Laboratory study effect of the width of the foundation, the relative density of sand and pressure on the settlement of strip footings | ||
| مهندسی زیر ساخت های حمل و نقل | ||
| Volume 8, Issue 2 - Serial Number 30, September 2022, Pages 131-148 PDF (1.31 M) | ||
| Document Type: Research Paper | ||
| DOI: 10.22075/jtie.2022.24827.1564 | ||
| Authors | ||
| Mahmoud Nikkhah* 1; S.M> Mir Mohammad Hosseini2; Saeed Abrishami3 | ||
| 1Department of Civil Engineering, Semnan Branch, Islamic Azad University, Semnan, Iran | ||
| 2Department of Civil Engineering and Environmental, Amirkabir University of Technology, Tehran, Iran | ||
| 3Department of Civil Engineering, Ferdousi University, Mashhad, Iran | ||
| Receive Date: 10 October 2021, Revise Date: 22 May 2022, Accept Date: 27 June 2022 | ||
| Abstract | ||
| Determining the bearing capacity of the soil and its subsidence is one of the most important parameters that must be carefully evaluated when designing a safe foundation. In the present study, using a physical model, the behavior of the foundation located on sandy soil under static loading and the effect of various factors on soil behavior have been investigated. In this laboratory study, the effect of foundation width, sandy soil density and amount of overhead on strip foundation subsidence has been investigated. The soil material used in this study is poorly grained medium sand (SP). The foundation model has a width of 5, 7.5 and 10 cm and its length is 34 cm. The sand raining technique has been selected to obtain a homogeneous sample with a definite relative density and repeatability of laboratory conditions. The loading system is compressed air that has the ability to apply a uniform and static load. The relationship between the final relative settlement and the width of the foundations located on medium-density sandy soils is linear, and as the foundation width increases, the final relative settlement reaches less than its final ultimate bearing capacity. At the same pressure, the settlement of the foundation located on medium-density sandy soils is about 10 % higher than the foundation located on dense sandy soils. Soil behavior up to a pressure of about 50% of the final bearing capacity is linearly elastic. The pressure- settlement relationship of the strip foundation is linear up to about 5% of the foundation width. General shear failure occurs at a relative settlement of about 12 to 14%. For this reason, it is suggested to determine the ultimate bearing capacity of the strip foundation located on sandy soil, the amount of pressure such as 12% . | ||
| Keywords | ||
| Foundation width; relative sand density; final relative settlement; pressure | ||
| References | ||
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Abu-Farsakh, M., Chen, Q. and Sharma, R. 2013. “An experimental evaluation of the behavior of footings on geosynthetic-reinforced sand”. Soils Found., 53(2): 335-348.
Badakhshan, E. and Noorzad, A. 2017. “Effect of footing shape and load eccentricity on behavior of geosynthetic reinforced sand bed”. Geotext. Geomembranes, 45(2): 58-67.
Bayram, A. T. E. Ş. and Şadoğlu, E. 2021. “Experimental and numerical investigation of load-settlement behaviour to model shallow foundation rest on sandy soil”. Erzincan Üniversitesi Fen Bilimleri Enstitüsü Dergisi, 14(2): 686-703.
Bharti, G., Shukla, B. K., Srinivasan, V. and Bansal, V. 2022. “Experimental study on eccentrically loaded rectangular footing on sand for embedded condition to enhance serviceability of structures”. Materials Today: Proceedings.
Boushehrian, A. H., Hataf, N. and Ghahramani, A. 2011. “Modeling of the cyclic behavior of shallow foundations resting on geomesh and grid-anchor reinforced sand”. Geotext. Geomembranes, 29(3): 242-248.
Dabiryan, H., Kargar, M., Aghabeigi, E., Mir Mohammad Hosseini, S. M. and Hosseini Varkiyani, S. M. 2017. “Evaluating the performance of geocells made from needle-punched nonwoven layers in the bearing capacity of reinforced soil”. J. Text. Inst., 108(10): 1747-1752.
Das, B. M. and Omar, M. T. 1994. “The effects of foundation width on model tests for the bearing capacity of sand with geogrid reinforcement”. Geotech. Geolog. Eng., 12(2): 133-141.
Dash, S. K., Krishnaswamy, N. R. and Rajagopal, K. 2001. “Bearing capacity of strip footings supported on geocell-reinforced sand”. Geotext. Geomembranes, 19(4): 235-256.
Dash, S. K., Sireesh, S. and Sitharam, T. G. 2003. “Model studies on circular footing supported on geocell reinforced sand underlain by soft clay”. Geotext. Geomembranes, 21(4): 197-219.
El Sawwaf, M. and Nazir, A. K. 2010. “Behavior of repeatedly loaded rectangular footings resting on reinforced sand”. Alexandria Eng. J., 49(4): 349-356.
Fakher, N. and Fakhruldin, M. 2021. “Experimental study of relative density effect on bearing capacity of sand reinforced with geogrid”. Kufa J. Eng., 12(3): 46-55.
Fazeli Dehkordi, P., Ghazavi, M. and Karim, U. F. 2021. “Bearing capacity-relative density behavior of circular footings resting on geocell-reinforced sand”. Eur. J. Environ. Civ. Eng., doi: 10.1080/19648189.2021.1884901
Fragaszy, R. J. and Lawton, E. 1984. “Bearing capacity of reinforced sand subgrades”. J. Geotech. Eng., 110(10): 1500-1507.
Gill, G., Mittal, R. K. and Dandautiya, R. 2021. “Pressure settlement behaviour of strip footing resting on unreinforced and tire chips reinforced copper slag”. KSCE J. Civ. Eng., 25(1): 92-106.
Kargar, M. and Mir Mohammad Hosseini, S. M. 2018. “Influence of reinforcement stiffness and strength on load-settlement response of geocell-reinforced sand bases”. Eur. J. Environ. Civ. Eng., 22(5): 596-613.
Khing, K. H., Das, B. M., Puri, V. K., Cook, E. E. and Yen, S. C. 1993. “The bearing capacity of a strip foundation on geogrid-reinforced sand”. Geotext. Geomembranes, 12(4): 351-361.
Latha, G. M. and Somwanshi, A. 2009. “Bearing capacity of square footings on geosynthetic reinforced sand”. Geotext. Geomembranes, 27(4): 281-294.
Moghaddas Tafreshi, S. N. and Dawson, A. R. 2010. “Comparison of bearing capacity of a strip footing on sand with geocell and with planar forms of geotextile reinforcement”. Geotext. Geomembranes, 28(1): 72-84.
Moghaddas Tafreshi, S. N. and Dawson, A. R. 2012. “A comparison of static and cyclic loading responses of foundations on geocell-reinforced sand”. Geotext. Geomembranes, 32: 55-68.
Mohamed, M. H. 2010. “Two-dimensional experimental study for the behaviour of surface footings on unreinforced and reinforced sand beds overlying soft pockets”. Geotext. Geomembranes, 28(6): 589-596.
Mosallanezhad, M., Hataf, N. and Ghahramani, A. 2008. “Experimental study of bearing capacity of granular soils, reinforced with innovative grid-anchor system”. Geotech. Geolog. Eng., 26(3): 299-312.
Patra, C. R., Das, B. M. and Atalar, C. 2005. “Bearing capacity of embedded strip foundation on geogrid-reinforced sand”. Geotext. Geomembranes, 23(5): 454-462.
Sireesh, S., Sitharam, T. G. and Dash, S. K. 2009. “Bearing capacity of circular footing on geocell–sand mattress overlying clay bed with void”. Geotext. Geomembranes, 27(2): 89-98.
Useche-Infante, D., Aiassa Martinez, G., Arrúa, P. and Eberhardt, M. 2022. “Experimental study of behaviour of circular footing on geogrid-reinforced sand”. Geomech. Geoeng., 17(1): 45-63.
Vesic, A. B. 1963. “Bearing capacity of deep foundations in sand”. Highway Res. Record, 39: 112-153.
Vesic, A. S. 1973. “Analysis of ultimate loads of shallow foundations”. J. Soil Mech. Found. Div., 99(1): 45-73. | ||
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