Influence of Consolidation Settlement to the Bearing Capacity of Shallow Foundation in Over-consolidated Organic Soil

The construction of shallow foundations on soft and over-consolidated organic soil may be challenging. The difficulty arises from the shear strength of the soil, its compressibility, and the ability of the soil to settle. The aspect of soil consolidation is also crucial in the long run. This is because it is associated with soil strengthening and improvement in the bearing capacity of the foundation. This study evaluates the effects of consolidation settlement on the bearing capacity of strip shallow foundations on over-consolidated organic soil through a series of FEM-based calculations in PLAXIS 2D. In this calculation, two factors are considered. The factors include the width of the strip foundation, ranging from 0.5 m to 3.0 m, and the thickness of the over-consolidated organic soil, ranging from 2 m to 12 m. To gain insight into how consolidation can affect the soil behavior during settlement, the calculation was done using a time-dependent loading condition. The results have emphasized that the increase in bearing capacity due to consolidation occurs to a large extent in the first 1000 to 1500 days. For all the test results, wider foundations performed with a higher bearing capacity. The results have emphasized that for high organic soil conditions, higher organic soil thickness resulted in less performance in the initial stages but contributed more to the advancements in strength. These observations emphasize the need for proper consideration of both the time involved for soil consolidation, the dimensions of the foundations, and the soil thickness in designing a shallow foundation.