ABSTRACT A case study involving slope foundation excavation located in northeast Taiwan is presented. Factors considered in the analyses and the corresponding measurements from a building foundation excavation on the toe of dip-slope is discussed. Extensive efforts were made to compare the numerical analysis results with the in-situ instrumentation measurements. Based on the analysis results from PLAXIS and STABLE, it demonstrates that the original proposed open-cut method is unsuitable for this dip-slope excavation condition. It was found that the sliding failure may occur under the rainfall and earthquake conditions. The sliding surface is extending along with the bedding slips. To minimize those safety problems, the alternative construction method using the pile retaining wall and the tie-back anchors are proposed. According to the numerical analysis results, both the rainfall and earthquake conditions for the alternative method are able to conform to the safety requirements outlined in the Taiwan Building Codes. It was concluded that the elasto-plastic analysis is not conservative for this slope foundation excavation. The analysis results from PLAXIS have the closest agreement with the field measurements. Furthermore, the deformation trends obtained from PLAXIS analyses match with those from field instrumentation measurements. However, the deformation values from the analyses are less than those from the field measurements. This could be attributed to the creep effects and assumed conditions.