California bearing ratio tests of enzyme-treated sedimentary residual soil show no improvement

Environmental concerns have significantly influenced the construction industry regarding the identification and use of environmentally sustainable construction materials. In this context, enzymes (organic materials) have been introduced recently for ground improvement projects such as pavements and embankments. The present experimental study was carried out in order to evaluate the compressive strength of a sedimentary residual soil treated with three different types of enzymes, as assessed through a California bearing ratio (CBR) test. Controlled untreated and treated soil samples containing four dosages (the recommended dose and two, five and 10 times the recommended dose) were prepared, sealed and cured for four months. Following the curing period, samples were soaked in water for four days before the CBR tests were administered. These tests showed no improvement in the soil is compressive strength; in other words, samples prepared even at higher dosages did not exhibit any improvement. Nuclear magnetic resonance (NMR) spectroscopy tests were carried out on three enzymes in order to study the functional groups present in them. Furthermore, X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) tests were executed for untreated and treated soil samples to determine if any chemical reaction took place between the soil and the enzymes. Neither of the tests (XRD nor FESEM) revealed any change. In fact, the XRD patterns and FESEM images for untreated and treated soil samples were indistinguishable

Stabilization expansive clayey with nano-lime to reduce environmental impact

For years, geotechnical engineers have been concerned about expansive soils. Expansive soils are characterized by large volumetric changes related to variations in moisture content. Variations in soil water content may take place naturally during seasonal changes or maybe manmade caused by dewatering activities. The quantity of shrinkage and swell is influenced by numerous parameters, including the quantity of minerals clay in the soil, moisture content, dry density, and climate change. In most countries, numerous structures, including pavements and buildings, are damaged as a result of this shrinkage/swelling. Several ground improvement techniques are available for stabilizing expansive soil to modify its engineering performance. These methods include soil replacement, mixing with chemical additives, and soil reinforcement. The present study expressions the effect of nano-lime (i.e., 0.1, 0.3, 0.5, 0.7, 1.0, 2.0 and 3.0%), and lime (1, 3, 5, 8, and 10%), as chemical additive to improve clayey soil (i.e., illite and kaolinite). The effect of nano-lime and lime were investigated using Atterberg’s limits tests. The Atterberg limits were screening significant changes in the proportion of additional nano-lime and lime. The results show that less amount of nano-lime (1% and 2% for illite and kaolinite respectively) decreased the plastic limit, while for lime it was reported 8% for illite and 5% for kaolinite respectively. In conclusion, less quantity of nano-lime (1-2%) is able to improve soil parameters

Examination of the Behavior of Gravity Quay Wall against Liquefaction under the Effect of Wall Width and Soil Improvement

Deformation of quay walls is one of the main sources of damage to port facility while liquefaction of backfill and base soil of the wall are the main reasons for failures of quay walls. During earthquakes, the most susceptible materials for liquefaction in seashore regions are loose saturated sand. In this study, effects of enhancing the wall width and the soil improvement on the behavior of gravity quay walls are examined in order to obtain the optimum improved region. The FLAC 2D software was used for analyzing and modeling progressed models of soil and loading under difference conditions. Also, the behavior of liquefiable soil is simulated by the use of “Finn” constitutive model in the analysis models. The “Finn” constitutive model is especially created to determine liquefaction phenomena and excess pore pressure generation

Higher desirability in solving multiple response optimization problems with committee machine

Many industrial problems need to be optimized several responses simultaneously. These problems are named multiple response optimization (MRO) and they can have different objectives such as Target, Minimization or Maximization. Committee machine (CM) as a set of some experts such as some artificial neural networks (ANNs) in combination with genetic algorithm (GA) is applied for modeling and optimization of MRO problems. In addition, optimization usually is done on Global Desirability (GD) function. Current article is a development for recent authors' work to determine economic run number for application of CM and GA in MRO problem solving. This study includes a committee machine with four different ANNs. The CM weights are determined with GA which its fitness function is minimizing the RMSE. Then, another GA specifies the final solution with object maximizing the global desirability. This algorithm was implemented on five case studies and the results represent the algorithm can get higher global desirability by repeating the runs and economic run number (ERN) depends on the MRO problem objective. ERN is ten for objective “Target”. This number for objectives which are mixture of minimization and maximization ERN is five. The repetition are continued until these ERN values have considerable increased in maximum GD with respect to average value of GD. More repetition from these ERN to forty five numbers cause a slight raise in maximum GD

Intelligent Multi-Agent Systems for Advanced Geotechnical Monitoring

Geotechnical monitoring, essential for ensuring the safety and longevity of infrastructures, has predominantly relied on centralized systems. However, as computational capabilities soar and advancements in Artificial Intelligence (AI) burgeon, the potential for decentralized solutions comes to the fore. This chapter intricately weaves the principles and applications of Multi-Agent Systems (MAS) into the fabric of geotechnical monitoring. It delves deep, elucidating the decentralized approach to monitoring aspects like soil quality and groundwater levels. Through a seamless interplay between agents, we witness real-time data acquisition, intricate analysis, and informed decision-making. While anchoring itself in theoretical foundations, the chapter also illuminates the real-world challenges and proffers potential solutions in geotechnical engineering, thereby mapping the past, present, and future of MAS in this domain

Application of Machine Learning in Geotechnical Engineering for Risk Assessment

Within the domain of geotechnical engineering, risk assessment is pivotal, acting as the linchpin for the safety, durability, and resilience of infrastructure projects. While traditional methodologies are robust, they frequently require extensive manual efforts and can prove laborious. With the onset of the digital era, machine learning (ML) introduces a paradigm shift in geotechnical risk assessment. This chapter delves into the confluence of ML and geotechnical engineering, spotlighting its enhanced predictive capabilities regarding soil behaviors, landslides, and structural resilience. Harnessing modern datasets and rich case studies, we offer an exhaustive examination that highlights the transformative role of ML in reshaping geotechnical risk assessment practices. Throughout our exploration of evolution, challenges, and future horizons, this chapter emphasizes the significance of ML in advancing and transforming geotechnical practices

A systematic review of the role of 4D printing in sustainable civil engineering solutions

This systematic review, not financially supported by any funding body, aims to synthesize the current knowledge on the applications, potential benefits, and challenges of 4D printing in civil engineering, with a focus on its role in sustainable solutions. Comprehensive searches were conducted in Scopus, Web of Science, and Google Scholar using related keywords. Articles that discussed 4D printing within civil engineering and construction contexts, encompassing both conceptual and empirical studies, were included. The findings suggest that 4D printing, with its time-responsive transformation feature, can enhance design freedom, improve structural performance, and increase environmental efficiency in construction. However, challenges persist in material performance, scalability, and cost. Despite these, ongoing advancements signal potential future developments that could widen the opportunities for large-scale applications of 4D printing in civil engineering. The potential use of renewable, bio-based materials could also lead to more sustainable construction practices. This review highlights the transformative potential of 4D printing, underlining the need for further research to fully leverage its capabilities and address current limitations. 4D printing emerges as a promising avenue for sustainable civil engineering solutions, offering a transformative approach that calls for continued exploration and development

A review : assessment of stabilization dust using liquid enzymes

Roads play a significant part of economic development. Due to financial constraints, in many developing countries like Botswana, there are large networks of unpaved roads. The major detriment effect of unpaved or gravel roads is dust emissions. Dust affects the climate change which in turn increases the generation of dust. This has a huge impact on human health which has risen to great concern. The best solution to mitigate dust emission from gravel roads is to seal the gravel roads but this cannot be easily achieved due to financial constraints. Traditionally, road managers have controlled dust by applying calcium chloride or magnesium chloride to the road surface. However, these salts easily leach out of the soil during precipitation events and may not be an option in environmentally sensitive areas. Bio-enzymes have emerged as environmentally friendly soil stabilizers. They are cheap and can easily be available. In this review paper the use of bio-enzymes as stabilizers and a solution to reducing dust will be reviewed, health effects of dust in this exercise to try and see if they can mitigate dust on earth roads that have been constructed using material at site or calcrete. The findings could spread the awareness of effects of dust in Botswana so that the public and private sector can help in supplying the enzymes to reduce health issues affecting the society in Botswana. It will also help decision-makers to make a wise choice of which bio-enzyme to be used effectively

Fundamentals of soil stabilization

Abstract Clayey soils are usually stiff when they are dry and give up their stiffness as they become saturated. Soft clays are associated with low compressive strength and excessive settlement. This reduction in strength due to moisture leads to severe damages to buildings and foundations. The soil behavior can be a challenge to the designer build infrastructure plans to on clay deposits. The damage due to the expansive soils every year is expected to be $1 billion in the USA, £150 million in the UK, and many billions of pounds worldwide. The damages associated with expansive soils are not because of the lack of inadequate engineering solutions but to the failure to identify the existence and magnitude of expansion of these soils in the early stage of project planning. One of the methods for soil improvement is that the problematic soil is replaced by suitable soil. The high cost involved in this method has led researchers to identify alternative methods, and soil stabilization with different additives is one of those methods. Recently, modern scientific techniques of soil stabilization are on offer for this purpose. Stabilized soil is a composite material that is obtained from the combination and optimization of properties of constituent materials. Adding cementing agents such as lime, cement and industrial byproducts like fly ash and slag, with soil results in improved geotechnical properties. However, during the past few decades, a number of cases have been reported where sulfate-rich soils stabilized by cement or lime underwent a significant amount of heave leading to pavement failure. This research paper addressed the some fundamental and success soil improvement that used in civil engineering field