Design and construction technology of displacement control in deep miscellaneous fill foundation pits

Displacement and settlement are easily generated in foundation pits at miscellaneous fill site because of arbitrary fills, component complexity and heterogeneous characteristics and have lower cohesive force and internal friction angle. There is a foundation pit with deep miscellaneous fill in Jinan. The fills are construction wastes and domestic refuse for 30 years and the depth is up to 18~20 m. The pit needs to be excavated to more than 11 m in depth. There is a freestone retaining wall 3.0 m away from the slope top and the wall is 3.0~3.5 m higher than the slope crest. Design of displacement control is required in deep miscellaneous fill site due to damages of freestone retaining wall and road induced by large deformation of the pit. According to engineering geology and surrounding environment, the pile-anchor support is used and the reinforcement in active and passive zones are taken into accounted simultaneously. Through the monitoring data, the displacement control of the pit achieves better results, and it may provide reference for similar projects.