Abstract
The stress or the failure zone of footings placed at close proximity interfere altering the performance of the footings. The present study pertains finite element analysis of two closely spaced rough, rigid strip footings embedded in cohesion-less foundation soil medium using the commercially available software ABAQUS. The interfering footings are considered to be supported on homogeneous reinforced and unreinforced soil medium. The failure criterion of the soil is directed to follow Mohr–Coulomb criterion with the non-associated flow rule. The influence of interference phenomenon on the ultimate bearing capacity, settlement and load-settlement characteristics have been explored by considering and varying the various parameters such as depth of embedment, soil friction angle, depth of reinforcement (first layer and subsequent layer), number of reinforcement layers and length of reinforcement. The soil friction angle is one of the important factors to have an effect on bearing capacity, and the friction angle is varied between 20° to 40°. The ultimate bearing capacity of closely spaced footings over unreinforced and reinforced soils are represented by non-dimensionless efficiency factors (ξUR and ξR). The analyses results conclude that interference has a significant influence on bearing capacity and settlement of footings supported over unreinforced and reinforced soil medium. Although, soil friction angle affects the interference significantly (higher friction angle has the highest peak of efficiency factor), depth of footing embedment also has remarkable influence over the same. The peak of efficiency factor decreases with an increase in the depth of footing embedment for a specified soil friction angle; however, the same increases with increase in soil friction angle for a specified depth of footing embedment. The interference effect is found to be decreasing with increase in the embedment depth. The bearing capacity of interfering footings on reinforced soil is enhanced noticeably compared to that on unreinforced footings; however, the settlement is not predominant.
Similar content being viewed by others
References
ABAQUS. ABAQUS/Standard user’s manual, volume II version 6.10, year 2010. Rhode Island: Hibbitt Karlsson and Sorenson Inc.
Abu-Farsakh MY, Gu J, Voyiadjis GZ, Chen Q (2014) Mechanistic–empirical analysis of the results of finite element analysis on flexible pavement with geogrid base reinforcement. Int J Pavement Eng 15(9):786–798
Al-Ashou MO, Sulaiman RM, Mandal JN (1994) Effect of number of reinforcing layers on the interference between footings on reinforced sand. Indian Geotech J 24:285–301
Basudhar PK, Saha S, Deb K (2007) Circular footings resting on geotextile-reinforced sand bed. Geotext Geomembr 25:377–384
Basudhar PK, Dixit PM, Gharpure A, Deb K (2008) Finite element analysis of geotextile-reinforced sand-bed subjected to strip loading. Geotext Geomembr 26:91–99
Biswas S, Mittal S (2017) Square footing on geocell reinforced cohesionless soils. Geomech Eng 13:641–651
Boushehrian JH, Hataf N (2003) Experimental and numerical investigation of the bearing capacity of model circular and ring footings on reinforced sand. Geotext Geomembr 21:241–256
Das BM, Larbi-Cherif S (1983) Bearing capacity of two closely-spaced shallow foundations on sand. Soils Found 23:1–7
De Borst R, Vermeer PA (1984) Possibilites and limitations of finite elements for limit analysis. Geotechnique 34(2):199–210
Deb K, Konai S (2014) Bearing capacity of geotextile-reinforced sand with varying fine fraction. Geomech Eng 6:33–45
Deb K, Sivakugan N, Chandra S, Basudhar PK (2007) Numerical analysis of multi layer geosynthetic-reinforced granular bed over soft fill. Geotech Geol Eng 25:639–646
Erickson HL, Drescher A (2002) Bearing capacity of circular footings. J Geotech Geoenviron Eng 128:38–43
Frydman S, Burd HJ (1997) Numerical studies of bearing-capacity factor Nγ. J Geotech Geoenviron Eng 123:20–29
Ghazavi M, Lavasan AA (2008) Interference effect of shallow foundations constructed on sand reinforced with geosynthetics. Geotext Geomembr 26:404–415
Ghosh P, Kumar S (2011) Interference effect of two nearby strip surface footings on cohesionless layered soil. Int J Geotech Eng 5:87–94
Graham J, Raymond GP, Suppiah A (1984) Bearing capacity of three closely-spaced footings on sand. Geotechnique 34:173–182
Griffiths DV (1982) Computation of bearing capacity factors using finite elements. Geotechnique 32(3):195–202
Huang CC, Menq FY (1997) Deep-footing and wide-slab effects in reinforced sandy ground. J Geotech Geoenviron Eng 123:30–36
Khing KH, Das BM, Yen SC et al (1992) Interference effect of two closely-spaced shallow strip foundations on geogrid-reinforced sand. Geotech Geol Eng 10:257–271
Khing KH, Das BM, Puri VK, Cook EE, Yen SC (1993) The bearing-capacity of a strip foundation on geogrid-reinforced sand. Geotextiles and Geomembranes 12 (4):351–361
Kouzer KM, Kumar J (2008) Ultimate bearing capacity of equally spaced multiple strip footings on cohesionless soils without surcharge. Int J Numer Anal Methods Geomech 32:1417–1426
Kumar J, Bhattacharya P (2010) Bearing capacity of interfering multiple strip footings by using lower bound finite elements limit analysis. Comput Geotech 37:731–736
Kumar J, Bhoi MK (2008) Interference of multiple strip footings on sand using small scale model tests. Geotech Geol Eng 26:469
Kumar J, Bhoi MK (2009) Interference of two closely spaced strip footings on sand using model tests. J Geotech Geoenviron Eng 135:595–604
Kumar J, Ghosh P (2007a) Ultimate bearing capacity of two interfering rough strip footings. Int J Geomech 7:53–62
Kumar J, Ghosh P (2007b) Upper bound limit analysis for finding interference effect of two nearby strip footings on sand. Geotech Geol Eng 25:499
Kumar J, Kouzer KM (2008) Bearing capacity of two interfering footings. Int J Numer Anal Methods Geomech 32:251–264
Kumar A, Saran S (2003) Closely spaced footings on geogrid-reinforced sand. J Geotech Geoenviron Eng 129:660–664
Kumar A, Saran S (2004) Closely spaced rectangular footings on reinforced sand. Geotech Geol Eng 22:497–524
Lavasan AA, Ghazavi M (2012) Behavior of closely spaced square and circular footings on reinforced sand. Soils Found 52:160–167
Mabrouki A, Benmeddour D, Frank R, Mellas M (2010) Numerical study of the bearing capacity for two interfering strip footings on sands. Comput Geotech 37:431–439
Meyerhof GG (1951) The ultimate bearing capacity of foundations. Geotechnique 2:301–332
Meyerhof GG (1963) Some recent research on the bearing capacity of foundations. Can Geotech J 1:16–26
Naderi E, Hataf N (2014) Model testing and numerical investigation of interference effect of closely spaced ring and circular footings on reinforced sand. Geotext Geomembr 42:191–200
Nainegali LS, Basudhar PK, Ghosh P (2013) Interference of two asymmetric closely spaced strip footings resting on nonhomogeneous and linearly elastic soil bed. Int J Geomech 13:840–851
Nainegali L, Basudhar PK, Ghosh P (2018) Interference of strip footings resting on nonlinearly elastic foundation bed: a finite element analysis. Iran J Sci Technol Trans Civ Eng 42:199–206
Nazzal MD, Abu-Farsakh MY, Mohammad LN (2010) Implementation of a critical state two-surface model to evaluate the response of geosynthetic reinforced pavements. Int J Geomech 10(5):202–212
Noorzad R, Manavirad E (2014) Bearing capacity of two close strip footings on soft clay reinforced with geotextile. Arab J Geosci 7:623–639
Omar MT, Das BM, Puri VK, Yen SC (1993a) Ultimate bearing capacity of shallow foundations on sand with geogrid reinforcement. Can Geotech J 30:545–549
Omar MT, Das BM, Yen S-C et al (1993b) Ultimate bearing capacity of rectangular foundations on geogrid-reinforced sand. Geotech Test J 16:246–252
Patra CR, Das BM, Atalar C (2005) Bearing capacity of embedded strip foundation on geogrid-reinforced sand. Geotext Geomembr 23:454–462
Patra CR, Das BM, Bhoi M, Shin EC (2006) Eccentrically loaded strip foundation on geogrid-reinforced sand. Geotext Geomembr 24:254–259
Stuart JG (1962) Interference between foundations, with special reference to surface footings in sand. Geotechnique 12:15–22
Terzaghi K (1943) Theoretical soil mechanics. Wiley, New York
Vesic AS (1973) Analysis of ultimate loads of shallow foundations. J Soil Mech Found Div 99
Vivek P (2011) Static and dynamic interference of strip footings in layered soil. M.Tech. Dissertation, Department of Civil Engineering, Indian Institute of Technology, Kanpur
Yetimoglu T, Wu JT, Saglamer A (1994) Bearing capacity of rectangular footings on geogrid-reinforced sand. J Geotech Eng 120:2083–2099
Yin JH, Wang YJ, Selvadurai APS (2001) Influence of nonassociativity on the bearing capacity of a strip footing. J Geotech Geoenviron Eng 127(11):985–989
Yu HS, Sloan SW (1997) Finite element limit analysis of reinforced soils. Comput Struct 63(3):567–577
Author information
Authors and Affiliations
Corresponding author
Additional information
Responsible Editor: Wissem Frikha
Rights and permissions
About this article
Cite this article
Ekbote, A.G., Nainegali, L. Interference of two closely spaced footings embedded in unreinforced and reinforced soil medium: a finite element approach using ABAQUS. Arab J Geosci 12, 683 (2019). https://doi.org/10.1007/s12517-019-4868-0
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s12517-019-4868-0