In engineering construction such as underground space development, urban renewal, and renovation of existing buildings, anti-floating of underground structures is a common issue. Conventionaluplift pilesor anti-floating anchors have defects such as complicated waterproofing, easy cracking of pile concrete or anchor grout under tension, and waste of steel. To address these defects, CABR Foundation has developed the composite anchor uplift pile, which features high bearing capacity, steel savings, reliable pile-head waterproofing, and simple and rapid construction.

The composite anchor uplift pile consists of a pile shaft, a tendon tube inside the pile shaft, grout inside the tendon tube, and steel strand tendons. The pile shaft diameter is generally 200 mm to 800 mm, the tendon tube is generally a DN25 to DN100 steel pipe, and the tendon is generally steel strand. The commonly used ultimate uplift bearing capacity is 200 kN to 3000 kN.

The technical features and advantages are:

1. High efficiency

The strength of the tendon can be fully utilized; the pile shaft can adopt the long spiral drilling pressure-groutedconcrete processmaking construction simple and rapid.

2. Fewer defects

The load-bearing steelis completely isolated from corrosive media, giving good durability; the pile-head waterproofing method is simple and the waterproofing quality is reliable.

3. Low cost

Compared with ordinary anti-floating anchors or uplift piles, the composite anchor uplift pile can save more than 10% of the anti-floating engineering cost.

4. Low-carbon and environmentally friendly

The tendon mainly uses high-strength steel strand, and the pile shaft is generally concrete. Compared with ordinary uplift piles and anchors, it saves steel and cement, with significant material and energy savings.

The composite anchor uplift pile has been successfully applied in dozens of foundation anti-floating projects, including the Beijing Dongsheng Science and Technology Park project, theNational Convention Center Phase IIproject, the China Institute for Reform and Development (Sanya) International Academic Exchange Center project, and the Yueyuntai project in Zengcheng District, Guangzhou, achieving good economic, social, and environmental benefits.

Beijing Dongsheng Science and Technology Park Project

Patent for Composite Anchor Uplift Pile Technology