Abstract: The upward horizontal slicing mining method is a kind of mining method widely used at home and abroad，and the main purpose of backfilled body is to provide the upward mining work platform.The strength of backfilled body should fulfill the operating conditions of efficient trackless equipment.In order to analyze the mechanism of the upward horizontal slicing backfilled body more accurately，and to establish a more appropriate strength model of the backfilled body，the backfilled body are classified into two parts to make study，namely the cemented layer and the tailing backfilled body.According to the action mechanism and the stress analysis of backfilled body under the vehicle dynamic load，a half sine pulse load is selected to represent the dynamic role of wheel load vehicle load model，by referring to subgrade and pavement design principle in subgrade pavement engineering.The corresponding strength model is worked out using elastic mechanics method，and the thickness design method of the cemented backfilled body under trackless equipment load is concluded.This model is applied in the strength design for the upward horizontal slicing backfilled body of west ore block in Dahongshan copper mine.The practice proves that this model is reasonable and reliable.

Key words: Upward slicing mining method, Backfilled body, Strength, Equipment load