Design decisions in geotechnical engineering typically need to be made under considerable uncertainty, both regarding presentgeotechnical conditions and future events occurring during the service life of the structure. To optimize the utility of societalinvestments, design decisions should consider the life cycle cost (LCC) and not only the construction cost. This paper investigates theapplicability of Bayesian statistical decision theory to assist in this decision making. The paper illustrates the concepts with a practicalexample, where a geotechnical engineer considers three design alternatives for the foundation of a road embankment: pre-fabricatedvertical drains with a surcharge, end-bearing and floating dry deep mixing columns. The effect of a potential extreme groundwaterdrawdown event on the LCC of these alternatives is analyzed and discussed. Concluding remarks are made on the relevance of suchdesign tools in a structured risk management in geotechnical engineering projects.

Following an increased focus on societal sustainability, life-cycle considerations have become more important for owners of geotechnical engineering structures. A structural design shall not only perform well at the completion of the structure, but facilitate structural performance over the whole service life. A sustainable geotechnical design should therefore strive to minimise the total life-cycle cost of the structure. As a consequence, the design needs to consider the effect of potential future hazards and allow for cost-effective maintenance.

This report takes a first step toward risk-based life-cycle assessments in geotechnical design. The report reviews the current state of the art of probabilistic life-cycle assessments in civil engineering, with a focus on geotechnical design. Based on this, a probabilistic decision tool for geotechnical design from a life-cycle perspective is proposed. The applicability of the tool is then illustrated for a practical case, where different design alternatives for an embankment foundation on soft clay (vertical drains or dry deep mixing columns) are evaluated with respect to a potential groundwater drawdown event, occurring during the service life of the embankment. To facilitate this life-cycle cost assessment, novel reliability-based design methodologies were developed both for surcharges on vertical drains and for dry deep mixing columns. The research results are summarised in this final report and in six scientific articles, which have been appended.

Samhällets ökade intresse för hållbar utveckling har gjort livscykelanalyser alltmer relevanta för ägare av geotekniska anläggningar. Konstruktionens utformning ska inte bara avse förhållandena vid invigning, utan även fungera under konstruktionens hela dimensionerande livslängd. En geotekniker bör därför sträva efter att konstruktionens livscykelkostnad minimeras. Utformningen behöver därför väljas med beaktande av såväl framtida hot från extrema laster som kostnadseffektiva möjligheter till underhåll. 

Denna rapport tar ett första steg mot riskbaserade livcykelkostnadsanalyser inom geotekniken. Rapporten redogör för det nuvarande forskningsläget kring sannolikhetsbaserade livscykelanalyser inom anläggningsbyggande, med särskilt fokus på geotekniken. Utifrån detta har ett sannolikhetsbaserat beslutsverktyg tagits fram. Verktyget analyserar val mellan olika möjliga designalternativ utifrån möjliga effekter under hela livscykeln. Verktygets användbarhet visas genom ett illustrativt beräkningsexempel, där olika grundläggningsalternativ för en vägbank (vertikaldräner med överlast och kalkcementpelare av olika längd) utvärderas med avseende på effekten av en extrem grundvattensänkning, som potentiellt kan inträffa under vägbankens livslängd. För att kunna förse verktyget med relevant indata har även nya sannolikhetsbaserade metoder utvecklats för dimensionering av dessa grundläggningsalternativ. Forskningsresultaten sammanfattas i denna slutrapport, som även inkluderar sex vetenskapliga artiklar.

espite the new Swedish client requirement to reduce the climate impact from the construction of roads, there has been relatively little research so far on how the optimization measures regarding the environmental impact of road pavements can be integrated in the traditional design. An increase in axle weights, changes of the traditional ways of travel, e.g. the use of automated and guided vehicles, and stricter customer requirements on reducing the climate impact require new approaches to steer the road and pavement industry towards more climate neutral solutions. This paper analyzes the latest standards for sustainability assessment of engineering works in an attempt to adjust these standards for assessing various road design options in a comparable and fair way, also when various materials are included.

This paper presents results of documented soil motions in the ground based on full scale field tests of vibro-driven sheet piles. A novel simplified analytical view of the transfer mechanisms is presented for singular and in interlock driven sheet piles, describing the dynamic vibro-pile-soil-interaction at shaft as well at pile toe. The view comes out of experiences from numerous conducted field tests, based on a range of different results from self-developed sensors that's been mounted; on the driven piles, left in place on preinstalled piles, on- and in-depth of the soil at different radial distances in the soil volume beside the driven pile. The vibration transfer to soil at the pile-soil interface boils down to the pile motion. The motion of the pile is a consequence of how the driving force enters the driven profile. Results of infield observed soil motion are presented, the effects of how the pile vibrates both vertically, horizontally as well as transversally and how the motion of the driven profile connected to the adjoining sheet pile wall, is set into motion as well and therefore also transfers vibrations into the nearby soil. 

Geoteknikern hanterar i sin vardag många och ofta stora risker. Men trots att kostnaden för negativa utfall av geotekniska risker årligen bedöms ligga på flera miljarder kronor, används tillgängliga verktyg för strukturerad riskhantering sparsamt. I ett SBUF-projekt har vi tagit fram en vägledning för hur sådana verktyg kan användas i praktiken. Vi har i denna vägledning särskilt fokuserat på den för riskhanteringen så viktiga systemförståelsen av det geotekniska sammanhanget som man verkar i. Denna artikel är en sammanfattande kortversion av den slutrapport som författarna skrivit inom ramen för SBUF-projektet.

Due to increasing demand to maintain vibration levels below strict limits during construction, it is important to develop a better understanding of how vibrations emanate from the shaft and the toe during vibratory sheet pile driving. It is still unclear whether it is the shaft or the toe that contributes the most regarding induced ground vibration levels. A sheet pile shaft has a significantly larger area compared to the toe area. It is therefore expected that the shaft would contribute the more significantly. However, results from full scale field studies have shown that the sheet pile toe also has a large influence on ground vibration levels as the toe passes measurement points buried in the ground close to the vibrodriven sheet piles. This paper employs a numerical model developed to investigate the hypothesis that most of the ground vibrations emanate from the shaft during vibratory sheet pile driving. The results indicate during driving in clay the contribution from the toe and shaft to ground vibration depends on the sheet pile penetration depth, with the shaft dominating vertical ground vibrations for large penetration depths. 

Vibrations due to sheet pile driving are a problem in many urban areas today. Increased knowledgeof the vibration transfer process from source to nearby objects is important in order to enableminimization of induced vibrations. The transfer of vibrations from sheet pile to soil is dependent onthe sheet pile behaviour during driving. This paper presents a 3D finite element study of thebehaviour of a vibratory driven sheet pile, complementing results from a full-scale field test. Thefinite element model accounts for strain dependent soil stiffness using an equivalent linear soilmodel. The conclusion is that the sheet pile bends considerably during driving with eccentricclamping. Furthermore, it is shown that the bending mode is similar irrespective of sheet pilepenetration depth.

Vibrations due to pile and sheet pile driving are known to cause discomfort for people, aswell as damage to nearby buildings and structures. To enable prediction of ground vibration levels itis important to acknowledge the wave patterns induced in the ground to correctly determine whichattenuation model to adopt. This paper presents wave patterns in the ground due to vibratory sheetpile driving based on field measurements from three case studies. The results show different wavepatterns in the ground. At the ground surface the wave patterns are elliptical, resembling Rayleighwaves. At depth in the soil the wave patterns are instead strongly polarized in different directions,indicating the presence of P- and S-waves. Moreover, wave patterns tend to become more irregularwith increasing distance from the source. This paper contributes to an improved understanding ofwave patterns in the ground during vibratory sheet pile driving, forming a platform for thedevelopment of a reliable prediction model.

Vibrations due to pile and sheet pile driving are part of a complex process involving several factors that influence both vibration magnitude and frequency. Better understanding and prediction of the vibrations generated will greatly benefit the civil engineering practice as well as the construction industry. An important component in understanding vibrations due to pile driving is to comprehend and understand working procedures and the influence of different factors. The objective is to present and discuss factors and working procedures that influence vibrations caused by pile driving, based on three current field tests and formerly presented experience from literature. It is concluded that the factors have the highest impact on ground vibrations due to pile driving are the geotechnical conditions, the vibration generated at the source, the distance from the source and the installation method.