Soil Treatment & Soil Reinforcement Techniques

Albania is a relatively small country that has recently gone through several transitional phases. As such it has a growing economy and in the last few years infrastructure projects, play an important role, in development. Due to a need for connection corridors in the country as well as internationally, new roads are being opened. The country has a difficult terrain that often can become a hindrance to such projects. This has lead the way to the use of new geotechnical and engineering solutions and technology. The Fier‐Tepelene junction is one of the first projects where new engineering methods were utilized, notwithstanding the fact that this is one of the largest projects in Albania. This will be a study of how slopes were reinforces throughout this road axes and what has been the impact of these technologies in following projects.

Diese Arbeit beschäftigt sich vorrangig mit der Ermittlung von Bemessungsbeiwerten zur Berücksichtigung des Langzeitverhaltens von Holz-Glas-Verbundelementen. Um dieses Thema diskutieren zu können, müssen zu Beginn der Terminus des Kriechens und die diversen dazugehörigen Verhaltensmodelle eines Werkstoffs definiert und erklärt werden. Es wird gezeigt, in welcher Form eine Zunahme der Verformung unter andauernder Belastung sowie eine etwaige Abnahme der Festigkeit als direkte Folge der Verformungszunahme die Bemessung von Klebefugen aus Silikon beeinflusst. Für lastabtragende Silikonverklebungen existiert bis dato lediglich eine Richtlinie, aber keine Norm. Es sind für eine Verklebung dieser Art auch noch keinerlei Bemessungsbeiwerte auf Basis des semiprobalistischen Sicherheitskonzeptes entwickelt und normativ verankert. Dieser Aspekt soll in der vorliegenden Arbeit grundlegend behandelt und ein Vorschlag für mögliche Sicherheitsbeiwerte getroffen werden. Dafür werden zu Beginn ber...

As industrial and agricultural activities intensify and technology rapidly advances, soil pollution has escalated to alarming levels. The increasing contamination of agricultural areas and the crops cultivated therein has emerged as a significant contemporary issue. Phytoremediation, the use of plants to remove pollutants, is a promising method for mitigating soil heavy metal contamination.
This study investigates the bioaccumulation capacity of purslane (Portulaca oleracea L.), a potential phytoremediator, in soils artificially contaminated with cadmium (Cd), nickel (Ni), and copper (Cu). The purslane was cultivated under controlled conditions with varying doses of Cd, Ni, and Cu. After 55 days, the plants were harvested and analysed for heavy metal concentrations in their roots, stems, and leaves. The results demonstrated a direct correlation between environmental heavy metal concentration and plant heavy metal content, with the most significant accumulation occurring in the roots. The leaf chlorophyll content was adversely affected by increased Cd, Ni, and Cu applications. The highest Cu, Ni, and Cd contents were found in the roots at 140 mg kg-1 Cu, 80 mg kg-1 Ni, and 20 mg kg-1 Cd applications, respectively. The bio-transfer coefficient (BTC), a measure of heavy metal transport from the root region to the leaves, was calculated. The BTC values ranged from 0.84-1.09 for Cu, 0.39-0.84 for Ni, and >1 for Cd at the Control and 5 mg Cd kg-1 treatments. These findings suggest that purslane has potential for phytoremediation of heavy metal-contaminated soils, although the bioaccumulation and bio-transfer of heavy metals are dependent on the specific metal and its concentration in the soil. The study also highlights the potential risks associated with the consumption of plants grown in heavy metal-contaminated soils, as heavy metals can accumulate in different plant tissues, potentially entering the food chain.

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Expansive soil is a problematic material for construction due to its high potential for volume change, which can cause damage to road infrastructure. This study aims to investigate the effect of glass fiber and rubber on the properties of expansive soil and its suitability as subgrade reinforcement in road applications. The maximum dry density (MDD), optimum moisture content (OMC), and California Bearing Ratio (CBR) were evaluated for varying percentages of glass fiber and rubber in the soil. The results showed that the addition of glass fiber and rubber had a positive effect on the soil properties. The MDD and CBR increased with increasing fiber and rubber content, while the OMC decreased. Additionally, the reinforced soil exhibited a significant improvement in strength compared to the unreinforced soil. The study suggests that the incorporation of glass fiber and rubber can enhance the performance of expansive soil as subgrade reinforcement in road applications.

In diesem Beitrag wird die innere und äußere Tragwirkung von Sicherungen von Geländesprüngen mittels Stützscheiben bzw. schalenartig wirkenden Tragwerken numerisch untersucht. Solche Lösungsansätze zur Sicherung, z. B. von Baugrubenböschungen, können zum Einsatz kommen, wenn der Einbau von Zugelementen wie Anker oder Nägel, z. B. aufgrund von eingeschränkter Nutzbarkeit von Nachbargrundstücken, nicht möglich oder gewollt ist. Stützscheiben können durch überschnittene Großbohrpfähle, DSV‐Säulen oder Einmischelemente hergestellt werden. Der Nachweis der äußeren Tragfähigkeit erfolgt dabei im Allgemeinen durch ein vereinfachtes analytisches Verfahren, der sog. Palisadentheorie. Ein Nachweis der inneren Tragfähigkeit ist mit analytischen Verfahren praktisch kaum möglich. In den in diesem Beitrag diskutierten numerischen Untersuchungen wird das große Optimierungspotenzial derartiger Tragsysteme in Bezug auf die äußere Tragfähigkeit aufgezeigt, und auf Basis geeigneter Stoffmodelle für Bo...

The development of a Python-based coding tool for soil classification represents a significant stride in geotechnical engineering, merging traditional practices with modern computational efficiency. This research outlines the creation of an automated system that processes soil characteristic data, such as grain-size distribution and Atterberg limits, to classify soils according to the Unified Soil Classification System (USCS). By integrating sieve analysis results and plasticity data, the code discerns between granular and fine-grained soils, and determines their suitability for various construction purposes. This tool not only expedites the classification process but also enhances the reliability of soil assessments, potentially reducing the risk of geotechnical failures. The proposed software stands as a testament to the advancements in digital tools for civil engineering, showcasing the integration of technical knowledge with software solutions to achieve greater accuracy and operational efficiency in soil analysis.

Managed aquifer recharge (MAR) is known to increase available water quantity and to improve water quality. However, its implementation is hindered by the concern of polluting aquifers, which might lead to onerous treatment and regulatory requirements for the source water. These requirements might make MAR unsustainable both economically and energetically. To address these concerns, we tested reactive barriers laid at the bottom of infiltration basins to enhance water quality improvement during soil passage. The goal of the barriers was to (1) provide a range of sorption sites to favor the retention of chemical contaminants and pathogens; (2) favor the development of a sequence of redox states to promote the degradation of the most recalcitrant chemical contaminants; and (3) promote the growth of plants both to reduce clogging, and to supply organic carbon and sorption sites. We summarized our experience to show that the barriers did enhance the removal of organic pollutants of conce...

The presence of expansive soils on construction sites is problematic in geotechnical engineering. The swell-shrink behaviour makes these soils not suitable to be used in their natural state. The expansive soil damages cause financial loss yearly more than floods, hurricanes, tornadoes, and earthquakes combined. Moreover, the cost of cut to spoil of expansive soils during construction projects has continued to rise because of the high cost of earthworks, haulage, and the increasing scarcity of spoil areas because of the built environment. Nonetheless, a proper stabilization technique can significantly enhance the expansive soil's properties. The research project attempts to review, report the limits and merits of mechanical and chemical methods utilized to stabilize expansive soils in line with their efficiency, environmental concerns, and cost-effectiveness. A review of mechanical and chemical treatment techniques is conducted in this regard. Ultimately, each stabilization method exhibits its merits and limitations. The lack of standards for the treatment of swelling soils is a significant problem in engineering practice. Specialists in the domain of soil treatment must work together to obtain an optimized stabilization approach and protocol. Moreover, engineers should perform a geoenvironmental assessment appropriate for chemical stabilization methods and additives utilized. This research work contributes as a guideline in the selection and application of chemical and mechanical stabilization methods.

In projects that involve surcharge and prefabricated vertical drains (PVDs) systems for the treatment of weak underlying layers, embankment failures, tension cracks, and differential settlements, surficial heaves, and foundation failures were addressed in various literature. Overestimation and unrealistic design assumptions made by geotechnical and structural engineers are the main reasons for most of the cases. In all these cases a simple collaboration between different parties in the project ranging from designers to field engineers could have decreased or prevented these undesirable outcomes. The problem of neglecting the infiltration of the embankment in the ground as a new distinct layer with all the necessary requirements, and also disturbance caused as a result of PVDs installation in four cases: preloading case, fill removal, main structure construction, and post-construction phase are discussed. A few design recommendations are given regarding the stated issues. Since after the completion of soil treatment operations, the soil engineering parameters and in some cases even soil stratification had changed, care should be taken to use the new treated parameters in the final design process, not the preliminary site report parameters. Neglecting this issue may lead to severe malfunctions and even unpredictable failures. BIM technology has the possibility of integrating all aspects, and complexities of geotechnical engineering in the structuralarchitectural platform as a whole, which would revolutionize the construction industry. Till now only the structuralarchitectural part is done and further research and investment are necessary for the geotechnical aspect.

In projects that involve surcharge and prefabricated vertical drains (PVDs) systems for the treatment of weak underlying layers, embankment failures, tension cracks, and differential settlements, surficial heaves, and foundation failures were addressed in various literature. Overestimation and unrealistic design assumptions made by geotechnical and structural engineers are the main reasons for most of the cases. In all these cases a simple collaboration between different parties in the project ranging from designers to field engineers could have decreased or prevented these undesirable outcomes. The problem of neglecting the infiltration of the embankment in the ground as a new distinct layer with all the necessary requirements, and also disturbance caused as a result of PVDs installation in four cases: preloading case, fill removal, main structure construction, and post-construction phase are discussed. A few design recommendations are given regarding the stated issues. Since after the completion of soil treatment operations, the soil engineering parameters and in some cases even soil stratification had changed, care should be taken to use the new treated parameters in the final design process, not the preliminary site report parameters. Neglecting this issue may lead to severe malfunctions and even unpredictable failures. BIM technology has the possibility of integrating all aspects, and complexities of geotechnical engineering in the structuralarchitectural platform as a whole, which would revolutionize the construction industry. Till now only the structuralarchitectural part is done and further research and investment are necessary for the geotechnical aspect.

The use of biochar as a soil amendment in agricultural systems and greenhouse experiments has yielded promising results. However, little is known about spoil soil remediation using biochar. Therefore, the effect of the application of biochar from oil palm residues on the remediation of mine waste from open-cast coal mines was examined. Experimental seed germination and root growth of buffelgrass (Cenchrusciliaris L) and Brachiaria (Brachiaria decumbens) on mine waste were examined. Incubation experiments in Petri dishes and pot bioassays demonstrated that the biochar application rate influenced seedling growth and seed germination.

The effect of particle size on shear strength of<br> granular materials are investigated using direct shear tests. Small<br> direct shear test (60 mm by 60 mm by 24 mm deep) were conducted<br> for particles passing the sieves with opening size of 2.36 mm.<br> Meanwhile, particles passing the standard 20 mm sieves were tested<br> using large direct shear test (300 mm by 300 mm by 200 mm deep).<br> The large direct shear tests and the small direct shear tests carried out<br> using the same shearing rate of 0.09 mm/min and similar normal<br> stresses of 100, 200 and 300 kPa. The results show that the peak and<br> residual shear strength increases as particle size increases.

The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) has been detected in water bodies worldwide, precluding their use for water supply. Despite this, scientific studies assessing the behavior of herbicides in water treatment systems are scarce, which motivated this study on 2,4-D removal. 2,4-D removal and its relationship with absorbance were investigated using a pilot system comprising coagulation, sedimentation, filtration, granular activated carbon (GAC) adsorption, and chlorinated disinfection. 2,4-D removal ranged from 15 to 64% after sedimentation, from negative values to 19% after filtration, and from 5 to 16% after chlorination, with total removal rates of 19 to 70%. Breakthrough curves showed an adsorption capacity of 0.70 mg g−1 GAC for a C/C0 ratio of 0.50 and a VTW/VGAC ratio of 3.598 for a breakthrough concentration of 30 ± 3 μg L−1. The positive correlation between absorbance and 2,4-D (R2 = 0.78) in the GAC column effluent indicated that absorbance can be used for e...

Republic of Macedonia is positioned at the crossroads of Corridor 8 (East – West) and Corridor 10 (North–South). The Corridor 10 is the most important communication and transportation route connecting the Hellenic Republic with Austria and further with the rest of Europe. On the section between Veles and Katlanovo revitalizations of 10 bridges has been planned. The project is aiming to upgrade the structural capacity of the bridges as well as the abutments. It is financially supported by NATO as a strategic partner to R. Macedonia. In the past 30 years of exploitation significant settlements and deformations on the road-bridge transition elements had developed. Several unsuccessful attempts using surface improvement techniques have been made. Therefore this time, more comprehensive study has been prepared which considers different techniques, such as: jet grouting, earth reinforcement and end-bearing piles. The final decision regarding the methods used and reconstruction solution ha...

The Iosegun valley is a deep meltwater channel partially infilled with very soft deposits. Twinning of Highway 43 required a new crossing of the Iosegun River and associated valley. The site conditions presented geotechnical challenges for the highway and bridge design that were mitigated with innovative design and construction techniques. Stability and settlement of the 6 m high bridge headslope, and 13 m high approach fill embankment, were the primary concerns. Secondary issues included stability of approach cuts into the valley wall, seepage and erosion control. Mitigative design features included: saddle berms; wick drains; drainage layers; surcharge fills; staged construction; pore pressure, settlement and lateral deflection monitoring; geogrid reinforced bridge headslopes; and bitumen coated bridge piles. The paper provides an overview of the salient geotechnical issues for the investigation; design and construction of the twinning across the Iosegun River valley. A companion ...

In this literature a case study that includes surcharge and prefabricated vertical drains (PVDs) was introduced and verified using finite element program Geostudio 2018R2. Based on the verified model, the lateral displacement and horizontal strains were calculated. It was shown that the safe zone for this special case study is 40 m that is approximately equal to the length of the constructed embankment. In urban areas as a result of the existence of water and wastewater pipes, optical fibers, oil and gas transition lines or trenches and excavations, these infrastructures are in serious danger due to the lateral displacements and horizontal strains. The same case is true for constructions in industrial areas. Since the mentioned infrastructures do have special importance in passive defense doctrine, exclusive attention should be considered by the owners, consultants and contractors in such projects all phases including preliminary investigation, during the construction and after the compilation of the treatment process in the case of permanent embankment. It was shown that due to the obstacles related to surcharge and PVDs treatment, this method is not suitable in urban areas.

This study presents the moisture variations of<br> unbound layers from April 2012 to January 2014 in the Interstate 40<br> (I-40) pavement section in New Mexico. Three moisture probes were<br> installed at different layers inside the pavement which measure the<br> continuous moisture variations of the unbound layers. Data show that<br> the moisture contents of unbound layers are typically constant<br> throughout the day and month unless there is rainfall. Moisture<br> contents of all unbound layers change with rainfall. Change in ground<br> water table may affect the moisture content of unbound layers which<br> has not been investigated in this study. In addition, the Level 3<br> predictions of moisture contents using the Pavement Mechanistic-<br> Empirical (ME) Design software were compared and found quite<br> reasonable. However, results presented in the current study may not<br> be applicable for paveme...

A portion of the proposed location of the Metropolitan Atlanta Rapid Transit Authority (MARTA) Chamblee Station was underlain by uncontrolled fill and soft sandy alluvial soils atop residual Piedmont soils. Due to high groundwater conditions and adjacent railroad tracks, it was not considered viable to excavate and replace these soils. Since this area was to support a Reinforced Earth (TM) wall and the station platform, deep foundations were considered unacceptable due to concerns over differential settlements between the wall, trackway, and platform. The original design called for dewatering, placement of fill, and a surcharge load to preconsolidate the soils. The area was to be monitored with settlement platforms and observation wells that were to be extended as fill was placed. The authors jointly devised a plan to utilize vibrating wire settlement transducers and piezometers to monitor pore pressure dissipation and consolidation. These instruments were used in conjunction with c...

Prosopis species were introduced to the United Arab Emirates (UAE) region for desert greening. However, the species now pose a great threat to the native plant diversity. This study used high-resolution satellite imagery (1990–2019) to understand the history and current distribution of Prosopis species and their impact on fresh groundwater. The results show that the Prosopis invasion in the study area reached its maximum expansion rate in 2019 and covered an area of about 16 km2 compared to 0.2 km2 in 1990. The areas near Sharjah Airport, Umm Fannan, and Al Talla, located at a lower elevation of the sand dune area, are heavily invaded. Prosopis groundwater requirement derived using evapotranspiration shows that groundwater consumption has changed drastically after 2010 and consumed about 22.22 million m3 of groundwater in 2019, which is about a 7372% increase in groundwater consumption from the year 1990 to 2019. The results can be useful for setting up a management plan for the sus...

The effect of particle size on shear strength of<br> granular materials are investigated using direct shear tests. Small<br> direct shear test (60 mm by 60 mm by 24 mm deep) were conducted<br> for particles passing the sieves with opening size of 2.36 mm.<br> Meanwhile, particles passing the standard 20 mm sieves were tested<br> using large direct shear test (300 mm by 300 mm by 200 mm deep).<br> The large direct shear tests and the small direct shear tests carried out<br> using the same shearing rate of 0.09 mm/min and similar normal<br> stresses of 100, 200 and 300 kPa. The results show that the peak and<br> residual shear strength increases as particle size increases.

Republic of Macedonia is positioned at the crossroads of Corridor 8 (East – West) and Corridor 10 (North–South). The Corridor 10 is the most important communication and transportation route connecting the Hellenic Republic with Austria and further with the rest of Europe. On the section between Veles and Katlanovo revitalizations of 10 bridges has been planned. The project is aiming to upgrade the structural capacity of the bridges as well as the abutments. It is financially supported by NATO as a strategic partner to R. Macedonia. In the past 30 years of exploitation significant settlements and deformations on the road-bridge transition elements had developed. Several unsuccessful attempts using surface improvement techniques have been made. Therefore this time, more comprehensive study has been prepared which considers different techniques, such as: jet grouting, earth reinforcement and end-bearing piles. The final decision regarding the methods used and reconstruction solution ha...

A method is presented for the design of steep slopes constructed from low-permeability fill reinforced with draining geogrids. A parametric variation of the drainage characteristics of the fill and the geometry of the steep slope indicates that the vertical spacing and the length of the reinforcement are important design considerations. For typical values of the coefficients of volume compressibility and consolidation in low-permeability fills an optimum vertical spacing of the reinforcement of 0.5 m was determined. At a vertical spacing of 0.5 m a draining geogrid will dissipate pore water pressures, over the full range of likely drainage properties encountered in low-permeability fills, inside 24 hours. Furthermore, at this vertical spacing the required transmissivity of the geogrids is independent of the length of the draining geogrid. Finally it is economically viable to manufacture draining geogrids with the drainage characteristics required to dissipate pore water pressures in...

Der Untergrund mit seinen speziellen Eigenschaften ist für jedes Bauwerk von wesentlicher Bedeutung. Insbesondere wichtig ist eine gute Verdichtung. Verfahren zur Oberflächenverdichtung und entsprechende Geräte wurden in den letzten Jahren stetig verbessert. Die Überprüfung des Verdichtungserfolges gewinnt immer mehr an Bedeutung, jedoch sind die meisten Prüfmethoden immer noch punktuell, weshalb die Ergebnisse mit Unsicherheiten behaftet sind. In dieser Arbeit werden zunächst die theoretischen Grundlagen der Oberflächenverdichtung erörtert und die verschiedenen Anregungsarten der Walzen und ihre Betriebszustände erläutert. Auch werden die momentan eingesetzten Arten der Prüfmethoden des Verdichtungserfolges genannt und kurz beschrieben. Neben den theoretischen Grundlagen sind Feldversuche ein wichtiger Ausgangspunkt und Bestandteil dieser Arbeit. Ausführlich werden die im Frühjahr 2014 in Fischamend durchgeführten Versuche zur Oberflächenverdichtung vorgestellt. Das Versuchskonzept...

In this study, Drilling is a metal removal process and is important for the final fabrication stage prior to application. This paper discusses the influence of cutting parameters on drilling characteristics of metal matrix composites (MMCs)-Al6061/SiC320grit. The composites are fabricated using stir casting method. In order to determine the mechanical properties of the produced composites, hardness and tensile tests were performed. Moreover, the effects of the machining parameters such as cutting speed, feed rate, particle fraction and cutting-tool material, and of their interactions on the thrust force and cutting torque were determined by means of Taguchi experimental design. In addition the drilling parameters were optimized in terms of cutting forces (thrust force and torque). Furthermore, an analysis of variance (ANOVA) was conducted to obtain the degree of the effect of the parameters. Therefore, the most influential control factor for the cutting forces was found to be the pa...