scholarly journals Bearing Capacity of Interfered Adjacent Strip Footings on Granular Bed Overlying Soft Clay: An Analytical Approach

2021 ◽  
Vol 7 (7) ◽  
pp. 1244-1263
Author(s):  
R. Shivashankar ◽  
S. Anaswara

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. Doi: 10.28991/cej-2021-03091723 Full Text: PDF

2020 ◽  
Vol 20 (08) ◽  
pp. 2050094
Author(s):  
Wanxiang Chen ◽  
Lisheng Luo ◽  
Zhikun Guo ◽  
Yingjie Wang

Fully clamped reinforced concrete (RC) slab is a common structural component possessing better load-carrying capacity over simply supported slab. Currently, typical yield line theory is a popular approach to estimate the bearing capacity of fully clamped RC slab, although it would greatly underestimate the actual ultimate resistance. This paper is devoted to enriching the knowledge of membrane action and its contribution to the load-carrying capacity of the clamped slab. The resistance trajectory of fully clamped RC slab from loading to failure undergoes three phases: the ascending branch raised by outward movement prevention, the descending branch due to crushed concrete and the re-ascending branch caused by reinforcement strain. Applied load–deflection curves of RC slab accompanying compressive-membrane actions are achieved according to the bending theory of normal cross-section. The reserve capacities accompanying tensile-membrane actions in the condition of large deformations are further derived. The whole load–deflection curves that considered compressive-tensile membrane effects are finally presented, where the mid-span displacements are revised by the deflection equations and the softening coefficient of flexural rigidity. It is indicated that the load–deflection relationships of fully clamped RC slabs can be reasonably depicted by taking compressive-tensile membrane effects into account, which are fairly different from yield line approaches. Comparative analysis shows that analytical results are in good agreement with experimental data reported by Park et al. and illustrates that the proposed model is capable of predicting the bearing capacity of fully clamped RC slab with very good accuracy.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Yogendra K. Tandel ◽  
Chandresh H. Solanki ◽  
Atul K. Desai

Stone column is often employed for strengthening of an embankment seated on deep soft clay. But in very soft clay having undrained shear strength less than or equal to 15 kPa, stone column may not derive adequate load carrying capacity and undergo large lateral deformation due to inadequate lateral confinement. In such circumstances, reinforcement to individual stone column by geosynthetics enhances load carrying capacity and reduces lateral deformation. This paper addresses parametric study on behaviour of embankment resting on Geosynthetic Reinforced Stone Column (GRSC) considering parameters such as stone column spacing to diameter ratio, deformation modulus of stone column material, geosynthetic stiffness, thickness of soft clay, and height of embankment by 3D numerical analysis. Finally, equation for Settlement Improvement Factor (SIF), defined as ratio between settlement of embankment without treatment and with geosynthetic reinforced stone column, is proposed that correlates with the major influence parameters such as stone column spacing to diameter ratio, deformation modulus of soft clay, and geosynthetic stiffness.


2021 ◽  
Vol 83 (4) ◽  
pp. 31-39
Author(s):  
Gathot Heri Sudibyo ◽  
Nor Intang Setyo Hermanto ◽  
Hsuan-Teh Hu ◽  
Yanuar Haryanto ◽  
Laurencius Nugroho ◽  
...  

Bamboo has been significantly and rapidly used to build temporal and permanent structures since time immemorial. However, this renewable natural material has a low bearing capacity, limiting its application to structures under light loads. Therefore, this research was carried out to determine an innovative scheme capable of enhancing bamboo's load-bearing by filling the cavity with cement mortar. Furthermore, a study was carried out to experiment flexural load carrying capacity and the deflection of mortar-filled structural bamboo by considering the diameter and node parameters. A total of 12 specimens were examined using a four-point bending protocol. The result showed the ultimate flexural load carrying capacity of mortar-filled bamboo specimens are higher than those of the conventional bamboo specimens. Specifically, mortar filled bamboo specimen with a diameter of 70 mm was significantly better, 41.10 and 47.06%, as compared than the conventional bamboo in terms of its flexural load carrying capacity for specimen without and with nodes, respectively. Increases in flexural load carrying capacity were also observed for the mortar-filled bamboo specimens having 80 and 90 mm diameter and these observed increases were recorded as 104.55 and 112.00%, and 48.72 and 60.74%, respectively for specimen without and with nodes. Furthermore, the deflection of mortar-filled bamboo elements are substantially greater than those of conventional. Finally, the advantages of the bamboo diameter and bamboo nodes on the flexural load carrying capacity indicated that these essential findings need to be carefully considered in designing structural elements for both mortar-filled and conventional bamboos.


2019 ◽  
Vol 52 (1) ◽  
pp. 38-52
Author(s):  
Pooya Saremi ◽  
Wei Lu ◽  
Jari Puttonen ◽  
Dan Pada ◽  
Jyrki Kesti

The load-carrying capacity of a K-type joint inside a floor truss is studied both experimentally and numerically. The joint tested is a scaled-down, isolated joint. The tubular braces, plate chord, and division plate are made of SSAB Domex steel. Comparison of load displacement curves received by finite element analyses with curves obtained from tests confirms that numerical models describe joint behaviour reasonable. The paper demonstrates that joints with high load-bearing capacity can be investigated experimentally by scaling the dimensions of the joint down when testing devices can affect the required capacity of the joint. The results presented can also be used for optimizing failure mechanism of similar joints in practice.


Eng ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 240-248
Author(s):  
Mohammad Nurul Islam

Construction of civil engineering structures on or next to a slope requires special attention to meet the bearing capacity requirements of soils. In this paper, to address such a challenge, we present laboratory-scale model tests to investigate the effect of footing shape on the sloped surface. The model comprised of a well stiffened mild steel box with three sides fixed and one side open. We considered both with and without reinforcement to assess the effectiveness of reinforcement on the sloped surface. Also, we used three types of footing (i.e., square, rectangular, and circular) to measure the footing shape effects. We considered three different slope angles to evaluate the impact of the sloped face corresponding to the applied load and the reinforcement application. We obtained that the maximum load carrying capacity in the square footing was higher than the rectangular and the circular footing for both the reinforced and the unreinforced soil. With the increase of geo-reinforcement in all three footing shapes and three sloped angles, the load carrying capacity increased. We also noticed a limiting condition in geo-reinforcement placement effectiveness. And we found that with the increase of slope, the load bearing capacity decreased. For a steep slope, the geo-reinforcement placement and the footing shape selection is crucial in achieving the external load sustainability, which we addressed herein.


2014 ◽  
Vol 638-640 ◽  
pp. 998-1001
Author(s):  
Xiao Liu ◽  
Ru Heng Wang ◽  
Bin Jia

Bridge piers generate local destruction at impact point after suffering medium and low speed impact, and then their bearing capacities decrease a lot. In order to analyze the reliability of piers with damage, based on the formula in code, this thesis used ANSYS to analyze surplus normal section load-carrying capacity of reinforced concrete bridge piers with notches in different sizes. The relation curve between axial bearing capacity of piers and scaling area of concrete was obtained. After comparing with formula in code, a new formula was obtained, which can be used in calculating surplus normal section load-carrying capacity of chipped bridge piers.


2011 ◽  
Vol 311-313 ◽  
pp. 1012-1016 ◽  
Author(s):  
Shan Shan Liu ◽  
Han Chen ◽  
Xue Dong Chen

A vacuum preloaded circular aerostatic bearing was designed and its static characteristics were investigated experimentally. The load carrying capacity and air film thickness of the bearing were measured for different air supply pressure and vacuum pressure values. An orthogonal table was constructed to optimize the experimental measurement. Regression analysis was performed on the experimental results to obtain an analytical model of the bearing stiffness as a function of the load carrying capacity, air supply pressure and vacuum pressure. Accuracy of this analytical model in predicting static characteristics of the aerostatic bearing was validated by comparison with experimental data, and influences of the functioning parameters were also discussed.


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