Andreas SjölanderKTH Royal Institute of Technology | KTH · Department of Concrete Structures
Andreas Sjölander
Doctor of Philosophy
About
28
Publications
9,235
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
97
Citations
Citations since 2017
Introduction
Postdoctoral researcher at the divison of Concrete Structures at KTH Royal Institute of Technology. My research is focused on the structural behaviour of fibre reinforced shotcrete in interaction with hard rock and rock-bolts. Currenty, my research is focused on developing an autonomous inspection system for tunnels with a focus on crack-detection and evaluation of different fibre types to use as reinforcement in shotcrete.
Additional affiliations
January 2015 - January 2020
Position
- PhD Student
Description
- PhD student at the Division of Concrete Structures. The focus of my PhD project was the structural behaviour of fibre-reinforced shotcrete in interaction with hard rock and rock bolts.
Education
August 2010 - June 2012
Publications
Publications (28)
In recent decades, many cities have become densely populated due to increased urbanization , and the transportation infrastructure system has been heavily used. The downtime of important parts of the infrastructure, such as tunnels and bridges, seriously affects the transportation system's efficiency. For this reason, a safe and reliable infrastruc...
![Figure 2. Flow chart for calculation of RMR value; redrawn from [31].](publication/368626253/figure/fig1/AS:11431281120962482@1676727692396/Flow-chart-for-calculation-of-RMR-value-redrawn-from-31_Q320.jpg)
Fibre-reinforced shotcrete (sprayed concrete) is one of the major components in the support system for tunnels in hard rock. Several empirical design methodologies have been developed over the years due to the complexity and many uncertainties involved in rock support design. Therefore, this paper aims to highlight how the choice of design methodol...
Fibre-reinforced shotcrete is the most common support method for hard rock tunnels in the Nordic countries. The design of shotcrete is often based on empirical methods or simplified analytical equations, which neglect variations in mechanical properties and shotcrete thickness. Data collected from the field shows that significant variations in shot...
In this dataset, data from experimental testing of fibre-reinforced shotcrete is presented. The dataset contains five different fibres made of steel (Dramix 3D, Dramix 4D and Dramix5D), synthetic (BarChip R54) and basalt (MiniBar). Preparation of specimens and testing were performed by Vattenfall R&D in Älvkarleby, Sweden. This first version of the...
Today, Digital Image Correlation (DIC) has become a standardized method to track displacements and crack-propagation of civil engineering structures in a laboratory environment. The benefit of using DIC over other standard methods is that it is contact-free and only requires a standard DSLR camera. Moreover, the displacement can be tracked over the...
Tunnels in hard rock are typically supported with a thin layer of fibre-reinforced shotcrete in combination with rock bolts. Cracks in the shotcrete could lead to corrosion of the fibres, which reduces the residual strength and could lead to downfall of shotcrete. Therefore, routine inspections are carried out to maintain a safe tunnel. Today, visu...
![Fig. 2. Comparison of force-displacement curves from Dong et al. [17]...](profile/Andreas-Sjoelander/publication/353749994/figure/fig1/AS:1054761155584000@1628486064390/Comparison-of-force-displacement-curves-from-Dong-et-al-17-and-simulations-with-a_Q320.jpg)
Fibre reinforced shotcrete (sprayed concrete) is often used to support tunnels in hard rock. The shotcrete should be designed to carry the load from a loose block, which is assumed to be transferred to the surrounding rock mass over a narrow band. It is commonly accepted that the width of this band is constant, and independent of the shotcrete thic...
Civil infrastructures, such as tunnels and bridges, are directly related to the overall economic and demographic growth of countries. The aging of these infrastructures increases the probability of catastrophic failures that results in loss of lives and high repair costs; all over the world, these factors drive the need for advanced infrastructure...
![Fig. 3. Experimental results from El Zain [23] compared to numerical...](profile/Andreas-Sjoelander/publication/343041930/figure/fig1/AS:917411045859328@1595739246353/Experimental-results-from-El-Zain-23-compared-to-numerical-simulations-The-geometry_Q320.jpg)
![Fig. 4. Experimental results from Holmgren [4] (Test 4), shows...](profile/Andreas-Sjoelander/publication/343041930/figure/fig2/AS:917411045863427@1595739246404/Experimental-results-from-Holmgren-4-Test-4-shows-displacement-on-the-left-and-right_Q320.jpg)
![Fig. 5. Experimental results from Dong [9-11] shows relationship...](profile/Andreas-Sjoelander/publication/343041930/figure/fig3/AS:917411045851138@1595739246444/Experimental-results-from-Dong-9-11-shows-relationship-between-force-and-crack-mouth_Q320.jpg)
![Fig. 6. Experimental results from Li [16] compared to numerical...](profile/Andreas-Sjoelander/publication/343041930/figure/fig4/AS:917411045851139@1595739246489/Experimental-results-from-Li-16-compared-to-numerical-simulations-for-concrete-with-a_Q320.jpg)
Falling or sliding of loose blocks is one of the most common failure modes in a rock tunnel. For tunnels in hard and jointed rock, fibre-reinforced shotcrete (sprayed concrete) in combination with rock bolts is one of the most commonly used supports to prevent such failures. The structural behaviour, and especially the failure, of this type of rock...
Shotcrete is widely used as rock support and can support the load from blocks ei-ther by bonding to the rock or by bending between rock bolts. By introducing fibres, the ductili-ty of the shotcrete will increase and the crack widths decrease. Predictions of the structural be-haviour for fibre reinforced shotcrete (FRS) are however complicated due t...
Shotcrete is widely used as rock support and can support the load from blocks ei-ther by bonding to the rock or by bending between rock bolts. By introducing fibres, the ductili-ty of the shotcrete will increase and the crack widths decrease. Predictions of the structural be-haviour for fibre reinforced shotcrete (FRS) are however complicated due t...
Tunnels in hard and jointed rock are normally excavated in an arch shape to enable the rock mass to support its weight. Since the beginning of the 1980's, fibre reinforced shotcrete (FRS) in combination with rock bolts have been the dominating support method for hard rock tunnels. This type of rock support is a complex composite structure in which...
During the construction of a rock tunnel in Stockholm, several sections with leaching shotcrete (sprayed concrete) were found one year after the spraying was completed. An investigation was therefore conducted, and its results are presented in this paper. The amount of leaching after such a short time indicated that a one-sided water pressure exist...
Shotcrete is widely used as rock support and can support the load from blocks ei-ther by bonding to the rock or by bending between rock bolts. By introducing fibres, the ductili-ty of the shotcrete will increase and the crack widths decrease. Predictions of the structural be-haviour for fibre reinforced shotcrete (FRS) are however complicated due t...
Shotcrete is widely used as rock support and can support the load from blocks ei-ther by bonding to the rock or by bending between rock bolts. By introducing fibres, the ductili-ty of the shotcrete will increase and the crack widths decrease. Predictions of the structural be-haviour for fibre reinforced shotcrete (FRS) are however complicated due t...
A common support measure for underground excavations in jointed rock masses to support loose blocks is to apply a thin shotcrete layer to the periphery of the excavation and systematically install rockbolts into the surrounding rock mass. In this support system, large blocks are carried by the rockbolts and small blocks are carried by the thin shot...
I den här rapporten redovisas resultat från en utvärdering av nya fältmetoder för att mäta rörelser på sprutbetong i fält. Syftet var att föreslå en metod som är snabb och pålitlig och därmed användbar för att mäta deformationer i sprutbetong under pågående produktion.
Först utvärderas mekanisk mätning med skjutmått och mikrometer. Tanken var att...
Tunnels in hard and jointed rock are normally excavated with an arch shape to enable the rock to carry itself. The arch effect depends on the stability of individual blocks and too high or too low horizontal stresses could cause blocks to be pushed out or to fall down. To prevent this, systematic rock bolting in combination with fibre reinforced sp...
Tunnels in hard, jointed rock are commonly reinforced with shotcrete (sprayed concrete) applied directly on the irregular rock surface. The thickness for such linings can be as small as 50 mm, which result in a fast drying. The resulting shrinkage of the restrained lining is a well-known phenomenon, which leads to cracking. The installation of drai...
The first part of a project aiming at increase the knowledge and understanding of how shotcrete (sprayed concrete) in interaction with rock could better be modelled is presented. The study focus on how an irregular thickness of shotcrete will affect its structural capacity. Examples show that continuously bonded shotcrete have an ability to redistr...
Tunnels through hard jointed rock are commonly reinforced with a combination of fibre reinforced shotcrete (sprayed concrete), FRS, and rock bolts. The design of such reinforcement is a complex task. First, the interaction between rock bolts, FRS and rock should be considered. Secondly, a natural variation in important parameters such as thickness...
Tunnels through hard jointed rock are commonly reinforced with a combination of fibre reinforced shotcrete, FRS, and rock bolts. The design of such reinforcement is a complex task. First, the interaction between rock bolts, FRS and rock should be considered. Secondly, a natural variation in important parameters such as thickness of the shotcrete, f...
Shotcrete is sprayed concrete applied pneumatically under high pressure and was invented in the beginning of the 1900's. This new technique decreased the construction time and since steel fibres were introduced in the shotcrete during the 1970's, shotcrete has been the primary support method for tunnels.
Tunnels excavated with the drill and blast...
![Force-displacement curves from experimental tests [15] and numerical...](profile/Andreas-Sjoelander/publication/316712470/figure/fig2/AS:1086533155205124@1636061099091/Force-displacement-curves-from-experimental-tests-15-and-numerical-analyses_Q320.jpg)
Modern tunnels in hard rock are usually constructed by drill and blast with the rock reinforced by shotcrete (sprayed concrete) in combination with rock bolts. The irregular rock surface and the projection method of shotcrete lead to a tunnel lining of varying thickness with unevenly distributed stresses that affect the risk of cracking during shri...
![Figure 1: Early-age shrinkage as measured with a dilatometer [21].](profile/Richard-Malm/publication/303513341/figure/fig1/AS:365647985954817@1464188681281/Early-age-shrinkage-as-measured-with-a-dilatometer-21_Q320.jpg)
The behaviour of concrete at early-age is complex and involves several physical fieldssuch as temperature, moisture and deformations. In this paper a hygro-thermo-chemo-mechanicalmodel for the anal ...
Composite bridges in Sweden are commonly designed as a twin I-girder section. To stablizie the bridge during launching and concreting horizontal cross bracings are used. These are normally connected to a transverse web stiffener that is welded with a throat size of 5 mm regardless of the dimensions of the bridge.
During an inspection of Vårby Brid...
Questions
Question (1)
I have access to laser scans of tunnelsections before and after spraying the tunnel with shotcrete. Hence the first point cloud represents the geometry of the rock surfaces and the other point cloud represents the surfaces of the shotcrete.I would therefore like to use the pointcloud data to build a solid element to import in Abaqus for analysis.
I've tried to use programs such as VRMesh, Meshlab and Autocad and can easily create individual surfaces from the pointclouds, on for the rock surfaces and one for the shotcrete surface. I've so far been unable to join the surfaces to create a solid element. Booth surfaces are higly irregular so when i try to extrude one of the surfaces to create a solid element the geometry will clash into each other.
Any suggestion how to solve this problem?
