Deflection controlling measures and practices of deep foundation pits by use of top-down excavation method

By analyzing the case of deep excavation of Shanghai Urban Planning Exibition Center,some deflection controlling measures and principles were illustrated by use of the top-down excavation method.Base on the practices,it was concluded that the “Time-space effects” excavation method combining with the ground reinforcement could be employed to control the deflection in deep foundation pits under the top-down construction condition,and consequently to protect the neighboring facilities.