Stability of A-Jack concrete block armors protecting the riverbeds

Khalifehei, Kamran; Azizyan, Gholamreza; Shafai-Bajestan, M.; Chau, Kwok Wing

doi:10.1016/j.asej.2020.04.018

Cited by 14 publications

(6 citation statements)

References 32 publications

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“…Earlier studies also ascertained that the characteristics of final products were significantly affected by the organic materials and precarious pollutants that are presented in the sediment such as heavy metals in toxic level, clay particle, and salt, which hampered the cement hydration reactions and delayed as well are reduced the structural strength progress [4] [5]. Different applications of the use of sediment soil such as filling materials, solid partition, in particular blocks, and construction of paving blocks are already been reported in the literature [6] [7] . They obtained the compressive strength of approximately 1-3MPa, 14-17MPa, and 25-34MPa, for adding 47,5% 16% and 14% sediment, respectively.…”

Section: Introductionmentioning

confidence: 99%

The use of Dredged Marine Sediment in the Formulation of Air-foamed Concrete

elmoueden

Mouhamadou

Zambon

et al. 2021

Preprint

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A large quantity of sediments is dredged continuously worldwide. They are generally dumped in landfill areas which ensue in the increasing cost of the dredging operations and in soil-groundwater pollution. The objective of this work is to study the beneficial reuse of dredged sediments in foam mortar and particularly by studying the influence of the substitution of sand by dredged sediments. Air foam mortars/concrtes is an alternative to ordinary concrete, which presents the advantages of lightweight and low thermal conductivity. In this study, the density required ranges from 1200kg/m3 to 1600kg/m3 to the development of foam concrete building blocks and slabs for load-bearing and non-load-bearing structures. Twenty foam mortar mixes were prepared. Sediments were introduced by replacing 15%, 30%, and 50% mass of the sand. The foam percentage was introduced from 0–100% volume of mortar. Workability, compressive strength, and flexural strength at the age of 7, 28, and 60 days were monitored. The size distribution of foam bubbles and the effect of sediments on their stability is also studied. The results demonstrate that sediment has a good general effect on foam concrete and this opens up very promising new types of concretes. However, for a high substitution rate, a decrease in performances is denoted.

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Section: Introductionmentioning

confidence: 99%

The use of Dredged Marine Sediment in the Formulation of Air-foamed Concrete

elmoueden

Mouhamadou

Zambon

et al. 2021

Preprint

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“…Coastal infrastructures such as seawalls and breakwaters are widely employed to safeguard coastlines, people, and properties in nearshore areas, from extreme climatic hazards (Khalifehei et al 2020(Khalifehei et al , 2021Nazarnia et al 2020;Safari Ghaleh et al 2021;Truong et al 2021). With the increased threat of climate change and associated sea-level rise, extreme climatic events such as wave-induced overtopping are expected to be more acute in nearshore areas due to the reduction of crest freeboard of existing sea defences (IPCC 2018;ullivan et al 2020;Salauddin & Pearson 2020).…”

Section: Introductionmentioning

confidence: 99%

Numerical modelling of breaking wave impact loads on a vertical seawall retrofitted with different geometrical configurations of recurve parapets

Ravindar

Sriram

Salauddin

2022

Journal of Water and Climate Change

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Experiments are the traditional techniques used in coastal engineering to study complex wave structure interactions. However, with the advent of high-performance computing, even performing 1:1 scale numerical simulations has become a reality. The progress aids in extending the parametric investigation or repeating the procedure for comparable structures. In this study, a numerical model in OpenFOAM® with waves2Foam wave boundary conditions is used to simulate wave structure interactions at seawalls with varied geometrical configurations of recurved parapets. The numerical model is validated by employing ForschungsZentrum Küste (FZK)'s large-scale (1:1) experiments. The validated model is then applied to the plain parapet and vertical wall to understand better overtopping behaviour, pressure distribution, and structural loads. Numerical modelling is used in this study to visualise and assess intrinsic parameters such as the velocity profile, vorticity, air entrapment, and entrainment better to understand the dissipation characteristics of seawalls with recurved parapets.

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“…Samadi et al [10] and Sylvain and Claire-Eleuthèriane [11] studied the multivariate adaptive regression splines (MARS) approach that has been adopted as a new soft computing tool for estimating the equilibrium scour depth below free overfall spillways. Khalifehei et al [12,13] studies investigated the stability of sediment particles using A-Jack concrete block armors. In this regard, the general forms of the incipient motion and incipient failure of A-Jack armor were extracted based on dimensional analysis and particle stability analysis.…”

Section: Introductionmentioning

confidence: 99%

Performance Assessment of Shockwaves of Chute Spillways in Large Dams

Mousavimehr

Yamini

Kavianpour

2021

Shock and Vibration

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Spillways are the most important structures of large dams that are responsible for releasing the excessive flood discharge from the reservoir. Although many studies have been performed to determine the flow characteristics over these structures, however, the available information on the shockwaves’ characteristics for spillways’ design is limited. The supercritical flow below the chute piers generates an aerated flow known as shockwaves. Due to the flow interaction with the chute piers, three kinds of standing waves just downstream of the pier, in the middle of the chute, and on the sidewalls are generated. This phenomenon affects the flow domain and its hydraulic characteristics along the chute spillway. The height of the waves increases downstream, where they hit the chute walls and reflect again into the flow to interact together again. The process repeated and intensified downstream in a lozenge shape. The height of these waves can be more than twice the depth flow and thus run over the sidewalls. This is important for the design of chute walls in chute spillways with control gates. In this study, the experimental formation of the shockwaves and their behavior along the chute and their reduction measures are presented. Experiments were conducted on a scaled physical model (1/50) of Kheirabad Dam, Water Research Institute, Iran. It was realized that apart from the geometry of piers and chute spillway, Froude number of flow and gate opening are the main effective parameters on the hydraulic performance of shockwaves’ formation and their development on gated spillways.

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Stability of A-Jack concrete block armors protecting the riverbeds

Cited by 14 publications

References 32 publications

The use of Dredged Marine Sediment in the Formulation of Air-foamed Concrete

The use of Dredged Marine Sediment in the Formulation of Air-foamed Concrete

Numerical modelling of breaking wave impact loads on a vertical seawall retrofitted with different geometrical configurations of recurve parapets

Performance Assessment of Shockwaves of Chute Spillways in Large Dams

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