Abstract: A stepwise calculation method for the silt-replacement settlement section is established in the background of a barrier dam. The silt-replacement instantaneous settlement is searched according to the stability of silt for different silt-replacement depth of the earlier dump. Then the silt consolidation settlement numerical analysis model under the compaction of the earlier and later dump is established and the final dump silt settlement section is got based on the Biot consolidation theory and the modified Cambridge model. The calculation results show that the final dump silt-replacement settlement section is positively correlated to the dump， the dump silt-replacement section appears to be an inverted trapezoidal. Finally， the corresponding calculation method is verified by detecting the real dump silt-replacement settlement section in the engineering by the high density resistivity method.

Key words: dump silt-replacement settlement section, consolidation settlement, Biot consolidation theory, high density resistivity method