Abstract:The concept design method is applied to excavation in deep silty-fine sand combining with retaining and protection design of a deep foundation pit. The concept design method in excavation is proposed based on several reinforcements. Those reinforcement measurements include setting jet grouting pile in the middle of slope or the slope toe,installing steel bar in the slope and injecting concrete in the surface of slope. It is found that the reinforcement measurements can effectively improve the stability of the slope surface. It is also described that the continuous distributed mucky-silty-clay can be used effectively as the horizontal bedding of the foundation pit to seal the bottom,and that improving by adding some bentonite the jet grouting pile technology can effectively improve the reliability of the curtain for cutting off water at the same time. It has been proved that the proposed method can decrease cost and time and provides reference to similar design.