Causes of Sinking of Prefabricated Floor Slabs in Houses

The main causes of sinking of prefabricated floor slabs in houses include insufficient soil bearing capacity, non-standard construction, quality issues, environmental factors and the impact of service life, as well as factors related to the building itself.

Insufficient Soil Bearing Capacity: The underground soil conditions are complex, with significant variations in the bearing capacity of soil in different areas. If the foundation has not undergone professional reinforcement treatment, uneven settlement is likely to occur when bearing the weight of the prefabricated slabs and the upper structure. For example, on soft soil foundations, if effective foundation treatment measures such as replacement or piling are not taken, over time, the soil will gradually compress and deform under pressure, leading to the sinking of the prefabricated slabs.

Non-standard Construction: Failure to operate strictly in accordance with design drawings and specifications during construction can seriously affect the stability of the prefabricated slabs. For instance, if the flatness of the prefabricated slabs is not ensured during laying, resulting in an uneven surface; if the gaps during splicing are too large or not tight, preventing effective load transfer between slabs; if the slabs are not properly fixed during placement, causing them to shift; or if the joint treatment is improper, lacking adequate waterproofing and crack prevention measures, all these will reduce the overall performance of the prefabricated slabs and increase the risk of sinking.

Quality Issues: During the production process of prefabricated slabs, if the quality of raw materials does not meet standards, such as insufficient cement strength or non-compliant steel bar specifications, or if there are defects in the production process, such as improper curing or inadequate vibration compaction, the quality of the prefabricated slabs will vary. Prefabricated slabs of substandard quality have limited bearing capacity and are prone to sinking and cracking under a certain load.

Environmental Factors and the Impact of Service Life: Prefabricated slabs, when exposed to the natural environment for a long time, are affected by factors such as wind and rain erosion and temperature variations. Rainwater can seep into the interior of the prefabricated slabs, corroding the steel bars and reducing their strength; temperature variations can cause thermal expansion and contraction of the prefabricated slabs, and long-term repeated action can lead to material fatigue damage and gradual aging. As the service life increases, the bearing capacity of the prefabricated slabs will continuously decline, thereby increasing the possibility of sinking.

Factors Related to the Building Itself: Excessive weight of the building or uneven distribution of internal loads can also affect the prefabricated slabs. For example, stacking a large amount of heavy objects in a local area of the building causes the load borne by the foundation in that area to be much greater than that in other areas, resulting in excessive local bearing pressure on the foundation and subsequently triggering the sinking of the prefabricated slabs.