Journal of achievements in materials and manufacturing engineering | 2021
Study of bearing capacity of skirted\nirregular pentagonal footings\non different sands
Abstract
Purpose: The paper presents an experimental and numerical study to evaluate the bearing\ncapacity of unskirted, singly and doubly skirted irregular pentagonal footings on different\nsands (S1, S2, S3) at a relative density of 30 %. The skirt depth of the footing was varied\nfrom 0.0B to 1.5B (B is the width of the square footing).\nDesign/methodology/approach: The experimental and numerical study of the singly and\ndoubly skirted irregular pentagonal footing resting on sands was modelled in a test tank and\nPlaxis 3D software respectively.\nFindings: The results of this study reveal that the bearing capacity was higher for the skirted\nirregular pentagonal footings on sand S3 followed by sand S2 and S1. The lowest percentage\nimprovement for the singly skirted footing on sand S3 was 18.51% at a Ds/B = 0.25 whereas\nthe highest improvement was 90.81% at a Ds/B = 1.50 for the singly skirted footing on sand\nS2. The highest percentage improvement for the doubly skirted footing on sand S2 was\n95.13% at a Ds/B = 1.5 whereas the lowest improvement was 23.70% at a Ds/B = 0.25 the\ndoubly skirted footing on sand S3. The results further revealed that the numerically obtained\nbearing capacity was marginally higher in comparison to the one obtained experimentally\nfor the footings on all sands. Further, the experimental results validated the results obtained\nnumerically with an average deviation of 8%. The percentage improvement in the bearing\ncapacity was higher for the irregular pentagonal footing resting on sand S2 in comparison to\nsand S3 and S1. The settlement response of the irregular pentagonal footings is unchanged\nby increasing the number of elements beyond 7700. Both the experimental and numerical\nstudies revealed a linear elastic behaviour at Ds = 0.5B, while the experimentally obtained\npressure-settlement ratio plot shows a clear failure at Ds= 1B and 1.5B.\nResearch limitations/implications: The results presented in this paper were based on\nthe experimental and numerical study conducted on small scale model footings. However,\nfor the actual footings, further study is recommended using full-scale field size footings to\ngeneralize the results.\nOriginality/value: No experimental and numerical studies on singly and doubly skirted\nirregular pentagonal footings were conducted so far. Hence, an attempt was made in this\narticle to predict the bearing capacity of these footings experimentally and using Plaxis 3D\nrespectively.\n\n