Wednesday, 8 August 2018

SLIP FORM : Design Considerations

The Slipform should be designed so that the loads to which its various component parts are subjected are uniformly distributed, and the yokes are loaded as uniformly and axially as possible to avoid their overturning. The jacks should not be located in wall openings as for as possible. The loading should not exceed the lifting capacity of the jacks. 

The loads acting on Slipform can be classified as follows,

A. Basic Loads

1. Dead load due to the components

2. Live loads due to Concrete

3. Friction between form and concrete

4. Workmen

5. Materials

6. Machinery

7. Other installations

8. Auxiliary load due to the way of application of live loads

9. Crowds of workmen

10. Piles of materials

11. Shocks produced by material unloading

B. Accidental Loads

1. Wind pressure

2. Adhesion between concrete and form due to long interruption

3. Friction due to incorrect position of form

4. Failure of one jack

5. Extraordinary Loads

6. Breaking of certain members of the slipform

7. Failure of two adjacent jacks

Minimum concrete strength required for Slipform application,

2 Kg / cm2 - When releasing the Form

4 Kg / cm2 - When coming out from the Form

20 Kg / cm2 - After 24 hours since pouring

200 Kg / cm2 - After 28 days