Objectives and Methods

Whereas the behavior of geosynthetics in landfill engineering is well studied and documented since decades, little is known on application in applications such as coastal protection or ballast layers for wind energy plants.  

However, due to the rapid expansion of offshore wind energy, rising water levels and more extreme weather conditions as a result of climate change more and more hydraulic engineering projects will be realized in the future.

Construction with geosynthetics has various advantages, but it has to be ensured that there is no negative environmental impact from the application of geosynthetics in hydraulic engineering. 

It is expected that any effect will be visible only on the long-term. Therefore, accelerated testing is needed to derive requirements for geosynthetics in hydraulic engineering.

Unsuitable attempt to include geoplastic in the coastal protection construction (example of Pionerskiy, Kaliningrad Oblast, Russia)

Examples of using geotextile in coastal protection constructions (Kaliningrad Oblast, Russia)

Main project activities:

1. To investigate the degradation processes of geosynthetics in hydraulic engineering (BAM)

Objectives:

– Artificial accelerated ageing of geosynthetics supplied by European geoplastic companies

– Degradation and ageing enhance by microbiological activity

– Simulation of the exposure in the engineering application

Methods:

– Artificial ageing of geosynthetics in environmental simulation chambers (several climatic exposure test cabinets for testing at elevated temperature levels and continuing UV radiation);

– Mechanical stress can be simulated in upstream classifiers filled with sand and the geosynthetic samples;

– Storage of samples under environmental condition (Kaliningrad Oblast case study) for comparison with laboratory simulation;

– Sample characterization by microscopic methods (e.g. environmental scanning electron microscopy ESEM).

2. Ecotoxicological assessment and estimation of contaminant release will be examined with artificial aged material and materials from samples in field campaigns. Release of chemicals will be investigated with standardized column testing. Aim of the study: Determine acute and a sublethal ecotoxicological effects and modes of action of geosynthetics exposure on model organisms at different trophic levels at different stages of geosynthetics weathering.

Objectives:

– Summarize existing information on ecotoxicity of most common used geosynthetic in Baltic Sea region countries

– Perform acute and chronic toxicological tests with leachates of geosynthetics at different stages of artificial aging using the model organisms: algae Selenastrum capricornutum, crustaceans Daphnia magna, Ceriodaphnia dubia and amphipod Hyalella Azteca

– Characterize leachate toxicity trends in timescale of geosynthetics application process

Methods

– Ecotoxicity tests of leachates from different stages of geosynthetic accelerated aging (made by BAM) on determination of geosynthetics possible ecotoxicity will be performed according to ISO and EPA test standards (ISO 8692:2004 Water quality — Freshwater algal growth inhibition test with unicellular green algae; ISO 6341:2012 Water quality — Determination of the inhibition of the mobility of Daphnia magna Straus (Cladocera, Crustacea) — Acute toxicity test; ISO 20665:2008 Water quality — Determination of chronic toxicity to Ceriodaphnia dubia; ISO 16303:2013 Water quality — Determination of toxicity of fresh water sediments using Hyalella azteca

– Automated column test devices (available in BAM’s laboratories)

– Chemical (organic and inorganic) analysis (ICP-MS, HPLC, etc.)

3. Case study at the Baltic Sea shore at Kaliningrad Oblast (Russia)

Geosynthetic materials became widely used for coastal protection constructions at the Baltic Sea shore of the Kaliningrad Oblast of Russian Federation starting from 2005-2010. Geotextiles of different types are used in the basement of the protection constructions like walls, promenades, gabions walls. Aim of the case study is to analyze degradation, transport of debris particles of used geosynthetic materials inthe environmental conditions of South-Eastern Baltic, and assess the state of pollution of aquatic environment by components/additives of geosynthetic materials from local sources and pan-Baltic transport.

Objectives:

– Overview of existed installations containing geosynthetic materials and monitoring of the state of these materials in natural conditions

– Assessment of degradation rate, link with peculiarities of natural conditions

– Collection of samples from water environment around the installations to find the release of components/additives and their transport

– Assessment of the state of pollution of aquatic environment in Kaliningrad Oblast by components/additives of geosynthetic materials from local sources and pan-Baltic transport

– Numerical simulations of transport in the water considering colononisation and biofouling

In 2015-2016 the cliff shore in resort Svetlogorsk (Kaliningrad Oblast, Russia) suffering fro erosion was covered for protection by a 2-layers coverage  consisting of a geosynthetic drainage covered by a metallic net. Destroyed geocells (from PP, HDPE or PE fibers ) on the slope in Pionersky (Kaliningrad Oblast, Russia). After extremely powerful storm (Storm Herwart , October 27–29, 2017).
Geosynthetics before the placing into the coastal protection construction and after storm induced washing out  of its pieces

4. Geosynthetic particle transport will be modelled numerically – to develop and test parametrizations for transport numerical models to describe the changes of physical properties of geosynthetic debris in the aquatic environment in time due to degradation, mechanical damage and biofouling, to recommend the procedure of calibration of a numerical model with focus on parametrization of transport of geosynthetic particles.

Objectives:

– Analysis of existed data on settling velocities for different types of geosynthetic materials, fulfillment ofsupplementary experiments;

– Development of parametrizations for numerical modelling in Lagrangian and Eulerian approaches;

– Development of a methodology to calibrate the numerical model (with focus on parametrization of transport of debris of geosynthetic particles) against the results of laboratory and field experiments.

Methods

– Collection of data on settling velocities for different types of geosynthetic materials: variety in materials,shapes, state of degradation/ageing, biofouling; fulfillment of supplementary experiments;

– Collection of data on transport of geosynthetic particles (clean, after degradation/ageing and biofouling);

– Numerical simulations by testing of different parametrization.

(photo Esiukova E.E., Chubarenko B.V.)