Abstract: Taking the soil of the Great Wall of Ming Dynasty at Gulang segment as the research object, its mechanical strength and durability are studied by adding polymer material SH into remodeling samples under ultraviolet aging, freeze-thaw cycle, and salt and alkali resistant tests. In addition, scanning electronic microscope(SEM), energy dispersive spectrum(EDS) analysis and grain size analysis are used to study the mechanism of rammed earthen sites reinforced by SH material. The results show that the unconfined compressive strength of the solidified sample after ultraviolet aging test often increased at first and then decreased with the aging time. However, when the solid content of SH is very high in the remodeling samples, the strength of reinforced sample showes continuous increase trend after UV-aged tests. With the increase in cycling of freeze-thaw test, the unconfined compressive strength of the sample gradually decreases, and the mass loss rate gradually increases. The sample with SH solid content of 0.8% shows excellent frost resistance performance. Compared with raw soil, the salt and alkali resistant performance of samples reinforced by SH materials are improved obviously. SH materials mainly make the soil particles closely arranged and strengthen the connectivity through agglomeration, hydrogen bonding, bridging and wrapping. Thus it improves various properties of the soil at archaeological sites. which has good durability.

Key words: SH material, earthen sites, reinforcement, durability, mechanism analysis