Correct Answer - Option 3 : Short column
Explanation:
Column splices:
(i) A splice is a joint provided in the length of the member.
(ii) In case of column splice, if the load is truly concentric then theorectically no splice is required since compression wili be directly transfered through bearing. But truly axial load in column never occurs.
(iii) Also columns are most of the times also subjected to bending. This raise the necessity of column splices. Column sections are required to be spliced for the following cases
- When the available length of structural steel section is less than the required length of the column.
- In case of multi-storey buildings, the section of column required for the various storeys may be different.
- In multi-storeyed buildings, for convenience of fabrication it is kept at about 5 m lengths. So, splicing of column is necessary to join the fabrication along the length.
Specification for the design of splices:
(i) Where the ends of the compression members are faced for complete bearing over the whole area there the splices are designed to hold the members accurately in position and to resist any tension where bending is also there.
(ii) In case the connecting members are not faced for complete bearing then splices are designed to transmit all the forces to which they are subjected to.
(iii) Splices are designed as short columns.
(i) Ideally a splice plate should be located at a place where flexural moment in the column is zero i.e. at the location of point of contra flexure.
(ii) Due to direct load, there are two points of contra flexure varying from middle of the column to the points above or below the middle.
