Investigation of the effect of the different configurations of double-cutoff walls beneath hydraulic structures on uplift forces and exit hydraulic gradients

2020 ◽  
Vol 586 ◽  
pp. 124858 ◽  
Author(s):  
Farzin Salmasi ◽  
Bahram Nourani ◽  
John Abraham
Keyword(s):  
Hydraulic Structures ◽  
Cutoff Walls ◽  
Hydraulic Gradients ◽  
Uplift Forces

Performance of Cutoff Walls Under Hydraulic Structures Against Uplift Pressure and Piping Phenomenon

2014 ◽  
Vol 33 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Abdolreza Moharrami ◽  
Gholam Moradi ◽  
Masoud Hajialilue Bonab ◽  
Javad Katebi ◽  
Gholamreza Moharrami
Keyword(s):  
Hydraulic Structures ◽  
Uplift Pressure ◽  
Cutoff Walls

scholarly journals Mechanism of Steady and Unsteady Piping in Coastal and Hydraulic Structures with a Sloped Face

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1757
Author(s):  
V. Kirca ◽  
R. Kilci
Keyword(s):  
Balance Equation ◽  
Hydraulic Gradient ◽  
Force Balance ◽  
Hydraulic Structures ◽  
Pressure Gradients ◽  
Practical Applications ◽  
Hydraulic Gradients ◽  
Sloping Surface ◽  
Series Of Experiments ◽  
Force Balance Equation

Coastal and hydraulic structures, such as revetments, embankments and levees—as well as their underlying soil—may experience piping when exposed to outward pressure gradients. The aim of the present study is twofold: (1) to derive the force-balance equation for soils with a sloping surface exposed to a steady hydraulic gradient (relevant to hydraulic structures) and to seek a criterion for piping, including the friction terms; (2) to study the case of unsteady hydraulic gradient forcing (relevant to coastal structures) by means of a series of experiments. The derived force-balance equation is compared with the available experimental and numerical model data from the literature and extended to soils protected by a filter/armour layer or rip rap. The experiments conducted to study the mechanism of piping under unsteady hydraulic gradients involved two types of loadings; sudden and oscillatory. The results show that although the mechanism of steady and unsteady piping has some similar aspects, the soil is generally more prone to piping in the unsteady hydraulic loading compared to the steady case, attributed to the inertia terms. The hydraulic conductivity of the soil becomes more distinctive for the unsteady piping case. Finally, remarks are made about practical applications.

METHODS OF FORECAST CALCULATION OF GROUND WATER BACKWATER IN THE ZONE OF HYDRAULIC STRUCTURES INFLUENCE

2020 ◽  
pp. 109-116
Author(s):  
N.P. KARPENKO ◽  
◽  
M.A. SHIRYAEVA
Keyword(s):  
Numerical Model ◽  
Computer Program ◽  
Ground Water ◽  
Programming Language ◽  
Hydraulic Structure ◽  
Hydraulic Structures ◽  
Software Model ◽  
Computational Program ◽  
Specific Object ◽  
Zone Of Influence

The purpose of the work is to consider methods for calculating the forecast of groundwater backwater in the zone of influence of hydraulic structures. The analysis of analytical dependences of calculation of the forecast of groundwater backwater for various calculation schemes is carried out. For a homogeneous scheme of the geofiltration structure, a numerical model is proposed and a computational program for calculating the groundwater backwater is developed. It allows calculating the groundwater backwater from the channel at any time in the discrete mode. To simplify the solution of the problem of calculating the groundwater backwater, a computer program was created in the programming language Phyton Version 8.3 which quickly solves this hydrogeological problem. A possible range of geofiltration parameters is proposed for calculating the groundwater backwater near main channels. The adaptation and implementation of the software model was carried out for a specific object – the Bolshoy Stavropol channel-5, for which forecast calculations were made. The results of predictive calculations of groundwater backwater are the basis for the assessment of areas of possible flooding – the territory within which the level of ground water increases as a result of their backup by a hydraulic structure.

Shape Optimization of Hydraulic Structures: an Example of an Optimum Design of a Fish Passage

10.29007/2k64 ◽  
2018 ◽  
Author(s):  
Pat Prodanovic ◽  
Cedric Goeury ◽  
Fabrice Zaoui ◽  
Riadh Ata ◽  
Jacques Fontaine ◽  
...  
Keyword(s):  
Numerical Model ◽  
Shape Optimization ◽  
Objective Function ◽  
Optimum Design ◽  
Optimization Problem ◽  
A Priori ◽  
Coupled System ◽  
Fish Passage ◽  
Hydraulic Structures ◽  
Design Variables

This paper presents a practical methodology developed for shape optimization studies of hydraulic structures using environmental numerical modelling codes. The methodology starts by defining the optimization problem and identifying relevant problem constraints. Design variables in shape optimization studies are configuration of structures (such as length or spacing of groins, orientation and layout of breakwaters, etc.) whose optimal orientation is not known a priori. The optimization problem is solved numerically by coupling an optimization algorithm to a numerical model. The coupled system is able to define, test and evaluate a multitude of new shapes, which are internally generated and then simulated using a numerical model. The developed methodology is tested using an example of an optimum design of a fish passage, where the design variables are the length and the position of slots. In this paper an objective function is defined where a target is specified and the numerical optimizer is asked to retrieve the target solution. Such a definition of the objective function is used to validate the developed tool chain. This work uses the numerical model TELEMAC- 2Dfrom the TELEMAC-MASCARET suite of numerical solvers for the solution of shallow water equations, coupled with various numerical optimization algorithms available in the literature.

The Effect of Cutoffs on the Uplift Pressure Beneath the Hydraulic Structures Floor

2018 ◽  
Vol 6 (3) ◽  
pp. 20-28
Author(s):  
Faisal Al Tabatabaie ◽  
Dhabia Sabeeh Al Waily
Keyword(s):  
Potential Energy ◽  
Hydraulic Structure ◽  
Hydraulic Structures ◽  
Outer Face ◽  
Analogue Model ◽  
Electrical Analogue ◽  
Uplift Pressure ◽  
Different Depths ◽  
The Stability ◽  
Critical Sections

The use of cutoffs underneath the hydraulic structures is considered a safe solution to ensure the stability of hydraulic structure against uplift pressure and piping phenomenon in addition to the sliding and overturning forces of the water. These cutoffs are used at critical sections underneath the floor of hydraulic structure to substitute with their depths the horizontal lengths of the creep line of the hydraulic structure base. In this paper, the experimental method- by using electrical analogue model- was carried out to plot the flow net and study the efficiency of the front and rear faces of the cutoffs for dissipating the potential energy of the percolating water underneath the floor of hydraulic structure. An electrical analogue model which was used in this study consists of twenty five models with different depths of upstream and downstream cutoffs. After plotting the flow net for all models, it is concluded that the efficiency of the inner sides are less than that of the outer sides which were investigated before in this topic of this work that both faces reduction values in the uplift pressure are considered the same, where the efficiency of the outer face of upstream cutoff is (70.35) % and for the inner face is (29.64)%, while for the downstream cutoff the efficiency for the outer face is (76.21)% and for the inner face is (23.79)% .

An Investigation of the Quantity, Quality and Sources of Groundwater Seepage into the St. Clair River near Sarnia, Ontario, Canada

1986 ◽  
Vol 21 (3) ◽  
pp. 351-367 ◽  
Author(s):  
Michael Sklash ◽  
Sharon Mason ◽  
Suzanne Scott ◽  
Chris Pugsley
Keyword(s):  
Electrical Conductivity ◽  
River Water ◽  
Organic Contaminants ◽  
Shallow Groundwater ◽  
Seepage Rate ◽  
Groundwater Seepage ◽  
Seepage Meters ◽  
Groundwater Samples ◽  
Hydraulic Gradients ◽  
Unidentified Source

Abstract We used seepage meters and minipiezometers to survey a 100 m by 7 km band of streambed of the St. Clair River near Sarnia, Ontario, Canada, to determine the quantity, quality, and sources of groundwater seepage into the river. The average observed seepage rate, 1.4 x 10−8 m3/s/m2, suggests higher than expected hydraulic conductivities and/or hydraulic gradients in the streambed. We found detectable levels of some organic contaminants in streambed groundwater samples from 1.0 and 1.5 m depths, however , concentrations did not exceed drinking water guidelines. Our isotopic and electrical conductivity data indicate that: (l) the streambed groundwater is not just river water, (2) groundwater from the “freshwater aquifer” at the base of the overburden Is not a significant component of the streambed groundwater, (3) some of the streambed groundwater is partially derived from a shallow groundwater flow system, and (4) an unidentified source of water with low tritium, river water-like δ18O, and very high electrical conductivity, contributes to the streambed groundwater.

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