The Phenomenon of Houses Collapsing Due to Land Movement in Purwakarta, IPB University Experts Explain Factors and Characteristics to Watch Out for
Recently, three houses in Dian Anyar Housing, Cisereuh Village, Purwakarta Regency, West Java, suffered severe damage due to land movement. Responding to this incident, Ir Wahyu Purwakusuma, an expert from the Department of Soil Science and Land Resources at IPB University, explained the causal factors.
“Land movement occurs due to soil failure. This occurs when the soil loses its bearing capacity or the soil is no longer able to withstand the load on it. Loss of soil bearing capacity can be triggered when the load above it increases, for example in the case of additional floors/building height or other loads,” explained Ir Wahyu.
He continued, soil can also lose its bearing capacity due to certain factors that cause its shear strength to decrease. For example, when soil moisture increases due to rain (heavy) which causes pore pressure to increase, causing the shear strength of the soil to decrease and making it easier to move.
“Poor soil drainage increases moisture and pore pressure, which can trigger landslides on sloping land. Disturbed slope stability too, for example due to slope cutting, can lead to soil movement. Shocks such as earthquakes or mechanical disturbances can also weaken the shear strength of the soil,” he said.
He further explained that apart from heavy rainfall, land movement can also be caused by certain geological factors, such as movement of the earth’s crust or volcanic activity. “Another thing, it can also be caused by faults or faults as a result of the movement of the earth’s plates,” he said.
He explained the main characteristics of a building that will collapse due to moving soil, namely:
- Cracks appear on the walls or foundation of the building. These cracks can increase in size over time.
- The floor of the building becomes uneven due to a shift in the foundation of the building.
- The shifting of the building or foundation can have an impact on the construction of doors / or windows so that the doors / windows become difficult / start to be difficult to open or close or even become tilted.
- The walls and structure of the building are tilted. The slope of the structure may indicate that there is ground movement underneath.
- Changes in the landscape around the building, such as changes in land slope, cracks appearing, trees tilting, and others.
- Crackling sounds appear in the building structure as a result of movement.
“There are steps that the community can take to reduce the risk of land movement. First, people need to understand the history of the land, where a building is located, related to the carrying capacity of the soil and its geological history,” he explained.
Second, he continued, people should not just add buildings if they do not know the carrying capacity of the soil, because the soil has a carrying capacity limit. “Consult with relevant agencies/parties if you are going to add floors to a building,” he advised.
He explained that moving soil also has an impact distance, depending on the type of soil movement. It ranges from a few centimeters per year in the case of soil creep, to tens of meters per minute in the case of landslides.
“If a building collapses due to land movement, it is likely to involve other buildings that are on the path of the land movement in question,” he added. (Lp) (IAAS/LAN)
