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2025 | Book

Proceedings of the 5th International Conference on Transportation Geotechnics (ICTG) 2024, Volume 7

Sustainable Infrastructure and Numerical Modeling in Roads, Rails, and Harbours

Editors: Cholachat Rujikiatkamjorn, Jianfeng Xue, Buddhima Indraratna

Publisher: Springer Nature Singapore

Book Series : Lecture Notes in Civil Engineering

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About this book

This book presents select proceedings of the 5th International Conference on Transportation Geotechnics (ICTG 2024). It includes papers on ground improvement methodologies, dynamics of transportation infrastructure, and geotechnical intricacies of mega projects. It covers topics such as underground transportation systems and heights of airfields and pavements. This book discusses diverse thematic landscapes, offering profound explorations into sensor technologies, data analytics, and machine learning applications. The publication highlights advanced practices, latest developments, and efforts to foster collaboration, innovation, and sustainable solutions for transportation infrastructure worldwide. The book can be a valuable reference for researchers and professionals interested in transportation geotechnics.

Table of Contents

Frontmatter
Assessment of Water Absorption and Retention Capacities of Waste-Based Stabilizers to Treat Soft Clay Used as Subgrade Soils

The free water content of surplus soils with high fine content is an effective parameter for evaluating the strength of clay stabilized with additives like cement or lime. Therefore, this study attempted to determine the water absorption rate Wab (the amount of water absorbed and retained by 1 g of stabilizer) of waste-based stabilizers such as paper sludge-based stabilizer (PSAS), coal fly ash (FA), biomass ash (BMA), and hemihydrate gypsum (HHG) by a suction filtration method. It was found that the Wab PSAS, FA, and BMA increased with curing time, while the Wab of HHG did not change significantly. Subsequently, clayey soils with high water contents were treated with each stabilizer by adding various proportions and curing for certain periods. Cone index tests were performed to evaluate the cone index qc to confirm the potential of the stabilized soft soils as a road subgrade, railway embankment, and harbor construction material. Based on the test results, the effects of the Wab on the qc were discussed, introducing a modified water content w*. The w* was calculated from the measured water content, Wab, and the addition ratio of stabilizer, A. As a result, the relationship between qc and w* evolved and showed a more reasonable trend than the relationship between qc and w. This relationship can therefore be utilized to estimate the potential of the stabilized soft soils as road subgrade, railway embankments, and harbor construction materials.

Alula Kassa, Ryo Sekine, Kimitoshi Hayano
Strength Evaluation of Lime-Stabilized Fly Ash for Pavement Construction in Layered Systems

The safe disposal of fly ash generated by coal-fired thermal power plants presents a significant challenge. To tackle this issue, the utilization of fly ash in geotechnical construction has emerged as a cost-effective and efficient solution. This study is centered on the evaluation of the strength parameters of lime-stabilized fly ash in layered systems, with the aim of addressing the limitations of the commonly used mixing method for incorporating fly ash into soil. Laboratory experiments were conducted to investigate the behavior of lime-stabilized fly ash under various conditions and enhance its specific qualities. These experiments included unconfined compression tests, Proctor compaction tests, California Bearing Ratio (CBR) tests, and laboratory model tests for load-bearing and distribution testing. These tests offered a controlled environment for exploring the relationships between strength parameters and predicting the performance of lime-stabilized fly ash in real-world scenarios. The findings of this research contribute to our understanding of the behavior and performance of lime-stabilized fly ash in geotechnical applications. The study provides insights into the suitability of lime-stabilized fly ash for various construction purposes, such as highway and railway embankments, landfills, road bases, and sub-bases. In summary, this study demonstrates the potential of lime-stabilized fly ash as a viable alternative and feasible method for large-scale construction, addressing both the safe disposal of fly ash and the enhancement of soft ground strength. The outcomes of this study have significant implications for both the industry and environmental conservation, enabling the sustainable management of fly ash with optimized cost and time efficiency.

Sivakumar Nandyala, Malabika Adak, Malay Kanti Ghosh, Anirban Mandal
Fundamental Study on Consistency, Compaction, and Strength Properties of Soils Treated with Rice Husk Ash

Highway, road, and airfield construction on weak soils is costly endeavor. Re-use of agricultural waste is widely employed as a stabilizing agent to improve engineering properties of these soils. In this study, rice husk ash (RHA), a by-product of incineration of husk from rice production, was used as a potential stabilizer. The water absorption and retention rate of the stabilizer, denoted as Wab, is determined by measuring the amount of water that is absorbed and retained by the stabilizer in relation to its initial dry mass. The study involved treating Ao clay, imitating a dredged soil with high water content, at various addition ratios (ARHA). Diverse curing periods were applied to assess the liquid limits (wL), plastic limits (wP), and cone index (qc) of the treated clays. Compaction characteristics were also determined for several ARHA and different curing periods. The test results show an increase in both wL and wP with decrease in plastic index (Ip) with increase in ARHA, but no remarkable change in wL and wP associated with curing. Compaction characteristics show a decline in ρdmax and increase in wopt with increase in ARHA, but no notable changes in ρdmax and wopt with cured samples. Increase in qc with ARHA, but no noteworthy change in qc with curing was discerned through cone index test. The trends for curing observed in the above test results were consistent with that observed for Wab. The results were then modified based on the Wab of stabilizer. The measured water content (w) and liquidity index (IL) were modified to account for absorbed water (w*), which gave a better correlation with qc than w. The compaction characteristics were also modified based on Wab, ARHA and the results suggest that treated clays were able to achieve modified dry density ( $$\rho_{{{\text{d}}\max }}^{*}$$ ρ d max ∗ ) at the same values of modified water content ( $$w_{{{\text{opt}}}}^{*}$$ w opt ∗ ).

Muhammad Abu-Bakr Jamil, Kimitoshi Hayano
Effect of Crumb Rubber Size on the Packing of 1/3 Scaled Ballast

Most of the world’s railways are on ballasted track—a versatile and cost-effective support solution that can be traced back to the nineteenth century. In the twenty-first century, heavier and faster trains (freight and passenger) create higher loads and maintenance requirements. Ballast degradation becomes an important issue and solutions to increase time intervals between maintenance interventions are necessary. Some proposals involve the incorporation of elastic elements such as crumb rubber mixtures in the ballast. The crumb rubber reduces dilatancy and particle breakage. However, there is a lack of consensus on some key parameters. For example, the optimum percentage of crumb rubber in ballast is often given as 10%, which results in beneficial changes in the stiffness and energy absorption properties of ballast. However, some studies refer to 10% by volume, while others refer to 10% by weight. This leads to very different outcomes, as 10% by weight is nearly double 10% by volume of the soil particles. The paper analyses the influence of incorporating crumb rubber with two different sizes of particle, at 10% by weight and 10% by volume of mineral particles, into 1/3 scaled ballast. The addition of crumb rubber densifies the natural volumetric packing of 1/3 scaled ballast. The maximum (emax) and minimum (emin) void ratios decreased for all situations tested. This is explained in part by voids filling. Under cyclic loading, crumb rubber segregation was observed.

Rafael Anjos, Margarida Pinho-Lopes, William Powrie
Stabilization of Expansive Soils with Agricultural Waste

The United States’ top provider of long-grain rice is Arkansas. The burning of the outer shell of paddy under controlled circumstances generates rice husk. A significant portion of the ash created during the rice-milling process is silicate, which is a pozzolanic substance that may enhance the strength of poor soils. By examining two local subgrade soils from Arkansas, the primary goal of this study is to determine the optimal amounts of hydrated lime, Rice Husk Ash (RHA), and RHA + lime. Various tests, including the Atterberg Limits, Modified Proctor, Unconfined Compressive Strength (UCS), California Bearing Ratio (CBR), pH, and Free Swell (FS), were performed on the treated soils. The findings of the tests indicate that the maximum dry density and plasticity of the soil are decreased by both RHA and lime. On the other hand, adding either RHA or lime improved the treated soils’ strength characteristics. According to the FS results, the soil’s swelling was decreased by both RHA and lime. But it was shown that lime was more successful than RHA in lowering the FS of soils. RHA has no discernible impact on soil pH; however, lime causes a significant rise in pH. It was found that the best dosages for treating both soils were 6% RHA and 3% lime. The swelling potential may be decreased, and the strength properties could be enhanced by the combination of RHA and lime. Based on laboratory test findings, it is recommended to stabilize poor subgrade soils using 4% RHA + 1% lime.

Fares Tarhuni, Zahid Hossain
Eggshell Powder as an Ameliorating Agent for Cement-Stabilised Expansive Soil in Road Construction

This paper introduces a novel technique to enhance the efficiency of cement stabilisation for expansive soil by adding a recycled waste material known as eggshell powder. Expansive soils pose significant challenges in construction and geotechnical engineering due to their high swell-shrink potential, resulting in undesirable volume changes. By incorporating eggshell powder into the cement stabilisation process, this paper explores the potential to improve the performance of expansive soil treatments. Eggshell powder, readily available as a by-product of the food industry, offers promising characteristics such as its chemical composition and particle size distribution. It contains calcium carbonate and is ideal for stabilising expansive soil. The powder is made by cleaning, sterilising, and grinding the eggshells. Various geotechnical tests, including compaction characteristics, California Bearing Ratio (CBR), swelling ratio, and direct shear tests, were conducted to assess the performance of the treated soil. The results indicate that adding eggshell powder to cement significantly enhances the engineering properties of the stabilised soil. The maximum improvement in unsoaked CBR and direct shear strength was achieved when 6% eggshell powder was added to 6% cement. Moreover, the research findings highlight the efficacy of the eggshell powder–cement soil treatment method in mitigating soil swelling compared to the eggshell powder-treating approach. Incorporating eggshell powder in cement improves the stabilised soil’s mechanical characteristics and provides an effective solution for controlling soil swelling, thereby enhancing the overall stability and performance of geotechnical structures.

Reem Alqaisi, Minh-Thang Le, Hadi Khabbaz, Behzad Fatahi
Direct Shear Testing of a Hardening Oil–Silica Sand Mixture in Dry Condition

Cemented sands have great potential as construction materials compared with clean sand due to the higher strength, but they have insignificant environmental benefits such as high embodied energy and carbon footprint. To provide an environmentally friendly, cost-effective, and reliable solution to create an engineered soil, this study explored how Tung oil, a Chinese traditional vegetable hardening oil, affects the mechanical behavior of silica sand. Sand with different grain size is mixed with various concentrations (1–5%) of Tung oil. Heating can accelerate hardening of Tung oil when mixed with sands and may contribute to the increase of shear strength and dilatancy compared with clean sand. Therefore, direct shear box tests are performed on samples equilibrated at 60 °C. The Tung oil–sand mixture was found to exhibit (1) increasing shear strength and dilatancy with increasing Tung oil concentration, but excessive Tung oil concentration will weaken the stabilization efficiency of coarse sand; (2) the larger shear strength and stress dilatancy for host sand with grain size ranges from 0.063 to 0.3 mm.

Ke Chen, Sérgio D. N. Lourenço
Determination of c-φ Properties of Lightly Stabilized Soils from Conventional Tensile and Compressive Testing

Cement stabilization of soils is a common technique to enhance engineering and mechanical properties of in situ soils in the field of road geotechnics. Usually, moderate quantities of cement are used, around 5–10% of the dry material. However, cement manufacturing is one of the biggest sources of greenhouse gas emissions, specifically carbon dioxide. For this reason, reducing cement content by a few percent in geotechnical structures made with cement-stabilized soils (CSS) has a high environmental interest, particularly in view of the involved volumes of material. This work aims to contribute to a better understanding of the mechanical characteristics of lightly stabilized soils. First, the mechanical behavior of a clayey and a sandy soil treated with 3% cement was studied for several curing times. Next, measured mechanical features were correlated. Finally, these measurements were used to characterize the Mohr–Coulomb failure criterion and compared with a conventional approach. Results point out that mechanical enhancement can be quantified in terms of cohesion. Friction angle seems to be independent of curing time. The proposed approach can be adapted in geotechnical applications based on the Mohr–Coulomb yielding criterion such as stability slopes, foundations, and retaining structures.

Mario Castaneda-Lopez, Thomas Lenoir, Luc Thorel, Jean-Pierre Sanfratello
A Laboratory Study on Basic Oxygen Furnace Slag and Granulated Blast Furnace Slag Mixtures

In Australia, a substantial quantity of metallurgical by-products, known as slag, is produced yearly, with the majority of slag generated from iron and steel-making industries. Common types of slag include blast furnace slag (BFS), granulated blast furnace slag (GBFS), and basic oxygen furnace slag (BOFS) (also known as steel slag). The BFS and GBFS have been successfully used in many engineering applications. However, fine BOFS (particle size <6 mm) has limited engineering applications due to the high percentages of free lime and magnesium oxide, which have a high potential to swell. This research focusses on stabilising BOFS using GBFS, a pozzolanic material. A detailed study was performed to understand the index properties, shear and swell behaviour for the selected blends of BOFS–GBFS. The BOFS and GBFS samples procured from the site were classified as well-graded sandy soil with gravel and poorly graded sand, and the results from the accelerated swell tests indicate that swelling in BOFS was reduced exponentially from 2.56 to 0.23% by adding 50% GBFS to BOFS. However, the peak deviatoric stress was decreased with an increased GBFS content. For instance, the peak friction angle $$({\text{\o}}_{{{\text{peak}}}}^{\prime} )$$ ( ø peak ′ ) was reduced to almost 40% for the blend with 50% GBFS. The optimal ratio of GBFS to BOFS for the road base application was identified between 25 and 30%, with swelling <1% and peak friction angle >43°.

Yeshwanth Sunkara, W. G. P. Kumari, Jayan S. Vinod, Benjamin Muscat
Influence of Curing Conditions on the Strength of Xanthan Gum-Stabilised Sand

Biopolymer-stabilised soil holds great promise as an environment-friendly material suitable for sustainable pavement construction. However, the impact of curing conditions, a vital aspect that can influence the mechanical properties of biopolymer-stabilised sand, remains uncertain. In this study, the influences of curing time and relative humidity on the compressive strength of the xanthan gum-stabilised sand were investigated through macroscopic and microscopic laboratory tests. The results indicate that the compressive strength of xanthan gum-stabilised sand is closely correlated with its residual moisture content. As the curing time increases, the residual moisture content gradually decreases, signifying the attainment of different specific residual moisture conditions. This reduction in moisture content is accompanied by an increase in compressive strength. And the strengths of stabilised specimens, tested after the final attainment of equivalent moisture content, are similar in both short-term and long-term curing. Furthermore, an optimal curing humidity of around 40% was identified. SEM test results demonstrate that under the optimal curing condition, thicker and more widely distributed gels bond adjacent sand particles, thereby contributing to the improved strength.

Mingwei Feng, Juan Wang, Shu Liu
Field Assessment of Lignin-Based By-Product-Stabilized Geomaterials

Nature geomaterials like soil and aggregate often exhibit poor engineering properties that make them unsuitable for use in road construction. To overcome this problem, stabilization methods are used to enhance the engineering properties of these materials by mixing them with chemicals. While cement has been the preferred chemical stabilizer for decades, its high cost and environmental concerns have prompted engineers to look for sustainable alternatives. Lignin, a by-product of the paper or biofuel industries, has shown promise as a sustainable alternative to cement for stabilizing geomaterials. Laboratory studies have demonstrated that lignin-treated geomaterials have improved strength capacity and moisture resistance, but these findings need to be validated in the field under local conditions. This study aims to evaluate the long-term field performance of lignin-treated geomaterials used on a granular road in Iowa. A pilot field demonstration site was constructed in 2018 in Buchanan County, Iowa, and a follow-up field evaluation of 4-year duration was executed at the project site. In addition to the lignin product, three proprietary chemical stabilizers and cement were utilized on different road segments for comparison purposes. This study evaluated lightweight deflectometer-derived elastic modulus, dust generation, in situ California bearing ratio (CBR), and roughness. The results showed lignin stabilization to be a viable and effective method for improving the engineering properties of road geomaterials. This study adds to the growing body of evidence supporting the use of lignin as a sustainable alternative to traditional chemical stabilizers in road construction.

Bo Yang, Mohammad Ahmad Alsheyab, Halil Ceylan, Sunghwan Kim, Yang Zhang
Full-Scale Accelerated Pavement Testing and Fatigue Damage Evaluation of Foamed Bitumen-Stabilised Crushed Rock and Recycled Materials

Foamed Bitumen-Stabilised (FBS) materials are used for in situ rehabilitation or strengthening treatment of unbound granular pavements but can also be manufactured ex situ for new pavement construction. This study examined the field performance, tested using full-scale accelerated pavement testing, of foamed bitumen-stabilised materials incorporating high concentrations of recycled pavement materials. The Australian Accelerated Loading Facility (ALF) was used to evaluate a 100% crushed rock FBS mix (control mix) and two recycled material blends (a 50% reclaimed asphalt pavement and 80% previously cemented material) all stabilised with 3% bitumen and 2% hydrated lime. The accelerated loading accumulated over 3.6 million ALF loading passes at 40 and 60 kN, with continuous monitoring of the pavement stiffness and surface condition. The effect of traffic on the FBS material fatigue damage was analysed by the ratio of modulus between the trafficked and untrafficked areas. Data showed that the incorporation of 50% RAP increased fatigue performance without a detrimental effect on rut resistance. The average field fatigue performance of the previously cement-stabilised mix was similar to that of 100% crushed rock. However, performance variability should be considered for a risk-based approach and high stress applications.

Didier Bodin, James Grenfell, Negin Zhalehjoo, Geoff Jameson, Andrew Papacostas, Michael Moffatt
Mechanical Behavior of a Subgrade Soil Reinforced with Piassava Fibers

This research presents a study about the influence of cement content and the piassava fibers (Attalea funifera) on the mechanical behavior of a fine-grained subgrade soil. Specimens of 10 cm in diameter and 20 cm in height were prepared from natural subgrade soil, 2wt.% of cement content, and 1,5wt.% piassava fiber from the Brazilian Amazon. Repeated load triaxial tests (RLT) with different stresses were conducted to provide permanent deformation behavior and the results were analyzed based on shakedown analysis. The aim was to verify if the addition of these fibers in a soil/cement matrix generates a significant effect on the mechanical behavior of the material regarding its permanent deformation, given the unsatisfactory geotechnical characteristics of the sedimentary soils in the Amazon region. It was found that the piassava fiber addition decreased the soil permanent deformation, although when mixed with cement, the permanent deformation was not significantly affected.

Antônio Carlos Rodrigues Guimarães, Sérgio Neves Monteiro, Lisley Madeira Coelho
Effect of Chemical and Mineralogical Composition of Quarry By-Products on Cement-Stabilization Efficiency Using Elastic Wave Signals

Quarry by-products (QB), residual aggregate materials produced from stone quarry operation, present significant challenges due to their substantial annual production volume. Research at the Illinois Center for Transportation (ICT) has explored the sustainable use of QB as a pavement foundation material, revealing that dolomitic QB demonstrates enhanced durability over limestone when subjected to long-term cementitious reactions for multiple years. This study investigates the influence of QB’s chemical and mineralogical characteristics on strength gain behavior during extended cement hydration curing periods. Using the Illinois Department of Transportation (IDOT) aggregate chemical testing procedures, the QB materials were classified as either dolomite or limestone. Further analysis was conducted on the QB materials using X-ray fluorescence (XRF) to determine the detailed chemical composition. Bender Element (BE) sensors, capable of transmitting shear wave signals, were installed in 3% cement-stabilized QB specimens with varying mineralogy and chemical compositions to continuously monitor strength development during the curing process. Specimens were cured at 104 °F (40 °C) for approximately 2 months, simulating long-term cementitious reaction. The findings revealed that limestone QB exhibited a faster hydration rate at the initial curing stage, as indicated by a higher shear wave velocity. However, a reversal trend was observed with continuous curing, where dolomitic QB demonstrated a faster shear wave velocity, suggesting it had a higher hydration rate and increased stiffness. The observation is attributed to the distinct chemical reactions and hydrate formations arising from the inherent mineralogical and chemical difference between QB types.

Taeyun Kong, Chirayu Kothari, Issam I. A. Qamhia, Erol Tutumluer, Nishant Garg
Utilization of Waste-Based Expansive Agents for Soft Clay Stabilization

Ordinary Portland Cement (OPC) has been extensively employed to stabilize soft clay. However, OPC exhibits inefficiency in treating high water content soft clay, necessitating a high dosage of OPC and resulting in significant CO2 emissions. Expansive agent (EA) is a cement additive that, during the hydration process, expands and fills some of the pores in the matrix. It has the potential to enhance the strength performance of OPC-treated soft clay. However, commercially available EA is currently costly and challenging to apply in cement-stabilized soft soil. In this study, EA derived from waste, including freshwater sludge (FS) and carbide slag (CS), was developed, and the feasibility of utilizing this waste-based EA in soft clay stabilization was examined. The EAs (both FS-CS based EA and commercial EA) were mixed with OPC and ground granulated blast-furnace slag (GGBS) for the stabilization of soft clay. The findings revealed that both FS-CS-based EA and commercial EA enhanced the unconfined compressive strength (UCS) of stabilized clay. FS-CS-based EA exhibited significantly better performance than the commercial EA in both OPC-stabilized clay and GGBS-stabilized clay. The strength enhancement effect of the FS-CS-based EA on GGBS-stabilized clay was significantly more pronounced than its effect on OPC-stabilized clay.

Jiawei Tan, Bo Xu, Junde Qin, Yaolin Yi
Natural Reinforcement of a Fine Soil for Unpaved Forest Roads—Cyclic CBR Tests

Unpaved roads are essential for transportation infrastructure, particularly for forest industry. Traditionally, unpaved roads are composed of layers using local soils. Poor local soils need to be replaced with gravel, crushed aggregate, or a mixture of materials. Due to traffic and weather conditions, unpaved roads require frequent maintenance and repair. To reduce the amount of quality materials and the frequency of maintenance operations, reinforcements can be used (synthetic or natural). This paper focussed on the behaviour of a fine soil reinforced with natural fibres from the forest value chain (pine needles), to assess their use on unpaved forest roads. Cyclic CBR tests were carried out to assess the resilient response of the soil (unreinforced and reinforced); the tests included initial monotonic loading, followed by cyclic loading. The force–penetration response and CBR value improved with the inclusion of pine needles; the best response corresponded to a percentage of incorporation of 1% (mass). For the cyclic loading phase, the permanent displacement decreased with the number of cycles, approaching a resilient response. The reinforcement with pine needles led to an improved elastic response, represented by an equivalent stiffness modulus. The best behaviour was, again, obtained for a percentage of incorporation of 1% (mass). The addition of fibres led to reduced displacements during the test, relatively to the unreinforced soil. The results showed that for unpaved forest roads, where the investment in soil characterisation is often very limited, cyclic CBR tests can be a promising approach in obtaining design parameters.

David Miranda Carlos, Joaquim Macedo, Margarida Pinho-Lopes
Ground Improvement Over Landfill for the Barton Park Recreational Precinct

This paper describes the selection, design, and execution of ground improvement to treat an old landfill site on which the Barton Park Recreational Precinct will be constructed. Barton Park encompasses an area of 19 ha, and is located over an old landfill that operated between 1940 and 1970. On this site, the St. George Football Stadium was constructed in 1976. By the 1980s, the stadium had become derelict and disused. In 2022, Bayside Council successfully applied for funding from the NSW Government’s Accelerated Infrastructure Fund that will go toward a major upgrade of the Barton Park project. The Barton Park project will provide a community recreation precinct including three full-size grass soccer fields, four tennis courts, two multipurpose courts, a cycleway and connecting walkways suitable for walking circuits as well as four change rooms with showers and toilets. The landfill underlying Barton Park extends to a depth of up to 9 m. Due to this there were serious concerns regarding post-construction settlements and differential settlements. A number of ground improvement options were considered, including the use of Rigid Inclusions, Dynamic Compaction, High Energy Impact Rolling and Geocells. After a program of laboratory testing, detailed assessment of potential settlement and rate of settlement; consideration of relative merits, risks, and cost; and a suitable combination of piling the stadium structures, impact rolling, and use of geogrids in areas more sensitive to differential settlements were adopted. The investigation program, assessment, and design of the ground improvement are presented in this paper.

Liam J. Smith, Patrick K. Wong
Comparative Analyses of Lime and Alkali-Activation Treatments for Expansive Soil Stabilization

Expansive soils pose significant challenges to various engineering applications due to their volume-changing behavior in response to moisture fluctuations. The expansive nature of these soils results in undesirable consequences such as swelling, shrinkage, and loss of structural integrity, affecting the stability of foundations, pavements, tunneling, etc. Globally, infrastructure has faced both short-term and long-term damage from these expansive soils. Numerous mechanical and chemical techniques have been extensively employed to mitigate the extent of soil expansiveness and the resultant damages. This paper presents an exploration, focusing on the comparative evaluation of two distinct stabilization approaches, i.e., lime treatment and alkali-activation treatment. Lime, as a traditional calcium-based stabilizer, engages in pozzolanic reactions to enhance soil stability. In contrast, alkali-activation treatment, a non-calcium-based technique, employs geopolymers to achieve analogous results. This investigation examines and compares the effects of both methods on reducing the swelling potential of expansive soils. Their performances are evaluated and discussed through swelling tests as well as corresponding microstructure analyses.

Hadeel Alzghool, Pan Hu, Chin Leo, Samanthika Liyanapathirana, Qinghua Zeng, Jeff Hsi, Reza Karimi
Lateral Resistant of Different Types of Sleepers with and Without Additional Stabilising Measures

Lateral restraint and stability are essential factors in preventing the buckling of railway tracks, especially as a result of the tendency of the rails to expand in hot weather. Many factors influence lateral restraint including sleeper type, weight, contact area between the sleeper and ballast, sleeper spacing, ballast grading and density, and the dimensions/geometry of any ballast shoulder. Additional stabilising measures sometimes provided to increase lateral stability include under-sleeper pads (USPs) and lateral restraint plates (LRPs). This paper presents the results of a series of experimental studies into the effects of these measures on different sleepers using the Southampton Railway Testing Facility (SRTF). The results show that attaching USP and LRP to a standard concrete sleeper increases the lateral resistance by about 50% and 47.46%, respectively. For other types, the weight of the sleeper influences the percentage increase/decrease in the lateral resistance.

Hammed O. Aminulai, Taufan Abadi, Darren Sharp, William Powrie
Decarbonisation of Small-Scale Railway Earthwork Interventions Using PAS 2080 Life-Cycle Methodology

Transport is responsible for about 23% of global energy-related CO2 emissions (also referred to as carbon or GHGs), in addition to those associated with building and maintaining the infrastructure. Thus, the transport sector must rapidly accelerate its decarbonisation efforts to help countries limit their emissions to meet Nationally Determined Contributions established in response to the Paris Agreement. This is especially important given IPCC estimates that the 1.5 °C line of global warming will be crossed in the early 2030s. Transportation sector CO2 emissions are attributable to the infrastructure (mainly in construction, maintenance, and repair) and vehicles using it. Both areas will require urgent attention. The carbon emissions associated with the construction and maintenance of railway infrastructure are currently not well understood, hence meaningful whole life-cycle analysis of railway geotechnical assets is problematic. Filling this knowledge gap requires measurement of the CO2 and carbon footprint associated with railway assets and identification of hot spots. This paper outlines tangible steps that can be taken, aligned to PAS 2080 life-cycle stages, for several types of mainline railway earthworks over differing temporal scales of earthwork interventions to decarbonise these interventions and help reach net zero. Research, based on a dataset of 50 small-scale mainline railway earthwork case studies in Great Britain, has found that for differing temporal interventions the carbon hotspots were in differing PAS 2080 life-cycle stages thereby requiring a range of different solutions to deliver decarbonisation.

Tracey Najafpour Navaei, Simon Blainey, William Powrie, John Preston
Case Study Comparing Embodied Carbon Emissions in Two Road-Over-Rail Bridge Foundation Designs

This paper examines and compares the embodied carbon emissions in the earthworks and foundation design for two road-over-rail integral bridges in Western Australia. The first bridge is supported on gravity footings and constructed using bottom-up methods, the second on load-bearing contiguous piles constructed using top-down methods. A Life-Cycle Assessment (LCA) for embodied carbon emissions was carried out for each bridge using the framework of PAS 2080. Construction-stage design information was used in the assessment, representing a bottom-up LCA approach to retrospectively identify carbon hotspots to inform future designs. The results are presented in total tonne CO2e per bridge and tonne CO2e per bridge deck area to allow direct comparison of the embodied carbon emissions of the two foundation systems. The carbon hotspots in each design are identified. The paper closes with the authors’ assessment of opportunities in the design process for geotechnical designers to have influence on embodied carbon over the design life of these bridge types.

Jessica Dalton, Stephen Barrett
Shakedown Limit Analysis of Asphaltic Support Layers for Railway Slab Tracks

Shakedown analysis is a valuable method for assessing the cumulative deformation characteristics of ballastless track beds and determining the safety factor of longitudinally continuous structures under moving train loading. Asphalt support layers (ASLs) emerge to enhance track structure stiffness and prevent water penetration. Key design considerations include the influence of temperature on asphalt concrete strengths and the concentrated stress effect at expansion joints. To evaluate the ASLs, empirical equations are used, incorporating temperature-dependent modulus of elasticity and cohesion. Shakedown limits are calculated for various thicknesses and temperatures under two loading conditions: continuous structure and joint positions. The shakedown limit of axial load serves as an evaluation index. Research shows that at low temperatures, the critical depth for subgrade lies within the upper roadbed, with the nature of fills in this layer playing a crucial role in determining the shakedown limit of axle load for the subgrade. Above a critical temperature, the critical depth shifts from the upper roadbed layer to the ASL surface layer. The maximum allowable temperature is determined at the intersection of the design axle load contour and the temperature-dependent shakedown limit curve. To meet shakedown limit requirements beyond this temperature limit, increasing the asphalt thickness or fill strength of the structural layer within critical depth is necessary.

Qingzhi Ye, Guishuai Feng, Qiang Luo, Tengfei Wang
Influence of Suction Linear Distribution on Strength for Unsaturated Silty Soil

This study investigates and verifies stress–strain properties and stiffness with a variation of total suction, which is over 2.8 MPa. The developed mold is prepared for this experimental research work, which is possible to apply suction incline in the soil specimen. As results, created soil moisture distribution is not uniformity. The suction was produced by vapor pressure technique, and a circulation system was installed to the testing system that all of the specimens have hydration phenomena related to slight deformations. Relative humidity is produced using sat solutions at 20 ℃ and is confirmed with relative humidity value mentioned test code in JGS. Particularly, a variety of different suctions applied at upper portion and bottom portion for specimen that unique suction distribution as straight line produced while suction controlling. Used soil is non-plastic silty soil with three different dry densities. Previously, soil–water characteristic curve is determined including evaluation of volume change, and unconfined compressive strength is decided for interpretation to the influence of suction incline distribution. Also, the distribution in the specimen for water content is determined through axial direction. This study then considered the influence of produced suction distribution in high suction ranges on unconfined compressive strength and stiffness such as hydraulic-mechanical properties. The tendency is common regardless of dry density for non-plastic silty soil.

Tomoyoshi Nishimura
Key Role of Reclamation Analysis from Repository Planning to Acceptance Management in Disposal Pond for Dredged Clay

In Japan, environmental concerns have made it difficult to construct new disposal ponds for dredged clays. Therefore, in order to maintain continuous navigation, dredging plans and acceptance management should consider the current capacity of disposal ponds and predicted future trends. In this paper, a detailed sedimentation prediction method from the repository planning stage to the time of dredged clay acceptance and management during operation is investigated using a reclamation analysis developed from the generalized consolidation theory. In order to perform this reclamation analysis, consolidation parameters related to the compressibility and consolidation rate of dredged clay under low confining pressure are required. We therefore propose a method for determining consolidation parameters and also a method for predicting the amount of dredged clay to be received at various stages. In the repository planning stage, these coefficients, determined from the liquid limit of the clay and the results of tests on several dredged clays in Japan, were applied as initial values of consolidation parameters. In the subsequent phase of accepting the dredged material, the values identified from the back-analysis using the changes in sediment surface elevation over time and the water content distribution of the sedimentary clay layer were applied as modification values. Thus, by setting the consolidation parameters, this dredged clay reclamation analysis can be effectively used for a wide range of tasks, from sediment disposal pond planning to acceptance completion prediction.

Masaaki Katagiri, Katsuhide Nishizono, Yoichi Watabe
Inclusive Approach in Advancing Sustainability in Road Construction

This paper presents the inclusive approach adopted by the Ministry of Transportation Ontario (MTO) to advance sustainability in road construction. Recognizing the significance of reducing greenhouse gas emissions and promoting sustainable practices, MTO emphasizes the conservation of natural aggregates and encourages the use of reclaimed materials in construction projects. By incorporating techniques such as in-place pavement recycling and optimizing the utilization of recycled materials like reclaimed asphalt pavement (RAP) and reclaimed concrete aggregate (RCA), MTO aims to minimize environmental impact, enhance economic efficiency, and deliver social benefits. The paper highlights MTO history of recycling initiatives, its specifications for road construction projects, and the challenges associated with integrating recycled materials. It emphasizes the importance of considering factors such as performance, engineering properties, life cycle costs, and availability when incorporating recycled materials. Through collaboration among stakeholders, including industry, government, and research institutions, the construction industry can further advance sustainable practices and reduce its environmental footprint. Efforts at the municipal level have been effective in advancing this initiative.

Stephen Lee, Stan Gonsalves
Role of Grain-Scale Characteristics on the Stiffness of Railway Ballast

The majority of the world’s railways are on ballasted track, which consists of rails attached to sleepers, supported by a granular layer (ballast) lying on the natural ground. The repeated passing of trains results in a gradual deterioration of track alignment, leading to the need for periodic maintenance of the ballast. Following a number of maintenance cycles, the ballast is considered degraded, and the track is renewed. Conventional track renewal is costly and potentially unsustainable, as it requires quarrying of fresh ballast, increasing the railway’s carbon footprint. A better understanding of the mechanical properties of used ballast, particularly how its stiffness compares to that of fresh ballast, could inform more extensive reuse of ballast. Previous research has demonstrated that the stiffness of granular materials is greatly influenced by their particle shape, size and surface characteristics. This project investigates the difference in stiffness in the vertical and horizontal directions between fresh and used ballast using advanced triaxial tests of 1/3rd scaled material. Fresh-scaled ballast can be readily sourced. “Used” scaled ballast was created by abrading fresh scaled ballast using a previously established procedure, which resulted in grain characteristics that closely mimic those of ballast recovered during track renewals after 30 years of use. The results from the advanced triaxial tests show that the “used” scaled ballast in this project had a greater stiffness in the vertical direction than the fresh scaled ballast. Additionally, the horizontal stiffness generally also remained higher for used ballast compared to fresh, suggesting that “life-expired” ballast has the potential to be reused.

Amy Seechurn, B. N. Madhusudhan, Antonis Zervos
Prediction of Light Rail Transit Vibrations and Vibration-Reducing Measures

Light Rail Transit (LRT) is a sustainable transport solution. Rail-wheel interaction by LRT generates ground-borne vibration, affecting the buildings near railway tracks, especially in urban areas. This impact must be minimized to avoid any negative impact on the buildings and also on people living and working in the neighborhood. The rolling stock vibration creates waves propagating through the ground and into nearby buildings, generating ground-borne vibration effects. The soil structure interaction under these circumstances is significant for the railway routes that will pass by existing structures, especially those designed for non-dynamic conditions and constructed decades ago and historical buildings. This paper discusses vibration assessment for LRT operations and mitigation requirements for sensitive areas. Different vibration models were assessed for determining the potential vibration impact of LRT on surrounding receivers. The predictions are based on in-situ test measurements. Two different approaches to determine the vibration levels from LRT will be presented. It is concluded that the use of LRT in urban areas can be an effective solution, contributing to sustainable development.

Saeed Hosseinzadeh, Zeynep Merve Ürkmez, Edo Vink, Otto Heeres, Gerhard Schulz, George Maftei
Sustainable Solutions for Overcoming Challenges of Railway-Induced Vibrations—A Practical Perspective

Railways (both for freight and passenger) play an essential role in the global target of CO2 reduction. Therefore, existing railway lines’ capacity must be increased by means of higher speed, axle loads, and frequency while ensuring safety, reliability, and availability. A balance between investment (CAPEX) and operation/maintenance (OPEX) needs to be achieved in which railway-induced vibrations, therewith geotechnics, play an important role. Examples of overcoming challenges in predicting railway vibration and the effect of railway vibration on the track itself (and therewith on the maintenance) and also on adjacent structures will be presented. The showcases include case studies and applications of semi-empirical and analytical approaches as well as advanced numerical modeling tools in railway projects worldwide. The application of the above methods leads to an optimized design of the railways and, thus, an increase in sustainability. International practices concerning assessing railway vibrations will be discussed. Actual vibration measurement data will be compared with the modeling predictions to demonstrate the reliability of the different methods.

Saeed Hosseinzadeh, Edo Vink, Otto Heeres, Gerhard Schulz, Zeynep Merve Ürkmez, George Maftei
Climate Resilience and Energy Harvesting of Thermo-Active Roads

The climate is changing rapidly, altering the long-term environmental loading parameters of roads. Increased frequency and severity of extreme weather events cause serious road damage and transport disruption, including melting roads in heatwaves and potholes due to freeze–thaw cycles, with highway repair and maintenance costing England alone £1.4 billion in 2021/2022. The recently established UK projects SaFEGround, Digital Roads, and an RAEng Research Fellowship will synergise ideas and methods to develop low-carbon and resilient roads. In particular, the RAEng Research Fellowship involves deploying an innovative shallow geothermal energy system (SGES) for subgrade heat storage/extraction and pavement temperature regulation. Such research is at the forefront of Transport and Energy Geotechnics. Very little research has been conducted on the pavement-pipe-subgrade SGES and factors affecting their performances, especially in the field of civil engineering (e.g. thermal properties enhancement of subgrade materials, pavement/pipe/subgrade interaction, complex thermo-mechanical behaviour under extreme climates). This paper provides an overview of the systematic research approach that fully characterises thermally improved road materials via physical modelling, finite element numerical analysis, field trials and LCA, with some preliminary results analysed. The proposed thermo-active road technology would be applicable to a wide range of transport projects in many regions to reduce climate-related road maintenance costs and carbon emissions.

Benyi Cao, Fei Jin, Sripriya Rengaraju, Abir Al-Tabbaa
Recycled Rubber Grids for Improved Performance of Ballasted Tracks

This paper presents a study examining the use of recycled rubber grids to enhance the performance of ballasted tracks. The rubber grids were manufactured from discarded conveyor belt panels using the waterjet cutting process. Different grids with two aperture shapes, i.e., square and circle, and varying effective area ratios were prepared. Large-scale impact tests were conducted on ballast specimens with and without these grids to assess their performance. Results of this study show that incorporating rubber grids in ballast yields numerous benefits. Firstly, they mitigate the high-frequency impact forces through enhanced damping. Secondly, they reduce subsequent vertical and lateral settlements of the ballast assembly. And finally, they minimise the breakage of ballast particles. The study concludes that using recycled rubber grids can improve ballast performance while also offering obvious environmental benefits and promoting the principles of the circular economy.

Anees Raja Siddiqui, Buddhima Indraratna, Trung Ngo, Cholachat Rujikiatkamjorn
Laboratory Characterisation of Locally Available Non-standard Materials for Road Pavement Application

The majority of the Australian road network consists of unbound granular pavements with a thin bituminous surfacing. In Queensland, regional and remote areas, economic and environmental considerations encourage the use of locally available materials for the provision of granular pavements resulting in lower use of finite resources and a reduction in material transportation costs and associated emissions. These materials, known as non-standard or marginal materials, typically do not meet all the Queensland standard specification requirements but provide satisfactory performance when properly managed. At present, a universally accepted testing procedure for assessing the performance of non-standard materials is lacking. This paper reports on the first completed stages of a study aiming to investigate the physical and mechanical properties of non-standard materials using a range of laboratory testing: wheel tracking, modified Texas triaxial, California bearing ratio tests, and physical characterisation testing such as particle size distribution, Atterberg limits, compaction test, and apparent particle density measurement. This paper assessed 10 different non-standard materials together with one standard material using the selected laboratory tests. Later stages of the ongoing project, conducted for the National Asset Centre of Excellence (NACoE), will expand this testing and aims to develop a performance-based non-standard material screening tool to assist in material selection and assessments for road pavement construction and maintenance in low-traffic and low rainfall areas.

Negin Zhalehjoo, Jaspreet Pooni, Damian Volker, Meera Creagh, Didier Bodin, Michael Moffatt
Laboratory Evaluation of the Recyclability Potential of Recycled Plastic-Modified Asphalt Concrete and Its Environmental Impact

The aim of this study is to investigate the feasibility of recycling the recycled plastic-modified asphaltic mixtures, particularly for surface course of road pavements and to examine its performance properties as well as the environmental impact with respect to water leachability. Three types of recycled plastic wastes, namely polypropylene (PP), polyethylene (PET), and polystyrene (PS) were used in the study. The recycled plastic-modified samples were prepared using dry mixing method and artificially aged in the oven following AASHTO R30 method to simulate 5–7 years of aging in the field. A series of laboratory tests such as Marshall stability, Indirect tensile strength, Cantabro abrasion loss, and resilient modulus tests were performed to evaluate the performance of recycled asphalt concrete containing 20% aged content. The results demonstrate that the recycled mix of plastic-modified recycled asphalt concrete performed better than the conventional mix in terms of metrics considered in our experiments. In terms of the environmental impact study, the results of the water leachability tests indicated that the recycled mix with inclusion of recycled plastic containing 20% aged content had an insignificant influence on the leachability of water contaminants. The findings suggest that the use of recycled mix containing waste plastic in asphalt mixes has the potential to contribute to reduced environmental impact and promote sustainable practices in the construction industry.

Sin Mei Lim, Meibo He, Gengren Hao, Ghim Ping Ong
Life Cycle Assessment of Ground Improvement Methods to Enhance the Efficiency of Thermo-Active Geostructures Within Transport Infrastructure

The integration of ground source energy systems with geostructures included in large transport projects–such as tunnels, pavements, retaining walls, and pile foundations–has multiple advantages. Harvesting geothermal energy from geostructures can provide operational energy savings by providing direct geothermal energy for space heating and cooling, deicing of pavements, etc. Incorporating multiple applications into one construction process streamlines construction and reduces cost, and in cases such as road tunnels, where excess heat is generated by traffic, the heat generated from activity and use of the infrastructure can be repurposed rather than wasted. Harnessing the full potential of ground source energy requires collecting and using the energy as efficiently as possible. Tailored ground improvement can assist in increasing the thermal conductivity of the soil surrounding energy geostructures, thereby increasing the efficiency and longevity of each system by allowing for faster heat extraction and dissipation. This article includes the use of life cycle assessment to estimate and assess the environmental impacts of several ground improvement strategies for a thermo-active pile over the full project lifetime, and explores key challenges and technical considerations related to the application of life cycle assessment to ground source energy systems in the context of transport infrastructure. The results of this analysis demonstrate the importance of weighing the environmental impacts of ground improvement additives against their role in improving the efficiency of ground source energy systems. This research is part of a UK government funded project SaFEGround (Sustainable, Flexible and Efficient Ground source heating and cooling systems) which aims to investigate, through multi-scale modelling and assessment, how ground source energy systems can be coupled with geostructures to deliver low-cost, low-carbon heating and cooling.

Natasha Balwit-Cheung, Maxine Beh, Sripriya Rengaraju, Abir Al-Tabbaa
Deformation Mechanism of Bound Soft-Rigid Granular Mixtures

Recycled tyre aggregates (soft particles) mixed with common granular material such as crushed rock (rigid particles) are considered effective solutions for a range of applications in transportation geotechnics in recent years. While extensive research has been conducted on the mechanical properties and behaviour of sand-rubber combinations as unbound soft-rigid mixtures, most studies on bound soft-rigid mixtures have focussed on utilizing brittle binders like Portland cement. On the other hand, there have been only a few studies in recent years exploring the behaviour of soft-rigid mixtures bonded with non-brittle binders. This study aims to enhance our understanding of the impact of binder elasticity and stiffness on the compressibility mechanism of soft-rigid granular mixtures. One-dimensional compression tests complemented with shear wave velocity measurements were conducted on bound samples, using different types of binders, to investigate how the characteristics of binders influence the fabric of the mixture and, consequently, its behaviour. The findings indicate a multiphase behaviour of bound mixtures, in contrast to the single-phase behaviour of unbound mixtures, particularly for higher contents of binder and for brittle and semi-flexible binders.

Abbas Rezamand, Mahdi M. Disfani, Amirhassan Mehdizadeh
Discussion Paper on Implementation of an Overarching Authority to Improve Sustainability in Transport Mega-Projects

To facilitate the cost burden of mega-transport projects, elected governments have traditionally staged projects, contracting each stage as a new award. While this method spreads the cost loading over multiple federal and state budgets, it ultimately brings a higher total cost burden on the tax payer. The current limited or delayed knowledge sharing, particularly between overlapping road and rail projects results in significant unwarranted additional site investigation, while construction access is often duplicated as a risk-mitigation measure. This paper delves into considerations we as an industry can promote to improve sustainability in construction. As an industry, we could eliminate around 90% of intrusive site investigations in the major cities by simply having all data and models controlled by an overarching authority. Building Information Modelling (BIM) is gaining huge traction to express the surficial and underground architecture of our cities, but currently poorly reflects the outstanding 3D geological and geotechnical models that have been developed through mega-transport projects completed to date. Digital twins are in development for Melbourne, but not publicly available for Sydney at this time. Further, the present staged approach to mega-project development results in significant site investigation, design, and construction duplication to avoid subsequent stages having to take ownership of risk. By adopting an overarching authority, who sign-off on both design and construction, this risk issue would be mitigated, and significant costs and time delays avoided.

Helen Baxter-Crawford
Thermal Performance Optimization of Ribbons-Based Electrically Heated Pavements: A Numerical Study

Infrastructures in many countries experience accumulations of snow. On pavements, this causes unsafe conditions for road users. An alternative technology to snow plowing and de-icing consists of embedding near the ride surface ribbon-like elements that melt snow and ice due to the Joule effect as an electrical current is passed through the ribbons. This study dealt with the optimization of electrically heated pavements utilizing such ribbons. For this, a thermal model was mathematically outlined; it considered the 2D heat equation applied to a three-layered domain representing such pavement. The top boundary (i.e., pavement surface) was subjected to a heat flux representing weather effects, which were quantified with measured data obtained in the UK. A large number of cases were considered for the optimization: ribbon spacing and embedment depth, thermal conductivity of the top layer representing AC, and energy consumption of the ribbons. Amongst all cases, for the considered weather data, it was found that the optimal heated pavement consists of a ribbon spacing of 0.2 m, an embedment depth of 0.07 m with a thermal conductivity of 2.5 $${\text{W}} \cdot {\text{m}}^{{ - 1}} \cdot {\text{K}}^{{ - 1}}$$ W · m - 1 · K - 1 for the asphalt concrete. The developed thermal model is seen as a tool that engineers can utilize for the thermal design of heated pavements.

Quentin Félix Adam, Abir Al-Tabbaa
Sustainability Assessment of Reinforced Soil Wall Options Frictional Versus Fine-Frictional Fill

In transportation infrastructure projects, earth-retaining structures are required to enable grade separation between assets. Globally, the reinforced soil wall (RSW) is a popular solution. Current design standards provide requirements for the reinforced fill (R-Fill) material, most notably grading and plasticity limits. In general, a coarse-grained soil with less than 10–15% fines is required. Such material is in high demand for use as an engineered fill but is not abundant in nature. As such, the standard requirements pose a hurdle for transport projects that lack a nearby source. Many projects choose to import R-Fill over the use of locally available fill. While this streamlines the geotechnical aspects, it increases cost and produces negative environmental and social externalities. This paper presents RSW models designed using R-Fill varying by fines content, reinforced by HDPE geogrids. Sustainability of models is compared using a simple method that can easily be replicated to suit project-specifics. The assessment showed that R-Fill with fines content up to 45% can be used to provide similar operational performance with enhanced sustainability, provided special conditions are met.

Eugene Lim, Rishabh Manglunia
Design of Working Platforms for Crawler Cranes Over Coode Island Silt

As part of the construction of the City Connections for the West Gate Tunnel Project in Melbourne, temporary platforms were required to support stable lifts for bridge components. The lifts required several large-capacity crawler cranes to be positioned over historical reclaimed lands near the Port of Melbourne comprising variable fill, overlying Holocene-age Coode Island Silt, characterized by soft compressible soils. The combination of the heavy payload of the bridge elements creating significant unbalanced loading under the crane tracks, together with small differential settlement tolerances of the cranes posed unique challenges in the design of temporary platforms that were economical, sustainable, and safe. A combination of bespoke structural crane mats comprising universal column sections over unbound temporary platforms constructed using recycled geomaterial was designed to support the lifts. Presented in this paper is the approach adopted to design the temporary platforms and the structural mats. The approach involved an initial platform design utilizing the bespoke structural mats using limit equilibrium and simplistic structural capacity calculations, followed by finite element assessment of immediate deflections of the platform and structural actions within the mats. The structural capacity of the nominated mats to support and effectively spread the crane loads was checked against the assessed actions and ground response. Real-time monitoring of the deflections against settlement predictions was also undertaken initially during the test loading of a crane lift to validate the design approach.

Mohsen Sadeghi, Tony Hughes, Adam Lander
BIM-Based Life Cycle Assessment to Quantify Carbon Dioxide Emissions During Road Construction

Carbon dioxide CO2 emissions are a major component of greenhouse gases and their evaluation during the service life of infrastructures is increasingly becoming a pivotal index during the project tendering phase. Construction activities largely generate CO2, among which onsite equipment usage accounts for a large amount in earthwork operations. However, the carbon dioxide emissions deriving from earthwork machineries have not been fully investigated and calculated yet due to the inner complexity of such quantification tasks. This study refers to a real road construction project in Trondheim, Norway as a case study to quantify earthwork volume and calculate the corresponding CO2 emissions generated by the vehicles employed during the earth moving process. Building Information Modeling (BIM) is adopted to streamline the necessary operations and the generated earthwork modeling can provide accurate data to calculate quantity take-off volumes. Three different hauling machines, namely wheel dozer, tractor scraper, and articulated dump truck are considered based on their economic haul distance. The corresponding carbon dioxide emissions are subsequently calculated and results indicate that the tractor scraper contributes to the highest CO2 amount while the wheel dozer leads to the lowest value. This study provides an innovative workflow to calculate the carbon footprint generated by earthwork machineries and that can be used as a central decision-making index during the early planning stages of construction activities.

Baowen Lou, Diego Maria Barbieri, Rolf André Bohne
Metadata
Title
Proceedings of the 5th International Conference on Transportation Geotechnics (ICTG) 2024, Volume 7
Editors
Cholachat Rujikiatkamjorn
Jianfeng Xue
Buddhima Indraratna
Copyright Year
2025
Publisher
Springer Nature Singapore
Electronic ISBN
978-981-9782-37-6
Print ISBN
978-981-9782-36-9
DOI
https://doi.org/10.1007/978-981-97-8237-6