Enhanced Shear For Pilecap Design In Ec2

s,req

1425 x 103 400

= 3563 mm2

There are no specific requirements within EC2 for the distribution of the calculated reinforcement. The provisions of BS 8110: Part 1: Clause 3.11.4.2 are adopted in this example.

With piles spaced at 3 times the diameter, the reinforcement may be uniformly distributed.

Use 8T25 at 275 mm crs. (3928 mm2

Maximum spacing =3h > 500 = 500 > 275 mm OK

Minimum =-- < 0.0015 bd = 0.0015 x 2100 x 675 = 2127 mm2. . OK

f yk

The reinforcement details are shown in Figure 7.8.

The reinforcement details are shown in Figure 7.8.

Figure 7.8 Details of pilecap reinforcement

Only in elements such as slabs may shear reinforcement be omitted where calculations justify.

Despite the classification for the pilecap given above, in line with common UK practice, it is not intended to provide shear reinforcement when VSd < l/Rd1.

Take the critical section for shear to be located at 20% of the pile diameter into the piles, extending the full width of the pilecap.

Distance from centre of loaded area x = 1350/2 - 0.3 x 450 = 540 mm

Shear resistance

n 2100 x 675

All of tension steel is to continue sufficiently past critical section; check when detailing.

yRdi = 0.34(1.2 + 40 x 0.00277) 2100 x 675 x 10"3 = 632 kN

Consider enhanced resistance close to the supports 2.5d 2.5 x 675

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