Actually, 4D spacing is medium value for avoiding the pile-soil-pile interaction (shadow effect). U0W2
3*?W2;Zw$
The p-multiplier for pile-soil-pile interaction in p-y curve method will reach 1 when the spacing G `eU
L[5U(`q[
equal 6D (O'Neill 1998). This p-multiplier is about 0.8 when S/D=4. All the results are based on b!/-9{
;i [;%
many tests(different soil(sand, clay), different pile length) including site test and centrifuge rNm_w>bq
V<}chLd,
test(Chang 2003). /nh3/[u
oBnes*
In China, we choose Spacing more than 4D, it shows that the pile-soil-pile effect is less 20%. (acceptable)