A Comparative Study of Soil Liquefaction Assessment Using Machine Learning Models

Geotechnical and Geological Engineering - Liquefaction of saturated granular soils is marked by the total loss of shear strength of soil under dynamic cyclic or transient loading conditions due to...     

Studying the effect of partial drainage on the response of soft clays reinforced with sand column groups

Acta Geotechnica - The drained and undrained response of soft clays reinforced with granular columns has been the subject of numerous geotechnical research efforts to date. Although these studies...     

Metamorphosis of marine organic matter in the jurassic deposits from Sharab area,Taiz Governorate of southwestern Yemen: Thermal effect of tertiary volcanic rocks

The Tertiary volcanic rocks are widely exposed in the Sharab area of Taiz Governorate, southwestern Yemen. The Jurassic calcareous shale and black limestone deposits collected closely to theTertiary volcanic rocks were investigated to provide information regarding the thermal effects of Tertiary volcanic rocks on organic materials. The bulk geochemical results indicate that the analysed Jurassic deposits are organically lean with present-day TOC values less than 0.95% and very low HI values (< 50 mg HC/g TOC), with a predominantly Type IV kerogen (inert carbon). This is attributed to thermal effect on the original organic matter as indicated by high thermal maturity data, consistent with post-mature to metagenesis stage. The present study also suggests that the high thermal maturity of the Jurassic marine deposits is due to the presence of the alkali basalts which have invaded the Jurassic rocks during late Oligocene to early Miocene (~10 Ma). Thus, the heat flow caused by Tertiary basaltic rocks further increased the temperature level and led to metamorphosis of organic matter and converted it to graphitic materials (inert carbon).     

Reliability-based design of spread footings on fibre-reinforced clay

The potential use of fibres in a number of geotechnical engineering applications is gaining more interest in the geotechnical community. A select application consists of the improvement of soft grounds to mitigate their problematic shear strength characteristics. Extensive experimental work has been reported on the response/behaviour of fibre-reinforced clay (FRC) and was recently complemented by several strength prediction models. The effectiveness of these models has not been thoroughly evaluated yet. The objectives of this study are to (1) quantify the model uncertainty of a newly developed FRC model that is aimed exclusively at predicting the “undrained” shear strength of FRCs, (2) combine the model uncertainty with other conventional sources of uncertainty to assess the reliability levels that are inherent in the ultimate limit state design of spread footings that rest on a top FRC layer underlain by weaker natural soft clay, and (3) recommend factors of safety that would ensure a target reliability level for these footings. Results indicate that the traditional safety factor of 3 should be used with caution as it may not be sufficient to yield the desired level of reliability, particularly for smaller footings, lower applied stresses, larger scales of fluctuation, and larger target reliability indices.     

Reliability-Based Design of Spatially Random Two-Layered Clayey Slopes

Geotechnical and Geological Engineering - Two-layered cohesive slopes are encountered in geotechnical applications involving embankments, dams, levees, and natural cut slopes. The reliability of...     

Reliability-based design of spread footings on clays reinforced with aggregate piers

ABSTRACT

The economical and safe design of footings supported on aggregate-pier-reinforced clay could benefit from the implementation of a reliability-based approach that incorporates the different sources of uncertainty. Monte Carlo simulations are conducted to quantify the probability distribution of the ultimate bearing capacity for practical design scenarios. A reliability analysis is then conducted to propose design charts that yield the required factor of safety as a function of the major input parameters. The novelty in the proposed methodology is the incorporation of a lower bound shear strength that is based on the remoulded undrained shear strength in the reliability analysis.     

A State-of-the-Art Review of Stone/Sand-Column Reinforced Clay Systems

This paper presents a state-of-the-art review of published research papers and reports that focus on the modeling, testing, and analysis of soft clays that are reinforced with sand/stone columns in relation to bearing capacity and settlement considerations. The review is presented in chronological order to shed light on the development of this field of research in the last 40+ years. The objective of the study is to assemble published results from field, laboratory, and numerical investigations of sand/stone columns in clay in one resource to provide future researchers and designers with easy access to information and data. The majority of the reviewed papers include an experimental component that is based on field or laboratory scale tests (1-g, triaxial, or centrifuge) conducted on clay specimens reinforced with partially or fully penetrating, encased or ordinary, stone or sand columns that were installed as single columns or as column groups. Some papers included numerical experiments that were based on finite element models, while others presented analytical solutions for modeling the response of the composite system. A compilation of the important findings from physical, numerical, and analytical models in addition to a summary table that facilitates access to information from various research efforts are presented in the paper.