[QUOTE=MJR-IN;60902]Dear All,

I have query regarding applying seismic load as a special loads in Bucket wheel stacker reclaimer machine

As per FEM

"In General the structures of handling appliances do not have to be checked for seismic effects. How ever, if local regulations or particular specifications so prescribe, special rules or recommendations must be applied in areas subject to earthquakes.

The supplier shall be advised of this requirement by the user of the installation who shall also provide the corresponding seismic spectra".

As per ISO 5049

" If the delivery contract includes data concerning the effects due to earthquakes, these loads shall be considered in calculation as special loads."

If we read the above two statement, it says that if the customer ask us to apply the seismic load we have to apply otherwise no need to apply.

my question is that

1. We will be considering seismic loads on the foundation of BWSR rail foundation then again why we need to apply the seismic loads on super strctures & undercarriage & slewing platforms.

(Any large machine will create seismic vibrations during operation whether it is moving or stationary doing work.)Any seismic activity will be transmitted to the foundation and then to the SRBWE (action reaction) to the seismic wave and its intensity. The rail foundation will react to the seismic vibration and transmit it accordingly. If a surface seismic wave occurs the same rule applies. if the seiismic wave or vibration is large enough it could shake the unit off the rails.

2. Is railway bogies structures (train compartment) are designed for seismic loads?

(the machines are assembled with cranes and connected together with nuts, bolts, and welds. The rail system is designed to support and hold the tramming motor frame in one place which carries the business end of things.

3. whether Seismic loads can be applied to moving equipment?

(Any large machine has mass and weight and if it moves it will create vibration and backround noise).

(The weight of the machine is spread over the rails and includes the counterbalance weights(if used) and the if the foundation is inadequate for the rail system the entire rail system and the STBWE will become one big bounciing mass.)

(if the foundation is in (poor soil or is poorly constructed without adequate surface area and depth of foundation to support the weight of the machine over each square foot of rail when it is fully extended) the effects of tramming and gravity will bounce through the rails into the foundation and then into the surrounding soils)

The electric power provided for the unit using either rail mounted pantograph or trailing cable should be examined as well and properly designed.

Dont forget the (entire weight) of the BWESR is riding on the small area of the steel wheel times X number of steel wheels contacting the two rail set!

Perhaps a tracked unit would be better in any case with poor soils if no pad foundation is constructed for the stock pile and rails.

A portable blasting vibration detector would show you exactly how much vibration is generated and tranmitted into the soils/rock when the SRBWE is operating.

lzaharis ■

The customer is not in charge of the situation. Applicable statutory codes will include seismic spectra for the region to which they apply.i.e. Irish Codes might not give seismic data whereas Icelandic codes very well might. The Code will be included or referenced in the contract documentation which you ought to read first.

To:

1. Seismic disturbances will move the track. Tracks carry flanged wheels. If the disturbance amplitude approaches or exceeds the rail head width then the flange might contact the rail bulb with considerable force. This force is then transmitted at definable speed throughout the supported superstructures. It is prudent practice to design structures to withstand this activity however tedious. Slewing gear is particularly vulnerable in this regard and we have to rely on operating realities. Many slewing drives are torque limited to protect against pile collision damage. You have to check how the clutch capacity compares to the seismic situation. There is obviously more to machine design than "as per ISO 5049".

2. Normal loads on rolling stock far exceed any seismic code data.

3. See 1 above. Of course seismic loads are applied to moving equipment. Such equipment cannot select the loads applied to it. Can moving equipment reject wind loads? ■