Numerical Simulation of Combined Pile Raft Foundation under Horizontal Loading

Mahalakshmi M,Civil Department, Bannari Amman Institute Of Technology, Sathyamangalam, India ,Hashini C D,Soundara B

doi:10.35940/ijeat.c4758.029320

Mahalakshmi M, Civil Department, Bannari Amman Institute Of Technology, Sathyamangalam, India + Show 2 more

Open Access

https://doi.org/10.35940/ijeat.c4758.029320

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Abstract

Raft foundations generally have the ability to reduce differential settlement, contrarily causing excessive settlement. In order to overcome this, piles are used along with the raft termed as combined pile-raft foundation system. Due to the lack of availability of simplified tools and intricacy of work, the combined pile raft foundation remains as an untouched area in research. This paper explores the performance of 2x2 numerically simulated combined pile-raft foundation embedded in sand exposed to pure horizontal load using ABAQUS 3D. The effect of horizontal loading in terms of displacement is studied by varying the raft thickness, length and spacing to diameter ratios respectively for the combined pile-raft foundation having a pile diameter of 500mm. The model is validated using the existing findings. Based on this study, it is inferred that the raft thickness effect remains inconsequential whereas the length to diameter ratio and spacing to diameter ratio has an impact on the static response of the combined pile-raft foundation system.

Highlights

Population migration and explosion goes hand in hand leading to rapid urbanization
After idealizing the various soil profile for combined pile raft foundation, Poulos [5,6] concluded that a uniform soil profile of relatively stiff clay or dense sand would be the favorable situations for Combined Pile raft foundation (CPRF)
Analysis techniques for pile group was first developed by Butterfield and Banerjee [7] as mentioned by Randolph [8], the analysis technique was developed for pile raft foundation by Davis and Poulos [9] and further simplified analysis methods were developed by Hooper [10], Sommer et al [11], Franke at al. [12], Ai et al [13]

Summary

INTRODUCTION

Population migration and explosion goes hand in hand leading to rapid urbanization This has resulted in the rise of colossal multi-story buildings and skyscrapers, where the foundation of the structure and soil plays a major role during the transfer of load. Katzenbach et al [2,3] mentioned the major design criterion to be the deformations and later marked that by considering the soil-structure interaction a safe and economic piled raft foundation can be achieved. Combined Pile raft foundation (CPRF) term was coined by Katzenbach et al [4] which consists of pile, raft and subsoil as the load bearing elements. Hooper [10] first used finite element method analysis to understand the complex piled raft foundation behavior. In addition to the earlier works carried out on laterally loaded CPRF, a focus on the effect of static horizontal loading and its behavior is studied using numerical simulation

VALIDATION OF MODEL

Study of Parameters

Effect of length to Diameters Ratios

Effect of Raft Thickness

CONCLUSION