Geotextile Containers Research Articles

Geotextile containers in hydraulic applications

This paper will give an introduction in geotextile containers, covering typical sizes and the materials used. A case study of a typical application highlights the advantages of geotextile tubes, which are a subcategory of geotextile containers, and explains their installation in challenging conditions.

Improvement of design parameters of geotextile containers made of polypropylene for removal of silt layers and industrial waste

The article deals with the issues of improving the design parameters of geotextile containers made of polypropylene for the removal of silt layers and industrial waste as exemplified by the Krasnodar reservoir. The article presents statistics of waste accumulation in the Russian Federation in recent years. A new technology for transportation and disposal of liquid waste is proposed. The calculation of the parameters of geotextile containers made of high-strength fabric materials based on polypropylene has been developed. The development of chemical industry has allowed us to offer a new cost-effective innovative technology of dewatering and waste disposal based on the use of geotextile containers made of high-strength fabric material. In the Russian Federation, more than 3.5 billion tons of waste are accumulated annually, the amount of which increases with the growth of economic activity. Of the waste produced in 2020, 47% was placed at the enterprises’ own facilities, and 19% was buried. In order to improve the state of the environment, it is necessary to improve waste storage and disposal technologies. The use of geotextile containers made of high-strength fabric materials for dewatering and waste disposal is the most environmentally and cost-effective technology that has no restrictions and contraindications for technical equipment and has all the necessary indicators of strength, rigidity and reliability for effective use.

Application of geotextile containers for removal of silt layers of the Krasnodar reservoir

The article deals with the issues of improving the methods of removing silt layers of the Krasnodar reservoir using geotextile containers. The new technology exceeds all the characteristics of the dewatering facilities available in Russia. The necessary stage of preparation of wastes for disposal is dewatering to a humidity of 50-60%, which allows you to reduce their volume tenfold and improve the structure of raw materials. For these purposes, Russia has quite a lot of different structures and a large number of sludge dewatering methods. For the construction of sludge dewatering facilities and various types of precipitation of sewage, much less time and economic costs are required than for the construction of mechanical cleaning facilities. Also, new technologies occupy quite a little free land area compared to silt sites and they do not depend on climatic factors because atmospheric precipitation falling on the container drains from its surface. The impact of negative temperatures provides the deep moisture drainage after thawing of organogenic silts and hydroxide slimes. Also, new technologies occupy. Geotextile container technology is ideal for silt maps cleaning, sludge storage facilities and reservoirs, for temporary storage of dewatered sludge on a site, and, most importantly, for disposal of wastes directly at the dewatering site in the form of a highly loaded landfill that is resistant to wind and water erosion. When reducing the area of silt maps, the containers can be used as an emergency reserve, since their guaranteed storage period is 25 years. The main principle of the technology is to provide the sludge into the container through a pulp pipeline and then wait for the free water to drain. When dewatering granular suspensions (from sand to dense slimes), the container is filled with natural pulp. When fine silts and hydroxide slimes are dewatered, a flocculant is added to the pulp. After the initial filling of the container with pulp, its subsequent pumping is carried out from 1 to 5 times, after which the process of consolidation of the dehydrated material to the limit of free water release occurs, the duration of which depends on the properties of the solid phase. The main thing is that waiting does not consume any resources, except for the area provided for containers. After consolidation, a loose or refractory material is formed, the size of which depends on the size of the geotextile container used.

Uni and bi-directional dewatering behaviour of open geotextile containers used for filtration of waste slurries

The simultaneous analysis of filtration mechanisms under vertical, horizontal, and bi-directional flow conditions has not yet been clarified for geotextile-dewatering involving different grain-sized slurries, therefore it is still not obvious which condition is dominant as particle sizes vary. In this paper, the differences associated to horizontal versus vertical filtration are investigated based on solids retention and effluent volume through the geotextiles. Three geotextile materials (two woven and a nonwoven) are separately employed for the filtration of three slurries with d50 ranging from 55 μm to 410 μm using an open dewatering unit. To facilitate the formation of a permeable filter cake on the inside of the geotextile surface, a range of particles with grain size distribution indicating internal stability was chosen for the slurries. The geotextile/slurry combinations targeted possible unfavorable retention conditions wherein only the particles of approximately the same size as the largest opening size of the filter could be retained (O90/d85≥ 1.0). A probabilistic model based on the geotextile pore size distribution curve and number of constrictions is added to the laboratory investigation to assess the geotextile retention reliability and confirms that for most cases slurry particles of all sizes can pass through the filters. Nonetheless, filtration efficiencies greater than 90% and control of particle loss are reached relatively fast for almost all experiments. In other words, it is a range of particles retained at the beginning of filtration tests that stimulates filter cake formation and governs further retention.

Geobag stability for riverbank erosion protection structures: Numerical model study

Flexible, sand-filled, geotextile bags (geobags) have been used in both India and Bangladesh along the banks of the Brahmaputra for protection against riverbank erosion. Geotextile containers have been researched extensively for their use in coastal structures; however, there is a gap in knowledge of the application of smaller geobags used in riverbank protection structures. In 2018, flume experiments (scaled 1:7) were performed to study the incipient motion of geobags and the methodology for sizing geobags. Building on the data collected from the flume experiments, numerical models have been employed to gain further insight into the hydraulic forces acting on the bags. The numerical models have been created using ANSYS CFX. While there is not enough data to obtain a Shields parameter which can be used for design purposes, initial estimates find the Shields value for geobags lies around 0.09, which is much larger than the value for rocks, around 0.045. The results from this study suggest that the Shields parameter varies with fill percentage of the bags. This paper also presents first results on the roughness of underwater geobag aprons.

LAND USE AND MITIGATION EFFECTS ON BARRIER BEACH EROSION IN STORMS: CASE STUDY IN RHODE ISLAND

Sea Level Rise (SLR) and storm intensification lead to re-evaluating inundation assessments along the North Atlantic US shoreline. A particular effort is devoted to assessing coastal community risk to “100-year storm” events in Rhode Island, US, using a chain of state-of-the-art storm surge, wave propagation, and coastal erosion 2D models. Damage risks imposed on infrastructures and services incited US federal and state agencies to come up with innovative engineering solutions to improve coastal resiliency while preserving natural coastal and marine environments. This study critically evaluates available design tools used to assess the performance of two types of Natural and Natural Based Features (NNBFs) for coastal protection: natural vegetated barrier islands and dunes reinforced with Geotextile Sand-filled Containers (GSCs), on urbanized barrier islands. Comparative analyses with field data identifies the capabilities and limitations of phase averaging and phase resolving hydro-morphodynamic models used for simulating bed level changes in dissipative beaches, during 3 Sallenger storm regimes. Recommendations are provided on modeling approaches for simulating effects of vegetation and using GSCs to limit coastal erosion.

Impacts of a geotextile container dune core on marine turtle nesting in Juno Beach, Florida, United States

Hard armoring technologies (e.g. rock revetments and seawalls), which are installed to protect homes from beach erosion, can diminish the aesthetics and amenity of the beach. Over time, these structures cause beach narrowing and often prevent marine turtle access to nesting habitat altogether. An alternative armoring technology, known as geotextile dune core systems (or geocores), has been developed and implemented to protect inland infrastructure from beach erosion, yet there remains an absence of research on possible effects on marine turtles. In this study, we examined the impacts of a geocore installed on Juno Beach, Florida, United States in February 2014 on loggerhead (Caretta caretta) and green turtle (Chelonia mydas) nesting success, hatching success, and emergence success. A before‐after‐control‐impact paired series design evaluated the difference in nesting success per week for the impact and control sites 4 years before (2010–2013) and 4 years after (2014–2017) the installation of the geocore. Neither loggerhead nor green turtle nesting success was significantly different after the installation of the geocore; however, when analyzing loggerhead crawls that came to within 5 m of the geotextile bags, nesting success decreased. Neither hatching nor emergence success was significantly different after the installation of the geocore for either species. Our results suggest that geocores may minimally affect loggerhead and green turtles and provide a suitable restoration technique for homeowners facing beach erosion.

Case study of application geotextile tube in the construction of sea dike and shore protection

Recently, because of the shortage of natural rock, traditional forms of the river and coastal structures have become very expensive to build and maintain. Therefore, the materials used in hydraulic and coastal structures are changing from the traditional rubble and concrete systems to the cheaper materials and systems. One of these alternatives employs geotextile tube technology in the construction of coastal and shore protection structures, such as embankment, groins, jetties, detached breakwaters and so on. Geotextile tube technology has changed from being an alternative construction technique and, in fact, has advanced to become the most effective solution of choice. Erosion problems in coastal zones are become increasingly serious due to the development of artificial activities related to the expansion of city functions, industrial complexes and harbour facilities, as well as the removal of sea sand for use in This erosion motion accelerates the regression of the coastal cliff due to the regression of the dunes or the shoreline. In addition, the regression leads to loss of real estate in the hinterland and ruins the shock-absorbing zone between land, and sea. Therefore, the destruction of the dunes may lead to a loss of the habitat or egg-laying grounds of living creatures. In addition, the erosion motion of coastal beach zones destroys the living sites of inhabitants who live in coastal beach zones, and the erosion problem harms the local economy by decreasing the number of visitors. The sea dikes can be easily damaged by the attack of seismic sea wave (Tsunami) due to massive earthquake like the Great East Japan Earthquake in 2011. For these reasons, concern is increasing for the protection of coastal line. Many nations are striving to prevent damage to such zones, as are private organizations and local self-governments. One such preventive effort is beach nourishment or construction of the coast structures. Geotextile containment such as small sandbag has been adopted for the construction of civil structures in the past, large volume geotextile containers are being applied widely in consideration of economical and easy installation, and also for the minimization of environmental effects. Especially, contaminated soil and sediments dredged from port area are utilized to fill in geotextile containment for reclamation. Geotextile containment is widely classified into geotextile bag, geotextile tube, and geotextile containment, and they are filled with soil to be shaped of structure. The filling method is normally hydraulic filling by means of pumping, and also mechanical method can be applied according to the site condition. Thus, Shore erosion is currently causing millions of dollars worth of damage to shorelines and public properties not only along the east coast of Korea but also around the world. Little else needs to be said to emphasize that, without adequate protection, a very significant part of our coastline will fall prey to the ravages of the sea and to man himself.

CASE STUDY: STABILISATION OF A RAPIDLY ERODING POINT USING AN INSITU-FILLED GEOTEXTILE CONTAINER GROYNE FIELD

Munna Point is a premiere recreational beach in the Noosa River which has been maintained by regular nourishment for over 20 years. As longevity of each nourishment was less than 6 months, the long-term costs were high and efforts were eventually suspended resulting in loss of the beach. In an effort to reinstate the amenity and provide a more stable beach, a groyne field accompanied by nourishment was proposed. To provide a low-impact, low-risk and low-cost solution, the groynes were designed with a low crest using sand-filled geotextile containers. To achieve the design, containers and scour mattresses were filled in-situ using a dredge, which was an innovative application of a methodology typically adopted for much larger containers. The first 3 groynes have successfully been installed as part of the first stage and 12 months of monitoring subsequently undertaken. The groynes have clearly been effective at extending the longevity of the nourishment and the wider intertidal profile has remained very stable. The beach is now successfully enhancing the amenity of the community and experiencing a high level of usage.

Comparative study on the behavior of soil fills on rigid acrylic and flexible geotextile containers

Comparative study has been performed to investigate the behavior of dredged fills on rigid (Model 1) and flexible (Model 2) containers. The study was focused on the sedimentation of soil fills and the development of total stresses. Model 1 is made of an acrylic cylinder and Model two is a scale-size geotextile tube. Results indicate that for rigid containers, significant decrease of the sediment height is apparent during the dewatering process. On the other hand, because the geotextile is permeable, the water is gradually dissipated during the filling process on flexible containers. Hence, significant loss in the tube height is not apparent during the duration of the test. Pressure spikes are apparent on rigid containers during the filling process which can be attributed to the confining effect due to hydrostatic pressure. For the flexible containers, the pressure readings gradually increases with time during the filling process and normalize at the end on the filling stage. No pressure spikes were apparent due to the gradual dissipation of pore water pressure.

Laboratory Investigations for Dewatering of Golden Horn Dredged Sludge with Geotextile Tubes

In this study, an effective means of dewatering the dredged material obtained from the sea-bottom in Istanbul is investigated through the use of additives and geotextile tubes (also known as geotubes, geotextile containers, and geotextile bags). Rapid dewatering test and geotube dewatering test are laboratory approaches, where the types and amounts of anionic and cationic additives for dewatering efficiency of dredged sludge can quickly and economically be examined. In this study, a best dosage amount of 1.5 kg/tonne was used as flocculant solution preparation with distilled water. After this process, twelve homogeneous sludge-polymer admixtures were prepared by adding 0.1, 0.5, and 1.0% polymers (anionic and cationic) by weight of the dredged material in rapid dewatering tests and another twelve homogeneous sludge-polymer admixtures were prepared by adding 0.1, 0.25, and 0.50% polymers (anionic and cationic) by weight of the dredged material in geotube dewatering tests. The results indicated that Golden Horn dredged sludge could be successfully dewatered and retained by geotextile tubes. The use of chemical cationic polymers is recommended with Golden Horn dredged sludge rather than the anionic polymers. Results also showed that use of flocculants can significantly increase the retention capacity of geotubes.

Optimization of Production Parameters of Geotextiles Used for Shoreline Protection

The use of geotextile sand containers (GSCs) in shoreline protection systems has moderately grown since the first applications in the 1970s and increasingly used as an alternative to natural stone, slag, and concrete. Due to their economical, technical and ecological advantages, the use of geotextiles and geocomposites for filter and drainage functions is increasing worldwide and has a 40 year history already. For coastal protection measures, nonwovens are proven to have long-term resistance against ultraviolet radiation and saltwater. High elongation behavior provides superior properties during loading in coastal protection means, which is determined as being the biggest risk for damaging geotextiles. Such applications require certain functional characteristics in the geotextiles, besides their basic properties, which are required to be engineered by the judicious optimization of the needlepunching process. In this study, the effect of the process parameters including punch density and depth of needle penetration has been investigated on the mechanical (tensile strengths in the machine and cross-machine directions) properties of needlepunched nonwoven geotextiles. These process parameters are then empirically related to the fabric properties by using a multiple regression technique.

Проектирование параметров геотекстильных контейнеров для обезвоживания донных отложений

This article describes an efficient method of clearing of small rivers in the dense housing floodplain. Presents disadvantages tive-rate documentation on the design of flexible containers. Developm HN dependence of the parameters of geotextile containers dehydrating-of sediment for practical design and monitoring.

Эмпирические зависимости для определения параметров геотекстильных контейнеров

Empirical dependences for determination of parameters
 of flexible geotextile containers from high-strength polypropylene
 fabrics are received when moving commensurable with sizes of a
 design and relative deformations of a material to 20%.

Инженерные зависимости для определения параметров геотекстильных контейнеров

The problem of the dehydration of the deposit formed in
 the course of sewage treatment is considered. The new foreign technology
 of the dehydration of suspensions in geotextile containers is
 offered. The main principle of the work of new technology is described.
 The divergence in a percentage parity between full elliptic
 integrals taken under the table and integrals calculated on expressions
 is shown.

Основы расчета геотекстильных контейнеров из тканевых материалов высокой прочности

The problem of processing, warehousing and a burial place
 of a various kind of a waste is considered. The analysis of the reasons
 of occurrence of degradation of the small rivers and its consequence
 has been made. The new economic innovative technology of dehydration
 and a burial place of a waste on the basis of containers from
 textile material is offered. Methods of calculation of geotextile containers
 are developed.

LONG TERM PERFORMANCE OF A SUBMERGED COASTAL CONTROL STRUCTURE: A CASE STUDY OF THE NARROWNECK MULTI-FUNCTIONAL ARTIFICIAL REEF

In response to the increasing occurrences of beach erosion along Surfers Paradise and Main Beaches - Gold Coast, Australia, the Northern Gold Coast Beach Protection Strategy [NGCBPS] was developed to widen the beach by 20-30m as well as improving surfing conditions as a secondary objective. The strategy, implemented in 1999- 2000, involved large-scale beach nourishment and construction of a submerged breakwater "reef† to act as a control point at Narrowneck. Construction of the reef involved innovative filling and placement methods using very large sand filled geotextile containers coupled with significant advances with regards to design of the geotextile material and containers. In the 11 years since construction, there has been substantial monitoring of the project since its completion in late 2000 including: - video imaging using webcams; hydrographic and beach surveys; aerial and oblique photography; surf and surf safety observations and GPS surfing track plots; and geotextile container condition and stability. This paper presents an update on the performance of the reef over the last four years. In particular, the response of the structure and the shoreline to a series of major storm events in 2009 has been examined. The results have shown that the erosion caused by these major events was accommodated within the wider beach created in 1999. Over the next 2 years there was a gradual recovery in the lee of the reef with a subtle groyne effect resulting in an even larger increase in the width of the updrift beach. A detailed underwater condition survey was also undertaken in 2011, to determine changes in the condition of the geotextile containers. This revealed a number of containers missing or damaged, and that seaward containers were covered by sand. The marine habitat which has been a feature of the reef has been impacted by the increased coverage of sand, but still shows high abundance and biodiversity.

Overland Flow Hydrograph Analogy: Filling and Draining a Permeable Bag

AbstractThe mathematics of filling and draining a permeable geotextile bag were developed in a previous investigation of how large geotextile containers can be used to dewater dredged material and mine tailings. The resulting outflow from the draining bag looks remarkably like an overland flow hydrograph. An analog model for overland flow is developed from the draining bag and compared with experimental runoff data obtained in the laboratory for a number of rolled erosion control blankets. The analog model is defined by a dimensionless parameter that includes a permittivity term that characterizes the rate of runoff. A comparison of the analog model with measured runoff is excellent across the entire range of natural and geosynthetic erosion control products investigated.

INVESTIGATIONS ON SCOUR DEVELOPMENT AROUND A GRAVITY FOUNDATION FOR OFFSHORE WIND TURBINES

Due to insufficient insights about the scour development around the STRABAG gravity foundation, the Franzius-Institute conducted small- and large-scale physical model tests in wave flumes on a scale of 1:50 and 1:17 in order to investigate the wave-induced scouring phenomena around the foundation and to design a scour protection system. The tests on scour development without a scour protection system show that the main areas which are vulnerable to scour are the contact areas of the foundation. Furthermore, the experiments show that a scour protection system is necessary for the given and investigated wave boundary conditions; the performance of the selected protection system using geotextile sand containers is verified. Additional numerical simulations indicate an amplification of the resulting flow around the foundation under combined loads (waves and current), but without significant change of the flow pattern

Hydraulic Stability of Submerged GSC structures

Geotextile Sand Containers (GSCs) are used for the construction of coastal structures as a low cost and softer alternative to expensive and hard structures made of concrete or rubble. However, the hydraulic stability of GSC-structures still needs to be investigated for a better understanding of the processes and the parameters of GSCs, which cause the failure. This study focused on the effect of the geotextile material, the sand fill ratio, and the inclination in GSC placement towards the hydraulic stability of submerged GSC structures. Four sets of specifically designed laboratory model experiments were carried out to study the influence of aforementioned parameters on the GSC stability. A new failure mode of GSCs was identified through the model experiments and named as “uplift and drift”. From the test results (wave and damage analysis), new stability curves were developed and compared with each test scenario. The influencing parameters were quantified and the relative importance of each parameter for the hydraulic stability of submerged GSC structures was assessed. Finally, it was concluded that the sand fill ratio is the key influencing parameter among all considered parameters. For the tested sand fill ratios, the hydraulic stability increases, when the sand fill ratio increases. Furthermore, it was concluded that the stability of inclined GSCs is higher than horizontally placed GSCs. However, stability decrement was concluded for GSC made from the woven geotextile material comparative to the nonwoven GSCs. Hence, the type of the geotextile material and the inclination of GSC placement were found to be two important aspects that need to be considered, when designing GSC-structures.