| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Olofsson, Thomas
(author)
-
Mathematical modelling of jointed rock masses
- 1985
-
Doctoral thesis (other academic/artistic)abstract
- In this thesis, a theoretical model of the mechanical behaviour of jointed rock masses is developed. An equivalent material approach is used to formulate the constitutive equations, where the structural components, intact rock and joints are assigned continuous material properties. The elastic and inelastic properties of the joints are modelled by an elasto-viscoplastic formulation. The model can be used to study general stress and strain paths for both two- and three-dimensional structures based on constitutive equations, i.e. stress-strain relations or in finite element codes. The rock mass model using the equivalent material approach can be applied to hard rock masses with several sets of intersecting continuous joints. The theoretical model developed for a single joint can also be used for discrete formulation of joint elements in finite element codes, cf. chapter 3. The intact rock is treated as a linearly elastic material. The elastic behaviour of the joint is modelled with a constant stiffness matrix. The onset of plastic flow is initiated when the normal stress exceeds the normal compressive strength of the joint asperities or the tensile normal strength of the joint. the shear stress exceeds the cohesive strength and frictional resistance of the joint surface. The normal tensile strength and the cohesion of the joints are assumed to be constant material properties. The frictional parameters the dilation rate, and the shear asperity angle, and the compressive normal strength are functions of the the compressive normal strength are functions of the applied stress field and joint displacement. Simple relations based on Barton's constants joint roughness coefficient, JRC, joint compressive strength, JCS, and the residual friction angle, 0r, simple relations are fitted to these parameters. This implies that input data to the model can be extracted from the Rock Mechanics literature for a wide variety of joints. Results from laboratory shear box test and numerical calculations has been made for a number of different joints. Good agreement was obtained. It shows, that peak shear strength behaviour of joint in principal is a function of dilation rate. Further, the calculations indicated that the elastic off-diagonal behaviour of joints, reported in the rock mechanics literature, is related to the dilation angle at the asperities in contact. By means of finite element technique the model is applied to a circular opening in a jointed rock mass. It is concluded that the model offers several advantages over a discrete formulation.
|
|
| 11. |
|
|
| 12. |
- Ståhl, Agneta
(author)
-
Changing Mobility Pattern and the Aging Population in Sweden
- 1987
-
In: Transportation Research Record. - 0361-1981. ; 1135, s. 37-41
-
Journal article (peer-reviewed)abstract
- A number of Investigations of travel habits and patterns of activity of the elderly have been carried out In Sweden during the 1980s. The results from a study made by the Department of Traffic Planning and Engineering at the Lund Institute ofTechnology are presented. The purpose of this study was to determine (a) older people's access to various means of transportation, (b) travel habits of older people and their difficulties. In using various means of transportation, and (c) the extent towhich these factors lnftuence the social situation of older people compared with various background variables such as age and physical Incapacity.
|
|
| 13. |
|
|
| 14. |
|
|
| 15. |
|
|
| 16. |
|
|
| 17. |
|
|
| 18. |
|
|
| 19. |
|
|
| 20. |
|
|
| 21. |
- Andersson, Kjell, et al.
(author)
-
The effects on accidents of compulsory use of running lights during daylight in Sweden
- 1981
-
Reports (other academic/artistic)abstract
- The report is an attempt to describe the effects on accidents of compulsory use of running lights - low beam or special lamps - during daylight in Sweden.The study is carried out on police reported traffic accidents with personal injury in Sweden. The before and after periods are two years before and two years after the operative day of the law, October 1st 1977.The use of running lights in the before-period was roughly speaking 50 % and in the after-period over 95 %.The basic assumption is that the use of running lights in daylight influences multiple accidents in daylight and only those. The method used is to study the relation of daylight to darkness numbers of multiple accidents. The corresponding relation for single vehicle accidents is taken as control.The estimated total effect depends both on the subdivision of accident data and the method used for accidents with unprotected road users. The estimates vary from 6 to 13 % reduction - from the before-period to the after period - of multiple accidents during daylight or 450 to 1100 less police reported accidents with personal injury per year. The estimated effects are not significant on a 5 % level.
|
|
| 22. |
|
|
| 23. |
|
|
| 24. |
|
|
| 25. |
|
|
| 26. |
|
|
| 27. |
|
|
| 28. |
|
|
| 29. |
|
|
| 30. |
|
|
| 31. |
|
|
| 32. |
|
|
| 33. |
|
|
| 34. |
|
|
| 35. |
|
|
| 36. |
- Bernander, Stig
(author)
-
On limit criteria for plastic failure in strain rate softening soils
- 1985
-
In: Proceedings of the eleventh International Conference on Soil Mechanics and Foundation Engineering. - Rotterdam : Balkema Publishers, A.A. / Taylor & Francis The Netherlands. - 9061915627 ; , s. 397-400
-
Conference paper (peer-reviewed)abstract
- Deals with aspects of stability criteria for extensive slopes if the limiting large strain strength of the soil is strain rate dependent. The issue is exemplified by means of a mechanical model
|
|
| 37. |
- Bernander, Stig, et al.
(author)
-
On the brittleness of soft clays
- 1983
-
In: Symposium on slopes on soft clays. - Linköping : Statens geotekniska institut (SGI). ; , s. 99-112
-
Conference paper (peer-reviewed)
|
|
| 38. |
|
|
| 39. |
|
|
| 40. |
- Bernander, Stig
(author)
-
The landslide at Tuve, nov. 1977
- 1983
-
In: Symposium on slopes on soft clays. - Linköping : Statens geotekniska institut (SGI). ; , s. 69-97
-
Conference paper (peer-reviewed)
|
|
| 41. |
|
|
| 42. |
|
|
| 43. |
|
|
| 44. |
|
|
| 45. |
|
|
| 46. |
|
|
| 47. |
|
|
| 48. |
|
|
| 49. |
|
|
| 50. |
|
|
