Sand utilization has increased over the past decades and is getting a scarce resource globally. In Singapore, no sand is available for construction purposes or land reclamation projects. The increasing scarceness of ''suitable'' sandy building materials around the world forces the dredging industry to consider the usage of alternative ''complex'' materials for land reclamation purposes. However, working with these kinds of ''complex'' materials introduces operational and technical challenges on the estimation of project duration and costs, due to their low permeability, high compressibility and complex consolidation behaviour of this slurry material.

The main involved departments on land reclamation projects are the production department and the geotechnical department. The production department is responsible for ''Production Estimation'' and estimates the rate of which soil can be produced by transporting it from the dredging area to the reclamation area, considering specific equipment choices and costs. The geotechnical department is responsible for ''Reclamation Engineering'' and handles the engineering of the soil brought in by production to be formed into a soil which is eventually usable for the client.

Two reclamation projects of the past; the ''Scandinavia'' and ''Black Sea'' project have proven that Production Estimation and Reclamation Engineering are closely connected when working with ''complex'' material. While working with ''suitable'' sandy materials primarily focuses on minimizing project costs through optimizing Production Estimation, the effects of Reclamation Engineering optimizations increases significantly when dealing with ''complex'' materials. This is due to their long duration of consolidation and the potentially high costs of soil improvements required before the asset can be delivered to the client.
In this context, optimizing Production Estimation by dredging at low initial density comes at the expense of Reclamation Engineering as low initial density often results in longer and more costly consolidation, and vice versa. Therefore, it can be concluded that a trade-off exists in optimizing for Production Estimation and Reclamation Engineering in minimizing project costs.

It becomes evident from the literature review that no specific research is dedicated to investigating the effect of the trade-off between optimizing Production Estimation or Reclamation Engineering in minimizing project costs. Therefore, the main research objective of this thesis is to answer the question:

''How can project costs be minimized by explicitly balancing the trade-off between optimizing for Production Estimation and Reclamation Engineering?''

This thesis provides a new framework for evaluating the effects of the trade-off between Production Estimation and Reclamation Engineering optimizations on total project costs, in order to answer the main research question. This framework couples production estimation models to geotechnical estimation models by OpenCLSim and a large-strain consolidation model. This integral approach enables the simulation of the continuous reclamation construction process, including filling, self-weight consolidation and long-term consolidation under the effect of ground improvement methods. The proposed framework is subjected to a case-study to asses how optimizations on Production Estimation and Production Engineering affect consolidation behaviour and project costs. In this analysis optimizations are implemented by varying initial density coming with hydraulic and mechanical dredging work methods. This thesis evaluates these optimizations in three stages; single production cycle, production - self-weight consolidation analysis, and a full scale case study including long-term consolidation under the effect of ground improvement methods. The full-scale case study is evaluated using a hydraulic work method of 1100 kg/m3 and a mechanical work method of 1300 kg/m3. The production and reclamation models are calibrated by the material characteristics from the case-study, whereas the large-strain consolidation method is calibrated and validated by physical samples from the project site.

Results from the full scale case-study show that utilizing a mechanical method at 1300 kg/m3 (aimed at optimizing Reclamation Engineering) results in a 1,86 more expensive project than using a hydraulic method at 1100 kg/m3 (aimed for optimizing Production Estimation). Almost no differences occur between Reclamation Engineering costs for the two dredging work methods as the case-study material quickly consolidates and converges to a similar compaction profile within a similar time-frame. Consequently, the potential advantage of achieving a higher initial density using the mechanical method is diminished by its lower production rates and high costs. By converging to a similar compaction state within the same duration creates no significant differences between the ground improvement methods needed to force the profile to comply to design requirements. This will lead to almost no differences in costs for Reclamation Engineering. As a result, only optimizations in Production Estimation can lead to minimization of the project costs for the considered case-study material.

Nevertheless, it can be concluded that it is possible to get insights on how to minimize project costs based on the trade-off between Production Estimation and Reclamation Engineering when using a framework which couples their interactions through self-weight (large-strain) consolidation and OpenCLSim. The existence of the trade-off and its magnitude on minimizing project costs depends on the soil type used in the project. ''Complex'' materials that tend towards relatively ''well-consolidating'' seem to reduce the magnitude of the trade-off, while it is believed that more ''poor-consolidating'' materials enhance the magnitude of the trade-off. Therefore, the predictability of the trade-off between Production Estimation and Reclamation Engineering optimizations is closely related to the understanding of production effects (varying initial density and varying duration between layer stacking) on the consolidation behaviour of the slurry material.

The proposed framework in this thesis is believed to be a first step in estimating project costs and duration based on a physics-based approach, compared to the current ''empirical estimations'' that are used to represent physical processes such as large-strain consolidation. The proposed framework could lead to a more integrated understanding between Production Estimation and Production Engineering when using ''complex'' material and more insights on how optimizations between the two departments can minimize project costs.