Tunnel Seismic Prediction (TSP) is a geophysical investigation method used to predict the rock conditions ahead of the tunnel face. The method has been used in different types of rock and rock conditions. The Swedish Transport Administration, Trafikverket, has used the investigation method in multiple locations in the large infrastructure project E4 The Stockholm Bypass. The method is however rather new to Swedish rock conditions, and there is therefore a need to evaluate the method to assess its strengths and weaknesses. In this thesis, the TSP method is compared to other investigation methods used in the Stockholm Bypass project at the location Sätra-Kungshatt where the tunnels cross underneath Lake Mälaren. The investigation methods include geological mapping and Measurement While Drilling (MWD). The TSP results are also compared to the engineering geological prognosis. An evaluation of how the seismic primary and secondary waves, Vp and Vs, correlates to rock quality was carried out, and a linear regression analysis was performed to determine if the wave velocities found using the TSP method correlate with the Q value retrieved through the geological mapping. It was found that the TSP method is capable of detecting weaker zones of rock mass, however no correlation between the wave velocities and the Q value used to describe the quality of the rock mass was found. When comparing the TSP results to the MWD results, it was found that the methods could be used as complements to each other as the different methods sometimes detected weakness zones where the other method did not. As the geology in this location of Stockholm Bypass overall was found to be complex with rather poor rock mass quality, it could be concluded that the TSP method might be better suited for less complex geology where the contrast in rock quality is greater. / Tunnel Seismic Prediction (TSP) är en geofysisk undersökningsmetod för att tillhandhålla en prognos av berget framför tunnelstuffen. Metoden har använts i olika typer av berg och bergförhållanden. I Sverige har metoden använts av Trafikverket vid flertalet tillfällen i infrastrukturprojektet E4 Förbifart Stockholm. Metoden är dock relativt ny för de svenska bergförhållandena, vilket gör att det finns ett behov av att utvärdera metodens styrkor och svagheter i dessa förhållanden. I detta masterprojekt har resultaten som tillhandahållits från TSP-metoden jämförts med resultat från andra undersökningsmetoder som använts vid vattenpassagen vid Sätra-Kungshatt där tunneln korsar under Mälaren. Dessa undersökningsmetoder inkluderar geologisk kartering och Measurement While Drilling (MWD). TSP-resultaten har även jämförts med den ingenjörsgeologiska prognosen för området. Vikt har lagts på hur den seismiska primärvågen, Vp, och sekundärvågen, Vs, förhåller sig till den karterade bergkvaliteten. En regressionsanalys har även utförts för att avgöra om resultaten från TSP-metoden korrelerar med resultaten från den geologiska karteringen. Jämförelsen mellan de olika undersökningsmetoderna visade på att TSP kan påvisa svaghetszoner i bergmassan. Dock kunde ingen korrelation mellan våghastigheterna och Q värdet påvisas. Jämförelsen mellan TSP och MWD visade att de båda metoderna generellt visade liknande resultat. Dock kunde vissa avvikelser mellan resultaten från metoderna hittas, vilket göra att metoderna skulle kunna användas som komplement till varandra. Detta då de olika metoderna ibland kunde identifiera svaghetszoner som den andra metoden inte kunde identifiera. De svåra geologiska förhållandena på platsen kan ha bidragit till att TSP-resultaten över lag är relativt svårtolkade, vilket gör att TSP-metoden möjligtvis är bättre lämpad för mindre komplexa bergförhållanden där kontrasten mellan bra och dålig bergkvalitet är tydligare.

In any underground facilities especially tunnels, it is essential to seal the area against water ingress and leakage of reserved materials. Grouting is a common method used to seal rocks around tunnels, successful grouting reduces the duration and cost of the construction, guarantees better working environment and higher safety, minimizes the maintenance and most important decreases the corresponding environmental hazards significantly. Achieving a sufficient grout spread is one of the prerequisites for a successful and efficient sealing, the penetration of a grout is defined as the length of how far grout penetrates in the rock through fractures from a bore hole. Chemical grouts and cement-based grouts are the prevailing ones among the grouting materials. Despite the better penetrability of chemical grouts, they are unfavorable to use due to environmental hazards associated to them, whilst cement-based grouts are more convenient to use because of their low cost and low environmental impact.The major drawback with cement-based grouts is their limited ability to penetrate the very narrow fractures which is directly related to their filtration tendency which is defined as the tendency of cement grains to agglomerate and build an impermeable filter cake during the flow. Many previous studies investigated the factors that affect the filtration tendency. They drew different conclusions and suggested various methods to improve the penetrability of cement-based grouts.The mixing method is one of the factors that have a great influence on the penetrability of the grout. An effective mixing method improves the dispersion of cement particles in the mixture, thus the penetrability of the grout. As it is known from previous studies, the finer the cement particles the harder to disperse. Grouts based on micro-fine cement (< 30 μm) are essential for the development of grouts that can seal very narrow fractures (20-50) μm compared to (70-80) μm at the present.In this study, the dispersion efficiency of three different mixing methods was evaluated, a conventional lab dissolver equipped with 90-mm disk, a conventional lab dissolver equipped with R/S system and an ultrasound UP400St device. Two cement types, INJ30 and UF12, that are similar in chemical composition but differ in degree of milling were tested. Dispersion was tested with filter pump.The results showed that the conventional lab dissolver equipped with 90-mm disk is ineffective method. The conventional lab dissolver equipped with R/S system is a better method compared to the 90-mm disk but still not effective enough especially when it comes to grouts based on ultra-fine cement (UF12). The ultrasound dispersion is not only the best method between the three methods in comparison, but even more stable and reliable. The best result obtained was grout based on UF12 passing through the 54 μm filter. This could mean that fracture aperture down to 55 μm now can be sealed. This is a significant improvement but there is still a marginal for further improvements. In combination with the dispersion efficiency of different dispersion methods, the study investigated the effect of additives on dispersion in particular and penetrability in general. Results showed that additives do not directly contribute to better dispersion, but they are necessary for better spread since they affect the flow properties.

When underground openings are constructed, groundwater inflow can occur, which might lead to ground settlements, namely in clay. In these types of construction projects, it is beneficial to be able to quantify risks related to these settlements. A framework developed by Sundell et al. (2019, Risk Analysis, Vol. 39, 105-124) deals with this, in which one part is a statistical settlement model. However, since their model only considers primary compression, a model that accounts for secondary compression (or creep) is necessary to better represent real conditions.In this thesis, an adaptation of Sundell’s et al. (2019) model that includes creep settlement was developed and applied on a focus area of the tunnel project Stockholm Bypass. First, distributions of parameters were created based on data from the project and complementary data from literature. Thereafter, a stochastic model based on an existing creep model was coupled with the Monte Carlo method.A cell where 8 m groundwater drawdown had previously been measured was simulated with the stochastic model. Results from this show wide settlement distribution. Moreover, a scenario with a sudden groundwater drawdown of 6 m was simulated over the entire focus area. Results from the scenario show larger settlements over a larger influence area when creep effects were included compared with simulations without creep effects.The proposed model was also verified against two other creep settlement models. The verification indicates an overestimation in initial settlements, but an underestimation of the excess pore pressure. The proposed model long-term settlement results were within 0.1 m of the compared models. A sensitivity analysis shows that different size of distributions of the permeable parameters and the creep parameters used in the model had low impact on settlement distribution in the presented model. / Undermarksanläggningar kan orsaka grundvattendränering, vilket kan leda till marksättningar. I dessa projekt är det fördelaktigt att kunna kvantifiera riskerna för dessa marksättningar. Ett ramverk utvecklat av Sundell et al. (2019, Risk Analysis, Vol. 39, 105-124) behandlar detta, och inbegriper bland annat en statistisk sättningsmodell. Eftersom modellen endast beaktar primärkonsolidering av jorden, är en modell som även behandlar sekundärkonsolidering (krypning) nödvändig för att bättre representera verkliga förhållanden.I denna uppsats utvecklades och tillämpades en anpassning av Sundells et al. (2019) modell till att inkludera krypsättningar på ett fokusområde i tunnelprojektet Förbifart Stockholm. Först skapades fördelningar av parametrar baserade på data från projektet samt kompletterande data från litteratur. Därefter byggdes en stokastisk modell baserat på en existerande krypmodell kopplat med Monte Carlo-metoden.Med den stokastiska modellen simulerades en punkt där 8 m grundvattensänkning hade skett. Resultatet från denna simulering visar att den beräknade sättningen är varierande. Därutöver simulerades hela fokusområdet för ett scenario med en konstant grundvattensänkning på 6 meter. Resultatet visar större sättningar över ett större påverkansområde när krypeffekter inkluderas jämfört med när de inte gjorde det.Den föreslagna modellen verifierades också mot två andra krypsättningsmodeller. Verifieringen antyder på en överskattning i de initiala sättningarna, men en underskattning av porövertrycket. Den föreslagna modellens långsiktiga sättningar låg inom 0,1 m jämfört med de andra modellernas sättningar. Genom en sensitivitetsanalys erhölls att storleken på variationskoefficienten hos permeabilitetsparametrar samt krypparametrar använda i modellen inte hade någon större påverkan på fördelningen av sättningar i den presenterade modellen.

<p dir="ltr">Over the past three to four decades, mechanically stabilized earth (MSE) walls have gained preference over other wall types due to the several advantages that they offer, such as ease of construction, flexibility to accommodate large differential settlements, architectural versatility, and low cost per unit area of wall face. Because of these advantages, several departments of transportation in the United States have adopted MSE walls to serve as abutments for highway and railway bridges. While the response of conventional MSE walls has been studied both experimentally and numerically, comparatively less work has been done to investigate the behavior of MSE walls used as abutments for bridge support. This dissertation presents a case study of the performance of a pile-supported, MSE bridge abutment in Whitestown, Indiana, during construction and while in service. A zone near the middle of the east MSE abutment wall was instrumented with earth pressure cells, strain gauges, inclinometers, and crackmeters to investigate the transfer of dead and live loads from the bridge to the foundation elements (pile cap and piles), and to assess the performance of the MSE abutment wall under these loading conditions. The data was collected continuously, both during and after construction, using multiplexers and dataloggers powered by solar panels. The values of key parameters used in MSE wall design were determined from the instrumentation results and compared with those obtained using design methods available in the literature. In addition, the measured dead loads carried by the instrumented piles were compared with the estimated dead loads used in the design of the MSE abutment. After the bridge was constructed, a live load test was performed by parking twelve triaxle trucks at different locations along the approach to the instrumented MSE abutment as well as on the bridge deck near the abutment. Finally, a series of three-dimensional finite element analyses of MSE walls and pile-supported MSE abutments were performed using a two-surface-plasticity constitutive sand model. The lateral stresses on the back of the wall facing and the reinforcement tensile loads obtained from the FE analyses were found to be in good agreement with those measured at the end of construction of the Whitestown MSE abutment. The results obtained from the FE analyses highlight the influence of wall height, backfill soil type, and pile offset on the magnitude and distribution of the lateral stresses on the back of the wall facing and the maximum tensile loads in the reinforcements.</p>

Site characterization is an important task in Geotechnical Engineering. In situ tests based on standard penetration test (SPT), cone penetration test (CPT) and shear wave velocity survey are popular among geotechnical engineers. Site characterization using any of these properties based on finite number of in-situ test data is an imperative task in probabilistic site characterization. These methods have been used to design future soil sampling programs for the site and to specify the soil stratification. It is never possible to know the geotechnical properties at every location beneath an actual site because, in order to do so, one would need to sample and/or test the entire subsurface profile. Therefore, the main objective of site characterization models is to predict the subsurface soil properties with minimum in-situ test data. The prediction of soil property is a difficult task due to the uncertainities. Spatial variability, measurement ‘noise’, measurement and model bias, and statistical error due to limited measurements are the sources of uncertainities. Liquefaction in soil is one of the other major problems in geotechnical earthquake engineering. It is defined as the transformation of a granular material from a solid to a liquefied state as a consequence of increased pore-water pressure and reduced effective stress. The generation of excess pore pressure under undrained loading conditions is a hallmark of all liquefaction phenomena. This phenomena was brought to the attention of engineers more so after Niigata(1964) and Alaska(1964) earthquakes. Liquefaction will cause building settlement or tipping, sand boils, ground cracks, landslides, dam instability, highway embankment failures, or other hazards. Such damages are generally of great concern to public safety and are of economic significance. Site-spefific evaluation of liquefaction susceptibility of sandy and silty soils is a first step in liquefaction hazard assessment. Many methods (intelligent models and simple methods as suggested by Seed and Idriss, 1971) have been suggested to evaluate liquefaction susceptibility based on the large data from the sites where soil has been liquefied / not liquefied. The rapid advance in information processing systems in recent decades directed engineering research towards the development of intelligent models that can model natural phenomena automatically. In intelligent model, a process of training is used to build up a model of the particular system, from which it is hoped to deduce responses of the system for situations that have yet to be observed. Intelligent models learn the input output relationship from the data itself. The quantity and quality of the data govern the performance of intelligent model. The objective of this study is to develop intelligent models [geostatistic, artificial neural network(ANN) and support vector machine(SVM)] to estimate corrected standard penetration test (SPT) value, Nc, in the three dimensional (3D) subsurface of Bangalore. The database consists of 766 boreholes spread over a 220 sq km area, with several SPT N values (uncorrected blow counts) in each of them. There are total 3015 N values in the 3D subsurface of Bangalore. To get the corrected blow counts, Nc, various corrections such as for overburden stress, size of borehole, type of sampler, hammer energy and length of connecting rod have been applied on the raw N values. Using a large database of Nc values in the 3D subsurface of Bangalore, three geostatistical models (simple kriging, ordinary kriging and disjunctive kriging) have been developed. Simple and ordinary kriging produces linear estimator whereas, disjunctive kriging produces nonlinear estimator. The knowledge of the semivariogram of the Nc data is used in the kriging theory to estimate the values at points in the subsurface of Bangalore where field measurements are not available. The capability of disjunctive kriging to be a nonlinear estimator and an estimator of the conditional probability is explored. A cross validation (Q1 and Q2) analysis is also done for the developed simple, ordinary and disjunctive kriging model. The result indicates that the performance of the disjunctive kriging model is better than simple as well as ordinary kriging model. This study also describes two ANN modelling techniques applied to predict Nc data at any point in the 3D subsurface of Bangalore. The first technique uses four layered feed-forward backpropagation (BP) model to approximate the function, Nc=f(x, y, z) where x, y, z are the coordinates of the 3D subsurface of Bangalore. The second technique uses generalized regression neural network (GRNN) that is trained with suitable spread(s) to approximate the function, Nc=f(x, y, z). In this BP model, the transfer function used in first and second hidden layer is tansig and logsig respectively. The logsig transfer function is used in the output layer. The maximum epoch has been set to 30000. A Levenberg-Marquardt algorithm has been used for BP model. The performance of the models obtained using both techniques is assessed in terms of prediction accuracy. BP ANN model outperforms GRNN model and all kriging models. SVM model, which is firmly based on the theory of statistical learning theory, uses regression technique by introducing -insensitive loss function has been also adopted to predict Nc data at any point in 3D subsurface of Bangalore. The SVM implements the structural risk minimization principle (SRMP), which has been shown to be superior to the more traditional empirical risk minimization principle (ERMP) employed by many of the other modelling techniques. The present study also highlights the capability of SVM over the developed geostatistic models (simple kriging, ordinary kriging and disjunctive kriging) and ANN models. Further in this thesis, Liquefaction susceptibility is evaluated from SPT, CPT and Vs data using BP-ANN and SVM. Intelligent models (based on ANN and SVM) are developed for prediction of liquefaction susceptibility using SPT data from the 1999 Chi-Chi earthquake, Taiwan. Two models (MODEL I and MODEL II) are developed. The SPT data from the work of Hwang and Yang (2001) has been used for this purpose. In MODEL I, cyclic stress ratio (CSR) and corrected SPT values (N1)60 have been used for prediction of liquefaction susceptibility. In MODEL II, only peak ground acceleration (PGA) and (N1)60 have been used for prediction of liquefaction susceptibility. Further, the generalization capability of the MODEL II has been examined using different case histories available globally (global SPT data) from the work of Goh (1994). This study also examines the capabilities of ANN and SVM to predict the liquefaction susceptibility of soils from CPT data obtained from the 1999 Chi-Chi earthquake, Taiwan. For determination of liquefaction susceptibility, both ANN and SVM use the classification technique. The CPT data has been taken from the work of Ku et al.(2004). In MODEL I, cone tip resistance (qc) and CSR values have been used for prediction of liquefaction susceptibility (using both ANN and SVM). In MODEL II, only PGA and qc have been used for prediction of liquefaction susceptibility. Further, developed MODEL II has been also applied to different case histories available globally (global CPT data) from the work of Goh (1996). Intelligent models (ANN and SVM) have been also adopted for liquefaction susceptibility prediction based on shear wave velocity (Vs). The Vs data has been collected from the work of Andrus and Stokoe (1997). The same procedures (as in SPT and CPT) have been applied for Vs also. SVM outperforms ANN model for all three models based on SPT, CPT and Vs data. CPT method gives better result than SPT and Vs for both ANN and SVM models. For CPT and SPT, two input parameters {PGA and qc or (N1)60} are sufficient input parameters to determine the liquefaction susceptibility using SVM model. In this study, an attempt has also been made to evaluate geotechnical site characterization by carrying out in situ tests using different in situ techniques such as CPT, SPT and multi channel analysis of surface wave (MASW) techniques. For this purpose a typical site was selected wherein a man made homogeneous embankment and as well natural ground has been met. For this typical site, in situ tests (SPT, CPT and MASW) have been carried out in different ground conditions and the obtained test results are compared. Three CPT continuous test profiles, fifty-four SPT tests and nine MASW test profiles with depth have been carried out for the selected site covering both homogeneous embankment and natural ground. Relationships have been developed between Vs, (N1)60 and qc values for this specific site. From the limited test results, it was found that there is a good correlation between qc and Vs. Liquefaction susceptibility is evaluated using the in situ test data from (N1)60, qc and Vs using ANN and SVM models. It has been shown to compare well with “Idriss and Boulanger, 2004” approach based on SPT test data. SVM model has been also adopted to determine over consolidation ratio (OCR) based on piezocone data. Sensitivity analysis has been performed to investigate the relative importance of each of the input parameters. SVM model outperforms all the available methods for OCR prediction.

In recent years, the increasing impacts of landslide hazards on human lives and lifeline facilities worldwide has advanced the necessity to find out both economically acceptable and useful techniques to predict the occurrence and destructive power of landslides. Though many projects exist to attain this goal, the current investigation set out to establish an understanding of the initiation and propagation mechanisms of landslides via numerical simulations, so that mitigation strategies to reduce the long-term losses from landslide hazards can be made. In this research, the Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD) have been used to investigate the mechanical and hydraulic behaviour of granular materials involved in landslides. The main challenge is to provide rational analyses of large scale landslides via small scale numerical simulations. To solve this problem, dimensional analyses have been performed on a simple granular column collapse model. The influence of governing dimensionless groups on the debris runout distance and deposit height has been studied for the terrestrial and submerged granular flows. 3D DEM investigations of granular flows in plane strain conditions have been performed in this research. The input parameters of the DEM model have been calibrated by the numerical triaxial tests, based on which, the relationships between the microscopic variables and the macroscopic soil strength properties are analysed. Using the simple granular column collapse model, the influences of column aspect ratio, characteristic strain, model size ratio and material internal friction angle on the runout distance and deposit height of granular materials have been examined. Additionally, the deformation and energy evolution of dry granular materials are also discussed. The DEM-CFD coupling model has been employed to study the mechanical and hydraulic behaviour of highly mobilized terrestrial / submarine landslides. This model has been validated via numerical simulations of fluid flow through a porous soil sample and grain batch sedimentations. The simulations of granular flows in the submerged environment have led to some meaningful insights into the flow mechanisms, such as the mobilization of sediments, the generation and dissipation of excess pore water pressures and the evolution of effective stresses. Overall, this study shows that the proposed numerical tools are capable of modelling the mechanical and hydraulic behaviour of terrestrial and submarine landslides.

The Canterbury Earthquakes of 2010-2011, in particular the 4th September 2010 Darfield earthquake and the 22nd February 2011 Christchurch earthquake, produced severe and widespread liquefaction in Christchurch and surrounding areas. The scale of the liquefaction was unprecedented, and caused extensive damage to a variety of man-made structures, including residential houses. Around 20,000 residential houses suffered serious damage as a direct result of the effects of liquefaction, and this resulted in approximately 7000 houses in the worst-hit areas being abandoned. Despite the good performance of light timber-framed houses under the inertial loads of the earthquake, these structures could not withstand the large loads and deformations associated with liquefaction, resulting in significant damage. The key structural component of houses subjected to liquefaction effects was found to be their foundations, as these are in direct contact with the ground. The performance of house foundations directly influenced the performance of the structure as a whole. Because of this, and due to the lack of research in this area, it was decided to investigate the performance of houses and in particular their foundations when subjected to the effects of liquefaction. The data from the inspections of approximately 500 houses conducted by a University of Canterbury summer research team following the 4th September 2010 earthquake in the worst-hit areas of Christchurch were analysed to determine the general performance of residential houses when subjected to high liquefaction loads. This was followed by the detailed inspection of around 170 houses with four different foundation types common to Christchurch and New Zealand: Concrete perimeter with short piers constructed to NZS3604, concrete slab-on-grade also to NZS3604, RibRaft slabs designed by Firth Industries and driven pile foundations. With a focus on foundations, floor levels and slopes were measured, and the damage to all areas of the house and property were recorded. Seven invasive inspections were also conducted on houses being demolished, to examine in more detail the deformation modes and the causes of damage in severely affected houses. The simplified modelling of concrete perimeter sections subjected to a variety of liquefaction-related scenarios was also performed, to examine the comparative performance of foundations built in different periods, and the loads generated under various bearing loss and lateral spreading cases. It was found that the level of foundation damage is directly related to the level of liquefaction experienced, and that foundation damage and liquefaction severity in turn influence the performance of the superstructure. Concrete perimeter foundations were found to have performed most poorly, suffering high local floor slopes and being likely to require foundation repairs even when liquefaction was low enough that no surface ejecta was seen. This was due to their weak, flexible foundation structure, which cannot withstand liquefaction loads without deforming. The vulnerability of concrete perimeter foundations was confirmed through modelling. Slab-on-grade foundations performed better, and were unlikely to require repairs at low levels of liquefaction. Ribraft and piled foundations performed the best, with repairs unlikely up to moderate levels of liquefaction. However, all foundation types were susceptible to significant damage at higher levels of liquefaction, with maximum differential settlements of 474mm, 202mm, 182mm and 250mm found for concrete perimeter, slab-on-grade, ribraft and piled foundations respectively when subjected to significant lateral spreading, the most severe loading scenario caused by liquefaction. It was found through the analysis of the data that the type of exterior wall cladding, either heavy or light, and the number of storeys, did not affect the performance of foundations. This was also shown through modelling for concrete perimeter foundations, and is due to the increased foundation strengths provided for heavily cladded and two-storey houses. Heavy roof claddings were found to increase the demands on foundations, worsening their performance. Pre-1930 concrete perimeter foundations were also found to be very vulnerable to damage under liquefaction loads, due to their weak and brittle construction.

The distinct element method (DEM) is a useful tool in rock engineering to model jointed rock masses. To simulate a jointed rock mass realistically, the main challenge is to be able to capture its complex geometry which consists of blocks with various shapes and sizes, and to model the interactions between these blocks. The main contribution of this thesis is the development of novel algorithms in the DEM to model jointed rock masses, namely rock slicing procedures for block generation, and algorithms for contact detection between polygonal blocks in 2-D or polyhedral blocks in 3-D. These algorithms make use of convex optimisation techniques, for which there exist efficient solution procedures. They do not rely on conventional vertex-edge-face hierarchical data structures and tedious housekeeping algorithms. The algorithms have been verified against analytical and numerical solutions, as well as validated against experimental results published in the literature. Among those, the results of DEM simulations were compared against the experimental model tests and numerical simulations of jointed beams carried out by Talesnick et al. (2007) and Tsesarsky & Talesnick (2007) respectively. Emphasis was placed on modelling the stiffness of the block interfaces accurately, and this was accomplished by reinterpreting the laboratory data published by the investigators. The capabilities of the numerical tools are also examined and demonstrated in areas for which the DEM has found practical application. A substantial fraction of this thesis is devoted to illustrating how these tools can assist the engineer in designing support systems; for example, designing the length and spacing of rock bolts and the lining thickness for a tunnel. Algorithms to model rock bolt and lining support were implemented for this purpose. Interesting comparisons with elastic solutions for supported openings were obtained. Further, it is shown that the relative benefit of introducing more rock bolts or thicker lining can be evaluated using the numerical tools with the aid of an interaction diagram. In the final part of this thesis, the case history of the 1963 Vaiont rock slide in Italy is studied. The 2-D analyses led to useful insights concerning the influence of the reservoir water level, the rock mass strength and deformability, and the slide surface shear stiffness. 3-D analyses were undertaken to investigate the influence of the eastern boundary of the slope, and interesting insights were obtained concerning the slope kinematics. Overall, the case study shows that the tools are capable of modelling problems with specific physical and geometrical detail in both 2-D and 3-D.

Vibratory driven sheet piles are a cost-effective retaining wall structure, and in coming decades the continued use of this method will be crucial for minimising costs within the construction sector. However, vibratory driven sheet piles are a source of ground vibrations, which may harm structures or induce disturbance. Most urban construction projects face strict limits on permissible vibration level. Being able to reliably predict the expected vibration level prior to construction is therefore highly important. Reliable prediction demands a profound knowledge of the vibration transfer process, from source to point of interest. This thesis focuses on clarifying the vibration transfer process and will serve as a platform for the future development of a reliable prediction model. The vibration transfer process is divided into two main parts: vibration source and vibrations in soil. The different parts in the vibration transfer process are studied and investigated with the help of a literature review, field tests and numerical modelling. Within the scope of this thesis, three field tests have been conducted and a new instrumentation system has been developed. The new instrumentation system enables recording of both sheet pile vibrations and ground vibrations at depth during the entire driving. The field tests aimed to study the vibration transfer from sheet pile to soil and the vibration transfer within a sheet pile wall, as well as the wave pattern in soil. To study sheet pile behaviour during driving a numerical model was developed, which is also meant to serve as a basis for further studies. The main scientific contribution of this thesis is the identification of the sheet pile behaviour during driving. For practical application, the main contribution is the development of an increased knowledge of the vibration transfer process from source to soil, together with the new instrumentation system and the development of the numerical model. / Vibrodriven spont är en kostnadseffektiv stödkonstruktion och i framtiden kommer den fortsatta användningen av denna metod att vara nödvändig för att minimera kostnader för byggprojekt. Vibrodriven spont är dock en källa till markvibrationer, som kan skada byggnader eller orsaka störningar. De flesta byggprojekt måste förhålla sig till strikta krav gällande vibrationsnivåer. Möjligheten att på ett tillförlitligt sätt förutsäga vibrationsnivåerna innan bygget startar är därför av största vikt. Tillförlitlig prognos av vibrationsnivåer i samband med vibrodrivning av spont kräver god kännedom om vibrationsöverföringsprocessen, från källan till det potentiella skadeobjektet. Denna avhandling fokuserar på att förtydliga vibrationsöverföringsprocessen och fungera som en plattform för framtida utveckling av en tillförlitlig prognosmodell. Vibrationsöverföringsprocessen delas in i två huvuddelar; vibrationskällan och vibrationer i jord. De olika delarna av vibrationsöverföringsprocessen studeras och undersöks med hjälp av litteraturstudie, fältförsök och numerisk modellering. Inom ramarna för denna avhandling har tre fältförsök utförts och ett nytt instrumenteringssystem har utvecklats. Det nya instrumenteringssystemet möjliggör mätning av både spontvibrationer och vibrationer på djup i jorden, under hela neddrivningsfasen. Fältförsöken syftade till att studera vibrationsöverföringen mellan spont och jord, vibrationsöverföringen inom en spontvägg samt vågmönstret i jorden under drivning. För att studera spontens beteende under neddrivning utvecklades en numerisk modell, som också kan fungera som en bas för framtida studier. Avhandlingens huvudsakliga vetenskapliga bidrag är identifieringen av spontens beteende under neddrivning. För praktisk tillämpning är det huvudsakliga bidraget förklaringen av vibrationsöverföringsprocessen från källa till jord, det nya instrumenteringssystemet samt utvecklingen av den numeriska modellen.

Correct modelling of embankment breach formation is essential for an accurate assessment of the associated flood risk. Modelling breach formation due to overflow requires a thorough understanding of the geotechnical processes in unsaturated soils as well as erosion processes under supercritical flow conditions. This thesis describes 1D slope stability analysis performed for unsaturated soils whose moisture content changes with time. The analysis performed shows that sediment-laden gravity flows play an important role in the erosion behaviour of embankments. The thesis also describes a practical, fast breach model based on a simplified description of the physical processes that can be used in modelling and decision support frameworks for flooding. To predict the breach hydrograph, the rapid model distinguishes between breach formation due to headcut erosion and surface erosion in the case of failure due to overflow. The model also predicts the breach hydrograph in the case of failure due to piping. The assumptions with respect to breach flow modelling are reviewed, and result in a new set of breadth-integrated Navier-Stokes equations, that account for wall shear stresses and a variable breadth geometry. The vertical 2D flow field described by the equations can be used to calculate accurately the stresses on the embankment during the early stages of breach formation. Pressure-correction methods are given for solving the 2D Navier-Stokes equations for a variable breadth, and good agreement is found when validating the flow model against analytical solutions.