Container House Drilling Specifications

Drilling in container houses must strictly adhere to structural safety specifications, with key points including hole diameter limitations, location selection, and structural protection measures. The specific specifications are as follows:

I. Hole Diameter Limitations
The steel structural framework of a container house is the primary load-bearing structure, and the maximum hole diameter must be determined based on the type of beam. For frame beams (main beams), it is recommended that the hole diameter be less than 100mm, and for secondary beams, less than 200mm. If the hole diameter is too large (e.g., exceeding one-third of the beam height) or if there are multiple holes in a single beam, it can disrupt the coordinated force between the concrete and steel reinforcement, leading to beam cracking or even loss of load-bearing capacity. For example, breaking the lower longitudinal reinforcement of a beam will transfer the tensile stress to the concrete, causing lower cracking and significantly reducing the seismic performance of low-rise houses.

II. Location Selection

1. Avoid Main Load-Bearing Reinforcement: Beams contain longitudinal reinforcement (upper and lower), stirrups, and web reinforcement. Drilling requires locating the reinforcement distribution using detection equipment (e.g., a rebar scanner). The lower longitudinal reinforcement of a beam is a critical load-bearing area and must not be broken. If the web height (hw) of the beam is ≥450mm and web reinforcement is required, drilling must avoid the web reinforcement location.
2. Prioritize Near Supports: Air conditioning copper pipes and other pipelines are typically laid close to beams, and drilling locations are often selected near the beam roots (near supports), where shear forces are smaller and the impact on the structure is lower.
3. Height Zoning Principle: The height of a beam can be divided into upper, middle, and lower zones. Drilling is prohibited in the lower zone, drilling in the middle zone is allowed only after confirming the absence of web reinforcement, and drilling in the upper zone has less impact but should avoid areas with dense stirrups.

III. Structural Protection Measures

1. Pre-Construction Verification: If modifications to the main structure are involved, a plan must be commissioned from the original design unit or a qualified organization, or a structural safety assessment must be conducted (Article 3.1.5 of the Code for Acceptance of Construction Quality of Building Decoration GB50210-2018).
2. Corrosion and Waterproofing Treatment: After drilling, the perimeter of the hole must be repaired with anti-corrosion coating to prevent steel corrosion. If the hole is used for pipeline penetration through walls, fire-resistant sealing materials must be used to fill gaps and prevent fire spread.
3. Multi-Story Structure Reinforcement: For double-story or contiguous container houses, drilling must consider the stability of frame connection nodes, and horizontal supports or reinforcing plates must be added if necessary.

IV. Special Scenario Specifications
If the container house is used for warehouses or other scenarios requiring line markings, drilling must maintain a safe distance from ground markings (e.g., main aisles, fire hydrant areas) to avoid damaging functional zones or causing forklift tipping risks.