Analysis of soil-structure interaction in buildings with deep foundation

In this paper it is presented how the influence of soil-structure interaction (SSI) interferes on reinforced concrete structures in small buildings with deep foundations, with the objective of analyzing the influence of SSI on the loads and repressions, global stability and costs of materials. The analysis were based on numerical-computational simulations of a commercial building using CAD/TQS commercial software. The building was simulated with 4, 6 and 8 floors with 3 different profiles of soils, generating 8 case studies. When considering SSI, the loads and repressions did not present significant variations and the parameters of global instability were within the normative recommendations. Among the variables analyzed, the material cost of the structure was the least affected item with the SSI consideration.

Keywords:
drilled pile; reinforced concrete; group effect; global stability

Authorship

M. G. RITTER

Universidade Comunitária da Região de Chapecó, Chapecó, SC, Brasil; marioritter@unochapeco.edu.br silvio@unochapeco.edu.brUniversidade Comunitária da Região de ChapecóBrazilChapecó, SC, Brazil Universidade Comunitária da Região de Chapecó, Chapecó, SC, Brasil; marioritter@unochapeco.edu.br silvio@unochapeco.edu.br

https://orcid.org/0000-0002-4158-7325

M. L. MENEGOTTO

Universidade Federal da Fronteira Sul, Chapecó, SC, Brasil; mauromenegotto@gmail.com pavan.uffs@gmail.com Universidade Federal da Fronteira SulBrazilChapecó, SC, Brazil Universidade Federal da Fronteira Sul, Chapecó, SC, Brasil; mauromenegotto@gmail.com pavan.uffs@gmail.com

https://orcid.org/0000-0002-0660-9795

M. F. COSTELLA

Faculdade Meridional, Passo Fundo, RS, Brasil. costella@unochapeco.edu.br Faculdade MeridionalBrasilPasso Fundo, RS, Brasil Faculdade Meridional, Passo Fundo, RS, Brasil. costella@unochapeco.edu.br

https://orcid.org/0000-0001-6471-9848

R. C. PAVAN

https://orcid.org/0000-0001-6946-0839

S. E. PILZ

https://orcid.org/0000-0003-0361-7658

SCIMAGO INSTITUTIONS RANKINGS

Faculdade Meridional, Passo Fundo, RS, Brasil. costella@unochapeco.edu.br Faculdade MeridionalBrasilPasso Fundo, RS, Brasil Faculdade Meridional, Passo Fundo, RS, Brasil. costella@unochapeco.edu.br

Figures | Tables

Figures (6)
Tables (13)

Column	Dimensions of the columns of the 4-floor buildings (cm)	Dimensions of the columns of the 6-floor buildings (cm)	Dimensions of the columns of the 8-floor buildings (cm)
1	20 x 20	25 x 25	25 x 25
2	30 x 25	30 x 30	30 x 30
3	30 x 25	30 x 30	30 x 30
4	20 x 20	25 x 25	25 x 25
5	25 x 25	30 x 25	30 x 30
6	45 x 30	55 x 30	65 x 35
7	40 x 30	55 x 30	65 x 35
8	25 x 25	30 x 25	30 x 30
9	25 x 25	30 x 25	30 x 30
10	30 x 45	30 x 55	35 x 65
11	30 x 45	30 x 55	35 x 65
12	25 x 25	30 x 25	30 x 30
13	25 x 25	30 x 25	30 x 30
14	45 x 30	55 x 30	65 x 35
15	45 x 30	55 x 30	65 x 35
16	25 x 25	30 x 25	30 x 30
17	20 x 20	25 x 25	25 x 25
18	30 x 25	40 x 35	40 x 30
19	20 x 20	25 x 25	25 x 25

Basic speed Vo	Ground factor S1	Roughness category S2	Statistical factor S3	Building class
45 m/s	1	IV	1	B

Description of the soil type	Typical values (KN/m²)
Very soft clay (SPT ≤ 2)	1000
Soft clay (SPT 2 to 5)	2000
Medium clay (SPT 6 to 10)	5000
Stiff clay (SPT 11 to 19)	8000
Hard clay (SPT > 19)	15000

Description of the soil type	υ
Very soft clay (SPT ≤ 2)	0.24
Soft clay (SPT 2 to 5)	0.23
Medium clay (SPT 6 to 10)	0.22
Stiff clay (SPT 11 to 19)	0.21
Hard clay (SPT > 19)	0.21

Permissible load (kN) for 20 m deep piles				Permissible load variation (%)
Diameter (cm)	Probe profile 1 (+10%)	Probe profile 2 (+10%)	Probe profile 3 (+10%)	Profile 2 to Profile 1	Profile 3 to Profile 2	Profile 3 to Profile 1
30	279.95	363.88	-	23.07	-	-
40	396.22	515.13	638.66	23.08	19.34	61.19
50	524.15	681.34	841.50	23.07	19.03	60.55
60	663.52	862.51	1061.61	23.07	18.75	60.00
70	814.44	1058.75	1298.99	23.08	18.49	59.49
80	976.80	1269.84	1553.75	23.08	18.27	59.07
Mean variation (%)				23.07	18.78	60.06

Probe profile 2				Probe profile 3
Column	Column	Column		Column	Block dimensions	Piles
Column	W x L x H (cm)	Ø (cm)	Prof. (m)	Column	W x L x H (cm)	Ø (cm)	Prof. (m)
P1	90 x 90 x 90	1 Ø 60	20	P1	80 x 80 x 80	1 Ø 50	20
P2	310 x 100 x 120	2 Ø 70	20	P2	270 x 90 x 120	2 Ø 60	20
P3	310 x 100 x 120	2 Ø 70	20	P3	270 x 90 x 120	2 Ø 60	20
P4	90 x 90 x 90	1 Ø 60	20	P4	80 x 80 x 80	1 Ø 50	20
P5	270 x 90 x 110	2 Ø 60	20	P5	230 x 80 x 110	2 Ø 50	20
P6	310 x 310 x 160	4 Ø 70	20	P6	270 x 270 x 150	4 Ø 60	20
P7	350 x 350 x 180	4 Ø 80	20	P7	270 x 270 x 150	4 Ø 60	20
P8	310 x 100 x 120	2 Ø 70	20	P8	270 x 90 x 120	2 Ø 60	20
P9	270 x 90 x 110	2 Ø 60	20	P9	230 x 80 x 110	2 Ø 50	20
P10	310 x 310 x 160	4 Ø 70	20	P10	270 x 270 x 150	4 Ø 60	20
P11	310 x 310 x 160	4 Ø 70	20	P11	270 x 270 x 150	4 Ø 60	20
P12	270 x 90 x 110	2 Ø 60	20	P12	230 x 80 x 110	2 Ø 50	20
P13	270 x 90 x 110	2 Ø 60	20	P13	230 x 80 x 110	2 Ø 50	20
P14	350 x 350 x 180	4 Ø 80	20	P14	310 x 310 x 160	4 Ø 70	20
P15	310 x 310 x 160	4 Ø 70	20	P15	270 x 270 x 150	4 Ø 60	20
P16	270 x 90 x 110	2 Ø 60	20	P16	230 x 80 x 110	2 Ø 50	20
P17	100 x 100 x 100	1 Ø 70	20	P17	90 x 90 x 90	1 Ø 60	20
P18	350 x 110 x 140	2 Ø 80	20	P18	310 x 100 x 120	2 Ø 70	20
P19	100 x 100 x 100	1 Ø 70	20	P19	90 x 90 x 90	1 Ø 60	20

Probe profile 1				Probe profile 2				Probe profile 3
Column	Block dimensions	Piles		Column	Block dimensions	Piles		Column	Block dimensions	Piles
Column	W x L x H (cm)	Ø (cm)	Prof. (m)		W x L x H (cm)	Ø (cm)	Prof. (m)		W x L x H (cm)	Ø (cm)	Prof. (m)
P1	90 x 90 x 90	1 Ø 60	20	P1	80 x 80 x 80	1 Ø 50	20	P1	70 x 70 x 70	1 Ø 40	20
P2	310 x 100 x 120	2 Ø 70	20	P2	270 x 90 x 110	2 Ø 60	20	P2	230 x 80 x 100	2 Ø 50	20
P3	310 x 100 x 120	2 Ø 70	20	P3	270 x 90 x 110	2 Ø 60	20	P3	230 x 80 x 100	2 Ø 50	20
P4	90 x 90 x 90	1 Ø 60	20	P4	80 x 80 x 80	1 Ø 50	20	P4	70 x 70 x 70	1 Ø 40	20
P5	270 x 90 x 105	2 Ø 60	20	P5	230 x 80 x 100	2 Ø 50	20	P5	190 x 70 x 70	2 Ø 40	20
P6	310 x 310 x 165	4 Ø 70	20	P6	270 x 270 x 160	4 Ø 60	20	P6	230 x 230 x 155	4 Ø 50	20
P7	350 x 350 x 185	4 Ø 80	20	P7	270 x 270 x 160	4 Ø 60	20	P7	230 x 230 x 155	4 Ø 50	20
P8	270 x 90 x 105	2 Ø 60	20	P8	230 x 80 x 100	2 Ø 50	20	P8	230 x 80 x 100	2 Ø 50	20
P9	270 x 90 x 105	2 Ø 60	20	P9	230 x 80 x 100	2 Ø 50	20	P9	190 x 70 x 70	2 Ø 40	20
P10	310 x 310 x 165	4 Ø 70	20	P10	270 x 270 x 160	4 Ø 60	20	P10	230 x 230 x 155	4 Ø 50	20
P11	270 x 270 x 145	4 Ø 60	20	P11	230 x 230 x 140	4 Ø 50	20	P11	190 x 190 x 135	4 Ø 40	20
P12	270 x 90 x 105	2 Ø 60	20	P12	230 x 80 x 100	2 Ø 50	20	P12	190 x 70 x 70	2 Ø 40	20
P13	270 x 90 x 105	2 Ø 60	20	P13	230 x 80 x 100	2 Ø 50	20	P13	190 x 70 x 70	2 Ø 40	20
P14	350 x 350 x 185	4 Ø 80	20	P14	270 x 270 x 160	4 Ø 60	20	P14	230 x 230 x 155	4 Ø 50	20
P15	310 x 310 x 165	4 Ø 70	20	P15	270 x 270 x 160	4 Ø 60	20	P15	230 x 230 x 155	4 Ø 50	20
P16	270 x 90 x 105	2 Ø 60	20	P16	230 x 80 x 100	2 Ø 50	20	P16	190 x 70 x 70	2 Ø 40	20
P17	100 x 100 x 100	1 Ø 70	20	P17	90 x 90 x 90	1 Ø 60	20	P17	80 x 80 x 80	1 Ø 50	20
P18	350 x 110 x 140	2 Ø 80	20	P18	270 x 90 x 105	2 Ø 60	20	P18	270 x 90 x 110	2 Ø 60	20
P19	100 x 100 x 100	1 Ø 70	20	P19	80 x 80 x 80	1 Ø 50	20	P19	80 x 80 x 80	1 Ø 50	20

	General trend	Largest load variation (%)	Largest settlement without SSI (mm)	Largest settlement with SSI (mm)
8 floors - probe profile 2	Yes	6.49	22.10	21.48
8 floors - probe profile 3	Yes	5.55	22.43	21.53
6 floors - probe profile 1	Yes	5.31	17.16	16.83
6 floors - probe profile 2	Yes	5.01	17.70	17.26
6 floors - probe profile 3	Yes	7.07	18.97	18.40
4 floors - probe profile 1	No	3.50	11.85	11.76
4 floors - probe profile 2	No	2.95	11.95	11.85
4 floors - probe profile 3	No	6.75	12.61	12.73

	Variations of the Gamma-Z instability parameter
	Probe profile 1			Probe profile 2			Probe profile 3
	Without SSI	With SSI	Variation (%)	Without SSI	With SSI	Variation (%)	Without SSI	With SSI	Variation (%)
8 floors	-	-	-	1.19	1.24	4.20	1.19	1.25	5.04
6 floors	1.19	1.24	4.20	1.19	1.25	5.04	1.19	1.26	5.88
4 floors	1.14	1.23	7.89	1.14	1.23	7.89	1.14	1.24	8.77

	Cost of structural elements (R$)
	Piles			Blocks
	Without SSI	With SSI	Var. (%)	Without SSI	With SSI	Var. (%)
8 floors - probe profile 2	102514.97	102514.97	0.00	71691.34	71102.96	-0.82
8 floors - probe profile 3	73551.27	73551.27	0.00	51941.38	51333.72	-1.17
6 floors - probe profile 1	98979.81	98979.81	0.00	64739.00	64701.91	-0.06
6 floors - probe profile 2	66548.80	66548.80	0.00	43499.83	43614.59	0.26
6 floors - probe profile 3	47540.96	47540.96	0.00	31399.57	31387.60	-0.04
4 floors - probe profile 1	60779.13	60779.13	0.00	24963.51	25047.32	0.34
4 floors - probe profile 2	42202.43	42202.43	0.00	17399.81	17325.35	-0.43
4 floors - probe profile 3	33255.06	33255.06	0.00	14654.82	14584.74	-0.48

	Cost of structural elements (R$)
	Beams			Columns			Slabs and Stairs
	Without SSI	With SSI	Var. (%)	Without SSI	With SSI	Var. (%)	Without SSI	With SSI	Var. (%)
8 floors - probe profile 2	157802.12	157388.94	-0.26	69890.93	71552.12	2.38	313360.21	313360.21	0.00
8 floors - probe profile 3	157802.12	158117.48	0.20	69693.54	70929.58	1.77	313360.21	313360.21	0.00
6 floors - probe profile 1	120257.41	120066.44	-0.16	41157.29	41674.71	1.26	232308.38	232308.38	0.00
6 floors - probe profile 2	120257.41	120201.64	-0.05	41010.70	41105.02	0.23	232308.38	232308.38	0.00
6 floors - probe profile 3	120257.41	120536.27	0.23	41072.02	41592.07	1.27	232308.38	232308.38	0.00
4 floors - probe profile 1	85725.14	85601.62	-0.14	20839.41	21462.25	2.99	157954.09	157954.09	0.00
4 floors - probe profile 2	85725.14	85701.48	-0.03	20772.54	20950.66	0.86	157954.09	157954.09	0.00
4 floors - probe profile 3	85725.14	85819.74	0.11	20790.65	21037.68	1.19	157954.09	157954.09	0.00

	Global, infrastructure and superstructure costs (R$)
	Infrastructure costs			Superstructure costs			Global costs
	W/O SSI	W/ SSI	Var. (%)	W/O SSI	W/ SSI	Var. (%)	W/O SSI	W/ SSI	Var. (%)
8 floors - probe profile 2	174206.31	173617.93	-0.34	541053.26	542301.26	0.23	715259.57	715919.19	0.09
8 floors - probe profile 3	125492.64	124884.99	-0.48	540855.86	542407.26	0.29	666348.51	667292.25	0.14
6 floors - probe profile 1	163718.81	163681.72	-0.02	393723.08	394049.53	0.08	557441.88	557731.26	0.05
6 floors - probe profile 2	110048.63	110163.39	0.10	393576.49	393615.04	0.01	503625.13	503778.43	0.03
6 floors - probe profile 3	78940.53	78928.56	-0.02	393637.81	394436.72	0.20	472578.34	473365.28	0.17
4 floors - probe profile 1	85742.64	85826.44	0.10	264518.63	265017.95	0.19	350261.27	350844.40	0.17
4 floors - probe profile 2	59602.24	59527.78	-0.12	264451.76	264606.23	0.06	324054.01	324134.01	0.02
4 floors - probe profile 3	47909.89	47839.81	-0.15	264469.87	264811.51	0.13	312379.76	312651.32	0.09