Design grid line

Effective depth, d d = 300 - 30 - 20 - 20 / 2 = 240 mm Flexure: column strip, sagging: MEd = 75.5 kNm / m

By inspection, z = 228 mm <Concise EC2 Table 15.5>

As = MEd / fydz = 75.5 x 106 / (228 x 500 / 1.15) = 761 mm2 / m

Deflection: column strip: By inspection, OK. Flexure: middle strip, sagging: MEd = 37.1 kNm / m By inspection, z = 228 mm As = MEd / fydz = 37.1 x 106 / (228 x 500 / 1.15) = 374 mm2 / m

By inspection, deflection OK. Try H10 @ 200 B2 (393 mm2 / m)

Flexure: column strip, hogging: MEd = 113.3 kNm / m

K = MEd / bd2fck = 113.3 x 106 / (1000 x 2402 x 30) = 0.065 <Concise EC2 Table 15.5>

As = MEd / fydz = 113.3 x 106 / (225 x 500 / 1.15) = 1158 mm2 / m

Flexure: middle strip, hogging: MEd = 18.5 kNm / m By inspection, z = 228 mm

As = MEd / fydz = 18.5 x 106 / (228 x 500 / 1.15) = 187 mm2 / m <Concise EC2 Table 15.5>

As before minimum area of reinforcement governs

As,min = 0.26 x 0.30 x 300666 x 1000 x 240 / 500 = 361 mm2 / m <9.3.1.1, 9.2.1.1>

Requirements:

Regarding the requirement to place 50% of At within a width equal to 0.125 of <9.4.1(2)>

ssss The hogging moment could have been considered at face of support to reduce the amount of reinforcement required.

the panel width on either side of the column. Area required = (3.0 x 1158 + 6.1 x 187) / 2 mm2 = 2307 mm2

Within = 2 x 0.125 x 6.0 m = 1500 mm centred on the column centreline.

i.e. require 2307 / 1.5 = 1538 mm2 / m for 750 mm either side of the column centreline.

Use H20 @ 200T2 (1570 mm2 / m) 750 mm either side of centre of support (p = 0.60%)

In column strip, outside middle 1500 mm, requirement is for 3.0 x 1158-15 x 1570 = 1119 mm2 in 1500 mm, i.e. 764 mm2 / m

Use H16 @ 250 T2 (804 mm2 / m) in remainder of column strip

In middle strip

Greener Homes for You

Greener Homes for You

Get All The Support And Guidance You Need To Be A Success At Living Green. This Book Is One Of The Most Valuable Resources In The World When It Comes To Great Tips on Buying, Designing and Building an Eco-friendly Home.

Get My Free Ebook


Post a comment