About me

My name is Tim van Koelen. I have finished my bachelor of Civil Engineering and currently I am a master student Geo-Engineering at the TU Delft.

To conclude the master program of the TU Delft, I am currently working on my Master's Thesis. Updates will follow here as soon as the first results are booked.

Besides my study I took place in the board of the Dispute of Geo-Engineering 'De Ondergrondse'. This is an association for students of the master Geo-Engineering. I focussed mainly on the education of the master, but also on the education of the faculty of Civil Engineering as a whole. As a student representative, I furthermore took place in the board of KIVI TTOW (Tunneling and Underground Works).

Bachelor Thesis

Drinking water quality of PDAM Tirtawening kota Bandung

Clean drinking water is one of the basic necessities of life. To be able to guarantee safe and reliable drinking water, water treatment plants need to operate efficiently and constantly. Since the population in Bandung is ever increasing, there is a large demand for clean drinking water. The water treatment plant of Bandung has to keep up with this demand and therefore the plant has been upgraded about 40 years ago with a newly build part. But unfortunately, this part of the water treatment plant is not functioning as good as it could.

Together with another student, I have been to Bandung on the island Java during the summer of 2015 for my bachelor thesis, to investigate why the drinking water quality of the water treatment plant in Bandung is of such a low quality. Also research has been done on the increase of the production quantity, but this appeared to automatically follow from an increase of water quality in early stages of the water treatment.

Every day we took daily measurements of the turbidity and pH to be able to monitor the whole system. These points have been taken at the in- and outflows of the labyrinth, lamella separator and rapid sand filters. Also more and specific measurements were done when a part was cleaned or had to be monitored more closely.

During the project, we looked into the cleaning of the treatment steps, the flow rates, the velocity gradients and the dosing of coagulant. What we found out was that the cleaning and the dosing of coagulant were the steps that could best be improved.

The basic cleaning with a fire hose and brushes proved not to be enough to clean a part of the treatment plant, a more thorough cleaning is needed. Unfortunately there was no high pressure washer available, but it is recommended to make use of a high pressure washer to clean the systems until they are very clean.

With the dosing of aluminium we first tried to find the optimum dosage for the water, and compare it with the amount that is being dosed in the system. The optimum found with the help of a jar test appeared to be more than was being dosed at the water treatment plant. This was also confirmed by taking a sample from the labyrinth with the dose in it and adding some additional coagulant to that sample. Exactly the same optimum was found, and during the last days of the project we were allowed to prove in the real system that the dosage was better. The turbidity values decreased drastically, which was the best possible outcome of the real scale test!

In November 2015 two new students will continue where we left. The changes that should be made to the water treatment plant of Bandung will be implemented to improve the water quality and production quantity. Therefore this project has created added value to the city of Bandung and to the knowledge of the water treatment plant.

Master Geo-Engineering

Geotechnical Engineering is the branch of Civil Engineering concerned with the engineering behaviour of earth materials. Geotechnical Engineers:

  • Use principles of soil and rock mechanics to investigate subsurface conditions and materials;
  • Determine the relevant mechanical and chemical properties of these materials;
  • Evaluate stability of natural slopes and man-made soil deposits;
  • Assess risks posed by site conditions;
  • Design earthworks and structure foundations;
  • And monitor site conditions, earthwork and foundation construction.

"Everything you see around you is supported by soil or rock. Geotechnical Engineers are responsible for that. Anything that is not supported by soil or rock, either floats, flies or falls down."

A typical Geotechnical Engineering project begins with a review of project needs to define the required material properties. Then follows a site investigation of soil, rock, fault distribution and bedrock properties on and below an area of interest to determine their engineering properties including how they will interact with, on or in a proposed construction. Site investigations are needed to gain an understanding of the area in or on which the engineering will take place.

A Geotechnical Engineer then determines and designs the type of foundations, earthworks, and/or pavement subgrades required for the intended man-made structures to be built. Foundations are designed and constructed for structures of various sizes, such as high-rise buildings, bridges and smaller structures where the soil conditions do not allow code-based design.

Foundations built for above-ground structures include shallow and deep foundations. Retaining structures include earth-filled dams and retaining walls. Earthworks include embankments, tunnels, dikes and levees, channels, reservoirs, deposition of hazardous waste and sanitary landfills.

Master Thesis

The not-so-concise topic of my Master Thesis is currenly formulated as:

Spatial correlations under man-made structures on soft soils:
The structure's influence on the spatial correlations and the influence of the spatial correlations on the reliability of the structure.

Further updates about my Master Thesis will follow when the first results are booked.


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