
“Due to this soil piping, the layer of sand above the sewage channel has moved, leaving an empty space under the brick pavement that covers the surface.”“The triggering factor behind the sudden sinking of that area was the unfortunate victim having stepped on the stone pavement. “With her weight on that already eroded pavement, the sudden sinking of the soil happened and the victim was swallowed by the hole,” he said.
Ibrahim stressed the importance of the construction of new underground infrastructure such as water pipes and sewer lines in Kuala Lumpur to be properly engineered.
Otherwise, the lack thereof might cause utility leakage and sudden sinking of the soil, he said.
