The Background

Soil Types: Plain fill soil, silty clay, fractured limestone, rubble concrete, and karst caves.

The foundation is raft foundation. The building as a whole has experienced uneven settlement, with the structure tilting towards the northwest.

Height of the Settlement Residential Building:103m

Total Settlement Amount:70mm.

The Problem

There are karst caves of varying sizes on the north, west, and south sides of the building's perimeter. Additionally, the rubble concrete has numerous and large internal voids and a high degree of strength dispersion, leading to uneven settlement.

The Solution

Utilizing the complementary principle of pile-raft for shallow reinforcement and strengthening, and deep karst cave filling and reinforcement. After completing the shallow reinforcement, continue drilling downwards, penetrating the karst caves, and filling and reinforcing the karst caves and the fractured stone zones, forming an integral lithified body. Finally, by leveraging the reaction force of the soil, lift the foundation back to the original elevation, restoring the tilted building to its original position.

The Result

After the treatment, the foundation bearing system was optimized, significantly improving the foundation's load transfer effectiveness, and effectively enhancing the foundation's bearing capacity. The expansion joints were restored within the original design range, completing the building's lifting and rectification tasks.

Construction Period: 20 days

Total Lift Amount: 70mm