In 2005, a pipeline construction was undertaken under the river IJ in Amsterdam. The microtunneling method was used and it consisted of a closed front TBM of 1800mm diameter over a length of 785m in Pleistocene Sand and extremely soft Holocene sediments and anthropogenic sediments. This construction was accompanied by instrumentation that registered the drilling process with force measurements in the main jacks and intermediate jacking stations, strain in the concrete, joint width, tilt of the element and displacement measurements.
All this data was analysed with the focus on the friction development over the entire boring length. The first part of data analysis was to plot and describe the findings of the available parameters, along the total route, that could have an influence on the friction. Next, the microtunnel route was divided into six sections based on changes in soil conditions and in alignment so the analysed parameters (horizontal and vertical deviations, tilt, main jacking force , front force and friction) could be correlated. In order to better understand the results, a Pearson’s correlation analysis was created to identify any statistically relevant correlation between the available parameters. The final analysis was performed to estimate the impact that subsequent pipe segment installations have on the friction over time at a specific location.
The friction development over the entire length at the boring under the river IJ (less than 2kPa, with the exception of the start) was compared with the friction coefficient value described in the NEN 3650 when overcut and lubrication are used for concrete pipes (f =7.5 kPa). The friction coefficient is overestimated during design phase and can be optimized. Also for all six sections, after a standstill, an increase in friction is observed. At locations where correlation between alignment and forces are apparently present, the horizontal deviation is observed as the influencing parameter. This is also confirmed by the Pearson’s correlation analysis results. Regarding the impact that subsequent pipe segment installations have on the friction, the results of this analysis clearly shows a tendency for a decrease in friction when considering soil type and changes in alignment.
Overall, this work indicates the need of a more thorough friction prediction calculation to be included in the design standards. One that includes more influencing parameters other than overcut and lubricant. Such understanding would enable more accurate predictions in future projects, reducing both risks and costs.

This thesis aims to explore the influence of borehole alignment accuracy and other soil and pipe parameters on the pullback forces during the pullback phase in Hor- izontal Directional Drilling (HDD) operations. To that end a model inspired by PipeForce V1 was implemented and expanded upon in Python. The model was used to calculate the pullback forces based on the measured product pipe naviga- tional coordinates obtained from actual HDD projects. Calculated pullback force data was compared to actual measurements. It was found that pullback forces tend to decrease with increasing borehole alignment accuracy. The extent of the influ- ence depends on the length of the installation under consideration. Furthermore, through analysing ballasting and specific gravity of slurry, it was found that a bal- ance between those factors resulted in a decrease in the maximal pullback forces, through optimising the effective vertical force on the product pipe. Lastly, it was found that the originally proposed model PipeForce V1 should not be applied to longer installations due to an almost quadratic growth in one of the calculated fac- tors, which was not checked for in the original publication.

The Noordtunnel is an immersed tunnel open to roadway service since 1990 in The Netherlands. Over the past thirty years of its operation time, a significant differential settlement behaviour has been observed, and this ongoing settlement potentially imposes safety concerns to the tunnel, such as joint leakage. However, the underlying factor triggering this differential settlement behavior remains unknown. To ensure the tunnel's serviceability, this thesis aims to investigate the underlying causes of the occurring excessive settlement, predict future settlements, and assess its impact on tunnel structural safety within its designed lifetime.

The analysis starts by reconstructing the settlement time history of the Noordtunnel. The process involves determining the most reliable reference point and performing back analysis to estimate the settlement magnitude during the unmeasured period. Further, the settlement history is reconstructed by combining all the settlement data of all the periods. It is found that the settlement history at all immersion joints show a logarithmic trendline, with a maximum estimated settlement of about 94.36 mm occurring at immersion joint 2. Subsequently, the soil profile and geotechnical parameters were determined for the simulation. The provided Cone Penetration Test (CPT)s data and borehole ensure the soil profile depicted in the given situation map. Additionally, in the absence of laboratory data, the Hardening Soil Model (HS Model) and Soft Soil Creep Model (SSC) parameters are estimated based on CPT - NEN Table 2b correlations.

Afterward, the Two Dimensions (2D) Finite Element Method (FEM) simulations were carried out in PLAXIS (a commercial simulation software), while considering the variations of load acting on top of the subsoil. Two types of soil constitutive law were chosen to simulate the settlement in the Noordtunnel: HS Model and SSC Model. The optimum model, which can simulate the settlement behaviour in the field, was selected by aligning the simulation outcomes to the reconstructed historical settlement. The simulation results show that only settlement at immersion joint 2 has the same tendency as the SSC Model, while the other immersion joints tend to have a similar tendency to the HS Model. The simulation outcomes also indicate that excessive settlement at immersion joint 2 occurs due to the soft soil underneath the tunnel and the natural sedimentation on top of it. The soft soil is responsible for at least 20 mm of settlement, while the sedimentation contributes to a minimum of 8 mm of settlement during 30 years of tunnel operation. Subsequently, the sensitivity analysis is conducted to examine how much the simulation outcomes may deviate when accounting for soil variability in the field. Due to the narrow distribution of the reference values, adjusting the most sensitive parameter will only deviate the results by a maximum of 5.48% at immersion joint 2 and 4% at the other immersion joints. These results indicate that the model is robust enough and expected to generate reasonable future settlement predictions. An additional settlement of 15.13 mm of settlement is predicted to occur at immersion joint 2, while 4 to 5 mm of additional settlement is anticipated at the other immersion joints over the tunnel's remaining lifespan.

The differential settlement at the tunnel longitudinal direction has triggered element tilting and further induced compression and decompression to the GINA gasket at immersion joints. It has been observed that while uneven settlement contributes to joint decompression, the external forces acting on the GINA gasket remain considerably lower in magnitude compared to the overall friction force. Therefore, the impact of uneven settlement on the water tightness is generally minimal. Additionally, considering the limitations of the current monitoring procedure, an optimized monitoring plan based on the Distributed Optical Fiber Sensor (DOFS) system is proposed. Finally, future recommendations to improve the current thesis are also put forward.

This research addresses the complex challenge of mitigating uplift within a water-retaining system, specifically focusing on the Valmeer Energy Storage Lake (ESL), an integral part of the DELTA21 project. The need for rapid emptying of the ESL during storm surges, often within a tight 12-hour window, has raised concerns about potential seabed uplift and associated volume loss. The central objective of this research is to ensure the stability and integrity of the ESL under these drawdown conditions, particularly by investigating how the soil at the lake’s bottom can achieve equilibrium.
This study explores the Delta21 plan and the energy storage lake concept. Subsequently, it investigates the geological characterisation of the ESL site, providing data for subsequent analyses. Furthermore, a possible solution for using anchor piles is proposed; for that, a review of the Eurocode is done to understand the mechanisms of anchor piles and anchor pile groups. This research study employs Finite Element Method (FEM) calculations to assess bottom stability, both with and without incorporating anchor piles.

Throughout the research, a combination of hand calculations and Finite Element Method (FEM) analysis was employed to understand the subject matter comprehensively. The optimal centre-to-centre distance of 1.2m emerged as the key to effectively preventing uplift. The study also explores the interchangeability of volume elements and embedded piles within the FEM analysis, highlighting their comparable functionality.
Furthermore, an investigation into complete collapse scenarios suggests that tension piles ́ contribution to soil stability might be closely related to their weight rather than their spacing. Nevertheless, the spacing implementation presents challenges, emphasising the necessity for innovative solutions.
Additional soil investigations are recommended to understand the impermeable layer's exact location further. With its potential for uplift due to backpressure, this impermeable layer adds complexity to the interaction between soil layers. Recognising the constraints of the research scope, it is evident that further field investigations and research endeavours are indispensable for a comprehensive understanding of the site conditions and the impermeable layer’s behaviour.
In the final stages, the research concludes with a discussion and recommendations for the DELTA 21 plan specifically and presents the results obtained during this research.

The 1st Heinenoordtunnel is an immersed tube which has been open for service in the Netherlands since 1969. Over the past 50 years, a large and increasing settlement has been measured along the tunnel alignment. The greatest value of settlement (65 mm) occurs in tunnel element 1 from 1978 to 2018. The maximum differential settlement has reached 30 mm between element 1 and 2 which causes a potential threat to the tunnel serviceability. In addition, Distributed Optical Fiber Sensors (DOFS) was used to measure daily joint deformation of immersed tunnel. The result of DOFS has shown a periodic settlement under tide.
The aim of this thesis is to investigate the long-term and daily settlement behavior of Heinenoordtunnel. The study starts with the geological information investigation, followed by settlement analysis using 2D Finite Element Modeling. Both long-term settlement and daily cyclic settlement are simulated and compared with the monitoring data.
In long term settlement analysis, the results show that the consolidation settlement of tunnel element is trivial (<0.5mm) over the 50 years operation. The calculated result does not match with the monitoring data under a constant load assumption over the operational period. Therefore, three additional factors are considered which can be the possible causes of the excessive settlement. Those factors are the growth of traffic volume, fluvial deposition on riverbed and secondary compaction on the foundation. The main results are summarized as follows:
(1) The settlement due to extreme traffic growth is between 10 and 20 mm which increases gradually from 1979 to 2018.
(2) The fluvial deposition causes an average settlement of 1.68 mm over the past 40 years of operation.
(3) The secondary compaction result is in between 5.30 and 10.70 mm, while the exact value depends on the selection of creep parameter.
(4) The combined settlement is in between 18.27 and 30.62 mm that is significantly less than the monitoring data.
Based on the above findings, the combination of those three factors cannot provide a sound explanation on monitoring data. Hence, a sensitivity analysis will be conducted in the final stage of the research.
In the daily settlement response simulation, a coupled flow simulation is applied on both traverse and longitudinal direction under tidal fluctuation. The summary of results is indicated as below:
(1) A phase delay of excess pore water pressure occurs for soil under the low permeable layer. This causes periodic rebound and settlement on the tunnel element
(2) The amplitude of tunnel cyclic settlement is in between 0.143 and 0.215 mm
(3) The deformation of intermediate immersion joint is under 0.059 mm
Since the difference between calculation and monitoring results is over 0.2 mm in joint 6, it is important to conduct sensitivity analysis on the Plaxis model.
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To verify the importance of soil variability, the sensitivity analysis is conducted by reducing the stiffness parameter with two standard deviation value in long term settlement analysis and one standard deviation value in daily settlement analysis. The long-term settlement become twice as the initial value after the parameter adjustment. The difference between monitoring data and Finite Element result reduces by 30 to 192 percent of the original value. On the other hand, the daily settlement of tunnel reduces by 4 to 17 percent under the one standard deviation increment. The daily response of tunnel is closer to the monitoring data after parameter adjustment.
In conclusion, the three factors considered in this research causes a significant change on the total settlement of immersed tunnel. The periodic response of tunnel settlement is verified from the coupled flow mode. Finally, some recommendations are made for future study.

The soil-grout interface friction was measured to be in between 0.0 [kPa] and 14 [kPa]. To measure this friction, a special research method was invented that enabled a tunnel to be recreated. With this setup, any formation could be used. The formation could be created with a hole in the middle which simulated a borehole. Next, by filling and pressurising this hole with a bentonite-water suspension, a stable borehole could be simulated. This borehole was then filled with drillgrout to recreate a tunnel filled with grout. This grout column could then be pulled out of the soil formation so that the friction between the drillgrout and soil could be measured. In this setup, no normal forces were present. Due to the absence of normal forces no friction angle could be deducted which made it impossible to estimate the effect of the friction at the depth where a pipe laid by HDD would generally be found. It was concluded that based on the data found, it is not recommended to use grout as a borehole filling around heat transportation pipes. Although the friction would be mainly determined by the filter cake strength, which is comparable to a weak clay, effects like irregular borehole diameters and large soil stresses at the depth of the pipe, would create a frictional force that is large enough to cause buckling or failure of the insulating PUR layer.

Many immersed tunnels have already reached or are about to reach the halfway point of their intended lifespan of 100 years. Around this time, several structural problems were noticed during inspection which have led to performance deterioration and durability issues of the tunnel. Often large- scale maintenance was required to meet the design life of immersed tunnels. To counter these problems and improve the constructability of tunnels several design changes have been developed over the past two decades. Furthermore, the current monitoring plan lacks in terms of frequency, accuracy and often requires tunnel tube closure. This thesis aims to improve the life cycle operation of immersed tunnels based on long-term structural problems encountered during their design life.

To achieve this, common structural problems encountered were initially identified by reviewing literature and maintenance reports of past projects. Excess deformations, joint gap opening/closure, concrete cracking, corrosion and leakage were determined as the five typical structural problems. These problems were then further analysed based on construction technique, geotechnical engineering and design flaw from a mechanical and structural perspective. Once the structural problems were identified, recent design changes were inventoried based on element material, cross-section design, transverse prestressing, foundation treatment, waterproofing and joint formation. The primary objective of this step was to understand the impact of these design changes in mitigating structural problems.

Following the structural problem study, an improved monitoring plan was developed to serve as an early warning system for structural problems. Firstly, the parameters to be monitored were determined based on how they influenced structural problems. These parameters were vertical displacement, transverse displacement, joint width, crack width, shear key force, leakage detection, chloride diusivity, pH in concrete, concrete strain and foundation soil stiffness. Subsequently, threshold limits for each parameter were set to implement quick remedial actions once these limits were crossed. Afterward, an inventory of sensors and monitoring techniques were selected to monitor these parameters based on accuracy, frequency and how helpful they were to contractors in current-day practice. Remediation measures specific to each structural problem were also briefly discussed.

Offshore pipelines are considered the arteries of the offshore oil and gas industry and transport hydrocarbon products as well as other fluids. During the installation process of an offshore pipeline, the pipeline is most often located in a trench and covered with backfill material. The burial of the pipeline ensures onbottom stability as well as mechanical protection. With a Trailer Suction Hopper Dredger (TSHD) sand can be deposited in the trench, thereby covering the pipeline in a relatively controlled manner. One major risks associated with this backfilling method is the risk of vertical upward displacement of the pipeline during the backfilling process. The vertical upward movement of the pipe is referred to as pipeline flotation and may result in unprotected or damaged pipes. With the rising use of small diameter and lighter pipelines this risk has become more prevalent.

Pipeline flotation is induced by augmented buoyancy which originates from the presence of the water-sand mixture around the pipeline. The particle concentration of the water-sand mixture and the embedment rate of the pipe are leading in the assessment of the buoyancy force acting on the pipeline. The weight of the pipeline is the major force counteracting buoyancy force. In addition, a friction force, resulting from the contact between the pipe and the new formed sand layer around the pipe, counteracts the buoyancy force.

The aim of this research is to develop and validate a simplified numerical model for the analysis of offshore pipeline flotation during sand backfilling with a TSHD. The numerical model has been validated against the small-scale physical experiments of Eikhout (2021). The small-scale physical experiments have been developed and used by Yang (2020) and Eikhout (2021) to simulate a simplified sand backfilling process.

The numerical model is developed to simulate the sedimentation process and has been developed in the finite element software COMSOL Multiphysics. The model is capable of effectively simulating the simplified backfilling process from the small-scale experiments by Eikhout (2021). Moreover, the sedimentation model is able to simulate the inflow of material over time in the physical domain. The sedimentation process has been modelled with a convection equation in which the settling velocity of the water-sand mixture is described with the hindered settling formulation proposed by Metha (1986). The hindered settling formulation describes the velocity of the suspension as a function of its local particle concentration. The numerical data has been processed and used in a force balance which is able to predict the occurrence or absence of pipeline flotation.

The parameters in the hindered settling formulation as well as the numerical settings have been described from a theoretical perspective as well as their practical impact on the numerical solution. After validation against the small-scale physical experiments the numerical model has been used to simulate a more practical scenario. In addition a simplified, spreadsheet friendly, calculation method is proposed.

The historic inner-cities in The Netherlands are largely known for their iconic channels and their accompanying quay walls, of which a significant number were constructed over 100 years ago. Due to the limited available space in the sub-surface of the urban environment, a high number of utility lines (i.e. potable water pipes and sewer systems) are situated in the vicinity of these quay walls. In recent years, a number of quay wall collapses have occured in the inner-city of Amsterdam, some of which have been attributed to utility line leakages. However, research into the interaction between inner-city quay walls and utility lines is lacking. Thus, the aim of this report is to answer the following question: "How does utility line leakage relate to deformation and failure of Amsterdam's inner-city quay walls and when does this interaction become significant?". The interaction between utility lines and inner-city quay walls works in both ways, thus the research is split up accordingly. The effects of utility line leakages on quay wall displacement and failure were qualitative studied using a literature study. The effects of quay wall displacement on utility line leakages were quantitatively studied using an analytical model. In this model, the interaction between utility line and surrounding soil was represented using a beam on a Winkler foundation, i.e. a beam supported by a distributed spring. The stiffness of the spring was represented as bi-linear, resulting from the equilibrium bearing capacity of the soil. Quay wall displacements ranging from 20 up to 100 mm were applied to the most common types and outer diameters of utility lines found in the vicinity of quay walls. Utility line leakage is deemed to occur if a predetermined threshold is passed of either maximum angular deflection, maximum allowable bending moment or maximum allowable shear force, each resulting from the utility line displacement. Although the scope of the study is the inner-city of Amsterdam, the study can be used in other cities with inner-city quay walls, given the circumstances are similar.

The literature study showed that quay wall displacement and failure due to utility line leakage follows from internal erosion processes. Two requirements have to be met for instigation of internal erosion: a local head difference between the water level in the channel and the groundwater level in the soil body behind the quay wall, and an open connection in the quay wall structure in the vicinity of the aforementioned local head difference, enabling the flow of soil via water. The rise of the groundwater level can be the result of a potable water pipe leakage, but can also follow from external factors like heavy rainfall. Three forms of open connections were appointed. The first is scour protection screen leakage, which can result in erosion underneath the structure. The second is quay wall floor leakage, which can result in both erosion underneath structure and erosion in the soil body behind the quay wall. The third is sewer leakage, which can result in erosion in the soil body behind the quay wall. In the latter, the aforementioned head difference is not required. This is because the direction of groundwater flow is not towards the channel, but towards the sewer leakage, given that the sewer pipe is located below the groundwater level. Erosion underneath the quay wall floor can result in quay wall displacement towards the channel, while erosion in the soil body behind the structure can result in the formation of a subsidence pit.

Both erosion underneath- as well as behind the structure can result in (further) deformations of utility lines. The former through quay wall displacement towards the channel, resulting in local soil displacement in which said utility line is embedded in. The latter trough local loss of soil, resulting in a local reduction of support. Both have the potential to result in relative utility line displacements, which can result in leakages. This process is can be denoted as a positive feedback loop. Actual failure of the quay wall due to utility line leakage can come in the form of collapse of the quay wall towards the channel or collapse of the road on top of the structure in the formed subsidence pit. Due to the dependence on external factors, quay wall failure resulting from utility line leakage can be described as a second order effect.

It was found that exceedance of the maximum allowable angular deflection of the utility line joints is most likely to result in leakages. Leakage due to exceedance of maximum allowable bending moment is relatively less likely but still significant, while leakage due to exceedance of maximum allowable shear force is unlikely. In all utility lines, a higher bending stiffness resulted in a lower susceptibility to leakage. If utility lines are deemed susceptible to leakage, it is advised that these are monitored intensely.

Differential settlement is a big issue for an immersed tunnel. This will lead to large stress concentrations in the tunnel construction, giving rise to local cracking, failure of the construction, leakage, deterioration of exposed rebar, etc. Variety factors will influence it, like the consolidation process, the action time of different loads when construction, and the sub-soil condition, etc. To protect the integrity of the structure, settlements should be kept within limits. Although the immersed tunnels are generally designed to withstand buoyancy by a margin of 4%, the settlements have been observed which severely exceed the predictions in the Kiltunnel. In this case, a complicating factor is a fact that the dikes on both sides have been reconstructed after immersing the elements, but not at the same location as before the immersion trench was dredged. Consolidation (at first) and creep due to this relatively new load on the subsoil can play a role as well. These aspects contribute to the problem of the differential settlements which have resulted in leaking joints and consequently increased maintenance costs. In addition, how and to what extent uneven settlement affects the structural safety of tunnels and their users, and how to reduce the durability of tunnels are unknown. As a result, it is necessary for us to do research about the settlement in Kiltunnel.

During the boring of a tunnel in soft soils with a slurry TBM, support pressure is used to achieve equilibrium at the face of the TBM. When this equilibrium is not reached, when the face support pressure is too low or too high, settlements will occur. In this research settlement and pore water pressure measurements are used to monitor the behavior of the soil and estimate the stability of the tunnel face. During boring of the tunnel, the exact stability of the face is not known. The TBM driver has to rely on the provided stratigraphy data, the advised face support pressures range provided by the geotechnical engineers and the experience of the tunnel boring team. Monitoring is not yet used to determine the face stability during construction. To do so, field data from a case study at RijnlandRoute is compared with analytical and numerical models. Sensitivity of the measurement equipment, and of both the analytical (DIN) and numerical model (Plaxis 3D) with respect to soil parameters, are considered. It has been found that the strength parameters of the layer in which the face is located have the highest influence on the minimum face support pressure. For the maximum face support pressure this is the volumetric weight of the entire soil profile above the face. For comparing the (soft soil) field data with numerical results, a Plaxis 3D model is built, and it is determined that HSsmall is a suitable constitutive model to capture the interaction between face stability, tunneling operations and soil behavior. It is shown that the tail void injection influences the settlements above and in front of the cutter head, but this influence is discarded and replaced by a wished in place lining, to simplify the numerical model. A scenario analysis on the sensitivity of soil parameters shows settlements do not vary significantly between the characteristic low and high values. In this analysis correlation of parameters is taken into account. The failure mechanism for the minimum face support pressure coincides with the active cave-in failure mechanism found in literature. For the maximum face support pressure the failure mechanism found in Plaxis 3D does not coincide with the expected hydraulic fracturing failure mode. The continuum representation of the soil in Plaxis 3D does not allow a hydraulic fracturing like failure mechanism to develop. Instead, a blow-out approximately 10 m. in front of the cutterhead occurs. This behaviour better resembles the failure mechanism of a EPB TBM. The field data gathered from the case study shows a thrust wave in front of the cutter head in both settlement and pore water pressure measurements. This thrust wave reaches up to 20 to 40 meters in front of the TBM. The heave induced by the thrust wave reduces the amount of settlements after the TBM passage. Excess pore pressures, induced by a high thrust wave, affect the face stability negatively. The excess pore pressure mainly depends on the advance rate. The higher the advance rate, the less time the pore pressures have to dissipate, leading to an increase in excess pore pressure. The accuracy of the settlements measurement devices is 0.8 mm., and of the spade cells 1.0 kPa. In general, the field data shows settlement curves corresponding to the Peck (1969) Gaussian curve (in lateral and longitudinal direction). Comparing the case study settlements with the numerically generated settlement curves show similar trends. The field data shows lower settlements than the numerical results. This can be due to the presence of excess pore pressures, the accuracy of the TBM data or its interpretation. A method to increase the accuracy, which is expected to result in a better fit with the numerical results, was found in a late phase of the research. This method takes into account the settlements which are induced by the thrust wave in front of the TBM. Comparing the numerical and analytically determined limit support pressures, it is found that the minimum face support pressure are similar in both methods. As similar failure mechanisms are found, numerical modelling seems a reliable way of determining the face stability. However, due to the limited range of applied support pressures available from the TBM data set, limit states could not be fully analyzed. To assure the reliability of a numerical model to determine the actual face stability based on surface settlements during the construction phase, additional research must be done. It is suggested to extend the methods used in this research with physical modelling. For maximum face support pressures, the analytical and numerical models do not coincide. Hydraulic fracturing cannot be modelled in Plaxis 3D. It is recommended not to use numerical modelling to determine the face stability based on settlements at face pressures higher than the face pressures at which an equilibrium is achieved.

To fight increasing traffic in city centres, tunnelling can be used to move traffic under the surface of the busy city. However, to prevent damage to the surrounding buildings, the settlements induced by the tunnelling should be kept to a minimum. This thesis researches the influence of the TBM tail void and its grouting process on the settlements. To do so, the monitoring and TBM data from the North/South line in Amsterdam is used. The data of the settlements, grout pressures and grout volumes is searched for locations with sudden changes. For these locations, the development of the settlements as a function of the TBM movement is compared to find out if the changes in settlements are caused by the tail void. This turns out to be the case for half of the researched locations. Furthermore, the changes of the grout pressuresmeasured in the tail void, and the volume injected grout volume are compared for these locations. An increase in injected grout volume shows to decrease the settlements induced by the tail void, while the pressure does not show a correlation with the settlements. Because only one sensor was used for the pressuremeasurements, the grout pressures are then compared for all sensors in the tail void. Again, no correlation is found between the grout pressures and the settlements. A side step in the research shows the development of the grout pressures in the tail void. During the boring process the grout pressures fluctuate. During the boring and forward movement of the TBM the tail void is injected with grout and the grout pressures in the tail void increase. During the ring building phase, this grouting stops and the grout pressures start to dissipate. The amount of dissipation is influenced by the permeability of the surrounding soil. With the help of DIANA FEM software, the influence of the tail void on the total settlements is investigated. The calculations show that a different grouting behaviour caused a change of only 4mmin total settlements. Concluding, as long as the pressures in the tail void stay above the soil pressure the tail void can be filled with grout. The injected grout volume will fill the tail void, preventing the soil from moving into the tail void and with that minimising the settlements at the surface.

In a bored railway tunnel project in the Middle-East, difficulties in terms of ovalization, water leakages and settlement of several lining rings located in a fault zone were observed at the end of the construction stage. The present research attempted to find the cause for this lining behaviour. The determination of critical loading conditions, the application of the longitudinal beam model and the analytical and numerical modelling (in Plaxis) of a monolith tunnel lining in abrupt ground property transition were analyzed. Thereby, the global lining stiffness reduction due to joints was also considered. The literature review led to the following expected factors that caused difficulties in the Middle-East case: the squeezing and submerged ground conditions, the rock mass disturbance and the improper backfilling of the rings. Additionally, the ring stiffness reduction due to joints was an essential factor for lining behaviour. The geotechnical conditions, the lining design and the observed difficulties in the case were defined in the next section. Critical missing information, such as geotechnical properties of the fault zone material and limited monitoring data, led to essential assumptions. The settlements were expected to be caused by rock mass disturbance and improper backfilling. These altered the water flow during and after the boring operations and led to lowering of the groundwater level and increase of effective stresses. The water leakages were caused by ring ovalization in the soft fault zone, leading to opening of joints. The analysis for this research was divided in 2D transversal, 2D longitudinal and 3D modelling of the lining in and around the fault zone. The 3D model was seen as the integral model, which took into account the transversal and longitudinal behaviour of the lining. However, most of the behaviour of the lining was analyzed by carrying out parametric analysis for both directions in 2D. Moreover, the 2D models were used to validate the results of the 3D model to identify the influence of the third dimension. The assessment of the results from these analyses led to the following conclusions. The behaviour of the tunnel lining in small width fault zones was governed by the transversal action. The ovalization was mainly influenced by the ground stiffness, the vertical to horizontal stress ratio, the backfilling stiffness and the ring stiffness. Using Erdmann's analytical solution, the approximate lining forces can be determined. However, this overestimated the ground pressures acting on the lining, especially in cases where vertical to horizontal stress ratios were not equal to 0.5. This was because the 2D transversal behaviour did not take into account the longitudinal arching effect, which depended mostly on the stiffness ratio between ground types. The final conclusion was that the global reduction of lining stiffness due to the joints led to a discrepancy with regard to the distribution of the longitudinal displacements. A complementary analysis using a numerical model taking into account the joint structure and discontinuous behaviour between rings would probably allow a better prediction of longitudinal displacements.

This master thesis aims to do a detailed conceptual design of a tunnel to connect the road A15 and A12, which will cross the Pannerdens canal ( represented by red color in figure 1.1) and a deep comparisonwith the bridge plan solution which has already been adopted by the government, which was named ViA15 project.

Cement-Bentonite (CB) walls are low permeability vertical cut-off barriers that are mainly used to prevent groundwater flow and isolate contaminated areas. The hydraulic performance of the CB walls depends on the flow rate (discharge) through the wall. Therefore, the walls must achieve very low hydraulic conductivity. Poor in-situ hydraulic performance of these walls due to construction and post-construction defects may lead to surface settlements, groundwater contamination, and instability of the construction. This thesis investigates the range of in-situ hydraulic conductivity values of CB walls installed within the Netherlands. To achieve this, pump data for the various projects (Westerschelde Tunnel, A2 Motorway at Best, Motorway A4 Delft-Schiedam, Griftpark Utrecht, and Richard Hageman Akwadukt) were analyzed to determine the discharge through the walls. The in-situ hydraulic conductivity of the walls was calculated by Darcy’s law using groundwater level data and dimensions of the walls. The CB walls must be "keyed" into an underlying low permeable layer (aquitard), so that seepage of water through the aquitard is prevented. It was difficult to compute the in-situ hydraulic conductivity of the CB walls for Motorway A4 Delft-Schiedam and Griftpark Utrecht. The reason was that the walls in these projects were embedded in a permeable aquitard, which affected the total discharge value. The calculated in-situ hydraulic conductivity values were compared with the required hydraulic conductivity values and laboratory test results. In most of the cases, the in-situ hydraulic conductivity values of the walls were larger than the values acquired from the laboratory samples. The reason is that the estimation of the hydraulic conductivity of the CB walls from laboratory tests was based on small sample areas. This remains unreliable to evaluate the field performance of the CB walls. The average hydraulic conductivity of the CB walls at Richard Hageman Akwadukt was required to be less than or equal to 1·10-9 m/s. The calculated hydraulic conductivity values of the CB walls for the northern and southern polders were approximately 2.5·10-9 m/s and 2·10-8 m/s, respectively. This study also shows that the hydraulic performance of the CB walls is mainly affected by insufficient connections between the panels. Also, the impact of the defects on the discharge through the wall has been investigated by developing a threedimensional numerical groundwater flow model using MODFLOW. Simulations were performed for different types of defects, such as fully and partially penetrating windows, insufficient embedment, and connection between the panels of the CB walls. The results of the simulations indicated that fully penetrating windows have more impact on the discharge through the wall compared to partially penetrating windows. Partially penetrating windows with a hydraulic conductivity lower than 1·10-6 m/s are often insignificant. The size of a fully penetrating window also plays an important role. The difference in discharge (ΔQ) was calculated by subtracting the discharge through a perfect wall and imperfect wall (Qimperfect - Qperfect). The (ΔQ) through a CB wall with a window whose area is equal to 1 m2 can increase by a factor of 10 compared to a window whose area is equal to 0.1 m2. The location of the defects has no impact on the discharge through the wall. The simulations also show that the flow rate is unaffected by the embedment depth of the wall, but it must be ensured that the wall is in direct contact with the aquitard (low permeability soil layer). The vertical deviation of panels also affects the discharge through the wall. The MODFLOW results can be used to get an indication of the increase in discharge caused by various types of defects. From this, the possible defects for a particular project can be determined.

Vibratory installation of sheet piles is the most economic and suitable for the sandy soil because of its mechanism. However, the process induces excess pore pressure in saturated conditions leading to subsidence. This research focuses on the development of a tool-based solution to predict the excess pore pressure due to vibratory installation, which shall be verified by the postdiction of Kademuur Damrak measurements. This tool will help engineers quantify the impact of generated excess pore pressure on adjacent structures. The proposed work attempted to achieve its objective by answering the following main and sub research questions. How can the existing knowledge on generation and evolution of porewater pressure during vibratory installation be effectively integrated into a model/tool, which verified by the postdiction of Kademuur Damrak measurements, can practically estimate the porewater over-pressure during vibratory installations? • What are the parameters that influence the dissipation of the excess pore pressure? • How does the generation and dissipation of excess pore pressure vary in the liquefied zone from non-liquefied? • How can the vibration attenuation affect the generation of excess pore pressure in the sand? • What are the limitations and controlling parameters of this model or tool? The proposed work combines dynamic soil response and transient groundwater flow model to simulate the evolution of pore pressure due to vibratory loading. Based on the degree of modulus degradation due to the vibratory loading the soil, it is zoned into three. This is also termed as a multiscale computational framework. This allows for the formations liquefied and non-liquefied zone. The threshold acceleration of 0.1g - 0.3g must be available for the soil to liquefy [66]. The non- liquefied zone is fed by the groundwater flow from the liquefied zone. According to the Theis equation, head response due to constant pumping in an aquifer is influenced by the rate of discharge (V), storativity(S) and transmissivity(T), distance from the source. This inspired to model the driving of sheet pile with an analogous to the pumping of well. During the constant head loading due to the pumping, there is an increase in the head radially outward from the source. This resembles the phenomenon of pre-shearing in the field. The driving of the sheet pile was stimulated by the constant head loading. The application of time series analysis (PRIFICT method) [8] provides the first estimation of the pore pressure response from the first of three days of field piezometric data of Kademmur damrak. The semi-empirical model was formulated influenced by the head response of the slug test. The response of the time series analysis helped to calibrate the semi-empirical model. The relationship evolved between the physical and modelling parameters established that the hydraulic conductivity is the key parameter in both the generation and the dissipation of the excess pore pressure. The analysis of the field data establishes the conservative assumption of 1m for the width of the liquefaction zone. The analysis of accelerometer data from the Amsterdam noord zuid metro line tunnel helps to establish the dependency of liquefaction on acceleration amplitude. This bolstered the threshold acceleration for liquefaction to be 0.1 - 0.3g. The simple flow only Plaxis model helped to validate the proposed hypothesis. The hydraulic conductivity was established as the key parameter of the model. The integration of dynamic generation and transient groundwater flow model helped to analyse the evolution of excess pore pressure.

Dams and reservoirs pose safety concerns to society worldwide. In case of a disaster, the water impounded in the reservoir escapes and destroys everything in its path. Reasons for failure range from geology, hydrology and seismicity, to design problems, lack of maintenance and poor field investigation. Prior cases show that various dams gave away mainly due to geological causes, so there is a particular interest to see how the local terrain features could influence the longevity of the structure. Three historical case studies are discussed in order to emphasize the impact of geology regarding dam failure. The Saint Francis Dam is a prime example of poor site investigation, where the lack of knowledge on the foundation rock led to the rupture of the gravity dam. The Malpasset Dam gave away predominantly due to underestimated effects of the uplift, nevertheless, the geologists were unaware of an active fault system and the mechanical properties of the rock mass. The Baldwin Hills Reservoir comes with a more thorough site investigation, yet still, due to earth movements, the water from the reservoir infiltrated through the embankment. Therefore, geological features at the site need to be included in the design options of the dam in order to ensure a safe, feasible and economical project. With respect to the way we build nowadays, engineers have learnt important lessons from past experiences, however, issues such as ageing of the structures and the unpredictability of geology and weather, could still influence the safety of modern dams.

During construction in urban areas often noise and vibrations are not tolerated. For the installation of the foundation piles in these cases there is often chosen for screwed displacement piles. These piles can be installed without nuisance for the vicinity, but do induce large soil displacements during installation. The soil displacements can cause increased soil pressure on adjacent structures. Because urban areas are getting more densely built, these problems will occur more often in the future. The effects can be minimilized when they are known in advanced. This research looks into the possibility of predicting the installation effects of screwed displacements piles on adjacent structures. This is divided in the prediction of the soil displacement in a finite element analysis and in the effect of the soil displacement on adjacent piles. This is done with two case studies. First data from tests in Shanghai is used to create a finite element model. After this measurements are done in Rotterdam to verify this model for Dutch cases.
Combining all the analysis of the measured and modelled displacements showed that the displacement is depended on the stiffness of the soil layers, the initial displacement at the edge of the pile and the distance from the pile. The soil parameters influence the initial displacements in each soil layers. When the initial displacements are correctly determined with tests, it is possible to predict the soil displacement due to the installation of a screw pile with a finite element model. No conclusion could be made on the effect of the soil displacements on adjacent structures.

A series of finite element simulations via PLAXIS were carried out to investigate the effects of micro- tunnelling on nearby pile foundations. A numerical model concerning the large diameter tunnel boring machine was first established based on identical properties of the centrifuge experiment executed by Loganathan et al. (2000). Results from numerical simulation were validated by measured data from the centrifuge test. After the validation of the numerical modelling method, the model was adjusted to match the case of micro-tunnel and a new model regarding the micro-tunnelling procedure was generated based on geotechnical conditions of the North/South Metro Line Amsterdam. The Hardening Soil constitutive model was chosen for all soil layers. In the model, the condition of single bored pile with working load was activated in the greenfield condition before the simulation of micro- tunnel. Advancement procedure of the micro-tunnel was simulated, and pile responses were collected under the plane strain condition. Based on the study of the model, two load transfer mechanisms of piles during tunnel-pile interaction process were identified. Impact of tunnel advancement on adjacent piles was also interpreted. A set of parametric studies were implemented to study changes of pile settlement and bearing capacity with increasing volume loss. An influence zone around the micro- tunnel respecting the potential of pile critical movements was established. Although the lack of field data makes the validation of results hard, comparison with analytical prediction and measured data from the centrifuge test shows good agreements for soil movements and pile responses. The results of this research remain to be validated by field data but it can provide insights into the problem of the impact of micro-tunnelling on piles.

The starting point of this thesis lies in the area on Groningen, Netherlands. More specifically, induced earthquake activity is observed in this area due to gas extraction activities, which reduce underground gas pressure. In combination with the location’s geomorphology, liquefaction can occur due to earthquake excitations. Furthermore, the area of Groningen is a location with urban activity and infrastructure, such as pipelines, present. The post-liquefaction effect of these pipelines is their uplift, which can lead to failure, along with all its negative consequences. Furthermore, the creation of two different models, capable of describing the soil-structure interaction of pipelines and post-liquefied soil was the main objective of this thesis. The means by which these models were created was the implementation of the spring and dashpot method. More specifically, Kelvin-Voigt models were used for the ground’s behaviour to be modelled. These models required two main parameters to be specified in each case, the spring coefficient (k) and the dashpot coefficient (c). In order for the spring coefficient to be determined, the creation and usage of post-liquefaction p-y curves was deemed necessary while the problem specific dashpot coefficients used, had previously been determined by means of physical modelling. The ground profile consisted of fully saturated loose sand and the pipes investigated had diameters of 110, 160 and 200mm. The first model was a single degree of freedom one, with that being the vertical. As for the second one, it was a multi degree of freedom one. More specifically, it consisted on two degrees of freedom, the vertical and horizontal ones. The results of these models were validated by comparison to previous studies and further investigation of affecting parameters was carried out. More specifically, the way and the degree up to which several parameters of both ground and structure characteristics affect their interaction were investigated. More specifically, the first parameters considered were the pipelines’ diameter as well as their weight, resulting from their geometry and transported material. Next, the effect of the pipelines’ burial depth was considered and then, the effect of the soil’s initial stiffness. Finally, the effect of the dashpot coefficient was investigated for the multi degree of freedom models. A comparison between single and multi-degree of freedom solution results was also carried out. The results of this study were validated by comparison to previous research findings. Most results and conclusions were in complete agreement with the so far existing bibliography. However, what was found to be inaccurate was the previously determined dashpot coefficient for 110mm diameter pipelines and hence, these were left out of scope of study.