Sensitivity of the stability assessment of a deep excavation to the material characterisations and analysis methods

Ghadrdan, Mohsen; Shaghaghi, Tahereh; Tolooiyan, Ali

doi:10.1007/s40948-020-00186-6

Cited by 16 publications

(6 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, slope stability dominates in mine reclamation, becoming the critical factor in decision-making processes (Kasmer et al 2006;Poulsen et al 2014;Sharma and Roy 2015;Steiakakis et al 2009). Thus, an in-depth evaluation of the soil properties is necessary for a stability study due to the analysis's sensitivity on material characterisation (Ghadrdan et al 2020).…”

Section: Introductionmentioning

confidence: 99%

Α comprehensive geotechnical characterisation of overburden material from lignite mine excavations

Theocharis

Zevgolis

Koukouzas

2021

Geomech. Geophys. Geo-energ. Geo-resour.

View full text Add to dashboard Cite

For the sustainability of lignite and coal mining, engineers need the soils' appropriate geotechnical characterisation of the excavations. This characterisation relates to the slope stability, the overall area stability, and the sustainable exploitation of mining areas during operational and post-closure eras. This work presents a novel perspective on the soil characterisation of lignite mine excavations. Rather than focusing on one particular mine, a comprehensive geotechnical characterisation provides insights about the soils of related mining areas. Additionally, slope stability representative cases guide soil characterisation and analysis rather than following it. The Greek lignite mines are used as a representative example for the illustration of this framework. Initially, the two typical slope stability scenarios for Greek lignite mines are established: a slope in the presence of a weak zone and a homogeneous slope. The crucial geotechnical parameters are then statistically examined based on an extensive database established from laboratory results of various mines. Focus is on shear strength (friction angle and cohesion), the key to slope stability, and physical properties that can provide the strength through empirical correlations. Many soil layers exhibit a low residual friction angle from 5° to 15°, corresponding to the weak zone. Peak friction angle presents a mean value of 28.4°, and a characteristic value of 25.0°; cohesion presents a wide range with a mean value of 111kPa and a characteristic value of 84kPa. Finally, cross-correlations between geotechnical parameters present large scatter, but relations for estimating the residual and the peak friction angle reveal general trends. Article highlights• Lignite mines' geotechnical properties are statistically analysed based on laboratory tests' extensive database from various Greek mines.• Typical stratigraphy scenarios are established and guide the mines' geotechnical characterisation.• A weak zone of low residual strength can be observed that would dominate the mines' slope stability.

show abstract

Section: Introductionmentioning

confidence: 99%

Α comprehensive geotechnical characterisation of overburden material from lignite mine excavations

Theocharis

Zevgolis

Koukouzas

2021

Geomech. Geophys. Geo-energ. Geo-resour.

View full text Add to dashboard Cite

show abstract

“…Sections 3.5 and 3.6 verify the rationality of the model test results, according to the numerical simulation. Among them, the strength reduction method is adopted to calculate the stability of the h-type double-row piles support system, which has smaller limitations than the traditional limit equilibrium method [45] and is more convenient for calculation. According to the change of safety factor in the two stages of excavation, it can be seen that the overall stability and safety of deep excavation decrease with the increase of excavation depth.…”

Section: Discussionmentioning

confidence: 99%

Experimental Investigation of h-Type Supporting System for Excavation beneath Existing Underground Space

Yang

Wang

et al. 2022

Buildings

View full text Add to dashboard Cite

A double-row pile support system combined with existing and additional support piles offers an effective solution for further excavation beneath existing underground space. A large-scale test chamber was therefore built to simulate the whole construction process of underground space extension. Several parallel tests are conducted through observation, data monitoring, and analysis to study the influence of several parameters on an h-type support system containing double-row piles. The relevant parameters include pile row spacing, pile length ratio, pile-head constraint, and in-service foundation pile. The tests reveal that a significant load-transfer effect is generated between the pile rows, and increasing the spacing between pile rows within a certain range can lead to a more reasonable distribution of bending moments and pile force. The displacement of the pile top and its rate of increase are directly proportional to excavation depth, and additional excavation to the bottom of the back-row piles tends to be a critical point, after which the deformation will be significant. The stability of the system varies inversely with the reduction in pile length ratio, but is positively related to the existing pile-head constraint. Furthermore, in-service foundation piles can result in increased bending moments and reduced displacement of the pile top. Finally, the rationality of the model test results was verified according to the numerical simulation and the stability of the double-row piles support system was calculated.

show abstract

“…The immense shear strains developed on this thin zone during ground movements often lead its strength to its residual state, dominating the failure mech anism. This mechanism is frequently encountered in surface coal and lignite mines in several countries: Greece (Leonardos 2004), Turkey (Ural & Yuksel 2004), Poland , the Czech Republic (Mencl 1977), and Australia (Ghadrdan et al 2020). In addition to mining excavations, such a mechanism is also encountered in various landslide phenomena.…”

Section: Introductionmentioning

confidence: 98%

The Evolution of Geotech - 25 Years of Innovation

Hammah¹,

Yacoub²,

McQuillan³

et al. 2021

View full text Add to dashboard Cite

I have been teaching and researching rock engineering and practicing as a consultant since 1972. I have spent most of that time in underground mining. I have seen significant changes, both evolutionary and radical, in the sector. In this paper, I reflect on some of these changes in mining geomechanical practice. I will also comment on some of the positive and occasionally less positive impacts of these changes. One constant throughout my career is that geomechanical designs will always be fraught with uncertainty. As a result, we will discuss geomechanical design as being, in its essence, a risk management exercise. I will argue that, as impressive as modern numerical analysis techniques are, they do not on their own mitigate design risk; under worst-case scenarios, they make things worse. Empirical and simple models must be used as a check. The paper intends to provoke healthy skepticism in geomechanics practitioners, designers and managers regarding all the aspects of the geomechanical analysis and design process. A failure to recognize the risks in these processes can have catastrophic effects.

show abstract

Sensitivity of the stability assessment of a deep excavation to the material characterisations and analysis methods

Cited by 16 publications

References 40 publications

Α comprehensive geotechnical characterisation of overburden material from lignite mine excavations

Α comprehensive geotechnical characterisation of overburden material from lignite mine excavations

Experimental Investigation of h-Type Supporting System for Excavation beneath Existing Underground Space

The Evolution of Geotech - 25 Years of Innovation

Contact Info

Product

Resources

About