Doctoral Thesis

Design and analysis of precast dapped-end beams

Final Thesis 23.11 MB Summary of Thesis 2.41 MB

Author of thesis: Ing. Michal Hasa, Ph.D.

Acad. year: 2018/2019

Supervisor: doc. Ing. Miloš Zich, Ph.D.

Reviewers: doc. ing. Jaroslav Navrátil, CSc., prof. Ing. Jan Vítek, CSc.

Abstract:

The doctoral thesis deals with the analysis of the dapped-end beam detail, in terms of theoretical modelling and practical design using the strut-and-tie method as well as experimental verification of the bearing capacity and the behaviour of the detail under load by means of load tests and subsequent numerical nonlinear analysis. A summary of known structural and static designs explored in the literature has been presented. In addition, the strut-and-tie method has been introduced as an appropriate tool for a consistent design of the detail, element or the whole structure. The theoretical basis for the method has been described, including the general methodology for design and analysis. Practical problems have been discussed, specifically those resulting from the known design of the analysed detail based on the German approach; its modification has been processed theoretically taking into account the practical mode of reinforcement. An experiment has been suggested with a view to verify the presented calculation procedure and the influence of the used ratio of vertical to inclined hanger reinforcement on the bearing capacity and behaviour of the detail under load. The experiment also included accompanying material tests of the concrete which were used along with the inspection certificates issued for the used reinforcement as a basis for the nonlinear finite element analysis. Based on the results, the presented design procedure can be considered safe. These results also imply that the chosen ratio of vertical and inclined hanger reinforcements has no influence on the ultimate bearing capacity within practical reinforcement, as it only influences the formation, development and final width of cracks. With the growing ratio of the inclined hanger reinforcement, the width and density of cracks decreases at all stages of loading. Owing to their limitations, primarily during the service state, it is recommended that the minimal inclined reinforcement should be used.

Keywords:

concrete, detail, discontinuity, dapped-end, hanger reinforcement, strut-and-tie method, strut-and-tie model, experiment, nonlinear analysis

Date of defence

28.11.2018

Result of the defence

Defended (thesis was successfully defended)

znamkaPznamka

Language of thesis

Czech

Faculty

Department

Institute of Concrete and Masonry Structures

Study programme

Civil Engineering (D-K-C-SI (N))

Field of study

Constructions and Traffic Structures (KDS)

Composition of Committee

prof. Ing. Marcela Karmazínová, CSc. - předseda,
prof. Ing. Zbyněk Keršner, CSc. - místopředseda,
prof. Ing. Jan Vítek, CSc. - oponent,
doc. ing. Jaroslav Navrátil, CSc. - oponent,
prof. RNDr. Ing. Petr Štěpánek, CSc. - člen,
doc. Ing. Otto Plášek, Ph.D. - člen,
prof. Ing. Leonard Hobst, CSc. - člen,
prof. Ing. Jindřich Melcher, DrSc. - člen,
doc. Ing. Lumír Miča, Ph.D. - člen,
prof. Ing. Drahomír Novák, DrSc. - člen,
doc. Dr. Ing. Michal Varaus - člen,
prof. Ing. Stanislav Vejvoda, CSc. - člen,
Ing. Mojmír Nejezchleb - člen

Supervisor’s report
doc. Ing. Miloš Zich, Ph.D.

File inserted by supervisor Size
45443.pdf 124,11 kB

Reviewer’s report
doc. ing. Jaroslav Navrátil, CSc.

File inserted by the reviewer Size
45310.pdf 126,07 kB

Reviewer’s report
prof. Ing. Jan Vítek, CSc.

File inserted by the reviewer Size
45422.pdf 157,58 kB

Responsibility: Mgr. et Mgr. Hana Odstrčilová