Experimental Study on the Factors Influencing the Performance of Geogrid Encased Granular Pile Anchor Installed in Cohesionless Soils

Mohan Bajaj1, Gowtham Padmanabhan1
1Department of Earthquake Engineering, Indian Institute of Technology Roorkee, Roorkee, India

Tóm tắt

The increasing demand of infrastructure at the global level necessitated the importance of ground improvement and efficient foundation design techniques to cater special loads (e.g., tensile loads). Geogrid encased granular pile anchor (GGPA) is an advanced ground improvement technique which is capable of improving the pull-out capacity to counter the tensile loads in addition to the compressive loads. The present study focusses on the experimental investigation on Swan sand specimen treated with GGPAs under varying the length-by-diameter (L/D) ratio of the pile (5, 10, 13.3, and 16.6), angle of pile inclination (5°, 10°, and 15°) and relative density of the sandy soil (45%, 55%, and 65%). Increment in pull-out capacity has been observed with the increased angle of pile inclination and relative density. Encasement through geogrid increases the interface friction between soil–pile surface and cohesionless soil, and reduces the bulging of pile. Thus, the failure of the GGPAs was completely governed by the shaft failure of the pile and not much influenced by the pile bulging. From the experimental observations, it is clear that the efficiency of the GGPAs mainly depends on the length and diameter of the pile apart from pile inclination and relative density and not purely depends on L/D ratio.

Tài liệu tham khảo

Shukla SK, Chandra S (1994) The effect of prestressing on the settlement characteristics of geosynthetic-reinforced soil. Geotext Geomembr 13(8):531–543 Sharma A, Alzaylaie M, Vandanapu R, Khalaf K (2021) Numerical and analytical studies of 3D effects on pullout capacity of anchor blocks in granular compacted fill. Int J Geosy Ground Eng 7(1):1–8 Orekanti ER, Dommaraju GV (2019) Load-settlement response of geotextile encased laterally reinforced granular piles in expansive soil under compression. Int J Geosyn Ground Eng 5(3):1–8 Padmanabhan G, Shanmugam GK, Subramaniam S (2021) Sustainability approaches in ground improvement measures. Sustainable practices and innovations in civil engineering. Springer, pp 249–255 Shukla SK (2021) Geosynthetics and ground engineering: sustainability considerations. Int J Geosyn Ground Eng 7(1):1–3 Phanikumar BR, Muthukumar M (2014) Reducing heave of expansive clay beds through granular pile–anchor groups. Proc Inst Civ Eng Ground Improv 167(2):99–107 Phanikumar BR, Muthukumar M (2015) Swelling behaviour of GPA-reinforced expansive clay beds subjected to swell-shrink cycles. Geomech Geoeng 10(4):261–270 Muthukumar M, Shukla SK (2018) Swelling behaviour of expansive clay beds reinforced with encased granular pile anchors. Int J Geotech Eng 12(2):109–117 Phanikumar BR, Muthukumar M (2020) Influence of wetting–drying cycles on swell–shrink behaviour of GPA-reinforced expansive clay beds. Geomech Geoeng 15(3):172–185 Kranthikumar A, Sawant VA, Kumar P, Shukla SK (2017) Numerical and experimental investigations of granular anchor piles in loose sandy soil subjected to uplift loading. Int J Geomech 17(2):04016059 Kumar P and Ranjan G (1997). Pullout capacity of granular piles. In Indian Geotechnical Conference. pp. 349–352 Kumar BRP, Rao NR (2000) Increasing pull-out capacity of granular pile anchors in expansive soils using base geosynthetics. Can Geotech J 37(4):870–881 Phanikumar BR, Sharma RS, Rao AS, Madhav MR (2004) Granular pile anchor foundation (GPAF) system for improving the engineering behavior of expansive clay beds. Geotech Test J 27(3):279–287 Rao AS, Phanikumar BR, Babu RD, Suresh K (2007) Pullout behavior of granular pile-anchors in expansive clay beds in situ. J Geotechn Geoenviron Eng 133(5):531–538 Phanikumar BR (2016) Influence of geogrid reinforcement on pullout response of granular pile-anchors (GPAs) in expansive soils. Indian Geotech J 46(4):437–444 Choudhary AK, Pandit B, Babu GS (2017) Pullout behaviour of strip anchor in soil using flac2d. In Indian GEOTECHNICAL Conference Deb K, Basudhar PK, Chandra S (2007) Generalized model for geosynthetic-reinforced granular fill-soft soil with stone columns. Int J Geomech 7(4):266–276 Araujo GLS, Palmeira EM, Cunha RP (2009) Behaviour of geosynthetic-encased granular columns in porous collapsible soil. Geosynth Int 16(6):433–451 IS: 2720 (Part IV) (1985) Method of test for soils – Determination of grain size analysis. Bureau of Indian Standards, New Delhi Nazir A, Nasr A (2013) Pullout capacity of batter pile in sand. J Adv Res 4(2):147–154