The Background 

Soil Types:pebble, silty clay, and strongly weathered dolomite.

The architectural structure is the shear wall structure, and the foundation is the raft foundation. Three of the buildings have experienced settlement.

Settlement Of Residential Buildings Height:79.95m

Thickness Of The Raft: 1.3m

The Problem

The supporting layer of the foundation is the pebble layer with large porosity,and there is a weak soft clay layer below the pebble layer. At the same time,there are a large number of karst caves in the deep soil layer, and there aremany unstable karst caves with large porosity, resulting in weak soil layer structure and insufficient bearing capacity resulting in settlement. 

The Solution

Firstly, the weak soil layer of the bearing layer should be consolidated to form a composite foundation and improve the bearing capacity of the soil layer. Secondly, it is necessary to fill the karst caves, stabilize the soil layer structure,strengthen the bearing capacity, and fundamentally eliminate the two main factors causing settlement, so as to lift and correct the tilting, buildings.

The Result

The foundation settlement area has been reinforced and lifted, the verticality of the building meets the requirements, and no secondary settlement occurred post-construction. After expert evaluation, the quality of the project has met the acceptance standards.

Construction Period: 60 days

Total Lift Amount: 216mm.