Circular Pipe Column Bases: Where Steel Meets Concrete — The Right Way

Circular hollow section (CHS) columns need special base details — round base plates, ring-arranged anchor bolts and radial stiffeners. Below is GZ3 column base from an actual fabrication drawing.

---

Basic Specs

Item	Value
Column ID	GZ3
Column section	Φ650×20.0 (CHS)
Material	Q355B
Base plate shape	Circular
Anchor bolts	12 × M36
Bolt arrangement	Ring pattern, 30° spacing
Stiffener type	Radial rib plates
Column types covered	GZ1, GZ2, GZ3, GZ4, GZ5

---

Column Sections Overview

表格

Column	Section	Wall	Weight
GZ1	Φ600×18	18 mm	~260 kg/m
GZ2	Φ245×10	10 mm	~59 kg/m
GZ3	Φ650×20	20 mm	~315 kg/m
GZ4	Φ500×18	18 mm	~182 kg/m
GZ5	Φ245×12	12 mm	~70 kg/m

---

Construction Details

The circular column base consists of:

Base plate: circular steel plate, welded to column bottom

Anchor bolts: 12 pieces M36, ring-arranged around column

Radial stiffeners: rib plates between column wall and base plate

Shear lug: welded to underside of base plate

Grout layer: 50 mm non-shrink mortar after erection

---

Advantages

Symmetric load distribution — round plate spreads column load evenly in all directions

No weak axis — circular column plus round base has equal bending resistance both ways

Aesthetic look — exposed circular column bases fit modern architecture

Anchor bolt efficiency — ring arrangement uses bolts in tension/compression efficiently

Clean interior — no sharp corners inside the column for concrete fill (if cased)

---

Disadvantages / Limitations

Harder to fabricate — round plate cutting and radial stiffener welding take more labor

More expensive than square base — circular plate has higher scrap rate and cost

Anchor bolt alignment critical — ring pattern must be precisely positioned in formwork

Less compact footprint — round base extends further than equivalent square plate

Grout inspection harder — circular grout gap is harder to inspect completely

---

Typical Applications

Curtain wall columns — exposed circular columns in lobby and atrium

Space frame support columns — circular columns support roof space frames

Stadium & arena columns — circular columns around seating bowl

Pedestrian bridge piers — circular piers for urban footbridges

Atrium & lobby structures — aesthetic circular columns in commercial buildings

---

Installation Notes

Anchor bolts set in formwork before concrete pour, checked with template

Base plate level adjusted by nuts, then column placed on top

Column welded to base plate in shop (factory), field bolted to anchors

Grout poured after column alignment and bolt tightening

**WhatsApp**: +86‑13889862778, +86‑18242444407
**Email**: eddie@zdsteels.com, wells@zdsteels.com