Experimental study on semi-assembled floating foundation using sewer pipes for low-rise buildings on weak soil with filling sand layer

Abstract

The paper presents experimental research on using a sewer pipe as a semi-assembled floating foundation for low-rise houses with soft
soil having backfill sand above. Sewer pipes were placed in the backfill sand layer and sealed at the end with concrete slabs (foundation with closed-ended pipe). In addition, another sewer pipe, which was not bottom-sealed, but filled inside with compacted sand (foundation with open-ended pipe), was also studied for comparison. The results of static load tests on the natural soil and two types of foundations, including foundation with closed-ended pipe and foundation with open-ended pipe, showed positive settlement-decrease effects, especially for the first one — the floating foundation with closed-ended sewer pipe. Compared with the foundation having openended sewer pipe, the bearing capacity of floating foundation is 4 times higher and the settlement is 5 times lower. Semi-assembled foundations using closed-ended sewer pipe and open-ended sewer pipe can be put into practice. Depending on the workload, we can choose the appropriate foundation type.