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The dimensions of single layer concrete armour units (interlocking armour units) are calculated with a similar stability relation as the stability relation for quarry stone. In these design formulas an 'average/significant' wave load is used (Hs). Since quarry stone gains its stability only from gravity, this type of armour unit is constructed in a double layer and therefore some damage development is allowed. Interlocking armour units are constructed in a single layer and the design should be based on zero damage. This research investigates whether this different approach to damage leads to a different characteristic design wave load which will increase the accuracy of the design method for interlocking armour units. It is focussed on the influence of the wave height distribution on the stability of single layer concrete armour units in general and Xbloc in particular. For Xbloc, zero damage is defined as a criterion for rocking of the armour units: during design conditions "not more than 2% of the units are allowed to move during more than 2% of the waves". To find a stability relation based on this criterion, the stability of Xbloc is investigated according to rocking of armour units contrary to the conventionally approach to stability based on the number of displaced units from the armour layer. To find the relation between waves and rocking, physical model tests are performed. In these tests a model breakwater is loaded by wave series with different wave height distributions, wave steepness and groupiness. It resulted that every wave has a certain probability of causing rocking of an armour unit. This probability of rocking is mainly dependent on the height of individual waves and to a lesser extent on the groupiness of the wave series. The steepness of the waves appeared to have a negligible small influence. When the found rocking probability relation is combined with the criterion for rocking, it appears that H2% is mathematically a better fitting parameter for a stability relation according to rocking. A new stability relation for Xbloc is derived based on H2%. Additionally, it is found that very extreme wave heights can dislodge an armour unit in such a way that this armour unit does not interlock anymore. Because it is undesirable that armour units do not interlock anymore, dislodgement of armour units should be accounted for in the stability calculations. Therefore, also a stability relation based on dislodgement of units is provided.

After giving a short general introduction on the area and the general problems in that area, this report starts with an extensive list of relevant boundary conditions for the Jabodetabek area in chapter 2. The most notable parts of this chapter are the large subsidence for Jakarta and the river discharges in the Jabodetabek area. While still operating on a macro level, bottleneck maps for the situ-situ and sea defense were made in chapter 3. These were inventoried using fieldwork and previous studies. The results of this inventory are three bottleneck maps for the situ-situ with the location of the situ-situ together with a value of damage potential, failure potential or risk of the dam. This approach was not taken for the sea defense due to an utter lack of data. A part of the missing information is gathered by field trips, but not enough to make similar quantifications as for the situ-situ. Instead, a bottleneck map for the sea defense was made based on the visual inspection itself. These bottleneck maps are not meant to give a list of all bottlenecks in the entire Jabodetabek area; merely a list of bottlenecks with a high risk. Locations with a high risk are the most promising locations that could qualify for monitoring and emergency solutions. Before the applicability of monitoring and emergency solutions in the Jabodetabek area can be assessed, an overview of relevant failure mechanisms is given in chapter 4 for both the situ-situ and the sea defense. Likewise, an overview of available monitoring sensors and emergency measures is given in chapter 5 and 6 respectively. This information all comes together in chapter 7. A selection of monitoring sensors is made for selected bottlenecks (from chapter 3) based on the conditions in Jakarta (chapter 2). These conditions and bottlenecks define which failure mechanisms (chapter 4) are dominant for the selected bottlenecks, and which monitoring sensors (chapter 5) are applicable. The dominant failure mechanisms together with the local conditions also determine which emergency measure should be used. There is a strong coupling between monitoring sensor, failure mechanism and emergency measure. The dominant failure mechanism determines which monitoring sensor should be used, and the failure mechanism together with the monitoring sensor determine the warning time. The warning time and dominant failure mechanism determine which emergency measure could be used. Finally, a pre-feasibility of the emergency measures and monitoring sensors is given, compared to conventional, completely new designs. The recommended monitoring sensors and emergency measures are put to the test in chapter 8 and 9 for respectively a situ dam design and a sea defense design. Both these chapters contain an application of monitoring sensors and emergency measures for an existing and a fictional, new design.