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Articles 31 - 34 of 34

Full-Text Articles in Geotechnical Engineering

A New Volumetric Strain-Based Method For Determining The Crack Initiation Threshold Of Rocks Under Compression, Hao Li, Ruizhi Zhong, Leo Pel, David Smeulders, Zhenjiang You Jan 2023

A New Volumetric Strain-Based Method For Determining The Crack Initiation Threshold Of Rocks Under Compression, Hao Li, Ruizhi Zhong, Leo Pel, David Smeulders, Zhenjiang You

Research outputs 2022 to 2026

The crack initiation stress threshold ( ci) is an essential parameter in the brittle failure process of rocks. In this paper, a volumetric strain response method (VSRM) is proposed to determine the σci based on two new concepts, i.e., the dilatancy resistance state index ( ci) and the maximum value of the dilatancy resistance state index difference (| ci|), which represent the state of dilatancy resistance of the rock and the shear sliding resistance capacity of the crack-like pores during the compressive period, respectively. The deviatoric stress corresponding to the maximum | ci| is taken as the ci . We …


A Progress Insight Of The Formation Of Hydrogen Rich Syngas From Coal Gasification, Tawanda Matamba, Stefan Iglauer, Alireza Keshavarz Dec 2022

A Progress Insight Of The Formation Of Hydrogen Rich Syngas From Coal Gasification, Tawanda Matamba, Stefan Iglauer, Alireza Keshavarz

Research outputs 2022 to 2026

This review paper aims to explore the research progress in the formation of hydrogen rich gas from different innovative coal gasification parameters. Promotion effects of parameters such as pressure, temperature, catalyst, coal type, reactor setup, and gasification agents (H2O, O2, supercritical water) were extensively analysed. The formation of hydrogen gas through coal gasification was sub-divided into H2 production from fixed bed gasification system, fluidized bed system, and entrained flow system. The advantages of coal and biomass co-gasification towards clean energy formation was also reviewed. Co-gasification and elevated temperatures, pressures, and steam-carbon ratios were reported to positively influence the yields of …


The Influence Of Acidizing On Propped Fractures For Productivity Enhancement: Eagle Ford Laboratory Study, Mohsen Farrokhrouz, Abbas Taheri, Stefan Iglauer, Alireza Keshavarz Dec 2022

The Influence Of Acidizing On Propped Fractures For Productivity Enhancement: Eagle Ford Laboratory Study, Mohsen Farrokhrouz, Abbas Taheri, Stefan Iglauer, Alireza Keshavarz

Research outputs 2022 to 2026

Hydraulic fracturing of tight formations and placing proppants within induced fractures are commonly performed in unconventional shale reservoirs all over the world, especially in North America. However, the overall recovery of these oil and gas resources is very low and hence, production enhancement is inevitable. This study investigated the acidizing of propped fractures as a recovery enhancement method in Eagle Ford shale samples. Experiments were designed using sample slabs having proppants between them. Differing parameters were examined to optimize the fracture conductivity through acidizing. For a range of confining pressures, the fracture conductivity was maximized by minimizing the proppant embedment. …


Effect Of Biochar On Desiccation Of Marine Soils Under Constant And Cyclic Temperatures, Thellen Kumar Puspanathan, Vihan Shenal Jayawardane, Suvash Chandra Paul, Kong Sih Ying, Sanjay Kumar Shukla, Vivi Anggraini Jun 2022

Effect Of Biochar On Desiccation Of Marine Soils Under Constant And Cyclic Temperatures, Thellen Kumar Puspanathan, Vihan Shenal Jayawardane, Suvash Chandra Paul, Kong Sih Ying, Sanjay Kumar Shukla, Vivi Anggraini

Research outputs 2022 to 2026

Biochar has recently been gaining increasing attention as a stable and sustainable soil amendment material. However, the effect of biochar amendment on the desiccation behaviour of coastal soils has not yet been examined. Consequently, the present study primarily investigated the effect of exposing biochar-amended marine soil (BAS) to constant and cyclic temperatures on its swell–shrink, evaporation and desiccation cracking characteristics. Biochar contents of 1%, 2%, 4% and particle size ranges of PS-1 (600 μm < D ≤ 2000 μm), PS-2 (300 μm < D ≤ 600 μm), PS-3 (D ≤ 75 μm) (D: biochar particle diameter) were employed. It was revealed that the absolute volumetric shrinkage of both unamended and biochar-amended specimens increased as the number of thermal cycles increased. Under continuous heat exposure, 4% (PS-3) BAS in compacted state achieved the maximum reduction in volumetric shrinkage which was 42%. Moreover, under continuous heat exposure, 2% (PS-1) BAS in slurry state achieved the highest reduction in desiccation cracking, which was 73%. The present study highlights the importance of identifying the most effective combination of biochar content and particle size required to achieve a desired outcome, in order to gain the maximum benefit of biochar as an amendment material at the lowest possible cost.