How to Determine the Anchoring Depth of Exterior Wall GRC Components? Connection Safety and Qinglong Group Structural Design Guidelines

The anchoring depth of exterior wall GRC components is the lifeline ensuring safe connection to the main structure and resistance to wind and seismic loads. It must be scientifically determined through four key factors—load calculation, substrate strength, anchor performance, and safety factor—and never based on empirical values. Based on structural calculations and extensive test data, Qinglong Group stipulates: the anchoring depth of undercut anchors in concrete substrates must be ≥40mm (or 5 times the bolt diameter); in masonry or equivalent-strength substrates it must be ≥50mm, and on-site pull-out tests are required for verification (design pull-out resistance ≥3kN, safety factor ≥4). In the high-rise curtain wall project of the Shenzhen Yirui Biotechnology Building, we determined an anchoring depth of 45mm through finite element calculation and full-scale testing, with on-site sampled pull-out forces all ≥15kN, providing reliable protection for the building. Anchoring depth is the technical core of connection design.

Load Analysis Is the Basis of Calculation

Accurately calculate combined loads such as wind load, seismic action, and self-weight to determine the tensile and shear forces that each anchor must withstand. Load combinations follow the Load Code for the Design of Building Structures (GB 50009) and the seismic design code (GB 50011). We use professional software for load calculations to ensure data accuracy.

Substrate Strength Determines Anchoring Performance

Concrete strength grades (e.g., C25, C30) and masonry type and strength directly affect anchoring capacity. Substrate strength must be confirmed before design, with core drilling tests performed when necessary. For substrates with insufficient strength, reinforcement or through-type connections are required. We require documentation certifying substrate strength.

Anchor Performance and Installation Are Key

Select certified anchors (e.g., with ETA certification), whose technical documentation provides load capacities for different substrates and embedment depths. Construction strictly follows manufacturer requirements: drilling diameter and depth, thorough hole cleaning (three blows, two brushes), and torque control. We use torque wrenches and dedicated hole-cleaning tools to ensure installation quality.

Safety Factors and On-Site Verification Provide Assurance

Anchoring design requires an adequate safety factor (usually ≥3) to account for uncertainties. On-site pull-out tests are mandatory, with sampling quantities carried out per code requirements. We commission third-party testing agencies to perform on-site pull-out tests, with data archived for reference. Long-term monitoring is conducted for major projects.

Anchoring depth is safety expressed in numbers. Through rigorous calculation, quality products, and standardized construction, Qinglong Group forges solid connections for every building.