Articles written in Sadhana
Volume 45 All articles Published: 21 April 2020 Article ID 0089
Assessment of interaction mechanism and bearing capacity of strip footings located on slope face
Construction of residential and commercial buildings on the slope face is very commonly noted in the North-eastern and other mountainous terrains of India. Closely spaced buildings and the foundation elements located on such slope faces interact with each other, thereby influencing the stability of the slopes, which, in turn, affects the failure mechanism and bearing capacity estimation of such foundation systems. Several literatures are available highlighting the response of foundation located on the slope crest, while those elucidatingthe response of foundation located directly on the slope face are scanty. Among them, there are extremely few literatures available showcasing the interaction of footings located on slope face. Hence, considering the practical importance of the issue, this paper reports a numerical two-dimensional finite element-based study that is conducted to determine the failure mechanism and bearing capacity of interfering strip footings located on the face of a slope. The study aptly demonstrates that the response of interfering footings is governed by the soiltype, footing width, slope inclination, and the relative elevation between the footings. It is observed that upon increasing the footing width by two times, the bearing capacity of interfering footing increases by 33%, even though the interfering mechanism remains the same. It was also noted that with each successive increase in the slope inclination by 5°, the interfering bearing capacity gets reduced by 37 %. Under any parametric circumstances,maximum interference between the strip footings is noted when their relative height of separation (in terms of footing width) remains close to 2, while the interference is found to be completely disappearing when the relative height of separation is 8 or more. This finding should aid in the decision making about the proper choice of inclusion of interference effect during the analysis and design of foundations on slope face
Volume 46 All articles Published: 13 October 2021 Article ID 0210
Hillslope instability induced by toe excavation: A comparative study of LEM-based deterministic and probabilistic approaches
Toe cutting of hillslopes that are intended for the expansion of the transportation networks across the hilly regions need to follow an engineered basis to avert catastrophic failures. The commonly utilized deterministic Limit Equilibrium Method (LEM) does not incorporate the uncertainties in geotechnical propertiesand might exhibit inappropriate or erroneous consequences of toe excavation. In order to highlight the chances of toe-excavation induced slope failures, this paper reports the outcomes of the probabilistic stability analysis while considering one-dimensional spatial variability of soil shear strength parameters. The importance of such probabilistic analyses is established by finding that 79% of the toe-excavated slopes, which are judged safe from deterministic analysis, actually exhibit high probabilities of failure. Further, the influences of coefficient of variation (CoV) and the correlation between the shear strength parameters are also highlighted. The probability of failure of the cut slopes is found to be decreased by around 70% when the correlation coefficient of the shearstrength parameters decreased from +0.5 to -0.5. The permissible width of toe excavation is found to be governed by the indicators of spatial variability. It is revealed that for a CoV value of 0.2 and 0.3, a maximum horizontal extent of 7 m and 5 m can be excavated without leading to slope failure for a dimensionlesscorrelation length up to 0.2 and 0.1, respectively.
Volume 47 All articles Published: 22 February 2022 Article ID 0044
Influence of drainage blanket clogging on response of homogeneous earthen dams
Observations of drainage in earthen dams indicate that the phenomenon of clogging can lead to a radical reduction in the efficiency of drainage, making it non-functional within a few years after construction. This paper discusses the most common forms of clogging in drainage blankets and their influence on seepage and stability of earthen dams. Different clogging typologies are studied for both horizontal and inclined drainage blankets by reduction in drain length, thickness or by simulating random clogging scenarios. Two-dimensionalfinite element analysis is carried out to decipher the influence of clogging on the temporal seepage and stability response of earthen dams. The results of the study indicated that clogging typologies have recognizable effect on the response of the earthen dams. Inward clogging is identified as the most critical clogging scenario in earthen dams.
Volume 48, 2023
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