Browsing by Author "Saarinen, Olli"

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Ydinvoimalaitosten rakenneteknisen suunnittelun ja tarkastustoiminnan haasteet konsulttitoimistolle
(2010) Suhonen, Teemu
School of Engineering | Master's thesis
Osoiterekistereiden segmentointi suoramarkkinoinnissa - Yksi case-esimerkki
(1988) Saarinen, Olli
School of Business | Master's thesis
Piirilevyjen stanssauksen prosessiparametrit
(1997) Ståhlberg, Kimmo Olavi
Helsinki University of Technology | Master's thesis
Ydinvoimalaitoksen sisäsuojakuoren rakenteellinen suunnittelu
(2011) Huhtala, Juhani
School of Engineering | Master's thesis
This thesis applies the theory of structural design to analyse of the inner containment of the reactor building in a nuclear facility. In Finland, the planning of a nuclear plant is supervised and regulated by the Radiation and Nuclear Safety Authority (STUK). Designing a nuclear facility begins with defining the site-specific requirements of the plant. When approved by STUK, the ASME standard is applied to the dimensioning of the inner containment, supplemented by the Euro code. The ASME standard divides the loads of the containment into two categories: loads during operation, which are not multiplied by safety factors; and environment and accident loads, which are multiplied by safety factors. The dimensioning of compressive resistance is based on the combined effect of the dead load of the containment and it's and pre-stressing forces. The required thickness of the shell is determined by compression and shear resistances. As an alternative to increasing the thickness, the shell can also be strengthened by additional compression and shear steel reinforcement. An important parameter affecting the design is the permissible shear stress of the concrete used in the structure. This study presents the dimensioning equations based on the combination of different stress variables. In addition to normal forces and moments, the equations take into account the force resultants of pre-stressing and its losses. The force resultants in the containment comprise the force resultants of the membrane and bending state, splitting forces, steering forces, and friction and locking losses. The fire safety of the containment is based on a performance-based design philophy. The application examined in this study is containment with an ellipsoid geometry that is closely comparable with the shape of the chain curve loaded by its dead load. The examined shell had a height of 62 m, a width of 51 m and a thickness of 1.7 m. The concrete chosen for the vertical structures in the shell was high strength concrete C70/85-1 and, for the base plate, C35/45-1. The ducts of anchored tendons are grouted with grease. The analyses were made using the finite element method and STAAD.Pro and Abaqus software, and the dimensioning was performed according to the Euro code. The types of element that were used consisted of 8-node and 6-node solid elements and bar rod elements. The loading consisted of the dead load of the containment and its interior pressure loading. The critical structural property in the observed case was shear capacity, which was exceeded by 62%. The tensile strength was exceeded by 27% in the no-crack mode. However, only 42% of the compression capacity was used, and the percentage of used tendon capacity was 70%, including the 20% decrease of capacity from losses. The results show that a thickness of 1.7 m is not sufficient for the inner containment, but the tendons will sustain. As a conclusion, either the shell thickness should be increased in the examined case or shear steel reinforcement should be added to the structure. When losses remained at the moderate level of 6~12 per cent, the optimal amount of parts acting as a stress platform was observed to be four horizontal pilasters around the shell and a horizontal beam placed in the lower edge of its calotte shaped upper dome.
Uraaniheksafluoridin hydrolyysitutkimuksia
(1970) Saarinen, Olli
Helsinki University of Technology | Master's thesis
Tietomallinnuksen käyttö ja mahdollisuudet Länsimetron rakennesuunnittelussa
(2012) Ojutkangas, Terhi
School of Engineering | Master's thesis
Many designers have mistaken the plain usage of 3D tools in construction design as Building Information Modelling (BIM). However, the decision to use BIM requires a new kind of approach to designing and building constructions. All parties in a BIM project need to agree to use Building Information Modelling. BIM is used to enhance the design process and to facilitate the making of analysis, going beyond just producing two-dimensional drawings. The extension of the Helsinki underground line from Ruoholahti to Matinkylä is called the Länsimetro. In this thesis how BIM can be utilized in the structural designing of the Länsimetro was studied. The modelling programs surveyed closer were limited to the ones used in the actual design of the Länsimetro. Special attention was paid to the simulation of the rock surface. Preliminary plans were added to the actual plans regarding the handling of the rock surface as the tunnels were measured by means of laser scanning. Measurement data from built structures or the rock surfaces surrounding the structures to be built can be measured with laser scanning, obtaining a point cloud of the measured structures. The point cloud can be edited into a DWG format file that can then be used as a reference drawing within modelling software. It was observed that a number of BIM features cannot be utilized if BIM is only partially implemented in the project. Not all parties to the Länsimetro project used modelling because the official design data was ordered in a two-dimensional format and BIM was not required. The parties using modelling did, however, find it helpful because of the challenging geometry of the Länsimetro project. Design solutions used in the Länsimetro differ from ones used in ordinary building constructions thereby causing new challenges. Many contradictions emerged from the three-dimensional model that has not been noticed in two-dimensional drawings.