Journal Articles
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Item Study on Behaviour of Two Adjacent Strip Footings on Granular Bed Overlying Clay with a Void(Springer, 2020) Anaswara, S.; Shivashankar, R.This paper numerically examines the behaviour of two adjacent strip footings on granular bed over weak soil having a void. Voids could be formed in weak soil strata due to various reasons such as due to water leakage from the water supplying lines or sewer lines, poor drainage and erosion of soil, animal burrows, etc. A parametric study is carried out to understand the influence of granular bed thickness, width of footings, spacing between the footings, and the presence of a void beneath the footing in the weak soil, on the behaviour of footings. To understand the failure mechanism, shear strain contours, for different cases, are being studied. It is observed that there is a certain critical spacing between the two adjacent footings at which the footing/s carry the maximum load. This critical spacing depends on the type of loading, whether equal and simultaneous loading or unequal and sequential loading. The presence of voids also affects the performance of footings. Such voids tend to reduce the load carrying capacity of the footing/s and alter failure pattern. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.Item Interference Studies of Adjacent Strip Footings on Unreinforced and Reinforced Sands(Springer, 2020) Anaswara, S.; Lakshmy, G.S.; Shivashankar, R.Interference effects of two and three strip footings placed adjacent to each other on unreinforced and reinforced sands are being studied in this paper. Effects on stresses in foundation soil, bearing capacity, settlements and tilts of footings are being looked into. Parameters varied in this study are (i) the number of footings (In the case of two footings loaded simultaneously, both experimental and numerical studies are conducted. In the case of two footings loaded sequentially and three footings, numerical studies are done.), (ii) loading conditions, (iii) clear spacing between the footings and (iv) number of reinforcement layers in foundation soil. With two footings, two loading conditions are considered. In the first loading condition, both footings are loaded simultaneously up to failure. In the second loading condition, one of the footings representing an already existing foundation is loaded with half of the estimated failure load of single strip footing and adjacent footing loaded up to failure. With two adjacent strip footings on unreinforced and reinforced sands, both loaded simultaneously, some laboratory-scale experimental studies are also conducted to compare with the numerical results. It is observed that there is a certain critical spacing at which the footing/s carry the maximum load. This critical spacing depends on the loading condition. Reinforcements in the foundation soil used are in the form of hexagonal wire meshes. The effect of providing the reinforcements in layers in the foundation soil is seen in the increased bearing capacity, reduced settlements and reduced tilts of the footings under simultaneous loading condition. Tilts are also found to be influenced by the loading condition. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.Item Study on Behaviour of Two Adjacent Strip Footings on Unreinforced/Reinforced Granular Bed Overlying Clay with Voids(Springer Science and Business Media Deutschland GmbH, 2021) Anaswara, S.; Shivashankar, R.This paper numerically studies the behaviour of two adjacent strip footings on unreinforced and reinforced granular bed (RGB) overlying clay having voids. The influence of different parameters such as granular bed thickness, length of reinforcement/s, number of layers of reinforcement, presence of void/s beneath the footing/s in the weak soil, on the behaviour of footings are carried out in this study. It is found that there is a certain optimum spacing between the two adjacent strip footings at which the footing/s carry the maximum load. The voids could be formed in weak soil due to various reasons and the presence of voids may affect the performance of footings. Such voids tend to reduce the load carrying capacity of the footing/s. However, providing a RGB over weak soil can be used as an effective method to maintain the good performance of footings, even when voids could be formed in future. © 2020, Springer Nature Switzerland AG.Item Bearing capacity of interfered adjacent strip footings on granular bed overlying soft clay: An analytical approach(Salehan Institute of Higher Education, 2021) Shivashankar, R.; Anaswara, S.In the present paper, the interference effects on bearing capacity of two and three closely spaced strip footings resting on granular bed overlying clay are being studied. A simple analytical model is proposed to predict the load-carrying capacity and the interference factor of an interfered footing, when adjacent strip footings are optimally placed on the surface of a Granular Bed (GB) overlying clay and both the footings are simultaneously loaded. A punching shear failure mechanism is envisaged in the analytical model. The load-carrying capacity of the footing is taken as the sum of total shearing resistances along the two vertical planes through the edges of the strip footing in the upper granular layer and the load-carrying capacity of the soft clay beneath the GB. Insights gained from finite element simulations are used to develop the new modified punching shear model for interfering footing. Bearing capacity can be easily calculated by using the proposed punching shear model for interfering footing. The analytical model is validated with numerical analyses and previous experimental results and found to be in reasonably good agreement. The influence of different parameters such as granular bed thickness, width of footing, number of footings are carried out in this study. © 2021 by the authors. Licensee C.E.J, Tehran, Iran.