Compression Load Tests on Composite Foundations of Spread Footing Anchored by Helical Anchors

Table 4

Average soil pressures and compression resistances from footing and helical anchors.

Applied load on footing pier head (kN)	Average soil pressure underneath footing (kPa)			Compression resistance from footing (kN)			Percentage of compression resistance from helical anchors (%)
	CF1	CF2	CF3	CF1	CF2	CF3	CF1	CF2	CF3
180	6.6	17.7	7.0	29	78	31	83.8	56.6	83.0
270	11.8	28.0	14.0	52	123	62	80.8	54.3	77.2
360	16.7	37.7	21.0	74	166	93	79.5	53.8	74.3
450	21.3	46.1	26.8	94	203	118	79.1	54.8	73.8
540	26.2	54.9	32.5	115	242	144	78.6	55.7	73.4
630	30.3	63.0	37.0	134	278	163	78.8	55.9	74.1
720	36.7	68.9	41.4	162	304	183	77.5	57.8	74.6
810	41.9	75.9	46.4	185	335	205	77.2	58.7	74.7
900	48.7	83.8	51.3	215	370	226	76.2	58.9	74.8
990	54.6	92.3	58.0	241	407	256	75.7	58.9	74.2
1080	61.9	99.0	64.7	273	437	285	74.7	59.6	73.6
1170	—	109.4	72.9	—	482	321	—	58.8	72.5
1260	—	119.7	81.1	—	528	358	—	58.1	71.6