Conference Agenda

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This article presents an overview of climate change research, predictions of global sea level rise, the increasing effects on coastal and riverine areas all over the world and furthermore an extensive overview of geosynthetic applications for flood defenses and coastal protection. Sea level rise, an important consequence of climate change, will lead undeniably to increasing problems concerning the safety against flooding and major challenges in design and construc-tion of embankments. Where coastal and riverine areas are highly populated or have high eco-nomic value (business areas/industrial sites), flood protection schemes will require increasing efforts and capital investments. For climate adaption of flood defenses the application of geo-synthetics can be of major importance. Building with geosynthetics is highly sustainable and enables the use of local less suitable soils. This results in reducing the use of primary granular building material, limiting transport distances and most importantly: decreasing substantial CO2 emission. Other distinctive aspects are: increasing construction speed, optimized building cost efficiency and reducing the amount of required space. Geosynthetics can be applied to ensure stability (embankments with reinforced soil and geogrids), top soil erosion control (3D structural mats, reinforced grass), coastal protection (sand-filled elements with bags, tubes or containers), controlling water level differences (drainage mats) or sealing dikes (Geosynthetic Clay Liners - GCL). Implementing geosynthetics to meet one of these various functions to dikes or coastal protection can give a considerable boost to the ambitions of global flood pro-tection programs. For the big challenge to climate adaption geosynthetics will contribute to adapt safe and resilient living areas for humanity.

According to The Resilience Shift, infrastructure resilience is defined as the ability

to withstand, adapt to changing conditions, and recover positively from shocks and stresses (The Resilience Shift, 2020). Four properties are associated with engineering resilience: (1) Robustness to withstand unforeseen demands; (2) Redundancy to tolerate the loss or damage to a component; (3) Resourcefulness to identify a problem and to respond effectively; and (4) Rapidity to restore functionality quickly. This paper will examine the contribution of a unique enhanced lateral drainage reinforcement geosynthetic (ELDRG) towards the resilience of current and future infrastructure projects, especially roadways and working surfaces. Research summaries will demonstrate how the ELDRG is incorporated in civil projects to provide separation and mechanical stabilization as well as moisture management in saturated and unsaturated conditions. We will also show how to quantify the mechanical and hydraulic benefits of this moisture management system in pavement designs.

<p>For more than 50 years, asphalt reinforcing grids manufactured with polymeric fibres have been used to delay or even prevent the development of reflective cracking in pavement rehabilitation. Their positive performance has contributed to increase maintenance periods and to provide substantial economic and environmental benefits, reducing traffic disruptions and the use of exhaustible resources. This paper will present results of recent researches, which show the importance of some factors and the respective influence in the durability and performance of reinforced asphalt overlays, such as interlayer bonding and grid resistance to installation damage. Through practical experiences will be demonstrated the effect of the asphalt reinforcement on the long-term asset pavement performance. Additionally, a cost comparison and a detailed description of the calculation of CO₂ emissions savings between a reinforced and a not reinforced rehabilitation solution is given.</p>

<p>Adding resilience to flood defense structures is critical to mitigating the impacts of climate change and natural disasters. Integrating engineered erosion control systems with nature-based infrastructure provides an effective solution for hazard mitigation that yields environmental and economic benefits.</p>

<p>This presentation will highlight how Engineered Earth Armoring Systems can be combined with vegetation to provide resilient and long-term flood mitigation. It will also highlight fieldwork from a bank stabilization project on the Des Moines River.</p>

<p>Palo Alto is the 13^th largest agricultural producing county in Iowa, with an estimated $468,000,000 in crops and livestock reported in 2017. The West Fork of the Des Moines River cuts diagonally through the County, providing drainage for approximately 1,800 square miles of farmland. During rain events, the River would often flood this area, causing erosion on an upstream bend, and flood would impact nearby roadways and a historic bridge, resulting in an over 24-mile detour for travelers.</p>

<p>Between 2006 and 2019, flooding events caused severe bank erosion to occur on the river bend. Along roughly 700 linear feet of riverbank, up to 215 ft of horizontal erosion occurred, losing over 3 acres to erosion within this timeframe. If an erosion control solution was not implemented, then the historic bridge and surrounding roadway would continue to be at risk. The Sioux City Natural Resource Conservation Service (NRCS) and Palo Alto County originally considered the use of rock riprap or gabion hard armoring to control the erosion, but ultimately looked for a more cost-effective, nature-based solution.</p>

<p>A combination of the Engineered Earth Armoring Systems was used to stabilize the bank and protect against scour, erosion, and surficial slope instability while promoting vegetation.</p>

<p>In mining, it is common to direct rainwater to the nearest water bodies, seeking to reduce the accumulation and infiltration of water in mining structures. However, little is discussed about the minimization of turbidity in the generated effluent, using downstream dam structures, which stabilise and turbidity reduction of this effluent. In view of the environmental incidents in recent years, environmental agencies are imposing various impediments to the creation of new dam structures. With this, mining has sought other technologies for this purpose in an attempt to solve the problem of fine sediments in water bodies. The turbidity curtains act as filters and deflectors of suspended sediments, favoring the turbidity reduction process. The objective of this study is to carry out an analysis of the performance of two turbidity curtains, installed in a field experiment to investigate the performance of these structures in a place susceptible to high flow peaks, located downstream of a phosphate mine in Alto Paranaíba, MG, between October 21 and March 22, allowing the generation of data to support the design of new structures for future sediment containment.</p>

<p>Due to the environmental concerns, sustainable soil improvement methods are considered an essential part of the modern infrastructure development. Today's environmental sustainability policy often expects noise-free, chemical-free and low-carbon processes, while being economical. In this context, the application of prefabricated vertical drains (PVD) with preloading is considered a sustainable soil improvement Method. However, the presence of some unique hydraulic systems such as the artesian pressure and its effect on geo-structures is rarely discussed in the literature. Furthermore, the effect of the artesian pressure on the PVD’s performance is one of the most important questions that needs to be addressed. For that, a numerical modeling approach is used to study the performance of a well instrumented section of the high-speed line Embankment, over a shallow artesian aquifer in Drader compressible area, Morocco. In addition, a comparison between the performance of PVD-Preloading system with and without the artesian pressure is presented.</p>

<p>The present work aims to treat the behavior of geosynthetic products in saline environment. It has been found that the polymers constituting these products react poorly to sulphate attacks, in particular those causing undesirable modifications of the physicochemical and mechanical properties affecting their behavior and reducing their functional lifespan.</p>

<p>In this work two types of geosynthetic product are studied namely; a geotextile (400/50) polyethylene terephthalate and a geogrid (30/30) polypropylene will be exposed to certain degradation agents present in the sebkha of Oran.</p>

<p>In this study, special attention will be paid to the mechanical behavior of geosynthetic products. In order to reduce the effect of mechanical degradation during the production of geosynthetics and to guarantee their good long-term functioning, a very specific knowledge of the characteristics of the surrounding environment is essential to anticipate the behavior of geosynthetics with respect to each degradation parameter.</p>

<p>Monitoring the degradation evolution of the properties of geosynthetic products over time is the essential tracer of the state of degradation of these products depending on the conditions of use. On the other hand, the interpretation of the mechanical behavior of a geosynthetic product will be dealt with by measuring the variation likely to occur in the chemical parameters after degradation, given that the chemical structure of polymers influences their mechanical properties. To do this, the mechanical behavior in tension (short term) and creep behavior in tension (long term) as an indicator of degradation are studied. In addition, the quantitative of the molar mass as well as the degree of crystallinity is studied experimentally through specific characterization techniques. In addition, the physical characterization is analyzed through the evolution of the thickness of the geosynthetic product.</p>

<p><strong>Key words</strong>: geosynthetic products, degradation, tension, creep, mechanical behavior, saline environment.</p>

<p>In Australia and New Zealand many water storages and service reservoirs were renovated around 20 years ago and were fitted with geomembrane liners and floating covers based on flexible polypropylene (fPP). These fPP materials whether reinforced or not reinforced have suffered greatly from degradation as a result of their exposure to solar radiation and exposure to chlorine compounds in the water.</p>

<p>As a result there is a lot of work occurring to renovate these reservoirs and fit them with new liners and floating cover systems.</p>

<p>These renovations are seeing more and more use of double liner systems for better leakage control. In some cases an existing concrete liner might be utilised and in others the old liner might be sufficiently effective to function as a secondary liner whilst there are other projects where a choice has been made to install a complete new double liner system. Whilst high density polyethylene (HDPE) might be expected to dominate as the liner of choice there other materials being used such as chlorsulphonated polyethylene (CSPE), polyvinyl chloride with elvalloy plasticisers (PVC/Elvalloys), bitumen geoembranes and even coated fabric geomembranes are being considered.</p>

<p>These double liner systems have an underdrain system based on a geonet or geocomposite drainage layer and will often make use of conductive materials such as geotextiles to facillitate electronic leak location surveys. The result is that leakage rates are often very low which is a desirable outcome since these reservoirs are now being encroached upon by urban environments.</p>

<p>For floating covers the materials of choice remain CSPE and PVC/Elvalloys and the paper will discuss a range of comparative testing and practical issues with these materials. There is now a range of fPP materials with much improved formulations to provide much better testing performance compared to their predecessors especially with regard to solar exposure.</p>

In this study, the structural performance of road pavements with reduced layer thicknesses at different rates using geogrids was examined, and the benefits of geogrids in preventing rutting were investigated. Within the scope of the study, a total of 16 test sections of 50 meters in length, 12 with geogrids and four without geogrids, were constructed on the Adana - Kozan road determined by the General Directorate of Highways of Turkey (KGM). The constructed sections were divided into two, and besides the reference sections, two types of geogrids with different geometric structures were used in successive sections. Some layer thicknesses used in the study were determined following the specification, and the other part was determined through a pavement design program. In addition, to compare the effect of using geogrids in different locations on the pavement performance in the application sections, the geogrid was used in two positions, on the subbase layer and between the base layer. Data from the load, displacement and temperature sensors placed between the layers during the construction phase and on-site Heavy Weight Deflectometer (HWD) data at certain time intervals were used to observe the structural performances of the constructed pavement sections. In addition, GPS and IRI measurements are made regularly. The traffic values of the trial section are also monitored. Examining the obtained data aims to compare the economic gain achieved by reducing the layer thicknesses, the cost to be spent for the geogrid, and to make cost-benefit analyses.