Installation of cables for monitoring purposes in the ground by using Horizontal Directional Drilling
(2022) In ISRN VTGM01 20221Engineering Geology
Civil Engineering (M.Sc.Eng.)
- Abstract
- The median age for Swedish earth embankment dams is about 60 years. Due to its longevity, one of the major concerns is the internal erosion causing increased seepage through the dam, which ultimately may increases the risk for dam failure. To meet this challenge, there is a need for improved monitoring methods. This in turn requires sensors to be installed inside the earth embankment dams in order to achieve sufficient coverage and resolution, which is currently being investigated in an experimental dam at Vattenfall's laboratory in Älvkarleby.
Horizontal Directional Drilling (HDD) has been proposed as a method for installing sensors in the filter zone of earth embankment dams, but it needs to be investigated if this can be done without... (More) - The median age for Swedish earth embankment dams is about 60 years. Due to its longevity, one of the major concerns is the internal erosion causing increased seepage through the dam, which ultimately may increases the risk for dam failure. To meet this challenge, there is a need for improved monitoring methods. This in turn requires sensors to be installed inside the earth embankment dams in order to achieve sufficient coverage and resolution, which is currently being investigated in an experimental dam at Vattenfall's laboratory in Älvkarleby.
Horizontal Directional Drilling (HDD) has been proposed as a method for installing sensors in the filter zone of earth embankment dams, but it needs to be investigated if this can be done without damaging sensor cables or the dam itself. To approach the aim of the thesis, it was considered to carry out a field-test to install an Electrical Resistivity Tomography (ERT) cable with HDD, not in a dam but on a suitable test site, with similar material properties as parts of the dam, and finally to locate the installed cable with independent methods.
Several key questions are listed to track the degree of success of the experiment. Based on the answers to the key questions, it can be concluded that the field test to install the ERT cable with HDD was not successful. About locating the installed cable with independent methods, an idea for positioning of the cable through resistivity measurements was theoretically tried but, because the system of equations developed was analytically unsolvable, it was concluded that it was not feasible.
Unfortunately, based on the technologies used, it was not possible to make an accurate judgment on whether HDD is a suitable tool for installing sensors in hydropower earth embankment dams for monitoring purposes. Anyhow, certain recommendations can be drawn from it, such as to carry out an adequate preliminary study in advance to choose the optimal excavation site and to study the technical specification of the drill rig to find out if it is suitable for the drilling and subsequent cable installation. From this project, it is recommended to make a second drilling test in the future considering everything learned in this master thesis. (Less) - Popular Abstract
- Sweden currently bases a significant part of its power generation on hydropower plants, most of which were created more than 50 years ago. This is why it is important that the dams that store this energy in the form of water are in good condition.
Vattenfall, the Swedish state power company, has long sought ways to improve methods for accurately knowing the condition of dams.
An idea that seems promising at the moment is based on observing the internal changes of certain properties of the materials of the dam structure. If there are unexpected changes, it is likely that the dam has internal problems that can be catastrophic in the long run.
To do this, it is necessary to install cables with a series of sensors inside the dam,... (More) - Sweden currently bases a significant part of its power generation on hydropower plants, most of which were created more than 50 years ago. This is why it is important that the dams that store this energy in the form of water are in good condition.
Vattenfall, the Swedish state power company, has long sought ways to improve methods for accurately knowing the condition of dams.
An idea that seems promising at the moment is based on observing the internal changes of certain properties of the materials of the dam structure. If there are unexpected changes, it is likely that the dam has internal problems that can be catastrophic in the long run.
To do this, it is necessary to install cables with a series of sensors inside the dam, something that a priori seems very risky because, during installation, damage could be caused to the structure of the dam.
So how would it be possible to install those sensors without damaging the dam or the sensors themselves? Once the cable is installed, could its exact position inside the dam be known?
To answer these questions, it was proposed to investigate the use of a relatively modern drilling method called Horizontal Directional Drilling.
For safety reasons, it was decided not to directly test the drilling method in a dam, but in a place with similar geological conditions as its internal structure. A study was carried out to find a suitable place for the test and then the drilling method was tested.
Unfortunately, the installation attempt was not successful, so the cable could not be installed. It has not been possible to assess the objective of this thesis satisfactorily and therefore it is not possible to make an accurate judgment on whether Horizontal Directional Drilling is suitable for installing sensors in hydropower earth embankment dams.
Although the main objective could not be achieved, certain recommendations can be drawn from it:
It is important to carry out a proper preliminary study sufficiently in advance to choose the optimal drilling site.
For future drilling attempts, it is also recommended to carefully choose the drill rig to find out if it is suitable for the job. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9101866
- author
- Garcia Cañas, Eduardo LU
- supervisor
- organization
- alternative title
- Installation av kablar för övervakningsändamål i marken med hjälp av horisontell riktningsborrning
- course
- VTGM01 20221
- year
- 2022
- type
- H3 - Professional qualifications (4 Years - )
- subject
- keywords
- HDD, Earth Embankment Dam, Resistivity, ERT, IP
- publication/series
- ISRN
- other publication id
- ISRN LUTVDG(TVTG 5176 )/1-70 /(2022)
- language
- English
- additional info
- Examiner: Gerhard Barmen
- id
- 9101866
- date added to LUP
- 2022-10-18 13:53:59
- date last changed
- 2022-10-18 13:53:59
@misc{9101866,
abstract = {{The median age for Swedish earth embankment dams is about 60 years. Due to its longevity, one of the major concerns is the internal erosion causing increased seepage through the dam, which ultimately may increases the risk for dam failure. To meet this challenge, there is a need for improved monitoring methods. This in turn requires sensors to be installed inside the earth embankment dams in order to achieve sufficient coverage and resolution, which is currently being investigated in an experimental dam at Vattenfall's laboratory in Älvkarleby.
Horizontal Directional Drilling (HDD) has been proposed as a method for installing sensors in the filter zone of earth embankment dams, but it needs to be investigated if this can be done without damaging sensor cables or the dam itself. To approach the aim of the thesis, it was considered to carry out a field-test to install an Electrical Resistivity Tomography (ERT) cable with HDD, not in a dam but on a suitable test site, with similar material properties as parts of the dam, and finally to locate the installed cable with independent methods.
Several key questions are listed to track the degree of success of the experiment. Based on the answers to the key questions, it can be concluded that the field test to install the ERT cable with HDD was not successful. About locating the installed cable with independent methods, an idea for positioning of the cable through resistivity measurements was theoretically tried but, because the system of equations developed was analytically unsolvable, it was concluded that it was not feasible.
Unfortunately, based on the technologies used, it was not possible to make an accurate judgment on whether HDD is a suitable tool for installing sensors in hydropower earth embankment dams for monitoring purposes. Anyhow, certain recommendations can be drawn from it, such as to carry out an adequate preliminary study in advance to choose the optimal excavation site and to study the technical specification of the drill rig to find out if it is suitable for the drilling and subsequent cable installation. From this project, it is recommended to make a second drilling test in the future considering everything learned in this master thesis.}},
author = {{Garcia Cañas, Eduardo}},
language = {{eng}},
note = {{Student Paper}},
series = {{ISRN}},
title = {{Installation of cables for monitoring purposes in the ground by using Horizontal Directional Drilling}},
year = {{2022}},
}