Combined with a building foundation pit of Nanchang

the retaining and protecting structure of foundation excavation

the horizontal displacement

the settlement monitoring points’ disposal

observation methods and monitoring data processing

are described. Based on the results of monitoring

it would forebode the danger

estimate the safety of engineering and avoid the happening of engineering accident.The construction was supervised with the monitoring results; and the information feedback was optimized designed.There were groundwater inflow and sand inflow due to the abundance of groundwater after the excavation

which made the deeper part such as the elevator shaft pit can’t be excavated to the right location. A method that is forming a waterproof wall around the elevator shaft pit and back covering the bottom of well with jet grouting was brought forward for the limited drainage ability around the excavation. The results show that the elevator shaft pit could be excavated uprightness one day after the construction of jet grouting and there was not water yielding

which brought on favorable reinforced effect and economy benefit.