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There are various environmental risks in both the construction and operation phases of huge civil projects such as dam construction. As a result, it is critical to implement appropriate risk control and risk mitigation measures before the initiation of the activities posed by these schemes. The goal of this research is to identify and categorize the environmental risks posed by the Amirkabir Dam during its construction and operation phases. After identifying the risks, the risk factors were prioritized using the FMEA method, with the risks being ranked according to their severity, probability of occurrence, and ability to detect. The study’s findings revealed that the highest risk in the dam construction stage is associated with road construction and vehicle exhaust gases (RPNs of 280 and 252, respectively), and the highest risk in the operation phase is associated with borrow area overuse (erosion and sediment downstream of the dam) (RPN of 280).

In recent years, with the advances in the construction sector monitoring techniques have been extended to be used in geotechnical assets such as slopes, embankments, and retaining walls. The current study analyzed the slope stability problem near the Kyrenia Castel which belongs to the 7thcentury and is located in the northern part of Cyprus. In the current case, the landslide and RC/Stone walls built for rehabilitation purposes were monitored for a period of 2 years. As a conventional analysis method, the Finite Element Method (FEM) was adapted to back analyze the current condition of the site. On the other hand, close-range photogrammetry (CRP) was adopted by using an unmanned aircraft vehicle (UAV) to obtain the required photographs that are necessary to build the dense cloud model and detect the changes in geotechnical assets. The results show that the CRP method confirms the numerical analyses. As a result, this approach can be used vastly in various civil engineering applications, especially geotechnical engineering applications, as it is proven to be fast, cost-effective, and non-destructive when compared to conventional methods.

Plastic pollution is one of the most pressing environmental concerns today. Plastic wastes are usually left unattended and as they resist biodegradation, they pile up in the soil and in the sea environments. Therefore, their recovery and reuse in different applications should be recognized as the best remedial action. This study presents a tangible example of plastic reuse, where a sustainable method is proposed and tested by altering the plastic waste into useful material for soil stabilization. For this purpose, collected waste plastic bags were shredded into strips and they were mixed with clayey soil by 0.2, 0.3, and 0.4% of weight. The effect of adding plastic strips into soil on the mechanical properties of the mixture was then monitored through an experimental survey. Results depicted a meaningful increase in the California bearing ratio (CBR) and unconfined compressive strength (UCS) with increased percentage of plastic strips from 0 to 0.4%. The maximum dry density (MDD) was observed at 0.2% of plastic additions. It was concluded that mixing certain amounts of plastic bag strips to the clay samples could improve the geotechnical properties to a level where the mixture could be used as a subgrade layer while providing a useful reuse option that would potentially reduce plastic piling in the environment.

Liquefaction risk assessment is critical for the safety and economics of structures. As the soil strata of Ramsar area in north Iran is mostly composed of poorly graded clean sand and the ground water table is found at shallow depths, it is highly susceptible to liquefaction. In this study, a series of isotropic and anisotropic consolidated undrained triaxial tests were performed on reconstituted specimens of Ramsar sand to identify the liquefaction potential of the area. The specimens are consolidated isotropically to simulate the level ground condition, and anisotropically to simulate the soil condition on a slope and/or under a structure. The various states of soil behavior are studied by preparing specimens at different initial relative densities and applying different levels of effective stress. The critical state soil mechanics approach for identifying the liquefaction susceptibility is adopted and the observed phenomena are further explained in relation to the micro-mechanical behavior. As only four among the 27 conducted tests did not exhibit liquefactive behavior, Ramsar sand can be qualified as strongly susceptible to liquefaction. Furthermore, it is observed that the pore pressure ratio is a good indication of the liquefaction susceptibility.

Waste disposal is one of the important problems in the world. In general, wastes are categorized into different groups, and there are some special landfills and methods for disposing of each of these waste materials. However, it should be noted that although there are some rules and regulations that try to reduce the impact of waste disposal, landfills have negative effects on soil, air, water, and natural life. One of the most important sources of pollution in landfills is the leachate that is generated by the decomposition of waste. Leachate can penetrate into the soil and water resources, contaminate them, and can affect human life. Leachate generation has five different phases and each of these phases contains some reactions that have a direct impact on the quality and quantity of leachate. Leachate has four main types of pollution and each of these pollutants can contaminate soil and water resources and be hazardous for aquatic and animals in the soil. In addition, some of these contaminations can enter the food chain and affect the ecosystem and human life. The negative impacts of landfills remain even years after the landfill is closed. Therefore, it is important to consider the short-term and long-term effects of landfills on their surroundings to protect the environment and human health.

Nowadays plastic has a major role in our life use, but the increased usage of it led to a serious challenge which is plastic waste. Plastic waste is increasing day by day and which led to many bad disposal methods like burning and due to that there are many environmental and pollution problems. Therefore, there is a need to seek for safe and effective disposal methods to protect our plant and next generations’ future. One of the effective and safe solutions is using plastic waste in civil engineering construction as this solution is eco-friendly where it will provide a safe disposal as well as in engineering there is always a seek for economical materials and as plastic waste is almost for free. In addition, adding these materials may improve the properties of the construction materials. This article reviews all the published trials of using waste plastic bottles fibers as soil improvement material to examine the effectiveness of using this material as a reinforcing material in improving soil properties. As well as to provide a data base of information regarding the best dimensions and percentages. After reviewing the literature, it was found that waste plastic bottles can effectively be used as a reinforcing material and it is an eco-friendly solution. But the best benefit is it really economical as this solution has showed good improvement in soil properties this can reduce the thickness of the pavement in highways construction as well as it provided a good stabilization method rather than the other expensive methods. This material also can solve the problem of time as the other stabilization take much time which delay the construction process. Also, it was found that the addition of (0-5) % with higher aspect ratios give the optimum results.

The goal of this review study is to define the use of ceramic wastes as a raw material in soil structures and the construction of road pavement subgrades. The global output of ceramic waste powder (CWP) produced during the final polishing phase of ceramic tiles exceeds 22 billion tones. The application of (CWP) in landfill sites could create major environmental issues for soil, water and climate. It has been calculated that about 30% of the daily growth in the ceramic industry goes to waste. By trying to reduce this material, we can provide a big benefit of minimizing the use of natural products, decreasing the amount of money used and enhancing land conditions, based on the quantities we can use. Such wastes cannot be processed in any manner and thus create issues with the disposal and loss to the industry. Ceramic waste is strong, durable and resistant to all kind of declining powers, and these properties allow it to be substitute for replacements. Using various quantities of ceramic waste, we will obtain different results and characteristics of soil structures in different California bearing ratios, dry unit weight, unconfined soil density and optimum water content.

Measurement of tensile strength of soil by direct methods can be challenging due to difficulties in sample preparation and in fixing the specimen while applying uniaxial tension forces. However the tensile strength of soil samples can be measured by indirect tests, such as the Brazilian and double punch tests, assuming that tensile stress is distributed uniformly on the failure plane. In this study, the tensile strength of statically-compacted sand bentonite and cement-enhanced sand bentonite mixtures is measured in varying curing time periods using the “double punch” test. The compressive strengths of samples are also measured using the unconfined compression test, and the correlation between tensile and compressive strength is discussed in relation to curing time. A simple method is also applied to determine the undrained cohesion and internal friction angle of samples through the Mohr-Coulomb circle method, using the double punch tensile strength and unconfined compressive strength. The results show that cohesion increases in both sand bentonite and sand bentonite-cement samples along with curing time.

Slope stability analysis and design of manmade slopes has always been a challenging geotechnical problem. Different methods have been developed and created to examine two and three dimensional slope models based on various methods of assumption and assessment. Throughout this study two limit equilibrium, and finite element methods has been used to examine the stability of the slope and to determine the critical slip surface of failure by using PLAXIS, FLAC/Slope and SLOPE/W software programs respectively. Different values of shear strength parameters were chosen to investigate the efficiency of these methods. Various values of unit weight, cohesion, internal friction angle, and their impact on the safety factor were examined. Comparing the results for factor of safety indicated that finite element calculation used in PLAXIS gives more conservative results by 0.5% compared to SLOPE/W program. FLAC/Slope was observed as the most complicated software and finite difference method generally gave the lowest value for factor of safety in comparison with the other methods. Impact of internal friction angle, unit weight, and cohesion on length of failure arc was also evaluated, and no significant relation between length of failure arc (La) and safety factor was detected.

Expansive clays in semi-arid regions are known as problematic soils especially for low weight civil structures. Volume change is a critical issue, therefore determining expansive clays and quantifying their expandability, retractility and strength is a major step to be considered in geotechnical engineering. This research provides a study on the behaviour of expansive clays done under different geotechnical laboratory experiments on four different types of expansive clayey soils brought from various areas in Northern Cyprus, aiming to prepare a soil-properties map in these regions. Fundamental assessments were performed for determining soil index properties. Swell and consolidation behaviours were determined using one-dimensional oedometer apparatus. The results showed that the rate of the expansiveness of sample the bentonitic clay samples were the highest for the predicted ultimate swell with expandability index categorized as very high. Also, these samples showed the largest compressibility upon the consolidation test results. The results obtained were used to construct a relationship between compression and plasticity Index.

This article studies the strength properties of compacted sand-bentonite landfill barrier material with and without cement addition at different periods of aging. Test results indicated that strength values, both in compression and tension, increased up to threefold in cement added samples, as well as enhancing the ductile behavior. Cubic modulus, described as the slope of the elastic portion of the cubic compressive stress versus strain curves, is determined along with initial and flexural moduli, and all the strength and moduli values were correlated with each other. Finally, it is concluded that there is a marked improvement in strength properties and moduli with cement inclusion and that the effect of aging has been very effective.