CORRECTION FOR THE MUTUAL INTERFERENCE OF PILES (SEE FIG. 9.15)
Interference of pile 2 on pile 1
True depths of the piles: Dd99.25 93.006.25 m and the distance
between them, b 1 15 m
the correction, C(equation (9.10))
19(6.25/15)1/2(6.256.25)/50.53.03% ().
Therefore the corrected pressure behind (downstream side) the first piling
PC1/H 67 1.073.0371.10≈71% – d/sof pile 1.
(B) INTERMEDIATE PILING – PILE 2 (SEE FIG. 9.15)
Theoretical depth of piling, d7 m (pile 1) and hence 50.5/77.21
and the distance bfrom the piling to the upstream end of the floor
15.75 m.
b/b15.75/50.500.312; thus 1 b/b0.688.
From the pressure chart (left side diagram of Fig. 9.7) the pressure at
C – see the notes on the chart for computations – corresponding to
1 b/b0.688 on x-axis,PC/H31% which gives PE/H 100 31 69%.
Also,PD/H(from the right-hand diagram of Fig. 9.7)36% which
gives the actual
PD/H 100 36 64% since b/b(0.312)0.5.
ForPC/Hdirect use of left-hand diagram of Fig. 9.7 gives (for 7.21 and
b/b0.312)
PC/H53%.
Correction for floor thickness
ForPE/H(69 64)0.75/7 0.54%
ForPC/H(64 53)0.75/71.18%.
Correction for mutual interference
INFLUENCE OF PILE 1 ON PILE 2 – ON PE/H
AsDd, i.e. the piles 1 and 2 are of the same length, this effect is the
390 DIVERSION WORKS
