Chevron Bracing in Low-Rise Buildings - Modern Steel Construction

SteelWise 

CHEVRON BRACING 

IN LOW-RISE BUILDINGS 

Estimating member sizes for 

chevron bracing in low-rise 

steel-framed construction is 

easier than ever with this 

handy design aid. 

Schematic of typical chevron brace configurations. 

The details circled are highlighted in 

later figures in this article. 

Chevron braces are a common 

configuration for 

providing lateral-load resistance 

in steel-framed 

buildings. This handy 

chart will help you quickly estimate the 

brace size and connection material required 

for a given force in chevron 

bracing designed to resist lateral forces 

due to gravity, wind and low-seismic 

loads. 1 These rules of thumb don’t 

cover all situations, but they will provide 

a reasonable starting point for the 

preliminary brace and connection design 

or cost estimating. 

Estimated brace sizes, gusset plate 

thicknesses, and required number of 

bolts or size and length of the welds are 

tabulated for a practical range of unfac- 

`Modern Steel Construction • April 2002 

Roberta Marstellar, Keith Mueller, Jason Ericksen and Christopher Hewitt 

tored brace forces (tensile and compressive). 

The bolts and welds indicated 

are for the connection of the brace to 

the gusset plate. A 3” center-to-center 

bolt spacing and a 1 1 /2” edge distance 

were assumed in the connection design. 

Suggested details for the various 

connections involved in chevron bracing 

are also included for each of the 

bracing types: HSS, W-shapes, WTshapes 

and double angles. 

The connection(s) of the gusset plate 

to the beam and/or column are not addressed 

in the table. Also, drift control 

issues must be considered separately. 

The minimum length of the welds 

for the connection of the HSS to the 

gusset is 1.3 times the diameter of the 

round HSS or 1.3 times the side of the 

square HSS. Rectangular HSS are not 

included. This minimum length allows 

the welds to be designed with a shear 

lag coefficient U = 1 in the HSS. 2 A 

smaller weld length may be acceptable, 

provided the effects of shear lag are 

considered. 

Thanks to Victor Shneur, P.E., of 

Lejeune Steel Company in Minneapolis, 

MN, for laying the groundwork for 

this feature. 

Roberta (Bobbi) Marstellar is Director, 

Steel Solutions Center, Keith Mueller is Senior 

Engineer, Steel Solutions Center, and 

Jason Ericksen is Solutions Center Advisor. 

Christopher Hewitt is Staff Engineer– 

Structures in AISC’s Engineering and Research 

department. Email the Steel Solutions 

Center at [email protected], or visit 

them at the AISC web site, www.aisc.org.

Double Angles 

HSS 

W-Shape 

WT-Shape 

(Flange Connection) 

Unfactored Loads 

(Kips) 

Gusset Plate 

ASTM A36 

Double Angles 

Weld Bolts 

Bolts Flange Web 

ASTM A36 

3/4" Bolts / row 

ASTM A325 

7/8" Bolts / row 

ASTM A325 

30 50 75 100 150 200 

PL 

3/8" 

2L5x5x5/16 

(21 lb/ft) 

PL 

3/8" 

2L6x6x3/8 

(30 lb/ft) 

PL 

1/2" 

2L6x6x3/8 

(30 lb/ft) 

PL 

1/2" 

2L6x6x1/2 

(39 lb/ft) 

PL 

3/4" 

2L8x8x1/2 

(53 lb/ft) 

PL 

3/4" 

2L8x8x1/2 

(53 lb/ft) 

3 4 6 6 6 8 

3 4 4 6 5 6 

No. of Rows 1 1 1 1 2 2 

"a" (in) 

[See Details] 

"b" (in) ** 

[See Details] 

W-Shape 

ASTM A992 

Web Plates 

ASTM A36 

3/4" or 7/8" 

ASTM A325 Bolts 

Angles 

ASTM A36 

3/4" or 7/8" 

ASTM A325 Bolts 

WT-Shape 

ASTM A992 

3/4" Bolts 

ASTM A325 

7/8" Bolts 

ASTM A325 

Chevron Bracing in Low-Rise Buildings 

HSS 

5.000x0.375 

(18.5 lb/ft) 

HSS5x5x1/4 

(16 lb/ft) 

HSS 

6.000x0.312 

(19.0 lb/ft) 

HSS6x6x1/4 

(19 lb/ft) 

HSS 

6.000x0.500 

(29.4 lb/ft) 

HSS6x6x1/4 

(19 lb/ft) 

HSS 

6.875x0.500 

(34.1 lb/ft) 

HSS7x7x1/4 

(22 lb/ft) 

HSS 

8.625x0.500 

(43.4 lb/ft) 

HSS8x8x5/16 

(32 lb/ft) 

HSS 

9.625x0.500 

(48.8 lb/ft) 

HSS8x8x3/8 

(38 lb/ft) 

3/16 3/16 1/4 1/4 5/16 5/16 

7 8 8 

9 (Round) 

10 (Square) 

12 (Round) 

11 (Square) 

13 (Round) 

11 (Square) 

W6x20 W8x28 W8x31 W8x35 W8x48 W10x49 

(2) 

PL 3/8" 

4 - Gusset 

4 - Web 

(2) 

PL 3/8" 

4 - Gusset 

4 - Web 

(2) 

PL 3/8" 

4 - Gusset 

4 - Web 

(2) 

PL 3/8" 

4 - Gusset 

4 - Web 

(2) 

PL 3/8" 

4 - Gusset 

4 - Web 

(2) 

PL 3/8" 

4 - Gusset 

4 - Web 

4 L4x4x5/16 4 L4x4x5/16 4 L4x4x5/16 4 L4x4x5/16 4 L4x4x5/16 4 L4x4x5/16 

4 - Gusset 

8 - Flange 

4 - Gusset 

8 - Flange 

4 - Gusset 

8 - Flange 

4 - Gusset 

8 - Flange 

6 - Gusset 

12 - Flange 

8 - Gusset 

16 - Flange 

WT6x13 WT6x25 WT6x43.5 WT7x45 WT8x38.5 WT13.5x73 

4 4 4 6 6 8 

4 4 4 6 6 8 

** Weld lengths are based on 1.3H , where H is the outside diameter of a round HSS or leg dimension of a square HSS. 

REFERENCES 

Round HSS 

ASTM A500, Gr. B 

Square HSS 

ASTM A500, Gr. B 

1. Low-seismic loads are those for applications 

in which the seismic response 

modification factor R is 

taken equal to or less than 3. Structural 

elements and connections in 

such applications are designed to 

meet the requirements in the AISC 

Load and Resistance Factor Design 

(LRFD) Specification with no special 

seismic detailing. 

2. Kulak, Geoffrey L., and J. J. Roger 

Cheng, 2000, “Gusset Plate Connection 

to Round HSS Tension Members.” 

Engineering Journal Vol. 37 

No. 4 (Fourth Quarter): 133-139. 

Turn page for typical details 

April 2002 Modern Steel Construction

SteelWise 

`Modern Steel Construction April 2002 

SUGGESTED DETAILS FOR CHEVRON BRACING

SUGGESTED DETAILS FOR CHEVRON BRACING 

April 2002 Modern Steel Construction

Chevron Bracing in Low-Rise Buildings - Modern Steel Construction

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