| Author | Saksit Niyomvit |
| Call Number | AIT Thesis no. 49 |
| Subject(s) | Reinforced concrete construction|xModels|xTesting
|
| Note | A thesis submitted in partial fulfillment if the requirements for the degree of Master of Engineering in the SEATO Graduate School of Engineering, Bangkok, Thailand. |
| Publisher | Asian Institute of Technology |
| Abstract | The Scordelis-Morgan method was used to analyse a 180° fixed ended
helicoidal staircase. Two half-scale models of a 180° helicoidal staircase designed on this basis were then tested. For the first model two
forms of load were used. Firstly a concentrated elastic load was applied
at central span by hydraulic jacks. Secondly, after removing the concentrated load, distributed load was applied For the second model
distributed load only was used. The percentage of steel for both models
was the same as for the prototype. The models were fixed at both ends by
steel frames. For the second model the steel columns supporting the
upper platform were braced additionally by high tensile steel wires to
achieve a higher degree of fixity.
Horizontal and vertical displacements were obtained at various points
during the load tests by dial gauges and by a surveyor's level. Strains
were measured along both sides and lower face of the staircase at various
stations using mechanical strain gauges.
The results of the load tests were satisfactory for both models
although it was not found possible to load either model to collapse.
With the first model there was considerable movement of the columns
supporting the upper platform so that further loading was discontinued
before collapse. For the second model the large load became so precarious that further loading was not feasible.
The load factor at first crack for the first model was 2.86 and
for the second model 3.96. The highest load factors attained for the
two models were 7.56 and 9.83 respectively; these were not ultimate
values. In each model’, the first crack appeared at the upper surface
at the outside edge of the staircase near the lower support - the
critical section in the analysis. The measured strains from the experiments agreed reasonably with the analytical results at various sections. |
| Year | 1963 |
| Type | Thesis |
| School | Student Research Before 1979 |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Thesis (Year <=1979) |
| Degree | Thesis (M.Eng.) - SEATO Graduate School of Engineering |