Foundation Trench for Concrete Prefabricated Houses
During the construction of foundation trenches for concrete prefabricated houses, special attention should be paid to foundation treatment and structural adaptability. The core points include foundation trench base treatment, adaptability of prefabricated panel structures, and construction specification requirements.
Foundation Trench Base Treatment is Key
In the context of rural self-built houses, after excavating the foundation trench, a concrete cushion must be poured. This is a core measure to prevent house subsidence. The role of the cushion is to evenly distribute the upper loads and avoid uneven settlement of the foundation soil layer due to excessive local pressure. If cushion construction is omitted, even with prefabricated components, the house may still develop cracks or tilt due to foundation issues. The thickness of the cushion should be determined based on geological conditions, typically not less than 10 centimeters, and the concrete strength grade should be not less than C15 to ensure its load-bearing capacity.
Prefabricated Panel Structures Must Adapt to Foundation Trench Conditions
Case studies of renovating old houses indicate that the ground construction of prefabricated panel structures requires a strict assessment of existing conditions. When there is a 4-5 cm concrete leveling layer above the prefabricated panels, it is safe to chisel wire channels; if the thickness of the leveling layer is insufficient, forcing the chiseling will damage the structural integrity. This principle also applies to foundation trench construction: if the prefabricated house uses prefabricated panels as the floor or roof structure, the excavation of the foundation trench should avoid the joint positions of the prefabricated panels, and the depth control should consider the thickness of the prefabricated panels and the stability of the supporting structures below. For example, the depth of the foundation trench should not exceed one-third of the height of the supporting beams below the prefabricated panels to prevent local stress concentration and structural damage.
Construction Specifications Must be Strictly Followed
Foundation trench construction should follow the standardized process of "excavation-inspection-treatment-pouring." After excavation, the base should be compacted, and loose soil and debris should be removed to ensure that the foundation bearing capacity meets the design requirements. If weak soil layers are encountered, replacement or reinforcement treatment is required, such as backfilling with graded crushed stone and compacting it in layers. Before concrete pouring, a elevation control line should be set to ensure uniform cushion thickness. At the same time, an immersion vibrator should be used to densify the concrete to avoid quality defects such as honeycombs and pockmarks. After construction is completed, curing should be carried out for no less than 7 days to ensure that the concrete strength reaches the design value before subsequent construction can proceed.
