Results obtained from the laboratory tests provided an overall understanding of how the Xbloc+ performs under certain conditions. It was perceived that the permeability of the armor layer is low as it happens often with single layer units. Thus, the pressure gradient between the underlayer and armor layer is significantly high creating an uplift pressure that leads to a revetment-like failure mechanism.

Although the failure mechanism can be related to both slopes used during the laboratory tests, (3:4 and 1:2), the behavior of the armor layer differed completely between slopes. On a steeper slope, the armor layer remained undamaged for wave heights significantly higher than the design wave. However, once one unit was fully displaced, the damage was quite destructive.

In contrast, on a milder slope, failure occurred much faster but the damage was not as aggressive. Moreover, after the failure was reached, the structure gained a new level of stability in which remained to provide shelter without reflecting significant damage.

Furthermore, the wave height variation did not have much influence as the wave steepness. There was a noticeable difference between the performance of the structure during swell and wind waves. During swell waves, it could be seen that not only failure was achieved faster but it caused much more damage to the structure, while during wind waves the structure had a higher stability.","CoMEM; Breakwater; Xbloc+; Physical modelling; concrete units; stability","en","master thesis","","","","","","","","","","","","CoMEM - Coastal and Marine Engineering and Management","","" "uuid:dd7b9933-5810-4585-b1fe-a9db8b90dbd4","http://resolver.tudelft.nl/uuid:dd7b9933-5810-4585-b1fe-a9db8b90dbd4","Optimising the Input Filter of Traction Installations in DC Railway Power Systems","Jongeling, Alexander (Electrical Engineering, Mathematics and Computer Science; Electrical Sustainable Energy)","Winterling, Max (mentor); Bauer, Pavol (mentor); Gagic, Mladen (mentor); Shri, Aniel (mentor); Dong, Jianning (graduation committee); Cvetkovic, Milos (graduation committee); Delft University of Technology (degree granting institution)","2017","In the world of DC railway trains nowadays, asynchronous-traction machine with traction controllers, i.e. an inverter with variable output frequency, is implemented. This controller changes the incoming DC voltage into an AC voltage of a variable frequency and RMS amplitude. The disadvantages of switching inverters, compared to a pure sine wave source, are the harmonics they inject in both the output as in the input of the inverters connection. At the incoming power line, it is necessary to damp these harmonics, in order to avoid resonance issues or issues regarding other systems, for instance, train detection. For this purpose of harmonic and transient filtering, generated within as well as outside the train, an LC filter is utilised.

However, this LC-filter has also influence on stability. Due to the resulting impedance to current variation in the inductance of the LC-filter, the power flow dynamics towards the train are decreased. When applying a certain amount of power, the voltage over the capacitance can become unstable very quickly. In this thesis, a graphical user interface simulation model is made to simulate these stability phenomena in Simulink in order to find the optimum size of the LC-filter in a train on the Dutch DC railway.

The simulations are achieved with a model representing a generalised train. The model is simple to modify, and consists of the important parts for determining the stability of the system.

Different simulations have been carried out, in order to examine the effect certain parameter variations have on the stability. Two systems have been considered, a constant power controlled system and a system where the motors had no controlling regime. An important factor is the value of the capacitance and inductance. A larger filter inductor results in an unstable system. Likewise, implementing a higher value capacitance will cause the system to be more stable.

Simulations have shown that a motor controller with a simple constant power control regime is unstable with normal values for the inductance and capacitance. However a damping branch can solve this problem up to an extent. A system without any controlling regime has proven to be more stable with smaller capacitance.

By utilising the model presented in this thesis, the stability of the system, consisting purely of a controlled constant power load or as a non-controlled load, can be investigated, and the impact of the LC-filter can be determined.

The turbulence magnification factor (α) at the stability equation was derived by two different approaches. The first approach was based on the peaks of velocity associated to failure while the second one was described as a fitting parameter. The analysis concluded that the α values were close to 3 for both cases, in line with the expected value from previous studies. Finally, the new developed equation was compared with the original Pilarczyk equation and the modification proposed by the Rock Manual (2007). The comparison shows that the new developed equation described the required thickness of the block more accurately than the available equations. Thus, the results show that the proposed approach described the effect of turbulence accurately on a design equation. Additionally, all the relevant derived conclusions for design propose were summarized in a design guideline.","stability; Bed protection; Block mattress; Non-Uniform; Turbulence","en","master thesis","","","","","","","","2018-07-03","","","","CoMEM - Coastal and Marine Engineering and Management","","" "uuid:920e49c1-fd4c-4299-a686-43c9403e6a68","http://resolver.tudelft.nl/uuid:920e49c1-fd4c-4299-a686-43c9403e6a68","A method for actuator comparison for a stable humanoid robot","Klop, Wouter (Mechanical, Maritime and Materials Engineering; Biomechanical Engineering)","van der Weijde, Joost (mentor); Wisse, Martijn (mentor); van Ostayen, Ron (mentor); Delft University of Technology (degree granting institution)","2017","A humanoid robot is being developed, intended to operate robustly in a typical day-to-day human environment. Its ability to react quickly to stochastic disturbances, especially its ability to avoid falling, termed stability in this context, is of prime importance. The choosing of a suitable actuator that affords such stability is seen as a challenge in the current stage of the humanoid project. A novel method for comparing various actuators in terms of humanoid stability is investigated, to aid with this choice.

A common method for comparing actuators is the use of low-level actuator parameters, e.g. power density. With a low-level parameter, a specific actuator property can be compared between multiple actuators. To incorporate relevant properties of all actuators, a large set of actuator parameters is required. This becomes even more challenging when comparing a heterogeneous collection of actuators, e.g. muscle and hydraulics. Besides subjectiveness in parameter definitions and comparisons, the multidimensional set of actuator parameters needs to be related to a one-dimensional measure of humanoid stability. As low-level parameters and high-level humanoid stability are not directly relatable, subjective weighting factors are traditionally employed to reduce dimensionality.

Step time is introduced as a one-dimensional criterion for comparing different actuators. The ability to make fast movements is a critical component in defining humanoid stability. Therefore, by comparing step times of different actuators in a fixed test case, a measure of humanoid stability is obtained. The step movement represents a simplified motion of the lifting of a foot, in which essential elements of humanoid motion are incorporated.

A framework is developed, with which step times of Human Muscle (HM), ElectroMechanical Actuators (EMAs) and Hydraulic Actuators (HAs) are computed. While EMAs are often thought to have limited potential for humanoid applications, step times are similar to those of muscle. Supplemented with recent examples of successful EMA implementations, step time demonstrates the potential of EMAs. Furthermore, HA capability is also demonstrated, as step times can obtain lower values than those of HM and EMA.

Step time as developed in this thesis appears to be a powerful tool for comparing vastly different actuators. It provides a one-dimensional measure related to humanoid stability, evaluated directly for each specific actuator.

0.9, showed different results. The development of the increase in stability for constant values of the relative berm length showed a peak at B/L0 = 0.15. This peak seemed to flatten out as the water level on the berm became smaller. This process could possible link the findings of this study to the findings of Vermeer (1986), however, more research has to be done to confirm this hypothesis. Finally the two design principles, which in practice are used as indication of the increase in stability, were validated with the results of this study. The first principle applies stability formulae for uniform slopes on the average slope of a bermed profile. The second principle adopts the characteristics of low-crested structures on the bermed profile. The correlation between the predicted increase in stability and the results of the test series was very low. Apparently the complexity of the processes related to the (in)stability of armour layers on a bermed slope can not be overcome by means of the design principles. This is most probably caused by the influence of the return current, which has large impact on the stability, is not accounted for. Therefore both principles are not well suited to predict the increase in stability of armour layers on bermed slopes.","breakwater; berm; armour; layer; stability","en","master thesis","TU Delft, Civil Engineering and Geosciences, Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","","","","","" "uuid:00654c23-ac52-4e2d-a334-8cb4ab132e03","http://resolver.tudelft.nl/uuid:00654c23-ac52-4e2d-a334-8cb4ab132e03","Breakwater stability with damaged single layer armour units","De Rover, R.A.","Stive, M.J.F. (mentor); Verhagen, H.J. (mentor); Uijttewaal, W.S.J. (mentor); Van den Berge, A. (mentor)","2007","At breakwater and seawall projects at Port St Francis and Scarborough breakage of single layer interlocking armour units was observed. It is generally assumed that breakage of single layer armour units has a significant negative effect on the hydraulic stability of a rubble mound breakwater. The significant decrease of interlocking capacity and mass of the broken units would lead to displacement of these units and surrounding units. The broken parts of the damaged units would act like projectiles. The waves would ""throw"" these broken parts back and forth to the armour layer. More armour units would break due to the impact of these broken parts leading to rapid damage progression of the armour layer and finally to failure of the total construction. This damage behaviour has however never been confirmed. The main objective of this research is to determine the effect of single layer armour unit breakage on the hydraulic armour layer stability and potential damage progression. A 2-dimensional model of a rubble mound breakwater with typical cross section was tested with individual and clustered positioned broken Xbloc armour units around the still water line. The residual stability of the armour layer was determined. The armour unit displacement and damage progression was assessed. It is concluded that breakage of single layer armour units has a significant negative effect on start of damage of the armour layer. Breakage of single layer armour units has no significant effect on failure of the armour layer. This damage behaviour leads to a long and gradual damage progression. This type of damage progression looks more like the damage progression of an armour layer consisting of rip-rap rock. The majority of the broken parts show little to no movement. It is therefore unlikely that rapid damage progression occurs due to broken parts damaging other units.","breakwater; stability; damaged; armour; units","en","master thesis","TU Delft, Civil Engineering and Geosciences, Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","","","","","" "uuid:0528aadb-3415-43d0-876e-b0f399395030","http://resolver.tudelft.nl/uuid:0528aadb-3415-43d0-876e-b0f399395030","The impact of placement method on Antifer-block stability","Frens, A.B.","Stive, M.J.F. (mentor); van Gent, M.R.A. (mentor); Uijttewaal, W.S.J. (mentor); Olthof, J. (mentor); Verhagen, H.J. (mentor)","2007","The main objective of this research was to assess the impact of different placement methods, with different packing densities, on the stability of double layered Antifer-block armour layers. This was done by experimental research in the wave-flume of the Fluid mechanics laboratory of the Faculty of Civil Engineering and Geosciences at Delft University of Technology. 17 experiments were performed with packing densities between 44.8 and 61.1 percent. For every experiment the under layer, toe and armour layer were rebuilt. The placed Antifer layer was tested with eight irregular wave series with increasing significant wave heights from 9cm up to 20cm. From these experiments followed that regular placement methods behave more stable than irregular placement methods with a similar packing density. Also the more irregular (less accurate) positioning of blocks within a regular placement method caused a decrease in stability. Higher packing densities for equal placement methods lead to higher stabilities and higher reflection coefficients. The resulting -values were between 4.0 and 23.7. If the reflection coefficients during the first wave series were high, this resulted in more overtopping during the latest wave series, which indicates that there is a positive correlation between the reflection and the overtopping. Overall it could be concluded that, when the under layer and the toe are smooth and the blocks can be placed accurately, the best performing placement methods are the closed pyramid placement method for packing densities around 45% and 50% and the double pyramid placement method for packing densities around 55% and 60%. The size of the openings to the under layer, of the double pyramid placement method, influenced the reflection coefficients. When the second layer was shifted half a nominal diameter upwards the reflection coefficients were minimal. It is recommended to investigate the possible negative influence of oblique incoming waves on the stability of the double pyramid placement method. The eventual choice of the placement method and packing density depends on the allowed reflection and/or overtopping and the construction costs. The construction costs can be divided into the production costs, the placement costs and the constant costs. For equal constant costs and equal or small differences in placement costs the placement with the higher packing density and accompanying stability value is cheaper for high design wave heights. When the placement costs decrease for both placements or only for the placement with the higher packing density, then the placement with the higher packing density becomes also cheaper for lower wave heights.","antifer; placement; stability","en","master thesis","TU Delft, Civil Engineering and Geosciences, Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","","","","","" "uuid:9f5463f1-1aa7-4991-9c9b-fa1fb8bf146a","http://resolver.tudelft.nl/uuid:9f5463f1-1aa7-4991-9c9b-fa1fb8bf146a","Stability of rock on slopes under wave attack: Comparison and analysis of datasets Van der Meer [1988] and Van Gent [2003]","Mertens, M.","Stive, M.J.F. (mentor); Verhagen, H.J. (mentor); van der Meer, J.W. (mentor); Booij, R. (mentor)","2007","In VAN GENT [2004] graphs were presented in which the datasets of VAN DER MEER [1988] and VAN GENT ET AL. [2003] were compared, but in this comparison a number of parameters were not correctly transformed into a comparable format. In this M.Sc. thesis after an extensive analysis to the datasets all parameters of the datasets of Van der Meer were transformed into the same format as the parameters used by Van Gent. In the same way the dataset of THOMPSON & SHUTTLER [1975], which formed the basis of the work of Van der Meer, was treated. The inclusion of correction factors for the effects of stone roundness from LATHAM ET AL. [1988] gave remarkable effects on a certain part of the dataset of Van der Meer which showed more damage than average. After this still differences could be seen between the datasets of Van der Meer and Van Gent. Using the statistical T-test these differences are approved. Explanations for the differences found between the datasets of Van der Meer and Van Gent can be found in the fact that most of the tests of Van Gent. were done with shallow foreshores where Van der Meer did most tests with deep water conditions. Tests by a number of M.Sc. students at Delft University of Technology showed that tests with identical spectra, but with different foreshore slope angles show different damage patterns. In the dataset of Van Gent also the 1:30 foreshore slopes on average show more damage than the 1:100 slopes. In further research the influence of the foreshore should be incorporated in the stability formulae by a foreshore Iribarren parameter. Also a detailed investigation to the effects of wave breaking on shallow foreshores is needed. For this the complete dataset of Van Gent needs to be available and accessible.","Meer; Gent; stability; foreshore; rock","en","master thesis","TU Delft, Civil Engineering and Geosciences, Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","","" "uuid:8a91005b-31a1-48c7-8f61-1fa9077ea295","http://resolver.tudelft.nl/uuid:8a91005b-31a1-48c7-8f61-1fa9077ea295","Gabion stability","Beekx, R.H.P.A.","Vrijling, J.K. (mentor)","2006","South Korea is reclaiming land by constructing dams and polders. The large tidal differences along the Korean coast make building these dams a challenging job. One of the solutions in South Korea to cope with the high flow velocities in closure projects is to apply sack gabions. These are steel nets with rocks inside them that weigh up to 3 tons. It is not clear how stable these sack gabions are exactly. The objective of this report is to make a preliminary study on the stability of sack gabions. In 2006, the Saemangeum estuary in South Korea was closed with a dam. During the closure sack gabions were used in the bed protection, sill construction and dam heads. In a field trip to the Saemangeum project useful data was collected on the stability of gabions. Experimental data of RRI on model tests on the stability of gabions was also obtained. In addition model tests were done in Delft. All data are compared to come up with an advice for calculating the stability of gabions. To calculate the depth averaged critical velocity for 3t - 5t rock with 3t sack gabions mixtures, formula [15] proves to be useful. ucM = 2.513*x+5.4 [15 Where: ucM = critical velocity of a mixture of 50% rocks of 3.0 to 5.0 t and 50% 3.0 gabions x = the proportion of gabions in the mixture 0.2 < x < 0.5 For the calculation of the local critical velocity for a bed of sack gabions, it is advised to use Izbash' formula with a gabion stability factor (Gamma in formula [10]) while calculating the nominal diameter of a sack gabion as in formula [1] (a mass based approach): Delta Dn = (Beta*Uc2)/(Gamma*2*g) [10] Dn = (M/Rs)^1/3 [1] Where Gamma = 1.26 for sack gabions (while for loose rocks Gamma = 1) Also a qualitative analysis of the Delft model tests is made that leads to several considerations for the design of gabion bed protections: When applying gabions one has to take into account the difference in behavior between gabions and loose rocks. Another behavior that needs to be investigated further is the effect of applied pressure on a gabion bed. There is still much unknown about the stability of gabions and the report mentions several things that should be further investigated. Also it is advised to use sluices in the Netherlands or in South Korea as flumes for extensive prototype tests on the stability of gabions.","gabion; stability; South Korea","en","master thesis","TU Delft, Civil Engineering and Geosciences, Hydraulic Engineering Section","","","","","","","","Civil Engineering and Geosciences","","","","","" "uuid:e0998d8d-497a-4720-b393-803c207dcb16","http://resolver.tudelft.nl/uuid:e0998d8d-497a-4720-b393-803c207dcb16","Turbulence structures affecting stone stability in backward-facing step flow: Experiments by means of Particle Image Velocimetry","de Ruijter, R.","Battjes, J.A. (mentor); Booij, R. (mentor); Hofland, B. (mentor); Verhagen, H.J. (mentor)","2004","Downstream of man-made hydraulic structures, bed protections made of granular material are often used to prevent erosion of the bottom. The stones in the top layer of such granular filters must be able to withstand the hydraulic forces. Probably the best-known formula that is used to determine the stability of granular bed material is the design criterion by Shields (1936). However, this criterion is only valid for uniform flows. Little is known about the influence of turbulence on the stability of stones. In this thesis the influence of turbulence structures on the stability of stones in the top layer of a granular filter in one type of nonuniform flow that is often encountered near hydraulic structures, namely backward-facing step (BFS) flow, was investigated.","turbulence; stone; stability; step flow; structure","en","master thesis","TU Delft, Civil Engineering and Geosciences, Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","","","","","" "uuid:ab1b820e-ed76-4328-80d7-1eeafb6ac09f","http://resolver.tudelft.nl/uuid:ab1b820e-ed76-4328-80d7-1eeafb6ac09f","The influence of structural permeability on armour layer stability of rubble mound breakwaters","De Heij, J.","","2001","The first one who studied the problem of armour layer stability was Iribarren (1938). Iribarren derived stability criteria that were based on the acting physical processes on the slope of a structure. In the stability criteria of Iribarren only the influence of a few structural and hydraulic parameters were taken into account. In 1988 Van der Meer derived a stability relation in which the stability of armour layers was depending on several hydraulic and structural parameters. Van der Meer concluded that the stability of armour layers is strongly influenced by the composition of a structure. He implemented the influence of the composition of the structure in a permeability coefficient, P. This permeability coefficient is defined for four different structures. Van der Meer is a good tool for the design of armour layers, it has little physical background. The empirical character of the stability relation is found back in the definition of the permeability coefficient. If a different structure is designed than tested by Van der Meer, an estimation of this permeability coefficient has to be made. Since the permeability has large influence on the stability, new methods should be developed to calculate armour layer stability. Due to the irregularity of armour stones it would take a lot of effort to obtain a full analytical solution for the problem of armour layer stability. However, a good attempt into the direction of an analytical solution can be made, since good models are available that describe the water motion on and in coastal structures. An example of such a model is the model ODIFLOCS. ODIFLOCS stands for Qne dimensional flow Qn and in foastal structures. With ODIFLOCS it is possible to calculate the velocities on a coastal structure for certain hydraulic and structural parameters. With these velocities the hydrodynamic forces on the stones in the armour layer can be calculated. Iribarren (1938) proposed a model for armour layer stability. He assumed a hydrodynamic drag force that act on a stone, which is caused by the run-up or run-down, parallel to the slope of the structure. Two stability criteria for the stability of rock on a slope can be distinguished, which are upward and downward stability respectively. The drag force can be written as a function of the velocity on the slope of a breakwater. Iribarren was not able to calculate these velocities, since no models were available to calculate them, and estimated them by wave celerity in shallow water. Van den Berk (1999) was able to proceed the approach of Iribarren and calculated the velocities with the numerical model ODIFLOCS. He modelled homogeneous structures and calculated the armour layer stability for homogeneous structures for several hydraulic and structural conditions. He found that his results and the results ofVan der Meer were strongly correlated. In this research a next step will be made to see whether physical background can be given to the influence of structural permeability on armour layer stability. Structures with different permeabilities will be modelled and the velocities on the slope will be calculated for different hydraulic conditions. With the use of these velocities, which will be calculated with the numerical model ODIFLOCS, the stability can be determined. The test showed that the strongest increase in stability was found for gentle slopes in combination with low and high wave steepness. The test with steep slopes gave significant lower influence of structural permeability, compared with gentle slopes, on armour layer stability. This is contradicting with the findings of Van der Meer, who found a strong influence ofpenneability on the stability for high values of the surf similarity parameter. This shows that the penneabilities that are modelled in this research do not correspond to those tested by Van der Meer.","numerical model; breakwater; stability","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","","" "uuid:83968ad0-69f4-42b1-990b-7700304a59c4","http://resolver.tudelft.nl/uuid:83968ad0-69f4-42b1-990b-7700304a59c4","Tidal inlets on littoral drift shores","De Haas, M.J.","Van de Graaff, J. (mentor); Roelvink, J.A. (mentor); Huisman, P. (mentor); Kamphuis, J.W. (mentor)","1999","After consulting the ""Department of Environment"" in Australia it was suggested that an extensive generic study about Tidal Inlets on Littoral drift shores gives them an insight in the processes at work and also the possibilities to improve the stability in order to make tidal inlets suitable for safe navigation. This report describes the most important issues related to tidal inlets on littoral drift shores in general. It is written with the intention to provide some general information to readers who are interested in tidal inlets in general. However this report also provides some specific information to be able to study the stabilisation of the Nerang River Entrance, Queensland Australia.","tidal inlets; littoral drift shores; stability","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","","" "uuid:d4ba530a-eebe-456e-8d61-2a3300380f45","http://resolver.tudelft.nl/uuid:d4ba530a-eebe-456e-8d61-2a3300380f45","Hoofdstroming contra menglaag: De invloed van een menglaag op het begin van bewegen van bodemmateriaal","Zuurveld, J.","D' Angremond, K. (mentor); Fontijn, H.L. (mentor); Uijttewaal, W.S.J. (mentor); Van der Meulen, T. (mentor); Schiereck, G.J. (mentor)","1998","Experimental research on the stability of bed material behind a backward facing step. Measured is the stability as a function of the local velocity and the local turbulence (turbulence intensity) due to the eddy formation.","stability; turbulence; backwards facing step","nl","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","","" "uuid:e9b76cf8-17c2-4b4f-8e1b-6206f4fa26e5","http://resolver.tudelft.nl/uuid:e9b76cf8-17c2-4b4f-8e1b-6206f4fa26e5","Transport van stenen van een granulaire bodemverdediging","De Boer, G.M.","D' Angremond, K.D. (mentor); Fontijn, H.L. (mentor); Schiereck, G.J. (mentor); Van der Meulen, T. (mentor); Olthof, J. (mentor)","1998","Experimental research on the stability of bed protection and transport of stones on such a bottom protection. Investigated were the effects of duration and magnitude of the load, the shape, and placing density of the stones.","bed protection; stability; shields","nl","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","","" "uuid:98e5d9c0-31af-46b0-ac06-1a527ede7c64","http://resolver.tudelft.nl/uuid:98e5d9c0-31af-46b0-ac06-1a527ede7c64","Rock Behaviour near the Tunnel Face","Nuijten, G.A.","Verruijt, A. (mentor); Stille, H. (mentor); Isaksson, T. (mentor)","1997","For tunnels it is not only important, how the tunnel and the surrounding rock behave during the life time of the tunnel. It is also very meaningful to understand how the tunnel is behaving, while it is under construction. The basis for this thesis is to understand, how the tunnel behaviour, concerning deformation and stability, is for different rock conditions during the excavation process and what its influence is on the tunnel in final state. Additionally a case study is made of a praxis-example in Switzerland, in which it is pointed out, how difficult circumstances can be during the excavation and what measurements had to be done to cope with all the problems of excavating the tunnel. This example emphasises once more, how important a good understanding of rock behaviour during the excavation is. The report is built up in three more or less different sections: Chapters 2 to 4, chapters 5 and 6, and chapter 7. Chapters 2 to 4 form the first part, that is functioning as a basis for the calculations and analysis made in chapters 5 to 7. An analytical analysis about stress-deformation relations together with basic rock mechanic principles is worked out in chapter 2. Due to the complexity of the rock many rock classifications have been made to qualify different rock classes with their corresponding behaviour. One of these rock classes is used to obtain basic rock parameters, with which calculations are performed. This is, together with an description of different types a specific rock behaviour, outlined in chapter 3. An analytical approach for face stability problems is presented and further worked out in chapter 4. Chapters 5 to 6 are the main part with the calculations and the analysis, in which chapter 5 deals about the aspects, concerning the tunnel ring, and chapter 6 deals about the aspects, concerning the tunnel face. Basic rock calculation is given, about how the rock responds to the excavation of a tunnel. This calculating formed the basic for further calculations and research. The influence of different tunnel constructing aspects have been computed and compared with the basic rock-behaviour. In this way a good impression is obtained about how different constructing aspects, such as lining -constructed far away and close to the face-, pre-tunnelling, sequential excavation and rock improvement are performing in respect to stability and deformation of both the tunnel face and the tunnel lining. Chapter 7 is the case study of the Adler tunnel in Switzerland. Rock mechanical problems are analysed and described. It is also recapitulated, what measurements have been carried out to deal with the risen problems and how successful they were. The result of all these calculations for behaviour of the tunnel ring is, that lining gives an extensive reduction of the radial inward movement. The performance of the lining is at its most in the weakest rock and when the lining is constructed close to the face. The addition of a pre-tunnelled construction improves the performance in weaker rock. The deformation is further reduced. This is however not the case in good rock. In those cases pre-tunnelling should not be used, as it is a waste of time and money. An extra aspect of these performances is, that by reducing the lining the pressure on the lining is increased. The lining has to be dimensioned on these higher pressures. The most important aspect for the tunnel face is stability. Pre-tunnelling is not an option to stabilise the tunnel face. Grouting may introduce inadmissible tension stresses in the grouted area, which nullify the desired stabilisation. A good option for making the face more stabile is to excavate in sequences, because decreasing the diameter means a high reduction of the risk for face collapse. A stabile tunnel face is very much depending on the diameter of the tunnel, there where the depth of the tunnel determines the amount of plasticity around the tunnel face. Readers who are interested in typical geo-hydrological aspects of rock tunnelling, shield tunnelling, such as EPB and Slurry Shields, with counter pressures on the tunnel face, typical lining aspects, such as differences between different linings or the improvement of the lining strength in time, or time dependent behaviour of the rock are kindly requested to read other papers or reports. Those aspects, although very interesting and highly important, are not a part of this report.","excavation; stability; deformation","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","","" "uuid:b47d8033-9f16-4ed6-b980-11e4c14a98af","http://resolver.tudelft.nl/uuid:b47d8033-9f16-4ed6-b980-11e4c14a98af","Transport van tunnelelementen over zee","Coopmann, S.W.M.","Vrijling, J.K. (mentor); Bezuyen, K.G. (mentor); Journéé, J.M.J. (mentor); De Leeuw, W. (mentor)","1996","In Nederland wordt het steeds moeilijker om bouwdokken, voor het vervaardigen van afzinkelementen van een afzinktunnel, aan te leggen. Daarom wordt uitgeweken naar reeds bestaande bouwdokken, en worden de tunnelelementen over langere afstanden en ook over zee vervoerd. De krachten en momenten die door de golfbelasting, tijdens transport over zee, in de elementen worden opgewekt zullen door middel van voorspanning moeten worden opgenomen. Dit afstudeeronderzoek omvat een studie naar de optredende krachten en momenten in tunnelelementen als gevolg van golfbelastingen en de optimalisatie van de benodigde voorspanning alsmede de lengte van tunnelelementen. Bij het onderzoek is uitgegaan van het transport van de elementen van de Wijkertunnel, dat plaatsvindt over de Noordzee tussen de Nieuwe Waterweg en het Noordzeekanaal. De lange-termijn verdeling van golven op de Noordzee is bepaald met behulp van 3-uurlijkse waarnemingen, van twee meetstations op de Noordzee over een periode van 13 jaar voor de zomermaanden mei tot en met augustus, van de significante golfhoogte Hs, de piekperiode Tp en de invalshoek van de golven. Uit de waarnemingen blijkt dat de piekperiode, de pieksteilheid en de hoek van inval onafhankelijk zijn van elkaar, zodat de kans op voorkomen van een karakteristieke golf wordt verkregen door vermenigvuldiging van de verdelingsfuncties van deze variabelen. De piekperiode en pieksteilheid zijn normaal verdeeld met respectievelijk j1 = 5,326 ,~ = 1,034 seconde voor de periode en j1 = 1,9 %, ~ = 0,9 % voor de steilheid. De invalshoek is uniform verdeeld. Voor de deining is een significante hoogte van 0,5 m. met een piekperiode van 10 sec. aangehouden. Uit de beschrijving van golven met behulp van verdelingsfuncties volgt een probabilistische aanpak van het probleem. Om de krachten en momenten in de elementen te kunnen bepalen wordt, met behulp van spectraalanalyse, een karakteristieke golf vertaald naar een golfspectrum; door middel van overdrachtsfuncties worden dan de krachten- en momentenspectra bepaald. De overdrachtsfuncties zijn bepaald met een dynamisch rekenprogramma dat gebruikt maakt van de lineaire striptheorie, en zijn gecontroleerd aan de hand van overdrachtsfuncties bepaald met modelproeven voor de Wijkertunnel. Hieruit blijkt dat de berekende overdrachtsfuncties zeer goed voldoen aan de werkelijkheid. Met de momentenspectra zijn de significante buigende momenten bepaald, waaruit de significante benodigde voorspanning voor elke karakteristieke golf is berekend. De kans op falen van het tunnelelement tijdens zeetransport als functie van de voorspanning is gelijk aan de kans op overschrijden van de significante voorspanning tijdens transport over zee (extreme Rayleigh verdeling) vermenigvuldigd met de kans op voorkomen van een karakteristieke golf (Iange-termijn verdeling) gesommeerd over alle voorkomende golven. Met behulp van deze faalkans als functie van de voorspanning en eisen ten aanzien van de faalkans voor de gebruiks- en bezwijkfase van het transport is bepaald dat de benodigde voorspanning gelijk is aan Fp = 74000 kN. De gebruiksfase is hierbij maatgevend. De optimalisatie van de voorspanning is gedaan naar de kosten van bezwijken van een element tijdens transport. Het blijkt dat de optimale voorspanning lager Iigt dan de toegepaste voorspanning, echter omdat de gebruiksfase maatgevend is wordt de werkbaarheid, bij een lagere, optimale' voorspanning te klein. Kostenoptimalisatie van de voorspanning moet dus geschieden aan de hand van wachttijden voor de gebruiksfase.","immersed tunnel; tunnel elements; stability","nl","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","","" "uuid:51af1788-de9f-4ef3-8115-ffefb2e26f76","http://resolver.tudelft.nl/uuid:51af1788-de9f-4ef3-8115-ffefb2e26f76","Toe structure stability of rubble mound breakwaters","Gerding, E.","D'Angremond, K. (mentor); van der Meer, J.W. (mentor)","1993","In this report an analysis of data from a series of tests is presented on the stability of the toe structure of rubble mound breakwaters. The existing knowledge on toe stability and the influence of all governing parameters in the existing knowledge is reviewed. The tests which were performed for the present research are treated extensively. The main governing parameters, which determine toe stability in rubble mound breakwaters, are: Significant wave height : Hs Nominal stone diameter : Dn50 Stone mass density : ρ s Depth above the toe : ht Damage level : Nod Parameters investigated which appeared to have no significant influence are: the fictitious wave steepness sop and the width of the toe structure bt. The choice of the governing parameters, the definition of damage levels for the design of the toe structure and the way they are made dimensionless are motivated. The results from the present tests are compared with existing design formula. With the selected parameters two formulas have been derived from the available test data. One describes toe stability using the shallow water significant wave height Hs the other uses the shallow water 2% wave height H2%. The formulas are compared with existing test results and their range of application is given.","toe structure; breakwaters; rubble-mound; stability","en","master thesis","TU Delft, Civil Engineering and Geosciences, Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","","","","","" "uuid:cc85154f-5183-4df4-b649-00f380a3f175","http://resolver.tudelft.nl/uuid:cc85154f-5183-4df4-b649-00f380a3f175","Modelling of tidal inlets - Preliminary design of the configuration of the harbour lay-out of the proposed harbour at the Boca Vieja at La Ceiba","Bogers, P.","d' Angremond, K. (mentor); Noppen, J.P. (mentor); Roelvink, J.A. (mentor)","1991","At present no computer model is available that can determine the stability of an inlet or what will happen to the stability after some adjustment of the inlet. This study has the objective to develop a simple model th at combines all major parameters in order to determine the stability of an inlet and the effects of adjustments on the stability of an inlet. A computer model has been developed that incorporates these two basic elements. Stability is defined as the situation in which the ebb delta does not move. The effects of the tidal currents and longshore currents on the bottom profile are calculated separately. The effects of the longshore current are determined by using the theory of Pelnard Considere. The effects of the tidal currents are calculated by using a river sediment transport formula. The tidal currents are determined by applying a one dimensional long wave theory to the inlet bay system. The most important restrictions of the model are: Widening or closing of the access channel is not possible. The neglect of interaction between longshore current and tidal currents The effect of wave action on the sediment transport is neglected during the tidal cycle. It is th us likely that the sediment transport calculated in the tidal module is to low.","inlet; stability; computer model; bottom profile","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""