Seepage Analysis and Optimization of Reservoir Earthen Embankment with Double Textured HDPE Geo-Membrane Barrier (original) (raw)
Related papers
Geomembrane as an Upstream Impermeable Blanket of Embankment Dams - Laboratory and Numerical Study
Soils and Rocks, 2019
The use of geosynthetics has been a common practice in geotechnical engineering when the improvement of local soil characteristics is necessary. This paper presents an experimental and numerical study of the performance of HDPE geomembrane as impermeable blanket installed upstream of embankment dams, a treatment technique for very permeable foundation. Data based on project, field and laboratory tests of the Brazilian Salto Hydroelectric Power Plant were presented to gather information about the constructive method and to support further studies. A small-scale seepage model was constructed to represent the transverse section geometry of a hypothetical embankment dam, whose geometry was adopted based on Salto Hydroelectric Power Plant. Likewise, a numerical model was elaborated referring to the small-scale seepage model to perform several parametric analyses. The obtained results indicated that the geomembrane sealing system acts increasing the flow path through the dam foundation, resulting in lower pore-pressures into the dam. Additionally, the hydraulic parameters in the soil mass may vary considerably in case of damage to the geomembrane. In general, the study has shown that the use of synthetic membranes can be a good solution for treatment of pervious foundations and possible defects can lead to the reduction of their performance.
2015
It is not so common in dam engineering to design and construct earthfill dams with waterproof geomembrane liners instead of using clay cores. Since any dam failure cause catastrophic results and disasters over large areas located on the downstream side of the dams, dam design engineers generally avoid using geomembrane liners wherein any holes on the liners may cause seepage forces within the embankment materials. Therefore, engineers mostly prefer to use with well known traditional materials such as concrete face, clay fill, and asphalt membrane to provide water tightness for embankment dams. However, in recent years, in the World, there is an attempt to use geomembranes on the upstream faces of embankment dams as water barriers. There are recently some small dams with geomembrane water barriers constructed less than 30 meter heights in Turkey and in the World. In this study, for dam design engineers, it is shown that critical slope loading cases for dam slopes with geomembrane liners are different than those for conventional embankment dams with clay cores. So, this study will provide a technical source and a guide for dam engineers by the way of explaining some important criterions to analyze and design the slope of the geomembrane faced embankment dams along with Kızık dam. In addition this study briefly discusses also some other design principles of geomembrane faced dams. Moreover, the study shows how to optimize the outer slopes of geomembrane faced embankment dams in terms of safety and economy.
A comprehensive method for analyzing the effect of geotextile layers on embankment stability
Geotextiles and Geomembranes, 2009
Commercial software is used widely in slope stability analyses of reinforced embankments. Almost all of these programs consider the tensile strength of geotextiles and soil-geotextile interface friction. However, currently available commercial software generally does not consider the drainage function of nonwoven geotextile reinforcement. In this paper, a reinforced channel embankment reinforced by a nonwoven geotextile is analyzed using two methods. The first method only considers the tensile strength and soil-geotextile interface friction. The second method also considers the drainage function. In both cases, the reinforced embankment is modeled in rapid drawdown condition since this is one of the most important conditions with regard to stability of channel embankments. It is shown that for this type of application, modeling a nonwoven geotextile reinforced embankment using commercial software which neglects the drainage function of the geotextile may be unrealistic.
International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE), 2023
Many communities in northern Nigeria are in serious need of supplementary water supply systems to augment the scanty rainfall in the region with a population of majorly farmers who face a lot of hardship due to acute shortage of water in most part of the year. The aim of this study is to provide a well-designed and reliable dam for irrigation water supply. To achieve this aim, this study focused on the analysis of the stability of an earth dam embankment and its seepage, which is very vital for the safety, stability and economic (optimal) design of the dam. The conventional methods of slope stability analysis have major limitations which were addressed by numerical modelling techniques. This study was carried out using some analytical methods and then SLOPE/W and SEEP/W numerical modelling programs. The stability of the embankment slope was also modelled for rapid drawdown conditions based on worst case scenario. The safety factor results show that the embankment is safe from slope failure having a minimum safety factor value of 2.302. A minimum safety factor result of 1.416 was observed after a worst case scenario of rapid drawdown from the maximum anticipated flood water height of 7.6 m to 0 m in 24 hours which is satisfactory. The results of maximum hydraulic velocity and rate of seepage of 4.15E-04 m/sec and 1.27E-04 m3/sec respectively were indication of need for sufficient compaction and careful selection of core material with a very low permeability for adequate design against piping failure.
Strengthening of Reservoir Embankments
2021
This paper is a case study of breach of embankment of 12 lakh m 3 capacity raw water reservoirs, situated in Gujarat, India. Three reservoirs were constructed within a cellulose fibre plant to provide water for the plant and the colony. The embankment of one of these reservoirs along with mid-embankment was breached, resulting in minor losses to the property. The root cause analysis of the reservoir breach has been carried out, and rectification measures have been suggested after a detailed analysis. Slope stability and seepage analysis have been carried out by Geoslope software. All the safety measures were taken care for design, and the same have been implemented at site during execution.
Maritime Technology and Research
One of the common problems of coastal embankments is water seepage. The Senggarang Coastal Embankment (SCE) is examined in the present work, with the objective of proposing the improvement of the earth structure via chemical stabilization. The stabilized soil embankment was simulated and analyzed with PLAXIS 8 to identify a conceptual proposition of solution using a conventional and innovative stabilizer, i.e., lime-ZnO and cement-CSP (cockle shell powder). The base of the embankment was assumed to be bedrock, in order to eliminate the passage of water below the embankment. Stabilization was taken as 100 % for the embankment, i.e., a homogeneous earth structure made entirely of stabilized soil for seepage mitigation. Input parameters for the simulations were acquired from both field samples and past studies. Varying water levels due to tidal effect were applied in the model to determine the changes of pore pressure distribution which could potentially lead to instability of the emba...
3D numerical study of the performance of geosynthetic-reinforced and pile-supported embankments
Soils and Foundations, 2021
Geosynthetic-reinforced and pile-supported (GRPS) systems provide an economic and effective solution for embankments. The load transfer mechanisms are tridimensional ones and depend on the interaction between linked elements, such as piles, soil, and geosynthetics. This paper presents an extensive parametric study using three-dimensional numerical calculations for geosynthetic-reinforced and pile-supported embankments. The numerical analysis is conducted for both cohesive and non-cohesive embankment soils to emphasize the fill soil cohesion effect on the load and settlement efficacy of GRPS embankments. The influence of the embankment height, soft ground elastic modulus, improvement area ratio, geosynthetic tensile stiffness and fill soil properties are also investigated on the arching efficacy, GR membrane efficacy, differential settlement, geosynthetic tension, and settlement reduction performance. The numerical results indicated that the GRPS system shows a good performance for reducing the embankment settlements. The ratio of the embankment height to the pile spacing, subsoil stiffness, and fill soil properties are the most important design parameters to be considered in a GRPS design. The results also suggested that the fill soil cohesion strengthens the soil arching effect, and increases the loading efficacy. However, the soil arching mobilization is not necessarily at the peak state but could be reached at the critical state. Finally, the geosynthetic strains are not uniform along the geosynthetic, and the maximum geosynthetic strain occurs at the pile edge. The geosynthetic deformed shape is a curve that is closer to a circular shape than a parabolic one.