Random failure mechanism method for assessment of working platform bearing capacity with a linear trend in undrained shear strength

A bearing capacity evaluation for the surface strip foundation on a working platform modelled on a two-layered substrate is considered in the study. The upper layer is assumed as man-made and well-controlled and thus non-variable. The lower layer modelling natural cohesive soil is subjected to spati...

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Main Authors: Marcin Chwała, Marek Kawa
Format: Article
Language:English
Published: Elsevier 2021-12-01
Series:Journal of Rock Mechanics and Geotechnical Engineering
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S1674775521000883
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author Marcin Chwała
Marek Kawa
author_facet Marcin Chwała
Marek Kawa
author_sort Marcin Chwała
collection DOAJ
description A bearing capacity evaluation for the surface strip foundation on a working platform modelled on a two-layered substrate is considered in the study. The upper layer is assumed as man-made and well-controlled and thus non-variable. The lower layer modelling natural cohesive soil is subjected to spatial variability of undrained shear strength. The random failure mechanism method (RFMM) is used to evaluate the bearing capacity. This approach employs a kinematic assessment of the critical load and incorporates the averaging of three-dimensional (3D) random field along dissipation surfaces that result from the failure mechanism geometry. A novel version of the approach considering an additional linear trend of undrained shear strength in the spatially variable layer is proposed. The high efficiency of the RFMM algorithm is preserved. The influences of foundation length, trend slope in the spatially variable layer, fluctuation scales, and thickness of the homogenous sand layer on the resulting bearing capacity evaluations are analysed. Moreover, for selected cases, verification of the RFMM based assessment obtained using random finite difference method (RFDM) based on 3D analysis is provided. Two types of analyses are performed using RFDM based on associated and non-associated flow rules. For associated flow rule which corresponds to RFMM, the RFMM is conservative and efficient and thus it seems preferable. However, if RFDM employs non-associated flow rule (much lower dilation angle for sand layer), the efficient RFMM is no longer conservative. For this situation, a combined approach that improves the efficiency of the numerical method is suggested.
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spelling doaj.art-51c3661cdbc042f6a54680e308a561972022-12-21T23:09:27ZengElsevierJournal of Rock Mechanics and Geotechnical Engineering1674-77552021-12-0113615131530Random failure mechanism method for assessment of working platform bearing capacity with a linear trend in undrained shear strengthMarcin Chwała0Marek Kawa1Corresponding author.; Department of Civil Engineering, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, Wrocław, 50-370, PolandDepartment of Civil Engineering, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, Wrocław, 50-370, PolandA bearing capacity evaluation for the surface strip foundation on a working platform modelled on a two-layered substrate is considered in the study. The upper layer is assumed as man-made and well-controlled and thus non-variable. The lower layer modelling natural cohesive soil is subjected to spatial variability of undrained shear strength. The random failure mechanism method (RFMM) is used to evaluate the bearing capacity. This approach employs a kinematic assessment of the critical load and incorporates the averaging of three-dimensional (3D) random field along dissipation surfaces that result from the failure mechanism geometry. A novel version of the approach considering an additional linear trend of undrained shear strength in the spatially variable layer is proposed. The high efficiency of the RFMM algorithm is preserved. The influences of foundation length, trend slope in the spatially variable layer, fluctuation scales, and thickness of the homogenous sand layer on the resulting bearing capacity evaluations are analysed. Moreover, for selected cases, verification of the RFMM based assessment obtained using random finite difference method (RFDM) based on 3D analysis is provided. Two types of analyses are performed using RFDM based on associated and non-associated flow rules. For associated flow rule which corresponds to RFMM, the RFMM is conservative and efficient and thus it seems preferable. However, if RFDM employs non-associated flow rule (much lower dilation angle for sand layer), the efficient RFMM is no longer conservative. For this situation, a combined approach that improves the efficiency of the numerical method is suggested.http://www.sciencedirect.com/science/article/pii/S1674775521000883Two-layered soilRandom bearing capacityFluctuation scaleKinematical approachUpper boundRandom finite difference method (RFDM)
spellingShingle Marcin Chwała
Marek Kawa
Random failure mechanism method for assessment of working platform bearing capacity with a linear trend in undrained shear strength
Journal of Rock Mechanics and Geotechnical Engineering
Two-layered soil
Random bearing capacity
Fluctuation scale
Kinematical approach
Upper bound
Random finite difference method (RFDM)
title Random failure mechanism method for assessment of working platform bearing capacity with a linear trend in undrained shear strength
title_full Random failure mechanism method for assessment of working platform bearing capacity with a linear trend in undrained shear strength
title_fullStr Random failure mechanism method for assessment of working platform bearing capacity with a linear trend in undrained shear strength
title_full_unstemmed Random failure mechanism method for assessment of working platform bearing capacity with a linear trend in undrained shear strength
title_short Random failure mechanism method for assessment of working platform bearing capacity with a linear trend in undrained shear strength
title_sort random failure mechanism method for assessment of working platform bearing capacity with a linear trend in undrained shear strength
topic Two-layered soil
Random bearing capacity
Fluctuation scale
Kinematical approach
Upper bound
Random finite difference method (RFDM)
url http://www.sciencedirect.com/science/article/pii/S1674775521000883
work_keys_str_mv AT marcinchwała randomfailuremechanismmethodforassessmentofworkingplatformbearingcapacitywithalineartrendinundrainedshearstrength
AT marekkawa randomfailuremechanismmethodforassessmentofworkingplatformbearingcapacitywithalineartrendinundrainedshearstrength