scholarly journals New Experiences in Dike Construction with Soil-Ash Composites and Fine-Grained Dredged Materials

2017 ◽  
Vol 39 (4) ◽  
pp. 17-24 ◽  
Author(s):  
Remigiusz Duszyński ◽  
Angelika Duszyńska ◽  
Stefan Cantré

Abstract The supporting structure inside a coastal dike is often made of dredged non-uniform sand with good compaction properties. Due to the shortage of natural construction material for both coastal and river dikes and the surplus of different processed materials, new experiments were made with sand-ash mixtures and fine-grained dredged materials to replace both dike core and dike cover materials resulting in economical, environmentally friendly and sustainable dikes. Ash from EC Gdańsk and dredged sand from the Vistula river were mixed to form an engineering material used for dike construction. The optimum sand-ash composites were applied at a field test site to build a large-scale research dike. Fine-grained dredged materials from Germany were chosen to be applied in a second full-scale research dike in Rostock. All materials were investigated according to the standards for soil mechanical analysis. This includes basic soil properties, mechanical characteristics, such as grain-size distribution, compaction parameters, compressibility, shear strength, and water permeability. In the field, the infiltration of water into the dike body as well as the erosion resistance of the cover material against overflowing water was determined. Results of both laboratory and field testing are discussed in this paper. In conclusion, the mixing of bottom ash with mineral soil, such as relatively uniform dredged sand, fairly improves the geotechnical parameters of the composite, compared to the constituents. Depending on the composite, the materials may be suitable to build a dike core or an erosion-resistant dike cover.

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 41
Author(s):  
Tim Jurisch ◽  
Stefan Cantré ◽  
Fokke Saathoff

A variety of studies recently proved the applicability of different dried, fine-grained dredged materials as replacement material for erosion-resistant sea dike covers. In Rostock, Germany, a large-scale field experiment was conducted, in which different dredged materials were tested with regard to installation technology, stability, turf development, infiltration, and erosion resistance. The infiltration experiments to study the development of a seepage line in the dike body showed unexpected measurement results. Due to the high complexity of the problem, standard geo-hydraulic models proved to be unable to analyze these results. Therefore, different methods of inverse infiltration modeling were applied, such as the parameter estimation tool (PEST) and the AMALGAM algorithm. In the paper, the two approaches are compared and discussed. A sensitivity analysis proved the presumption of a non-linear model behavior for the infiltration problem and the Eigenvalue ratio indicates that the dike infiltration is an ill-posed problem. Although this complicates the inverse modeling (e.g., termination in local minima), parameter sets close to an optimum were found with both the PEST and the AMALGAM algorithms. Together with the field measurement data, this information supports the rating of the effective material properties of the applied dredged materials used as dike cover material.


2011 ◽  
Vol 250-253 ◽  
pp. 1001-1006 ◽  
Author(s):  
De Zhen Chen ◽  
Cui Jie Geng ◽  
Wen Zhou Sun

Evaluation indexes system has been put forward in this paper for quantifying thesystematical energy consumption, resources consumption, total emissions’ change and waste disposal capacity in road construction with recycled waste materials involved. With help of this evaluation indexes system, the contributions to environmental improvement caused by recycling waste materials in road construction can be quantified through calculating savings on environmental impact potentials, savings on energy consumption, on virgin materials’ consumption and waste disposal capacity provided by road construction. Based on the construction project of a road section numbered No.20 EWK0+400 ~ EWK0+600 of North highway to Shanghai Pudong international airport, which was the first trial project of using several kinds of recycled waste materials including bottom ash from incinerators to replace commonly used materials such as gravel in large scale in road pavement, the results of the four indexes, namely, savings on energy consumption and virgin materials’ consumption, environmental impact potentials as well as waste disposal capacity were obtained. It was found out that with multi recycled waste materials replacing part of the common construction material, systematical energy consumption can be reduced by 30%, a large amount of virgin resource consumption can be avoid and road construction also provides a remarkable large “dumping site” for solid wastes; while at the same time environmental impact potentials were saved for most impact categories except for increase in Ecotoxicity, water chronic, which was caused by heavy metals’ leaching and can be prevented by pre-treatment. Those results are useful for guiding the utilization of recycled waste materials, as well as for developing new technology process and advanced materials in road construction.


Author(s):  
Anne-Katrin GROßE ◽  
Stefan CANTRÉ ◽  
Fokke SAATHOFF

The use of ripened fine-grained organic dredged materials as construction materials, e.g. as top soil on slopes such as landfills or dikes, is an important contribution to environmental engineering science. The materials are legally considered a waste and need to be beneficially re-used. Therefore, not only standard geotechnical parameter shave to be determined but also their erosion resistance which is a particularly critical environmental parameter. There is a variety of different tests to determine the flow dependent erosion resistance of soils, such as the erosion function apparatus (Briaud et al. 2001). In this study, however, the focus lays on the aggregate stability as an indicator for the erosion resistance under static loading, which can be determined using wet sieving and disintegration tests. The disintegration tests after Weißmann (2003) and Endell (RPW 2006) have a similar setup; however, the specific boundary conditions for the tests as well as the evaluation procedures are different. Weißmann proposed his test to determine the erosion stability of dike cover materials while the Endell test should be used for mineral sealing liners in navigation channels. In this study both tests have been used to evaluate the aggregate stability of fine-grained organic dredged materials that have been installed in large-scale research dike facilities and in the recultivation layers of different landfills. The materials showed good visual performance with respect to rainfall induced erosion so far; however, problems in determining erosion and aggregate stability indices limit the value of the studies: both disintegration tests investigated have major limitations with respect to the organic soils tested. Particularly the evaluation methods are not suitable for the soils but also some boundary conditions are critical and are discussed in this paper. The gained knowledge is a valuable basis for the development of standard characterisation methods for dredged materials in environmental and geotechnical applications.


2014 ◽  
Vol 5 (3) ◽  
pp. 93-102 ◽  
Author(s):  
Stefan Cantré ◽  
Fokke Saathoff

In the project DredgDikes with partners from Poland and Germany different dredged materials from the South Baltic Sea region are investigated with respect to their application in dike construction. Two large-scale experimental dikes have been built, one in Germany and one in Poland. Additionally, an extensive laboratory testing programme has been realised and a considerable monitoring test programme will be followed. Based on a short general description of the project this paper covers the issue of installation technology for the dredged materials used and a discussion of geotechnical parameters to be determined for material evaluation and quality control. Due to the high and variable natural water contents of the organic soils together with their inhomogenous composition the compactability is difficult to predict and proctor values may not be reliably determined. During the installation three different compaction technologies were compared and no extreme differences could be found, which is why the compaction with a caterpillar was chosen for efficiency on site. The critical analysis of the data, however, shows slightly better compaction results for the roller compactors. In general the degree of compaction was comparably low. Therefore, different possibilities to improve compaction are discussed in this paper, such as the homogenisation of the dredged material by simple in situ mixing technologies, which will be issues for further research.


2017 ◽  
Vol 68 (10) ◽  
pp. 2367-2372 ◽  
Author(s):  
Ng Hooi Jun ◽  
Mirabela Georgiana Minciuna ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Tan Soo Jin ◽  
Andrei Victor Sandu ◽  
...  

Manufacturing of Portland cement consists of high volume of natural aggregates which depleted rapidly in today construction field. New substitutable material such as bottom ash replace and target for comparable properties with hydraulic or pozzolanic properties as Portland cement. This study investigates the replacement of different sizes of bottom ash into Portland cement by reducing the content of Portland cement and examined the mechanism between bottom ash (BA) and Portland cement. A cement composite developed by 10% replacement with 1, 7, 14, and 28 days of curing and exhibited excellent mechanical strength on day 28 (34.23 MPa) with 63 mm BA. The porous structure of BA results in lower density as the fineness particles size contains high specific surface area and consume high quantity of water. The morphology, mineralogical, and ternary phase analysis showed that pozzolanic reaction of bottom ash does not alter but complements and integrates the cement hydration process which facilitate effectively the potential of bottom ash to act as construction material.


2019 ◽  
Vol 22 (3) ◽  
pp. 365-380 ◽  
Author(s):  
Matthias Olthaar ◽  
Wilfred Dolfsma ◽  
Clemens Lutz ◽  
Florian Noseleit

In a competitive business environment at the Bottom of the Pyramid smallholders supplying global value chains may be thought to be at the whims of downstream large-scale players and local market forces, leaving no room for strategic entrepreneurial behavior. In such a context we test the relationship between the use of strategic resources and firm performance. We adopt the Resource Based Theory and show that seemingly homogenous smallholders deploy resources differently and, consequently, some do outperform others. We argue that the ‘resource-based theory’ results in a more fine-grained understanding of smallholder performance than approaches generally applied in agricultural economics. We develop a mixed-method approach that allows one to pinpoint relevant, industry-specific resources, and allows for empirical identification of the relative contribution of each resource to competitive advantage. The results show that proper use of quality labor, storage facilities, time of selling, and availability of animals are key capabilities.


Author(s):  
Anil S. Baslamisli ◽  
Partha Das ◽  
Hoang-An Le ◽  
Sezer Karaoglu ◽  
Theo Gevers

AbstractIn general, intrinsic image decomposition algorithms interpret shading as one unified component including all photometric effects. As shading transitions are generally smoother than reflectance (albedo) changes, these methods may fail in distinguishing strong photometric effects from reflectance variations. Therefore, in this paper, we propose to decompose the shading component into direct (illumination) and indirect shading (ambient light and shadows) subcomponents. The aim is to distinguish strong photometric effects from reflectance variations. An end-to-end deep convolutional neural network (ShadingNet) is proposed that operates in a fine-to-coarse manner with a specialized fusion and refinement unit exploiting the fine-grained shading model. It is designed to learn specific reflectance cues separated from specific photometric effects to analyze the disentanglement capability. A large-scale dataset of scene-level synthetic images of outdoor natural environments is provided with fine-grained intrinsic image ground-truths. Large scale experiments show that our approach using fine-grained shading decompositions outperforms state-of-the-art algorithms utilizing unified shading on NED, MPI Sintel, GTA V, IIW, MIT Intrinsic Images, 3DRMS and SRD datasets.


2021 ◽  
Vol 13 (16) ◽  
pp. 3065
Author(s):  
Libo Wang ◽  
Rui Li ◽  
Dongzhi Wang ◽  
Chenxi Duan ◽  
Teng Wang ◽  
...  

Semantic segmentation from very fine resolution (VFR) urban scene images plays a significant role in several application scenarios including autonomous driving, land cover classification, urban planning, etc. However, the tremendous details contained in the VFR image, especially the considerable variations in scale and appearance of objects, severely limit the potential of the existing deep learning approaches. Addressing such issues represents a promising research field in the remote sensing community, which paves the way for scene-level landscape pattern analysis and decision making. In this paper, we propose a Bilateral Awareness Network which contains a dependency path and a texture path to fully capture the long-range relationships and fine-grained details in VFR images. Specifically, the dependency path is conducted based on the ResT, a novel Transformer backbone with memory-efficient multi-head self-attention, while the texture path is built on the stacked convolution operation. In addition, using the linear attention mechanism, a feature aggregation module is designed to effectively fuse the dependency features and texture features. Extensive experiments conducted on the three large-scale urban scene image segmentation datasets, i.e., ISPRS Vaihingen dataset, ISPRS Potsdam dataset, and UAVid dataset, demonstrate the effectiveness of our BANet. Specifically, a 64.6% mIoU is achieved on the UAVid dataset.


2014 ◽  
Vol 526 ◽  
pp. 211-216
Author(s):  
Qiong Ying Lv ◽  
Yu Shi Mei ◽  
Xi Jia Tao

As the trend of large-scale wind Power, People pay more attention to wind energy, which as a clean, renewable energy. Traditional unarmed climbing and crane lifting has been unable to meet the requirements of the equipment maintenance. Magnetic climb car can automatically crawl along the wall of the steel tower, the maintenance equipment and personnel can be sent to any height of the tower. The quality of the magnetic wall-climbing car is 550kg, which can carry 1.3 tons load. In this paper completed the magnetic wall-climbing car design and modeling, mechanical analysis in static and dynamic, obtained with the air gap and Magnetic Force curves. The application shows that the magnetic wall-climbing car meets the reliable adsorption, heavy-duty operation, simple operation etc..


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