Experimental study on evaluating the lateral load capacity of raker pile in sloping ground

ABSTRACT

A lot of uncertainty is associated with the behavior of pile foundations on the sloping ground due to factors like soil – pile interface and vague evaluation of pile bearing capacity. These constraints have a considerable impact on the extensive implementation of deep foundation on sloping ground. Comprehensive research studies were carried out on laterally loaded vertical piles on horizontal ground whereas only a limited number of studies have been conducted on the behavior of the laterally loaded raker-pile system on sloping sites. Therefore, to address this knowledge gap, the current investigative research paper aimed to study the results of a series of static lateral load tests were conducted in the laboratory on a single aluminium model raker pile embedded in loose sandy soil on 1V: 2H sloping ground. The loading directions were varied considering either forward (close to the slope) or reverse (away from the slope) loading for all pile positions. The influence of the sloping ground was quantified by measuring the pile response for horizontal ground conditions. It was observed that there is a significant increase in the displacement of the pile for the sloping ground surface compared to the horizontal ground. With an increase in the edge distance from the slope crest towards the embankment, a reduction in the pile displacement was observed. The optimum distance from the slope crest towards the embankment where the effect of slope becomes nullified under both forward and reverse lateral loads was determined as 10D (D – Diameter of the pile). From the obtained results, it was evident that in the case of the level ground and sloping ground with forward loading, the negative raker piles offer more resistance to lateral loads than vertical piles. In contrast, the positive raker piles endure the least lateral load with increasing inclination angle.

KEYWORDS:

• Lateral load
• raker piles
• sloping ground
• forward loading
• reverse loading
• inclination angles

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notation

The following symbols were used in this research paper:

D = Diameter of the pile

E_pI_p= Bending stiffness of the pile

K_p= Passive earth pressure coefficient

ϒ = Unit weight of soil

L = Depth of pile embedment

S = Distance of pile from the crest

T = Stiffness factor

η_h = Modulus of subgrade reaction of soil

Additional information

Notes on contributors

S K Kayalvizhi

Mrs. S K Kayalvizhi is a Ph.D. research scholar at National Institute of Technology Tiruchorappalli. She is working on laterally loaded raker piles and pile groups. She has worked as a teaching faculty for undergraduate students at engineering colleges.

Kasinathan Muthukkumaran

Dr. Kasinathan Muthukkumaran is currently Professor in Civil Engineering at National Institute of Technology, Tiruchirappalli, India. He has more than 20 years of experience in teaching, research and consultancy in the field of Civil/Geotechnical Engineering. He has published more than 120 papers in international and national journals and conferences. He has completed 5 R & D (including ISRO - Chandrayaan- 2 Mission project) & 60 major consultancy projects in Geotechnical Engineering and published two patent including “Moon Soil” (A Method for Manufacture of Highland Lunar Soil Simulant). He is the Founder Chairman of Indian Geotechnical Society (IGS-Trichy) Trichy Chapter. He is a member of Technical Committee (TC-301 on ”Preservation of Historic Sites”) of International Society for Soil Mechanics and Geotechnical Engineering. Prof. Muthukkumaran area of research is in geotechnical engineering, which includes pile foundation, soil-structure interaction, marine geotechnics & foundations, field instrumentation, geotechnical physical modeling, ground improvement and forensic geotechnical engineering. He is a recipient of Bharat Vikas Award -2018.

Sanjay Kumar Shukla

Professor Sanjay Kumar Shukla is Founding Editor-in-Chief of International Journal of Geosynthetics and Ground Engineering. He is Founding Research Group Leader (Geotechnical and Geoenvironmental) at School of Engineering, Edith Cowan University, Perth, Australia. He holds Distinguished Professorship at seven universities. He has over 25 years of experience in teaching, research and consultancy in the field of Civil/Geotechnical Engineering. He has authored more than 270 research articles, including over 170 refereed journal publications. He is also author/editor of 23 books, including 7 textbooks, and 22 book chapters. He has been honoured with several awards, including the most prestigious IGS Award 2018 from International Geosynthetics Society (IGS), USA. He is a fellow of Engineers Australia, a life fellow of Institution of Engineers (India) and Indian Geotechnical Society, a member of American Society of Civil Engineers (ASCE), and several other professional bodies.